Phosphorus (max)

.030 .045 .030 .030 Sulphur (max) .030 .030 .030 .030 Silicon (max) .75 1.00 .75 .75 Nickel 8.0/11.0 10.0/14.0 9.0/13.0 9.0/13.0 Chromium 18.0/20.0 16.0/18.0 17.0/20.0 17.0/20.0 Molybdenum 2.0/3.0 Titanium (') Columbium (2) 1 Titanium may not be less than 5C and not more than 0.60% 2 Columbium may not be less than 10C and not more than 1.0%. TABLE 3-CHECK ANALYSIS TOLERANCES Tolerance (percent) over the maximum limit or Element Limit or maximum specified under the minimum limit (percent) Under min- Over maximum limit imum limit Carbon To 0.15 Incl 0.01 0.01 Over 0.15 to 0.40 incl .03 .04 Manganese To 0.60 incl .03 .03 Over 1.15 to 2.50 incl .05 .05 Phosphorus 1 All ranges .01 Sulphur All ranges .01 Silicon To 0.30 incl .02 .03 Over 0.30 to 1.00 incl .05 .05 Nickel Over 5.30 to 10.00 incl .10 .10 Over 10.00 to 14.00 incl .15 .15 Chromium To 0.90 ind .03 .03 Over 0.90 to 2.10 incl .05 .05 Over 15.00 to 20.00 incl .20 .20 866 Pipeline and Hazardous Materials Safety Admin., DOT § 178.53 TABLE 3-CHECK ANALYSIS TOLERANCES-Confinued Tolerance (percent) over the maximum limit or Limit or maximum specified under the minimum limit Element (percent) Under min- Over maximum limit Imum limit Molybdenum To 0.20 Incl .01 .01 Over 0.20 to 0.40 incl .02 .02 Over 1.75 to 3.0 incl .10 .10 Titanium All ranges .05 .05 Columbium All ranges .05 .05 1 Rephosphorized steels not subject to check analysis for phosphorus. (c) Identification of material. Material E = 1.0 (for all other areas). must be identified by any suitable (2) Calculation for a cylinder must be method except that plates and billets made by the formula: for hotdrawn cylinders must be marked with the heat number. S = [P(1.3D² + 0.4d²)] / (D² - dT¹²) (d) Manufacture. Cylinders must be Where: manufactured using equipment and S = wall stress in psi; processes adequate to ensure that each P = test pressure prescribed for water jacket cylinder produced conforms to the retest, i.e., at least two times service presquirements of this subpart. No defect is sure, in psig; permitted that is likely to weaken the D = outside diameter in inches; finished container appreciably. A rea- d = inside diameter in inches. sonably smooth and uniform surface (f) Heat treatment. The completed cylfinish is required. Welding procedures inders must be uniformly and properly and operators must be qualified in acheat-treated prior to tests. cordance with CGA Pamphlet C-3 (IBR, (g) Openings in container. Openings in see $171.7 of this subchapter). cylinders must comply with the fol- (e) Wall thickness. The wall stress at lowing: the minimum test pressure may not ex- (1) Each opening in the container, exceed 24,000 psi, except where steels cept those for safety devices, must be commercially known as 4130X, types provided with a fitting, boss, or pad, se- 304, 316, 321, and 347 stainless steels are curely attached to the container by used, stress at the test pressures may brazing or by welding or by threads. If not exceed 37,000 psi. The minimum threads are used, they must comply wall thickness for any container havwith the following: ing a capacity of 1,100 cubic inches or (i) Threads must be clean cut, even, less is 0.04 inch. The minimum wall without checks, and tapped to gauge. thickness for any container having a (ii) Taper threads must be of a length capacity in excess of 1,100 cubic inches not less than that specified for Ameris 0.095 inch. Calculations must be done ican Standard taper pipe threads. by the following: (iii) Straight threads, having at least (1) Calculation for a "sphere" must 4 engaged threads, must have a tight be made by the formula: fit and calculated shear strength of at least 10 times the test pressure of the S = PD / 4tE container. Gaskets, adequate to pre- Where: vent leakage. are required. S = wall stress in psi; (2) Closure of a fitting, boss, or pad P = test pressure prescribed for water jacket must be adequate to prevent leakage. test, i.e., at least two times service pres- (h) Hydrostatic test. Each cylinder sure, in psig; must successfully withstand a hydro- D = outside diameter in inches; static test, as follows: t - minimum wall thickness in inches; (1) The test must be by water-jacket, E = 0.85 (provides 85 percent weld efficiency or other suitable method, operated so factor which must be applied in the girth weld area and heat affected zones which as to obtain accurate data. A pressure zone must extend a distance of 6 times wall gauge must permit a reading to an acthickness from center line of weld): curacy of 1 percent. An expansion 867 $ 178.53 49 CFR Ch. I (10-1-06 Edition) gauge must permit reading of total ex- (1) Physical test for spheres are repansion to an accuracy of either 1 perquired on 2 specimens cut from a flat cent or 0.1 cubic centimeter. representative sample plate of the (2) Pressure must be maintained for same heat taken at random from the at least 30 seconds and sufficiently steel used to produce the sphere. This longer to ensure complete expansion. flat steel from which the 2 specimens Any internal pressure applied after are to be cut must receive the same heat-treatment and previous to the ofheat-treatment as the spheres themficial test may not exceed 90 percent of selves. Sample plates must be taken for the test pressure. If, due to failure of each lot of 200 or less spheres. the test apparatus, the test pressure (2) Specimens for spheres must have cannot be maintained, the test may be a gauge length 2 inches with a width repeated at a pressure increased by 10 not over 1½ inches, or a gauge length percent or 100 psig. whichever is the at least 24 times the thickness with a lower. width not over 6 times the thickness is (3) Permanent volumetric expansion authorized when a wall is not over 3/16 may not exceed 10 percent of the total inch thick. volumetric expansion at test pressure. (3) Physical test for cylinders is re- (4) Containers must be tested as folquired on 2 specimens cut from 1 cyllows: inder taken at random out of each lot (i) Each container to at least 2 times of 200 or less. For lots of 30 or less, service pressure; or physical tests are authorized to be (ii) One container out of each lot of made on a ring at least 8 inches long 200 or less to at least 3 times service cut from each cylinder and subjected to pressure. Others must be examined the same heat treatment as the finunder pressure of 2 times service presished cylinder. sure and show no defects. (4) Specimens for cylinders must con- (i) Flattening test for spheres and cylform to the following: inders. Spheres and cylinders must be (i) A gauge length of 8 inches with a subjected to a flattening test as folwidth not over 1½ inches, or a gauge lows: length of 2 inches with a width not (1) One sphere taken at random out over 1½ inches, or a gauge length at of each lot of 200 or less must be subleast 24 times the thickness with a jected to a flattening test as follows: width not over 6 times the thickness is (i) The test must be performed after authorized when a cylinder wall is not the hydrostatic test. over 3/15 inch thick. (ii) The test must be between parallel (ii) The specimen, exclusive of grip steel plates on a press with a welded ends. may not be flattened. Grip ends seam at right angles to the plates. Any may be flattened to within 1 inch of projecting appurtenances may be cut each end of the reduced section. Heatoff (by mechanical means only) prior to ing of the specimen for any purpose is crushing. not authorized. (2) One cylinder taken at random out (5) The yield strength in tension of each lot of 200 or less must be submust be the stress corresponding to a jected to a flattening test, as follows: permanent strain of 0.2 percent of the (i) The test must be performed after gauge length. The following conditions the hydrostatic test. apply: (ii) The test must be between knife (i) The yield strength must be deteredges, wedge shaped, 60° angle, rounded mined by either the "offset" method or to 1/2 inch radius. For lots of 30 or less, the "extension under load" method as physical tests are authorized to be prescribed in ASTM E 8 (IBR, see $171.7 made on a ring at least 8 inches long of this subchapter). cut from each cylinder and subjected to (ii) In using the "extension under the same heat treatment as the finload" method, the total strain (or "exished cylinder. tension under load") corresponding to (j) Physical test and specimens for the stress at which the 0.2 percent perspheres and cylinders. Spheres and cylmanent strain occurs may be deterinders must be subjected to a physical mined with sufficient accuracy by caltest as follows: culating the elastic extension of the 868 Pipeline and Hazardous Materials Safety Admin., DOT § 178.55 gauge length under appropriate load The maximum water capacity of this and adding thereto 0.2 percent of the cylinder is 12 pounds or 333 cubic gauge length. Elastic extension calinches and the service must be 240 psig. culations must be based on an elastic The maximum outside diameter of the modulus of 30,000,000. In the event of shell must be five inches and maximum controversy, the entire stress-strain length of the shell is 21 inches. Cyldiagram must be plotted and the yield inders closed in by a spinning process strength determined from the 0.2 perare authorized. cent offset. (b) Steel. Open-hearth, basic oxygen, (iii) For the purpose of strain measor electric steel of uniform quality urement, the initial strain must be set must be used. Plain carbon steel conwhile the specimen is under a stress of tent may not exceed the following: Car- 12,000 psi and the strain indicator readbon, 0.25; phosphorus, 0.045; sulfur, ing being set at the calculated cor- 0.050. The addition of other elements responding strain. for alloying effect is prohibited. (iv) Cross-head speed of the testing (c) Identification of material. Material machine may not exceed 1/8 inch per must be identified by any suitable minute during yield strength determethod. mination. (d) Manufacture. Cylinders must be (k) Acceptable results for physical and manufactured using equipment and flattening tests. Either of the following processes adequate to ensure that each is an acceptable result: (1) An elongation of at least 40 percylinder produced conforms to the recent for a 2 inch gauge length or at quirements of this subpart. No defect is least 20 percent in other cases and permitted that is likely to weaken the yield strength not over 73 percent of finished cylinder appreciably. A reatensile strength. In this instance, the sonably smooth and uniform surface flattening test is not required. finish is required. Heads may be at- (2) An elongation of at least 20 pertached to shells by lap brazing or may cent for a 2 inch gauge length or 10 perbe formed integrally. The thickness of cent in other cases. Flattening is rethe bottom of cylinders welded or quired to 50 percent of the original outformed by spinning is, under no condiside diameter without cracking. tion, to be less than two times the min- (1) Rejected cylinders. Reheat-treatimum wall thickness of the cylindrical ment is authorized for rejected cylshell. Such bottom thicknesses must be inders. Subsequent thereto, containers measured within an area bounded by a must pass all prescribed tests to be acline representing the points of contact ceptable. Repair of welded seams by between the cylinder and the floor welding prior to reheat-treatment is when the cylinder is in a vertical posiauthorized. tion. Seams must conform to the fol- (m) Marking. Marking on each conlowing: tainer by stamping plainly and perma- (1) Circumferential seams must be by nently are only authorized where the brazing only. Heads must be attached metal is at least 0.09 inch thick, or on to shells by the lap brazing method and a metal nameplate permanently semust overlap not less than four times cured to the container by means other the wall thickness. Brazing material than soft solder, or by means that must have a melting point of not less would not reduce the wall thickness. than 1000 °F. Heads must have a driving fit with the shell unless the shell is [Amdt. 178-114, 61 FR 25942, May 23, 1996, as amended at 66 FR 45386, 45388, Aug. 28, 2001; crimped, swedged, or curled over the 67 FR 51653, Aug. 8, 2002: 68 FR 75748, Dec. 31. skirt or flange of the head and be thor- 2003) oughly brazed until complete penetration of the joint by the brazing mate- § 178.55 Specification 4B240ET welded rial is secured. Brazed joints may be reor brazed cylinders. paired by brazing. (a) Type, spinning process, size and (2) Longitudinal seams in shell must service pressure. A DOT 4B240ET cylbe by electric resistance welded joints inder is a brazed type cylinder made only. No repairs to longitudinal joints from electric resistance welded tubing. is permitted. 869 $ 178.55 49 CFR Ch. I (10-1-06 Edition) (3) Welding procedures and operators (iii) Straight threads, having at least must be qualified in accordance with 4 engaged threads, to have tight fit and CGA C-3 (IBR, see § 171.7 of this subcalculated shear strength at least 10 chapter). times the test pressure of the cylinder; (e) Welding or brazing. Only the atgaskets required. adequate to prevent tachment, by welding or brazing, to the leakage. tops and bottoms of cylinders of (2) Closure of a fitting, boss, or pad neckrings, footrings, handles, bosses, must be adequate to prevent leakage. pads, and valve protection rings is au- (i) Hydrostatic test. Each cylinder thorized. Provided that such attachmust successfully withstand a hydroments and the portion of the container static test as follows: to which they are attached are made of (1) The test must be by water-jacket, weldable steel, the carbon content of or other suitable method, operated so which may not exceed 0.25 percent. as to obtain accurate data. The pres- (f) Wall thickness. The wall stress sure gauge must permit reading to an must be at least two times the service accuracy of 1 percent. The expansion pressure and may not exceed 18,000 psi. gauge must permit reading of total ex- The minimum wall thickness is 0.044 pansion to an accuracy of either 1 perinch. Calculation must be made by the cent or 0.1 cubic centimeter. following formula: (2) Pressure must be maintained for at least 30 seconds and sufficiently S = [P(1.3D² + 0.4d²)] / (D² - d2) longer to ensure complete expansion. Where: Any internal pressure applied after heat-treatment and previous to the of- S - wall stress in psig; ficial test may not exceed 90 percent of P = 2 times service pressure; D = outside diameter in inches; the test pressure. If, due to failure of d = Inside diameter in inches. the test apparatus, the test pressure cannot be maintained, the test may be (g) Heat treatment. Heads formed by repeated at a pressure increased by 10 drawing or pressing must be uniformly percent or 100 psig, whichever is the and properly heat treated prior to lower. tests. Cylinders with integral formed (3) Permanent volumetric expansion heads or bases must be subjected to a may not exceed 10 percent of total volnormalizing operation. Normalizing umetric expansion at test pressure. and brazing operations may be com- (4) Cylinders must be tested as folbined, provided the operation is carried lows: out at a temperature in excess of the (i) At least one cylinder selected at upper critical temperature of the steel. random out of each lot of 200 or less (h) Openings in cylinders. Openings in must be tested as outlined in paracylinders must comply with the folgraphs (i)(1), (i)(2), and (i)(3) of this seclowing: tion to at least two times service pres- (1) Each opening in cylinders, except sure. those for safety devices, must be pro- (ii) All cylinders not tested as outvided with a fitting, boss, or pad, selined in paragraph (i)(4)(i) of this seccurely attached to the cylinder by tion must be examined under pressure brazing or by welding or by threads. A of at least two times service pressure fitting, boss, or pad must be of steel and show no defect. suitable for the method of attachment (5) Each 1000 cylinders or less succesemployed, and which need not be idensively produced each day must contifled or verified as to analysis, except stitute a lot. One cylinder must be sethat if attachment is by welding, carlected from each lot and bon content may not exceed 0.25 perhydrostatically tested to destruction. cent. If threads are used, they must If this cylinder bursts below five times comply with the following: the service pressure, then two addi- (i) Threads must be clean cut, even tional cylinders must be selected and without checks, and tapped to gauge. subjected to this test. If either of these (ii) Taper threads to be of length not cylinders fails by bursting below five less than as specified for American times the service pressure then the en- Standard taper pipe threads. tire lot must be rejected. All cylinders 870 Pipeline and Hazardous Materials Safety Admin., DOT § 178.55 constituting a lot must be of identical prescribed in ASTM E 8 (IBR, see $171.7 size, construction heat-treatment, finof this subchapter). ish, and quality. (ii) In using the "extension under (j) Flattening test. Following the hyload" method, the total strain (or "exdrostatic test, one cylinder taken at tension under load") corresponding to random out of each lot of 200 or less, the stress at which the 0.2 percent permust be subjected to a flattening test manent strain occurs may be deterthat is between knife edges, wedge mined with sufficient accuracy by calshaped, 60° angle, rounded to 1/2 inch raculating the elastic extension of the dius. gauge length under appropriate load (k) Physical test. A physical test must and adding thereto 0.2 percent of the be conducted to determine yield gauge length. Elastic extension calstrength, tensile strength, elongation, culations must be based on an elastic and reduction of area of material, as modulus of 30,000,000. In the event of follows: controversy, the entire stress-strain (1) The test is required on 2 specidiagram must be plotted and the yield mens cut from 1 cylinder, or part strength determined from the 0.2 perthereof heat-treated as required, taken cent offset. at random out of each lot of 200 or less (iii) For the purpose of strain measin the case of cylinders of capacity urement, the initial strain must be set greater than 86 cubic inches and out of while the specimen is under a stress of each lot of 500 or less for cylinders hav- 12,000 psi and the strain indicator reading a capacity of 86 cubic inches or ing being set at the calculated corless. responding strain. (2) Specimens must conform to the (iv) Cross-head speed of the testing following: machine may not exceed 1/8 inch per (i) A gauge length of 8 inches with a minute during yield strength deterwidth not over 1½ inches, a gauge mination. length of 2 inches with a width not (1) Acceptable results for physical and over 1½ inches, or a gauge length at flattening tests. Acceptable results for least 24 times the thickness with a the physical and flattening tests are an width not over 6 times the thickness is elongation of at least 40 percent for a 2 authorized when a cylinder wall is not inch gauge length or at least 20 percent over 3/16 inch thick. in other cases and a yield strength not (ii) The specimen, exclusive of grip over 73 percent of tensile strength. In ends, may not be flattened. Grip ends this instance the flattening test is remay be flattened to within one inch of quired, without cracking, to six times each end of the reduced section. the wall thickness with a weld 90° from (iii) When size of cylinder does not the direction of the applied load. Two permit securing straight specimens, rings cut from the ends of length of the specimens may be taken in any lopipe used in production of a lot may be cation or direction and may be used for the flattening test provided straightened or flattened cold by presthe rings accompany the lot which sure only, not by blows. When specithey represent in all thermal procmens are so taken and prepared, the inessing operations. At least one of the spector's report must show in connecrings must pass the flattening test. tion with record of physical tests de- (m) Leakage test. All spun cylinders tailed information in regard to such and plugged cylinders must be tested specimens. for leakage by gas or air pressure after (iv) Heating of a specimen for any the bottom has been cleaned and is free purpose is not authorized. from all moisture, subject to the fol- (3) The yield strength in tension lowing conditions: must be the stress corresponding to a (1) Pressure, approximately the same permanent strain of 0.2 percent of the as but no less than service pressure, gauge length. The following conditions must be applied to one side of the finapply: ished bottom over an area of at least (i) The yield strength must be deter- 1/16 of the total area of the bottom but mined by either the "offset" method or not less than 3/4 inch in diameter, inthe "extension under load" method as cluding the closure, for at least 1 871 § 178.56 49 CFR Ch. I (10-1-06 Edition) minute, during which time the other psig. Closures welded by spinning procside of the bottom exposed to pressure ess not permitted. must be covered with water and closely (b) Steel. The limiting chemical comexamined for indications of leakage. position of steel authorized by this Except as provided in paragraph (n) of specification must be as shown in table this section, cylinders which are leak- I of appendix A to this part. ing must be rejected. (c) Identification of material. Material (2) A spun cylinder is one in which an must be identified by any suitable end closure in the finished cylinder has method except that plates and billets been welded by the spinning process. for hotdrawn cylinders must be marked (3) A plugged cylinder is one in which with the heat number. a permanent closure in the bottom of a (d) Manufacture. Cylinders must be finished cylinder has been effected by a manufactured using equipment and plug. processes adequate to ensure that each (4) As a safety precaution, if the cylinder produced conforms to the remanufacturer elects to make this test quirements of this subpart. No defect is before the hydrostatic test, he should permitted that is likely to weaken the design his apparatus so that the presfinished cylinder appreciably. A reasure is applied to the smallest area sonably smooth and uniform surface practicable, around the point of clofinish is required. Exposed bottom sure, and so as to use the smallest poswelds on cylinders over 18 inches long sible volume of air or gas. must be protected by footrings. Min- (n) Rejected cylinders. Repairs of re- Imum thickness of heads and bottoms jected cylinders is authorized. Cylmay not be less than 90 percent of the inders that are leaking must be rerequired thickness of the side wall. jected, except that: Seams must be made as follows: (1) Spun cylinders rejected under the (1) Circumferential seams must be provisions of paragraph (m) of this secwelded. Brazing is not authorized. tion may be removed from the spun (2) Longitudinal seams are not percylinder category by drilling to remove mitted. defective material, tapping, and plug- (3) Welding procedures and operators ging. must be qualified in accordance with (2) Brazed joints may be rebrazed. CGA C-3 (IBR, see $171.7 of this sub- (3) Subsequent to the operations chapter). noted in paragraphs (n)(1) and (n)(2) of (e) Welding. Only the welding of this section, acceptable cylinders must neckrings, footrings, bosses, pads, and pass all prescribed tests. valve protection rings to the tops and (o) Marking. Markings on each cylbottoms of cylinders is authorized. inder must be by stamping plainly and Provided that such attachments are permanently on shoulder, top head, made of weldable steel, the carbon conneck or valve protection collar which tent of which does not exceed 0.25 peris permanently attached to the cylcent. inders and forming an integral part (f) Wall thickness. The wall thickness thereof, provided that cylinders not of the cylinder must conform to the less than 0.090 inch thick may be following: stamped on the side wall adjacent to (1) For cylinders with an outside ditop head. ameter over 5 inches, the minimum wall thickness is 0.078 inch. In any [Amdt. 178-114, 61 FR 25942, May 23, 1996, as amended at 66 FR 45386, Aug. 28, 2001; 67 FR case, the minimum wall thickness 51653, Aug. 8, 2002; 68 FR 75748, 75749, Dec. 31, must be such that the calculated wall 2003] stress at the minimum test pressure (in paragraph (i) of this section) may not § 178.56 Specification 4AA480 welded exceed the lesser value of either of the steel cylinders. following: (a) Type, size, and service pressure. A (i) One-half of the minimum tensile DOT 4AA480 cylinder is a welded steel strength of the material determined as cylinder having a water capacity required in paragraph (j) of this sec- (nominal) not over 1,000 pounds water tion; or capacity and a service pressure of 480 (ii) 35,000 psi. 872 Pipeline and Hazardous Materials Safety Admin., DOT § 178.56 (2) Calculation must be made by the (1) The test must be by water jacket, formula: or other suitable method, operated so S = [P(1.3D² + 0.4d²)] / (D² - d²) as to obtain accurate data. The pressure gauge must permit reading to an Where: accuracy of 1 percent. The expansion S - wall stress in psi; gauge must permit reading of total ex- P = minimum test pressure prescribed for pansion to an accuracy of either 1 perwater jacket test; cent or 0.1 cubic centimeter. D = outside diameter in inches; (2) Pressure must be maintained for d = inside diameter in inches. at least 30 seconds or sufficiently (3) The ratio of tangential length to longer to assure complete expansion. outside diameter may not exceed 4.0 for Any internal pressure applied after cylinders with a wall thickness less heat-treatment and before the official than 0.100 inch. test may not exceed 90 percent of the (g) Heat treatment. Each cylinder test pressure. If, due to failure of test must be uniformly and properly heat apparatus, the test pressure cannot be treated prior to tests. Any suitable maintained, the test may be repeated heat treatment in excess of 1100 °F is at a pressure increased by 10 percent or authorized except that liquid quench- 100 psig, whichever is lower. ing is not permitted. Heat treatment (3) Permanent volumetric expansion must be accomplished after all forming may not exceed 10 percent of the total and welding operations. Heat treatvolumetric expansion at test pressure. ment is not required after welding (4) Cylinders must be tested as folweldable low carbon parts to attachlows: ments of similar material which have (i) At least one cylinder selected at been previously welded to the top or random out of each lot of 200 or less bottom of cylinders and properly heat must be tested as described in paratreated, provided such subsequent graphs (i)(1), (i)(2), and (1)(3) of this secwelding does not produce a temperation, to at least two times service presture in excess of 400 °F., in any part of sure. If a selected cylinder fails, then the top or bottom material. two additional specimens must be se- (h) Openings in cylinders. Openings in lected at random from the same lot and cylinders must conform to the folsubjected to the prescribed test. If eilowing: ther of these falls the test, then each (1) All openings must be in the heads cylinder in that lot must be so tested; or bases. and (2) Each opening in the cylinder, ex- (ii) Each cylinder not tested as precept those for safety devices, must be scribed in paragraph (i)(4)(i) of this secprovided with a fitting boss, or pad, setion must be examined under pressure curely attached to the cylinder by of at least two times service pressure welding or by threads. If threads are and must show no defect. A cylinder used they must comply with the folshowing a defect must be rejected unlowing: less it may be requalified under para- (i) Threads must be clean-cut, even graph (m) of this section. without checks and cut to gauge. (j) Physical test. A physical test must (ii) Taper threads to be of length not be conducted to determine yield less than as specified for American strength, tensile strength, elongation, Standard taper pipe threads. and reduction of area of material, as (iii) Straight threads having at least follows: 6 engaged threads, must have a tight (1) The test is required on 2 specifit and a calculated shear strength at mens cut from one cylinder having least 10 times the test pressure of the passed the hydrostatic test, or part cylinder. Gaskets, adequate to prevent thereof heat-treated as required, taken leakage, are required. at random out of each lot of 200 or less. (3) Closure of a fitting, boss or pad (2) Specimens must conform to the must be adequate to prevent leakage. following: (i) Hydrostatic test. Each cylinder (i) A gauge length of 8 inches with a must successfully withstand a hydrowidth not over 1½ inches, a gauge static test as follows: length of 2 inches with a width not 873 § 178.56 49 CFR Ch. I (10-1-06 Edition) over 1½ inches, or a gauge length at (k) Elongation. Physical test specileast 24 times the thickness with a mens must show at least a 40 percent width not over 6 times thickness is auelongation for 2-inch gauge lengths or thorized when the cylinder wall is not at least a 20 percent elongation in over 3/10 inch thick. other cases. Except that these elon- (ii) The specimen, exclusive of grip gation percentages may be reduced nuends, may not be flattened. Grip ends merically by 2 for 2-inch specimens and may be flattened to within one inch of by 1 in other cases for each 7,500 psi ineach end of the reduced section. crement of tensile strength above 50,000 (iii) When size of cylinder does not psi to a maximum of four such increpermit securing straight specimens, ments. the specimens may be taken in any lo- (1) Tests of welds. Welds must be testcation or direction and may be ed as follows: straightened or flattened cold, by pres- (1) Tensile test. A specimen must be sure only, not by blows. When specicut from one cylinder of each lot of 200 mens are so taken and prepared, the inor less, or a welded test plate. The spector's report must show in connecwelded test plate must be of one of the heats in the lot of 200 or less which it tion with record of physical tests detailed information in regard to such represents, in the same condition and specimens. approximately the same thickness as (iv) Heating of a specimen for any the cylinder wall except that it may not be of a lesser thickness than that purpose is not authorized. required for a quarter size Charpy im- (3) The yield strength in tension pact specimen. The weld must be made must be the stress corresponding to a by the same procedures and subjected permanent strain of 0.2 percent of the to the same heat treatment as the gauge length. The following conditions major weld on the cylinder. The speciapply: mens must be taken across the major (i) The yield strength must be deterseam and must be prepared and tested mined by either the "offset" method or in accordance with and must meet the the "extension under load" method as requirements of CGA Pamphlet C-3. prescribed in ASTM E 8 (IBR, see § 171.7 Should this specimen fail to meet the of this subchapter). requirements, specimens may be taken (ii) In using the "extension under from two additional cylinders or weldload" method, the total strain (or "exed test plates from the same lot and tension under load"), corresponding to tested. If either of the latter specimens the stress at which the 0.2 percent perfail to meet the requirements. the enmanent strain occurs may be detertire lot represented must be rejected. mined with sufficient accuracy by cal- (2) Guided bend test. A root bend test culating the elastic extension of the specimen must be cut from the cylgauge length under appropriate load inder or a welded test plate, used for and adding thereto 0.2 percent of the the tensile test specified in paragraph gauge length. Elastic extension cal- (1)(1) of this section. Specimens must culations must be based on an elastic be taken from across the major seam modulus of 30,000,000. In the event of and must be prepared and tested in accontroversy, the entire stress-strain cordance with and must meet the rediagram must be plotted and the yield quirements of CGA Pamphlet C-3. strength determined from the 0.2 per- (3) Alternate guided-bend test. This cent offset. test may be used and must be as re- (iii) For the purpose of strain measquired by CGA Pamphlet C-3. The specurement, the initial strain reference imen must be bent until the elongation must be set while the specimen is at the outer surface, adjacent to the under a stress of 12,000 psi and the root of the weld, between the lightly strain indicator reading being set at scribed gage lines-a to b, is at least 20 the calculated corresponding strain. percent, except that this percentage (iv) Cross-head speed of the testing may be reduced for steels having a tenmachine may not exceed 1/8 inch per sile strength in excess of 50,000 psi, as minute during yield strength deterprovided in paragraph (k) of this secmination. tion. 874 Pipellne and Hazardous Materials Safety Admin., DOT § 178.57 (m) Rejected cylinders. Reheat treat- (b) Material. Material use in the conment of rejected cylinders is authorstruction of this specification must ized. Subsequent thereto, cylinders conform to the following: must pass all prescribed tests to be ac- (1) Inner containment vessel (cylinder). ceptable. Repair of welded seams by Designations and limiting chemical welding is authorized. compositions of steel authorized by (n) Markings. Markings must be this specification must be as shown in stamped plainly and permanently in table 1 in paragraph (o) of this section. one of the following locations on the (2) Outer jacket. Steel or aluminum cylinder: may be used subject to the require- (1) On shoulders and top heads not ments of paragraph (o)(2) of this secless than 0.087 inch thick. tion. (2) On neck, valve boss, valve protec- (c) Identification of material. Material tion sleeve, or similar part permamust be identified by any suitable nently attached to top end of cylinder. method. (3) On a plate attached to the top of (d) Manufacture. Cylinders must be the cylinder or permanent part thereof: manufactured using equipment and sufficient space must be left on the processes adequate to ensure that each plate to provide for stamping at least cylinder produced conforms to the resix retest dates: the plate must be at quirements of this subpart and to the least 1/16 inch thick and must be atfollowing requirements: tached by welding or by brazing at a (1) No defect is permitted that is temperature of at least 1100 °F, likely to weaken the finished cylinder throughout all edges of the plate. appreciably. A reasonably smooth and (4) Variations in location of markuniform surface finish is required. The ings authorized only when necessitated shell portion must be a reasonably true by lack of space. cylinder. (2) The heads must be seamless, con- [Amdt. 178-114, 61 FR 25942. May 23, 1996, as amended at 66 FR 45386, Aug. 28, 2001: 67 FR cave side to the pressure, hemi- 51653, Aug. 8, 2002; 68 FR 75748, 75749, Dec. 31, spherical or ellipsoidal in shape with 2003) the major diameter not more than twice the minor diameter. Minimum § 178.57 Specification 4L welded insuthickness of heads may not be less lated cylinders. than 90 percent of the required thick- (a) Type, size, service pressure, and deness of the sidewall. The heads must be sign service temperature. A DOT 4L cylreasonably true to shape, have no abinder is a fusion welded insulated cylrupt shape changes, and the skirts inder with a water capacity (nominal) must be reasonably true to round. not over 1,000 pounds water capacity (3) The surface of the cylinder must and a service pressure of at least 40 but be insulated. The insulating material not greater than 500 psig conforming to must be fire resistant. The insulation the following requirements: on non-evacuated jackets must be cov- (1) For liquefied hydrogen service, ered with a steel jacket not less than the cylinders must be designed to stand 0.060-inch thick or an aluminum jacket on end, with the axis of the cylindrical not less than 0.070 inch thick, so conportion vertical. structed that moisture cannot come in (2) The design service temperature is contact with the insulating material. If the coldest temperature for which a a vacuum is maintained in the insulacylinder is suitable. The required detion space, the evacuated jacket must sign service temperatures for each be designed for a minimum collapsing cryogenic liquid is as follows: pressure of 30 psig differential whether made of steel or aluminum. The con- Cryogenic liquid Design service temperature struction must be such that the total Argon Minus 320 °F or colder. heat transfer, from the atmosphere at Helium Minus 452 °F or colder. ambient temperature to the contents Hydrogen Minus 42 3 °F or colder. of the cylinder, will not exceed 0.0005 Neon Minus 411 °F or colder. Btu per hour, per Fahrenheit degree Nitrogen Minus 320 °F or colder. Oxygen Minus 320 °F or colder. differential in temperature, per pound of water capacity of the cylinder. For 875 § 178.57 49 CFR Ch. I (10-1-06 Edition) hydrogen, cryogenic liquid service, the (3) One-half of the minimum tensile total heat transfer, with a temperature strength of the base metal determined differential of 520 Fahrenheit degrees, as required in paragraph (j) of this secmay not exceed that required to vent tion. 30 SCF of hydrogen gas per hour. (4) The yield strength of the base (4) For a cylinder having a design metal determined as required in paraservice temperature colder than minus graph (1) of this section. 320 °F, a calculation of the maximum (5) Further provided that wall stress weight of contents must be made and for cylinders having longitudinal that weight must be marked on the seams may not exceed 85 percent of the cylinder as prescribed in $178.35. above value, whichever applies. (5) Welding procedures and oper- (6) Calculation must be made by the ations must be qualified in accordance following formula: with CGA Pamphlet C-3 (IBR, see S = [P(1.3D² + 0.4d²)] / (D² - d²) § 171.7 of this subchapter). In addition, an impact test of the weld must be perwhere: formed in accordance with paragraph S = wall stress in pounds psi; (1) of this section as part of the quali- P = minimum test pressure prescribed for fication of each welding procedure and pressure test in psig; D = outside diameter in inches; operator. (e) Welding. Welding of the cylinder d = inside diameter in inches. must be as follows: (g) Heat treatment. Heat treatment is (1) All seams of the cylinder must be not permitted. fusion welded. A means must be pro- (h) Openings in cylinder. Openings in vided for accomplishing complete penecylinders must conform to the foltration of the joint. Only butt or joggle lowing: butt joints for the cylinder seams are (1) Openings are permitted in heads authorized. All joints in the cylinder only. They must be circular and may must have reasonably true alignment. not exceed 3 inches in diameter or one (2) All attachments to the sidewalls third of the cylinder diameter, whichand heads of the cylinder must be by ever is less. Each opening in the cylfusion welding and must be of a inder must be provided with a fitting, weldable material complying with the boss or pad, either integral with, or seimpact requirements of paragraph (1) of curely attached to, the cylinder body this section. by fusion welding. Attachments to a (3) For welding the cylinder, each fitting, boss or pad may be made by procedure and operator must be qualiwelding, brazing, mechanical attachfied in accordance with the sections of ment, or threading. CGA Pamphlet C-3 that apply. In addi- (2) Threads must comply with the foltion, impact tests of the weld must be lowing: performed in accordance with para- (i) Threads must be clean-cut, even, graph (1) of this section as part of the without checks and cut to gauge. qualification of each welding procedure (ii) Taper threads to be of a length and operator. not less than that specified for NPT. (4) Brazing, soldering and threading (iii) Straight threads must have at are permitted only for joints not made least 4 engaged threads, tight fit and directly to the cylinder body. Threads calculated shear strength at least 10 must comply with the requirements of times the test pressure of the cylinder. paragraph (h) of this section. Gaskets, which prevent leakage and (f) Wall thickness. The minimum wall are inert to the hazardous material, thickness of the cylinder must be such are required. that the calculated wall stress at the (i) Pressure test. Each cylinder, before minimum required test pressure may insulating and jacketing. must be exnot exceed the least value of the folamined under a pressure of at least 2 lowing: times the service pressure maintained (1) 45,000 psi. for at least 30 seconds without evidence (2) One-half of the minimum tensile of leakage, visible distortion or other strength across the welded seam deterdefect. The pressure gauge must permit mined in paragraph (I) of this section. reading to an accuracy of 1 percent. 876 Pipeline and Hazardous Materials Safety Admin., DOT § 178.57 (j) Physical test. A physical test must yield strength determined from the 0.2 be conducted to determine yield percent offset. strength, tensile strength, and elon- (iii) For the purpose of strain measgation as follows: urement, the initial strain reference (1) The test is required on 2 specimust be set while the specimen is mens selected from material of each under a stress of 12,000 psi and the heat and in the same condition as that strain indicator reading being set at in the completed cylinder. the calculated corresponding strain. (2) Specimens must conform to the (iv) Cross-head speed of the testing following: machine may not exceed 1/8 inch per (i) A gauge length of 8 inches with a minute during yield strength determination. width not over 1½ inches, a gauge length of 2 inches with width not over (k) Acceptable results for physical tests. 1½ inches, or a gauge length at least 24 Physical properties must meet the limtimes thickness with a width not over its specified in paragraph (o)(1), table 1, 6 times thickness (authorized when cylof this section, for the particular steel inder wall is not over 1/16 inch thick). in the annealed condition. The specimens must show at least a 20 percent (ii) The specimen, exclusive of grip elongation for a 2-inch gage length. Exends, may not be flattened. Grip ends cept that the percentage may be remay be flattened to within one inch of duced numerically by 2 for each 7,500 each end of the reduced section. psi increment of tensile strength above (iii) When size of the cylinder does 100,000 psi to a maximum of 5 such innot permit securing straight specicrements. Yield strength and tensile mens, the specimens may be taken in strength must meet the requirements any location or direction and may be of paragraph (o)(1), table 1, of this secstraightened or flattened cold by prestion. sure only, not by blows. When speci- (1) Tests of welds. Welds must be testmens are so taken and prepared, the ined as follows: spector's report must show in connec- (1) Tensile test. A specimen must be tion with record of physical tests decut from one cylinder of each lot of 200 tailed information in regard to such or less, or welded test plate. The weldspecimens. ed test plate must be of one of the (iv) Heating of a specimen for any heats in the lot of 200 or less which it purpose is not authorized. represents, in the same condition and (3) The yield strength in tension approximately the same thickness as must be the stress corresponding to a the cylinder wall except that it may permanent strain of 0.2 percent of the not be of a lesser thickness than that gauge length. The following conditions required for a quarter size Charpy imapply: pact specimen. The weld must be made (i) The yield strength must be deterby the same procedures and subjected mined by either the "offset" method or to the same heat treatment as the the "extension under load" method as major weld on the cylinder. The speciprescribed in ASTM E 8 (IBR, see $171.7 men must be taken across the major of this subchapter). seam and must be prepared in accord- (ii) In using the "extension under ance with and must meet the requireload" method, the total strain (or "exments of CGA Pamphlet C-3. Should tension under load"), corresponding to this specimen fail to meet the requirethe stress at which the 0.2 percent perments, specimens may be taken from manent strain occurs may be detertwo additional cylinders or welded test mined with sufficient accuracy by calplates from the same lot and tested. If culating the elastic expansion of the either of the latter specimens fails to gauge length under appropriate load meet the requirements, the entire lot and adding thereto 0.2 percent of the represented must be rejected. gauge length. Elastic extension cal- (2) Guided bend test. A "root" bend culations must be based on the elastic test specimen must be cut from the modulus of the material used. In the cylinder or welded test plate, used for event of controversy, the entire stressthe tensile test specified in paragraph strain diagram must be plotted and the (1)(1) of this section and from any other 877 § 178.57 49 CFR Ch. I (10-1-06 Edition) seam or equivalent welded test plate if imum, but not necessarily from one of the seam is welded by a procedure difthe heats used in the lot of cylinders. ferent from that used for the major The test piece must be welded by the seam. Specimens must be taken across same welding procedure as used on the the particular seam being tested and particular cylinder seam being qualimust be prepared and tested in accordfied and must be subjected to the same ance with and must meet the requireheat treatment. ments of CGA Pamphlet C-3. (vi) Impact test specimens must be (3) Alternate guided-bend test. This cooled to the design service temperatest may be used and must be as specified in CGA Pamphlet C-3. The speciture. The apparatus for testing the men must be bent until the elongation specimens must conform to requirements of ASTM Standard E 23. The test at the outer surface, adjacent to the root of the weld, between the lightly piece, as well as the handling tongs, scribed gage lines a to b, is at least 20 must be cooled for a length of time sufpercent, except that this percentage ficient to reach the service temperamay be reduced for steels having a tenture. The temperature of the cooling sile strength in excess of 100,000 psig, as device must be maintained within a provided in paragraph (c) of this secrange of plus or minus 3 °F. The specition. men must be quickly transferred from (4) Impact tests. One set of three imthe cooling device to the anvil of the pact test specimens (for each test) testing machine and broken within a must be prepared and tested for detertime lapse of not more than six secmining the impact properties of the deonds. posited weld metal- (vii) The impact properties of each (i) As part of the qualification of the set of impact specimens may not be welding procedure. less than the values in the following (ii) As part of the qualification of the table: operators. (iii) For each "heat" of welding rodor Minimum Minimum wire used. Impact value required for Impact value (iv) For each 1,000 feet of weld made Size of specimen avg. of each permitted on with the same heat of welding rod or set of three one only of a set of three specimens wire. (ft.-lb.) (ft-lb.) (v) All impact test specimens must be 10 mmx10 mm 15 10 of the charpy type, keyhole or milled 10 mmx7.5 mm 12.5 8.5 U-notch, and must conform in all re- 10 mmx5 mm 10 7.0 spects to ASTM E 23 (IBR, see $171.7 of 10 mmx2.5 mm 5 3.5 this subchapter). Each set of Impact specimens must be taken across the (viii) When the average value of the weld and have the notch located in the three specimens equals or exceeds the weld metal. When the cylinder mateminimum value permitted for a single rial thickness is 2.5 mm or thicker, imspecimen and the value for more than pact specimens must be cut from a cylone specimen is below the required avinder or welded test plate used for the erage value, or when the value for one tensile or bend test specimens. The dispecimen is below the minimum value mension along the axis of the notch must be reduced to the largest possible permitted for a single specimen, a of 10 mm, 7.5 mm, 5 mm or 2.5 mm, deretest of three additional specimens must be made. The value of each of pending upon cylinder thickness. When the material in the cylinder or welded these retest specimens must equal or test plate is not of sufficient thickness exceed the required average value. to prepare 2.5 mm impact test speci- When an erratic result is caused by a mens, 2.5 mm specimens must be predefective specimen, or there is uncerpared from a welded test plate made tainty in test procedure, a retest is aufrom 1/8 inch thick material meeting thorized. the requirements specified in para- (m) Radiographic examination. Cylgraph (o)(1), table 1, of this section and inders must be subject to a radiohaving a carbon analysis of .05 mingraphic examination as follows: 878 Pipeline and Hazardous Materials Safety Admin., DOT $ 178.57 (1) The techniques and acceptability TABLE 2-PHYSICAL PROPERTIES of radiographic inspection must conform to the standards set forth in CGA Physical properties Pamphlet C-3. (annealed) (2) One finished longitudinal seam Tensile strength, p.s.i. (minimum) 75,000 must be selected at random from each Yield strength, p.s.i. (minimum) 30,000 lot of 100 or less successively produced Elongation In 2 Inches (minimum) percent 30.0 and be radiographed throughout its en- Elongation other permissible gauge lengths tire length. Should the radiographic (minimum) percent 15.0 examination fail to meet the requirements of paragraph (m) of this sec- TABLE 3-CHECK ANALYSIS TOLERANCES tion, two additional seams of the same Tolerance lot must be examined, and if either of over the these fail to meet the requirements of Elements Limit or specified range maximum (m) (1) of this section, only those pass- (percent) limit or under the minimum ing are acceptable. limit (n) Rejected cylinders. Reheat treat- Carbon To 0.030, incl 0.005 ment of rejected cylinders is author- Over 0.30 to 0.20, incl 0.01 ized. Subsequent thereto, cylinders Manganese To 1.00 incl .03 must pass all prescribed tests to be ac- Over 1.00 to 3.00, incl 0.04 Phosphorus To 0.040, incl 0.005 ceptable. Welds may be repaired by Over 0.040 to 0.020 incl 0.010 suitable methods of fusion welding. Sulphur To .40 incl 0.005 (o) Authorized materials of construc- Silicon To 1.00, incl 0.05 tion. Authorized materials of construc- Nickel Over 5.00 to 10.00, incl 0.10 Over 10.00 to 20.00, incl 0.15 tion are as follows: Chromium Over 15.00 to 20.00, incl 0.20 (1) Inner containment vessel (cylinder). Rephosphorized steels not subject to check analysis for Electric furnace steel of uniform qualphosphorus. ity must be used. Chemical analysis must conform to ASTM A 240/A 240M (2) Outer jacket. (i) Nonflammable (IBR, see $171.7 of this subchapter), cryogenic liquids. Cylinders intended Type 304 stainless steel. Chemical analfor use in the transportation of nonysis must conform to ASTM A240, Type flammable cryogenic liquid must have 304 Stainless Steel. A heat of steel an outer jacket made of steel or aluminum. made under table 1 and table 2 in this paragraph (o)(1) is acceptable, even (ii) Flammable cryogenic liquids. though its check chemical analysis is Cylinders intended for use in the transslightly out of the specified range, if it portation of flammable cryogenic liqis satisfactory in all other respects, uid must have an outer jacket made of steel. provided the tolerances shown in table 3 in this paragraph (o)(1) are not ex- (p) Markings. (1) Markings must be ceeded. The following chemical analstamped plainly and permanently on yses and physical properties are aushoulder or top head of jacket or on a thorized: permanently attached plate or head protective ring. TABLE 1-AUTHORIZED MATERIALS (2) The letters "ST", followed by the design service temperature (for exam- Designation Chemical analysis, ple, ST-423F). must be marked on cyllimits in percent inders having a design service tempera- Carbon 0.08 max. ture of colder than minus 320 °F only. Manganese 2.00 max. Location to be just below the DOT Phasphorus 0.045 max. mark. Sulphur 0.030 max. (3) The maximum weight of contents, Silicon 1.00 max. in pounds (for example, "Max. Content Nickel 8.00-10.50. Chromium 18.00-20.00. 51 #''), must be marked on cylinders Molybdenum None. having a design service temperature Titanium None. colder than minus 320 °F only. Loca- Columbium None. tion to be near symbol. ¹The carbon analysis must be reported to the nearest hun- (4) Special orientation instructions dredth of one percent. must be marked on the cylinder (for 879 $ 178.58 49 CFR Ch. I (10-1-06 Edition) example, THIS END UP). if the cyl- TABLE 1-AUTHORIZED MATERIALS-Continued inder is used in an orientation other 4130 Percent than vertical with openings at the top of the cylinder. Chromium 0.80/1.10. (5) If the jacket of the cylinder is Molybdenum 0.15/0.25. constructed of aluminum, the letters "AL" must be marked after the service TABLE 2-CHECK ANALYSIS TOLERANCES pressure marking. Example: DOT-4L150 AL. Tolerance (percent) over the (6) Except for serial number and jackmaximum limit or et material designation, each marking under the min- Limit or maximum imum limit prescribed in this paragraph (p) must Element specified (parcent) be duplicated on each cylinder by any Under Over minmax- suitable means. Imum imum (q) Inspector's report. In addition to limit limit the information required by 178.35, the Carbon Over 0.15 to 0.40 incl .03 .04 inspector's reports must contain infor- Manganese To 0.60 Incl 03 .03 mation on: Phosphorus¹ All ranges .01 Sulphur All ranges .01 (1) The jacket material and insula- Silicon To 0.30 incl .02 .03 tion type; Over 0.30 to 1.00 incl .05 .05 (2) The design service temperature Chromium To 0.90 incl .03 .03 Over 0.90 to 2.10 incl .05 .05 (°F); and Molybdenum To 0.20 incl .01 .01 (3) The impact test results, on a lot Over 0.20 to 0.40, Incl .02 .02 basis. Rephosphorized steels not subject to check analysis for phosphorus. [Amdt. 178-114, 61 FR 25942, May 23, 1996, as amended at 66 FR 45386-45388, Aug. 28, 2001: 67 (c) Identification of material. Materials FR 51653, Aug. 8, 2002; 68 FR 75748, Dec. 31, must be identified by any suitable 2003] method except that plates and billets for hot-drawn containers must be § 178.58 Specification 4DA welded steel marked with the heat number. cylinders for aircraft use. (d) Manufacture. Cylinders must be (a) Type, size, and service pressure. A manufactured in accordance with the DOT 4DA is a welded steel sphere (two following requirements: seamless hemispheres) or a circum- (1) By best appliances and methods. ferentially welded cylinder (two seam- No defect is acceptable that is likely to less drawn shells) with a water capacweaken the finished container appreity not over 100 pounds and a service ciably. A reasonably smooth and unipressure of at least 500 but not over 900 form surface finish is required. No abpsig. rupt change in wall thickness is per- (b) Steel. Open-hearth or electric steel mitted. Welding procedures and operaof uniform quality must be used. A tors must be qualified in accordance heat of steel made under table 1 in this with CGA Pamphlet C-3 (IBR, see paragraph (b), check chemical analysis § 171.7 of this subchapter). of which is slightly out of the specified (2) All seams of the sphere or cylrange, is acceptable, if satisfactory in Inders must be fusion welded. Seams all other respects, provided the tolermust be of the butt or joggle butt type ances shown in table 2 in this paraand means must be provided for accomgraph (b) are not exceeded except as applishing complete penetration of the proved by the Associate Administrator. joint. The following chemical analyses are (e) Welding. Attachments to the conauthorized: tainer are authorized by fusion welding provided that such attachments are TABLE 1-AUTHORIZED MATERIALS made of weldable steel, the carbon con- 4130 Percent tent of which may not exceed 0.25 percent except in the case of 4130 steel. Carbon 0.28/0.33. (f) Wall thickness. The minimum wall Manganese 0.40/0.60. thickness must be such that the wall Phosphorus 0.040 max. Suffer 0.040 max. stress at the minimum specified test Silicon 0.15/0.35. pressure may not exceed 67 percent of 880 Pipeline and Hazardous Materials Safety Admin., DOT § 178.58 the minimum tensile strength of the cooling rate in excess of 80 percent of steel as determined from the physical the cooling rate of water, must be inand burst tests required and may not spected by the magnetic particle or dye be over 70,000 p.s.i. For any diameter penetrant method to detect the prescontainer, the minimum wall thickness ence of quenching cracks. Any cylinder is 0.040 inch. Calculations must be found to have a quench crack must be made by the formulas in (f)(1) or (f)(2) rejected and may not be requalified. of this section: (h) Openings in container. Openings in (1) Calculation for a sphere must be the container must comply with the made by the following formula: following requirements: S = PD / 4tE (1) Each opening in the container must be provided with a fitting, boss, Where: or pad of weldable steel securely at- S - wall stress in pounds psi: tached to the container by fusion weld- P = test pressure prescribed for water jacket ing. test, i.e., at least 2 times service pressure, (2) Attachments to a fitting. boss, or in psig: D = outside diameter in Inches; pad must be adequate to prevent leak- t = minimum wall thickness in inches; age. Threads must comply with the fol- E - 0.85 (provides 85 percent weld efficiency lowing: factor which must be applied in the girth (i) Threads must be clean cut, even, weld area and heat affected zones which without checks, and tapped to gauge. zone must extend a distance of 6 times wall thickness from center line of weld); (ii) Taper threads to be of length not E = 1.0 (for all other areas). less than as specified for American Standard taper pipe threads. (2) Calculation for a cylinder must be (iii) Straight threads, having at least made by the following formula: 4 engaged threads, to have tight fit and S = [P(1.3D² + 0.4d 2)] / (D² - d²) calculated shear strength at least 10 times the test pressure of the con- Where: tainer; gaskets required, adequate to S = wall stress in pounds psi; P = test pressure prescribed for water jacket prevent leakage. test, i.e., at least 2 times service pressure, (i) Hydrostatic test. Each cylinder in psig: must successfully withstand a hydro- D = outside diameter in inches; static test as follows: d = inside diameter in inches. (1) The test must be by water-jacket, (g) Heat treatment. The completed or other suitable method, operated so containers must be uniformly and as to obtain accurate data. The presproperly heat-treated prior to tests. sure gauge must permit reading to an Heat-treatment of containers of the auaccuracy of 1 percent. The expansion thorized analysis must be as follows: gauge must permit reading of total ex- (1) All containers must be quenched pansion to accuracy either of 1 percent by oil, or other suitable medium except or 0.1 cubic centimeter. as provided in paragraph (g)(4) of this (2) Pressure must be maintained for section. at least 30 seconds and sufficiently (2) The steel temperature on quenchlonger to ensure complete expansion. ing must be that recommended for the Any internal pressure applied after steel analysis, but may not exceed 1,750 heat-treatment and previous to the of- °F. ficial test may not exceed 90 percent of (3) The steel must be tempered at the the test pressure. If, due to failure of temperature most suitable for the the test apparatus, the test pressure analysis except that in no case shall cannot be maintained, the test may be the tempering temperature be less than repeated at a pressure increased by 10 1,000 F. percent or 100 psig, whichever is the (4) The steel may be normalized at a lower. temperature of 1,650 °F instead of being (3) Permanent volumetric expansion quenched, and containers so normalmay not exceed 10 percent of total volized need not be tempered. umetric expansion at test pressure. (5) All cylinders, if water quenched or (4) Each container must be tested to quenched with a liquid producing a at least 2 times service pressure. 881 $ 178.58 49 CFR Ch. I (10-1-06 Edition) (j) Burst test. One container taken at width not over 6 times thickness is aurandom out of 200 or less must be thorized when wall of sphere is not hydrostatically tested to destruction. over 3/16 inch thick. The rupture pressure must be included (3) A physical test for cylinders is reas part of the inspector's report. quired on 2 specimens cut from 1 cyl- (k) Flattening test. Spheres and cylinder taken at random out of each lot inders must be subjected to a flatof 200 or less. tening test as follows: (4) Specimens for cylinder must con- (1) Flattening test for spheres. One form to the following: sphere taken at random out of each lot (i) A gauge length of 8 inches with a of 200 or less must be subjected to a width not over 1½ inches, a gauge flattening test as follows: length of 2 inches with a width not (i) The test must be performed after over 1½ inches, a gauge length at least the hydrostatic test. 24 times thickness with a width not (ii) The test must be at the weld beover 6 times thickness is authorized tween the parallel steel plates on a when a cylinder wall is not over 3/16 press with a welded seam, at right an- Inch thick. gles to the plates. Any projecting ap- (ii) The specimen, exclusive of grip purtenances may be cut off (by meends, may not be flattened. Grip ends chanical means only) prior to crushing. may be flattened to within 1 inch of (2) Flattening test for cylinders. One each end of the reduced section. cylinder taken at random out of each (iii) Heating of a specimen for any lot of 200 or less, must be subjected to purpose is not authorized. a flattening test as follows: (5) The yield strength in tension (i) The test must be performed after must be the stress corresponding to a the hydrostatic test. permanent strain of 0.2 percent of the (ii) The test cylinder must be placed gauge length. The following conditions between wedge-shaped knife edges havapply: ing a 60° angle, rounded to a 1/2-inch ra- (i) The yield strength must be deterdius. mined by either the "offset" method or (1) Radiographic inspection. Radiothe "extension under load" method as graphic examinations is required on all prescribed in ASTM E 8 (IBR, see $171.7 welded joints which are subjected to inof this subchapter). ternal pressure, except that at the dis- (ii) In using the "extension under cretion of the disinterested inspector, load" method, the total strain (or "exopenings less than 25 percent of the tension under load") corresponding to sphere diameter need not be subjected the stress at which the 0.2 percent perto radiographic inspection. Evidence of manent strain occurs may be deterany defects likely to seriously weaken mined with sufficient accuracy by calthe container must be cause for rejecculating the elastic extension of the tion. gauge length under appropriate load (m) Physical test and specimens for and adding thereto 0.2 percent of the spheres and cylinders. Spheres and cylgauge length. Elastic extension calinders must be subjected to a physical culations must be based on an elastic test as follows: modulus of 30,000,000. In the event of (1) A physical test for a sphere is recontroversy, the entire stress-strain quired on 2 specimens cut from a flat diagram must be plotted and the yield representative sample plate of the strength determined from the 0.2 persame heat taken at random from the cent offset. steel used to produce the sphere. This (iii) For the purpose of strain measflat steel from which the 2 specimens urement, the initial strain must be set are to be cut must receive the same while the specimen is under a stress of heat-treatment as the spheres them- 12,000 psi and the strain indicator readselves. Sample plates to be taken for ing being set at the calculated coreach lot of 200 or less spheres. responding strain. (2) Specimens for spheres have a (iv) Cross-head speed of the testing gauge length of 2 inches with a width machine may not exceed 1/8 inch per not over 1½ inches, or a gauge length minute during yield strength deterat least 24 times thickness with a mination. 882 Pipeline and Hazardous Materials Safety Admin., DOT § 178.59 (n) Acceptable results for physical, flatfinished cylinder appreciably. A reatening, and burst tests. The following are sonably smooth and uniform surface acceptable results of the physical, flatfinish is required. Welding procedures tening and burst test: and operators must be qualified in ac- (1) Elongation must be at least 20 cordance with CGA Pamphlet C-3 (IBR, percent for a 2-inch gauge length or 10 see § 171.7 of this subchapter). percent in other cases. (e) Exposed bottom welds. Exposed bot- (2) Flattening is required to 50 pertom welds on cylinders over 18 inches cent of the original outside diameter long must be protected by footrings. without cracking. (f) Heat treatment. Body and heads (3) Burst pressure must be at least 3 formed by drawing or pressing must be times service pressure. uniformly and properly heat treated (o) Rejected containers. Reheat-treatprior to tests. ment of rejected cylinders is author- (g) Openings. Openings in the cylized. Subsequent thereto, containers inders must comply with the following: must pass all prescribed tests to be ac- (1) Standard taper pipe threads are ceptable. Repair of welded seams by required; welding prior to reheat-treatment is (2) Length may not be less than as authorized. specified for American Standard pipe (p) Marking. Markings on each conthreads; tapped to gauge; clean cut, tainer must be stamped plainly and even, and without checks. permanently on a permanent attach- (h) Hydrostatic test. Each cylinder ment or on a metal nameplate permamust successfully withstand a hydronently secured to the container by static test as follows: means other than soft solder. (1) The test must be by water-jacket, [Amdt. 178-114, 61 FR 25942, May 23, 1996, as or other suitable method, operated so amended at 66 FR 45386, 45388, Aug. 28, 2001; as to obtain accurate data. The pres- 67 FR 51654, Aug. 8, 2002; 67 FR 61015, Sept. 27, sure gauge must permit reading to an 2002; 68 FR 75748, Dec. 31, 2003] accuracy of 1 percent. The expansion gauge must permit reading of total ex- § 178.59 Specification 8 steel cylinders pansion to an accuracy of either 1 perwith porous fillings for acetylene. cent or 0.1 cubic centimeter. (a) Type and service pressure. A DOT 8 (2) Pressure must be maintained for cylinder is a seamless cylinder with a at least 30 seconds and sufficiently service pressure of 250 psig. The follonger to ensure complete expansion. lowing steel is authorized: Any internal pressure applied after (1) A longitudinal seam if forge lap heat-treatment and previous to the ofwelded; ficial test may not exceed 90 percent of (2) Attachment of heads by welding the test pressure. or by brazing by dipping process; or (3) Permanent volumetric expansion (3) A welded circumferential body may not exceed 10 percent of total volseam if the cylinder has no longituumetric expansion at test pressure. dinal seam. (4) One cylinder out of each lot of 200 (b) Steel. Open-hearth, electric or or less must be hydrostatically tested basic oxygen process steel of uniform to at least 750 psig. Cylinders not so quality must be used. Content percent tested must be examined under presmay not exceed the following: Carbon, sure of between 500 and 600 psig and 0.25; phosphorus, 0.045; sulphur, 0.050. show no defect. If hydrostatically test- (c) Identification of steel. Materials ed cylinder fails, each cylinder in the must be identified by any suitable lot may be hydrostatically tested and method except that plates and billets those passing are acceptable. for hot-drawn cylinders must be (i) Leakage test. Cylinders with botmarked with the heat number. toms closed in by spinning must be (d) Manufacture. Cylinders must be subjected to a leakage test by setting manufactured using equipment and the interior air or gas pressure to not processes adequate to ensure that each less than the service pressure. Cylcylinder produced conforms to the reinders which leak must be rejected. quirements of this subpart. No defect is (j) Physical test. A physical test must acceptable that is likely to weaken the be conducted as follows: 883 § 178.59 49 CFR Ch. I (10-1-06 Edition) (1) The test is required on 2 speci- (1) Porous filling. (1) Cylinders must mens cut longitudinally from 1 cylbe filled with a porous material in acinder or part thereof taken at random cordance with the following: out of each lot of 200 or less, after heat (i) The porous material may not distreatment. integrate or sag when wet with solvent (2) Specimens must conform to a or when subjected to normal service; gauge length of 8 inches with a width (ii) The porous filling material must not over 1½ inches, a gauge length of 2 be uniform in quality and free of voids, inches with width not over 1½, or a except that a well drilled into the fillgauge length at least 24 times thicking material beneath the valve is authorized if the well is filled with a maness with a width not over 6 times thickness is authorized when a cylinder terial of such type that the functions wall is not over 3/16 inch thick. of the filling material are not im- (3) The yield strength in tension paired; (iii) Overall shrinkage of the filling must be the stress corresponding to a material is authorized if the total permanent strain of 0.2 percent of the clearance between the cylinder shell gauge length. The following conditions and filling material, after solvent has apply: been added, does not exceed 1/2 of 1 per- (i) The yield strength must be detercent of the respective diameter or mined by either the "offset" method or length, but not to exceed 1/8 inch, measthe "extension under load" method as ured diametrically and longitudinally; prescribed in ASTM E 8 (IBR, see $171.7 (iv) The clearance may not impair of this subchapter). the functions of the filling material; (ii) In using the "extension under (v) The installed filling material load" method, the total strain (or "exmust meet the requirements of CGA C- tension under load") corresponding to 12 (IBR, see $171.7 of this subchapter); the stress at which the 0.2 percent perand manent strain occurs may be deter- (vi) Porosity of filling material may mined with sufficient accuracy by calnot exceed 80 percent except that fillculating the elastic extension of the ing material with a porosity of up to 92 gauge length under appropriate load percent may be used when tested with and adding thereto 0.2 percent of the satisfactory results in accordance with gauge length. Elastic extension cal- CGA Pamphlet C-12. culations must be based on an elastic (2) When the porosity of each cylmodulus of 30,000,000. In the event of inder is not known, a cylinder taken at controversy, the entire stress-strain random from a lot of 200 or less must diagram must be plotted and the yield be tested for porosity. If the test cylstrength determined from the 0.2 offinder fails, each cylinder in the lot set. may be tested individually and those (iii) For the purpose of strain meascylinders that pass the test are accepturement, the initial strain must be set able. while the specimen is under a stress of (3) For filling that is molded and 12,000 psi and the strain indicator readdried before insertion in cylinders, poing being set at the calculated corrosity test may be made on a sample responding strain. block taken at random from material (iv) Cross-head speed of the testing to be used. machine may not exceed 1/8 inch per (4) The porosity of the filling mateminute during yield strength deterrial must be determined. The amount mination. of solvent at 70 °F for a cylinder: (4) Yield strength may not exceed 73 (i) Having shell volumetric capacity percent of tensile strength. Elongation above 20 pounds water capacity (nomimust be at least 40 percent in 2 inch or nal) may not exceed the following: 20 percent in other cases. Maximum (k) Rejected cylinders. Reheat treatacetone sol- Percent porosity of filler vent percent ment of rejected cylinder is authorized. shell capac- Subsequent thereto, cylinders must ity by volume pass all prescribed tests to be acceptable. Repair by welding is authorized. 90 to 92 43.4 884 Pipeline and Hazardous Materials Safety Admin., DOT § 178.60 Maximum facture of the cylinders and, upon reacetone sol- Percent porosity of filler vent percent quest, to the purchaser. The test reshell capacports must be retained by the inspector ity by volume for fifteen years from the original test date of the cylinder. 87 to 90 42.0 83 to 87 40.0 (o) Marking. (1) Marking on each cyl- 80 to 83 38.6 inder must be stamped plainly and per- 75 to 80 36.2 manently on or near the shoulder, top 70 to 75 33.8 head, neck or valve protection collar 65 to 70 31.4 which is permanently attached to the (ii) Having volumetric capacity of 20 cylinder and forming integral part pounds or less water capacity (nomithereof. nal), may not exceed the following: (2) Tare weight of cylinder. in pounds and ounces, must be marked on the Maximum acetone solcylinder. Percent porosity of filler vent percent (3) Cylinders, not completed, when shell capacdelivered must each be marked for ity by volume identification of each lot of 200 or less. 90 to 92 41.8 [Amdt. 178-114, 61 FR 25942. May 23, 1996, as 83 to 90 38.5 amended at 66 FR 45386, Aug. 28, 2001; 67 FR 80 to 83 37.1 61016, Sept. 27, 2002; 67 FR 51654, Aug. 8, 2002; 75 to 80 34.8 32.5 68 FR 75748, 75749, Dec. 31, 2003) 70 to 75 65 to 70 30.2 $178.60 Specification 8AL steel cyl- (m) Tare weight. The tare weight is inders with porous fillings for the combined weight of the cylinder acetylene. proper, porous filling. valve, and sol- (a) Type and service pressure. A DOT vent, without removable cap. 8AL cylinder is a seamless steel cyl- (n) Duties of inspector. In addition to inder with a service pressure of 250 the requirements of $178.35, the inspecpsig. However, the attachment of heads tor is required toby welding or by brazing by dipping (1) Certify chemical analyses of steel process and a welded circumferential used, signed by manufacturer thereof; body seam is authorized. Longitudinal also verify by, check analyses of samseams are not authorized. ples taken from each heat or from 1 out (b) Authorized steel. The authorized of each lot of 200 or less, plates, shells, steel is as specified in table I of appenor tubes used. dix A to this part. (2) Verify compliance of cylinder (c) Identification of steel. Material shells with all shell requirements; inmust be identified by any suitable spect inside before closing in both ends; method except that plates and billets verify heat treatment as proper; obtain all samples for all tests and for check for hot-drawn cylinders must be marked with heat number. analyses; witness all tests; verify threads by gauge; report volumetric ca- (d) Manufacture. Cylinders must be pacity and minimum thickness of wall manufactured using equipment and noted. processes adequate to ensure that each (3) Prepare report on manufacture of cylinder produced conforms to the resteel shells in form prescribed in quirements of this subpart. No defect is § 178.35. Furnish one copy to manufacpermitted that is likely to weaken the turer and three copies to the company finished cylinder appreciably. A reathat is to complete the cylinders. sonably smooth and uniform surface (4) Determine porosity of filling and finish is required. Welding procedures tare weights; verify compliance of and operators must be qualified in acmarking with prescribed requirements; cordance with CGA Pamphlet C-3 (IBR, obtain necessary copies of steel shell see $171.7 of this subchapter). reports; and furnish complete reports (e) Footrings. Exposed bottom welds required by this specification to the on cylinders over 18 inches long must person who has completed the manube protected by footrings. 885 $ 178.60 49 CFR Ch. I (10-1-06 Edition) (f) Welding or brazing. Welding or that when brazed joints are used, heat brazing for any purpose whatsoever is treatment must follow any forming prohibited except as follows: and welding operations but may be (1) The attachment to the tops or done before, during, or after the brazbottoms of cylinders of neckrings, ing operations. Liquid quenching is not footrings, handlers, bosses, pads, and authorized. valve protecting rings is authorized (i) Openings. Standard taper pipe provided that such attachments and threads required in all openings. The the portion of the container to which length of the opening may not be less they are attached are made of weldable than as specified for American Standsteel, the carbon content of which may ard pipe threads; tapped to gauge; not exceed 0.25 percent. clean cut, even, and without checks. (2) Heat treatment is not required (j) Hydrostatic test. Each cylinder after welding or brazing weldable low must successfully withstand a hydrocarbon parts to attachments, specified static test as follows: in paragraph (f)(1) of this section, of (1) The test must be by water-jacket, similar material which have been preor other suitable method, operated so viously welded or brazed to the top or as to obtain accurate data. The presbottom of cylinders and properly heat sure gauge must permit reading to an treated, provided such subsequent accuracy of 1 percent. The expansion welding or brazing does not produce a gauge must permit reading of total extemperature in excess of 400 °F in any pansion to an accuracy of either 1 perpart of the top or bottom material. cent or 0.1 cubic centimeter. (g) Wall thickness; wall stress. The wall (2) Pressure must be maintained for thickness/wall stress of the cylinder at least 30 seconds and sufficiently must conform to the following: longer to ensure complete expansion. (1) The calculated wall stress at 750 Any internal pressure applied after psi may not exceed 35,000 psi, or oneheat-treatment and previous to the ofhalf of the minimum ultimate strength ficial test may not exceed 90 percent of of the steel as determined in paragraph the test pressure. (1) of this section, whichever value is (3) Permanent volumetric expansion the smaller. The measured wall thickmay not exceed 10 percent of total volness may not include galvanizing or umetric expansion at test pressure. other protective coating. (4) One cylinder out of each lot of 200 (i) Calculation of wall stress must be or less must be hydrostatically tested made by the formula: to at least 750 psig. Cylinders not so S = [P(1.3D² + 0.4d2)] / (D² - d²) tested must be examined under pressure of between 500 and 600 psig and Where: show no defect. If a hydrostatically S = wall stress in pounds psi: tested cylinder fails, each cylinder in P = 750 psig (minimum test pressure): the lot may be hydrostatically tested D = outside diameter in inches; and those passing are acceptable. d = inside diameter in inches. (k) Leakage test. Cylinders with bot- (ii) Either D or d must be calculated toms closed in by spinning must be from the relation D = d + 2t, where t = leakage tested by setting the interior minimum wall thickness. air or gas pressure at not less than the (2) Cylinders with a wall thickness service pressure. Any cylinder that less than 0.100 inch, the ratio of leaks must be rejected. straight side wall length to outside di- (1) Physical test. A physical test must ameter may not exceed 3.5. be conducted as follows; (3) For cylinders having outside di- (1) The test is required on 2 speciameter over 5 Inches, the minimum mens cut longitudinally from 1 cylwall thickness must be 0.087 inch. inder or part thereof taken at random (h) Heat treatment. Each cylinder out of each lot of 200 or less, after heat must be uniformly and properly heat treatment. treated, prior to tests, by any suitable (2) Specimens must conform to a method in excess of 1100 °F. Heat treatgauge length of 8 inches with a width ment must be accomplished after all not over 1½ inches, a gauge length 2 forming and welding operations, except inches with a width not over 1½ inches, 886 Pipeline and Hazardous Materials Safety Admin., DOT § 178.60 or a gauge length at least 24 times (1) Tensile test. A specimen must be thickness with a width not over 6 times cut from one cylinder of each lot of 200 thickness is authorized when a cylinder or less, or welded test plate. The speciwall is not over 3/16 inch thick. men must be taken from across the (3) The yield strength in tension major seam and must be prepared and must be the stress corresponding to a tested in accordance with and must permanent strain of 0.2 percent of the meet the requirements of CGA Pamgauge length. The following conditions phlet C-3. Should this specimen fail to apply: meet the requirements, specimens may (i) The yield strength must be deterbe taken from two additional cylinders mined by either the "offset" method or or welded test plates from the same lot the "extension under load" method as and tested. If either of the latter speciprescribed in ASTM E 8 (IBR, see $171.7 mens fail to meet the requirements, of this subchapter). the entire lot represented must be re- (ii) In using the "extension under jected. load" method, the total strain (or "ex- (2) Guided bend test. A root bend test tension under load") corresponding to specimen must be cut from the cylthe stress at which the 0.2 percent perinder or welded test plate, used for the manent strain occurs may be detertensile test specified in paragraph mined with sufficient accuracy by cal- (n)(1) of this section. Specimens must culating the elastic extension of the be prepared and tested in accordance gauge length under appropriate load with and must meet the requirements and adding thereto 0.2 percent of the of CGA Pamphlet C-3. gauge length. Elastic extension cal- (3) Alternate guided-bend test. This culations must be based on an elastic test may be used and must be as remodulus of 30,000,000. In the event of quired by CGA Pamphlet C-3. The speccontroversy, the entire stress-strain imen must be bent until the elongation diagram must be plotted and the yield at the outer surface, adjacent to the strength determined from the 0.2 offroot of the weld, between the lightly set. scribed gage lines-a to b, must be at (iii) For the purpose of strain measleast 20 percent, except that this perurement, the initial strain must be set centage may be reduced for steels havwhile the specimen is under a stress of ing a tensile strength in excess of 50,000 12,000 psi, the strain indicator reading psi, as provided in paragraph (m) of being set at the calculated corthis section. responding strain. (o) Rejected cylinders. Reheat treat- (iv) Cross-head speed of the testing ment of rejected cylinders is authormachine may not exceed 1/8 inch per ized. Subsequent thereto, cylinders minute during yield strength determust pass all prescribed tests to be acmination. ceptable. Repair by welding is author- (m) Elongation. Physical test speciized. mens must show at least a 40 percent (p) Porous filling. (1) Cylinders must elongation for a 2 inch gauge length or be filled with a porous material in acat least a 20 percent elongation in cordance with the following: other cases. Except that these elon- (i) The porous material may not disgation percentages may be reduced nuintegrate or sag when wet with solvent merically by 2 for 2 inch specimens and or when subjected to normal service; 1 in other cases for each 7,500 psi incre- (ii) The filling material must be uniment of tensile strength above 50,000 form in quality and free of voids, expsi to a maximum of four such increcept that a well drilled into the filling ments. material beneath the valve is author- (n) Weld tests. Specimens taken ized if the well is filled with a material across the circumferentially welded of such type that the functions of the seam must be cut from one cylinder filling material are not impaired: taken at random from each lot of 200 or (iii) Overall shrinkage of the filling less cylinders after heat treatment and material is authorized if the total must pass satisfactorily the following clearance between the cylinder shell tests: and filling material, after solvent has 887 § 178.60 49 CFR Ch. I (10-1-06 Edition) been added, does not exceed 1/2 of 1 perproper, porous filling, valve, and solcent of the respective diameter or vent, but without removable cap. length but not to exceed 1/8 inch, meas- (r) Duties of inspector. In addition to ured diametrically and longitudinally; the requirements of § 178.35, the inspec- (iv) The clearance may not impair tor shallthe functions of the filling material; (1) Certify chemical analyses of steel (v) The installed filling material used, signed by manufacturer thereof; must meet the requirements of CGA C- also verify by check analyses, of sam- 12 (IBR, see $171.7 of this subchapter); ples taken from each heat or from 1 out and of each lot of 200 or less plates, shells, (vi) Porosity of filling material may or tubes used. not exceed 80 percent except that fill- (2) Verify compliance of cylinder ing material with a porosity of up to 92 shells with all shell requirements, inpercent may be used when tested with spect inside before closing in both ends, satisfactory results in accordance with verify heat treatment as proper; obtain CGA Pamphlet C-12. all samples for all tests and for check (2) When the porosity of each cylanalyses, witness all tests; verify inder is not known, a cylinder taken at threads by gauge, report volumetric carandom from a lot of 200 or less must pacity and minimum thickness of wall be tested for porosity. If the test cylnoted. inder fails, each cylinder in the lot (3) Report percentage of each specimay be tested individually and those fied alloying element in the steel. Precylinders that pass the test are acceptpare report on manufacture of steel able. shells in form prescribed in $178.35. (3) For filling that is molded and Furnish one copy to manufacturer and dried before insertion in cylinders, pothree copies to the company that is to rosity test may be made on sample complete the cylinders. block taken at random from material (4) Determine porosity of filling and to be used. tare weights; verify compliance of (4) The porosity of the filling matemarking with prescribed requirements; rial must be determined; the amount of obtain necessary copies of steel shell solvent at 70 °F for a cylinder: reports prescribed in paragraph (b) of (i) Having shell volumetric capacity this section; and furnish complete test above 20 pounds water capacity (nomireports required by this specification nal) may not exceed the following: to the person who has completed the manufacturer of the cylinders and, Maximum acetone Percent porosity of filler solvent percent shell upon request, to the purchaser. The capacity by volume test reports must be retained by the in- 43.4 spector for fifteen years from the origi- 90 to 92 B7 to 90 42.0 nal test date of the cylinder. 83 to 87 40.0 (s) Marking. (1) Tare weight of cyl- 80 to 83 38.6 inder, in pounds and ounces, must be 75 to 80 36.2 70 to 75 33.8 marked on the cylinder. 65 to 70 31.4 (2) Cylinders, not completed, when delivered must each be marked for (ii) Having volumetric capacity of 20 identification of each lot of 200 or less. pounds or less water capacity (nomi- (3) Markings must be stamped plainly nal), may not exceed the following: and permanently in locations in accordance with the following: Maximum acetone Percent porosity of filler solvent percent shell (i) On shoulders and top heads not capacity by volume less than 0.087 inch thick; or 90 to 92 41.8 (ii) On neck, valve boss, valve protec- 83 to 90 38.5 tion sleeve, or similar part perma- 80 to 83 37.1 nently attached to the top end of cyl- 75 to 80 34.8 32.5 inder; or 70 to 75 65 to 70 30.2 (iii) On a plate of ferrous material attached to the top of the cylinder or (q) Tare weight. The tare weight is permanent part thereof; the plate must the combined weight of the cylinder be at least 1/16 inch thick, and must be 888 Pipeline and Hazardous Materials Safety Admin., DOT § 178.61 attached by welding, or by brazing at a footrings. Minimum thickness of heads temperature of at least 1,100 °F may not be less than 90 percent of the throughout all edges of the plate. Suffirequired thickness of the sidewall. cient space must be left on the plate to Heads must be concave to pressure. provide for stamping at least four (4) (2) Circumferential seams must be by retest dates. electric-arc welding. Joints must be [Amdt. 178-114, 61 FR 25942, May 23, 1996, as butt with one member offset (joggle amended at 66 FR 45386, 45388, Aug. 28, 2001; butt) or lap with minimum overlap of 67 FR 51654. Aug. 8, 2002; 68 FR 75748, 75749, at least four times nominal sheet Dec. 31, 2003] thickness. (3) Longitudinal seams in shells must § 178.61 Specification 4BW welded conform to the following: steel cylinders with electric-arc (i) Longitudinal electric-arc welded welded longitudinal seam. seams must be of the butt welded type. (a) Type, size and service pressure. A Welds must be made by a machine DOT 4BW cylinder is a welded type process including automatic feed and steel cylinder with a longitudinal elecwelding guidance mechanisms. Longitric-arc welded seam, a water capacity tudinal seams must have complete (nominal) not over 1,000 pounds and a joint penetration, and must be free service pressure at least 225 and not from undercuts, overlaps or abrupt over 500 psig gauge. Cylinders closed in ridges or valleys. Misalignment of matby spinning process are not authorized. ing butt edges may not exceed 1/6 of (b) Authorized steel. Steel used in the nominal sheet thickness or 1/32 inch construction of the cylinder must conwhichever is less. All joints with nomiform to the following: nal sheet thickness up to and including (1) The body of the cylinder must be 1/8 inch must be tightly butted. When constructed of steel conforming to the nominal sheet thickness is greater limits specified in table 1 of appendix A than 1/8 inch, the joint must be gapped to this part. with maximum distance equal to one- (2) Material for heads must meet the half the nominal sheet thickness or 1/32 requirements of paragraph (a) of this inch whichever is less. Joint design, section or be open hearth, electric or preparation and fit-up must be such basic oxygen carbon steel of uniform that requirements of this paragraph (d) quality. Content percent may not exare satisfied. ceed the following: Carbon 0.25, Man- (ii) Maximum joint efficiency must ganese 0.60, Phosphorus 0.045, Sulfur be 1.0 when each seam is radiographed 0.050. Heads must be hemispherical or completely. Maximum joint efficiency ellipsoidal in shape with a maximum must be 0.90 when one cylinder from ratio of 2.1. If low carbon steel is used, each lot of 50 consecutively welded cylthe thickness of such heads must be deinders is spot radiographed. In additermined by using a maximum wall tion, one out of the first five cylinders stress of 24,000 p.s.i. in the formula dewelded following a shut down of weldscribed in paragraph (f)(4) of this secing operations exceeding four hours tion. must be spot radiographed. Spot (c) Identification of material. Material radiographs, when required, must be must be identified by any suitable made of a finished welded cylinder and method. must include the girth weld for 2 (d) Manufacture. Cylinders must be inches in both directions from the manufactured using equipment and intersection of the longitudinal and processes adequate to ensure that each girth welds and include at least 6 cylinder produced conforms to the reinches of the longitudinal weld. Maxquirements of this subpart and the folimum joint efficacy of 0.75 must be perlowing: missible without radiography. (1) No defect is permitted that is (4) Welding procedures and operators likely to weaken the finished cylinder must be qualified in accordance with appreciably. A reasonably smooth and CGA Pamphlet C-3 (IBR. see $171.7 of uniform surface is required. Exposed this subchapter). bottom welds on cylinders over 18 (e) Welding of attachments. The atinches long must be protected by tachment to the tops and bottoms only 889 § 178.61 49 CFR Ch. I (10-1-06 Edition) of cylinders by welding of neckrings, (1) All openings must be in the heads footrings, handles, bosses, pads and or bases. valve protection rings is authorized (2) Openings in cylinders must be proprovided that such attachments and vided with adequate fittings, bosses, or the portion of the container to which pads, integral with or securely atthey are attached are made of weldable tached to the cylinder by welding. steel, the carbon content of which may (3) Threads must comply with the folnot exceed 0.25 percent. lowing: (f) Wall thickness. For outside diame- (i) Threads must be clean cut and to ters over 6 inches the minimum wall gauge. thickness must be 0.078 inch. For a cyl- (ii) Taper threads must be of length inder with a wall thickness less than not less than as specified for American 0.100 inch, the ratio of tangential Standard Taper Pipe threads. length to outside diameter may not ex- (iii) Straight threads, having at least ceed 4 tol (4:1). In any case the min- 4 engaged threads, to have tight fit and imum wall thickness must be such that calculated shear strength at least 10 the wall stress calculated by the fortimes the test pressure of the cylinder; mula listed in paragraph (f)(4) of this gaskets required, adequate to prevent section may not exceed the lesser value leakage. of any of the following: (4) Closure of fittings, boss or pads (1) The value referenced in paragraph must be adequate to prevent leakage. (b) of this section for the particular (1) Hydrostatic test. Cylinders must material under consideration. withstand a hydrostatic test, as fol- (2) One-half of the minimum tensile lows: strength of the material determined as (1) The test must be by water-jacket, required in paragraph (j) of this secor other suitable method, operated so tion. as to obtain accurate data. The pres- (3) 35,000 psi. sure gauge must permit readings to an (4) Stress must be calculated by the accuracy of 1 percent. The expansion following formula: gauge must permit readings of total S = [2P(1.3D² + 0.4d²)] / [E(D² - d²)] volumetric expansion to an accuracy either of 1 percent or 0.1 cubic centiwhere: meter. S = wall stress, psi; (2) Pressure must be maintained for P - service pressure, psig; at least 30 seconds and sufficiently D = outside diameter, inches; longer to ensure complete expansion. d = inside diameter, inches; Any internal pressure applied after E = joint efficiency of the longitudinal seam heat treatment and previous to the of- (from paragraph (d) of this section). ficial test may not exceed 90 percent of (g) Heat treatment. Each cylinder the test pressure. must be uniformly and properly heat (3) Permanent volumetric expansion treated prior to test by the applicable may not exceed 10 percent of the total method referenced in Table 1 of appenvolumetric expansion at test pressure. dix A to this part. Heat treatment (4) Cylinders must be tested as folmust be accomplished after all forming lows: and welding operations. Heat treat- (i) At least 1 cylinder selected at ranment is not required after welding or dom out of each lot of 200 or less must brazing of weldable low carbon parts to be tested as outlined in paragraphs attachments of similar material which (i)(1), (i)(2). and (i)(3) of this section to have been previously welded to the top at least two times service pressure. or bottom of cylinders and properly (ii) All cylinders not tested as outheat treated, provided such subsequent lined in paragraph (i)(4)(i) of this secwelding or brazing does not produce a tion must be examined under pressure temperature in excess of 400 °F in any of at least two times service pressure part of the top or bottom material. and show no defect. (h) Openings in cylinders. Openings in (5) One finished cylinder selected at the cylinder must conform to the folrandom out of each lot of 500 or less lowing: successively produced must be 890 Pipeline and Hazardous Materials Safety Admin., DOT § 178.61 hydrostatically tested to 4 times servor the "extension under load" method ice pressure without bursting. as prescribed in ASTM E 8 (IBR, see (j) Physical tests. Cylinders must be $171.7 of this subchapter). subjected to a physical test as follows: (ii) In using the "extension under (1) Specimens must be taken from load" method, the total strain (or "exone cylinder after heat treatment and tension under load"), corresponding to chosen at random from each lot of 200 the stress at which the 0.2-percent peror less, as follows: manent strain occurs may be deter- (i) Body specimen. One specimen mined with sufficient accuracy by calmust be taken longitudinally from the culating the elastic extension of the body section at least 90 degrees away gauge length under appropriate load from the weld. and adding thereto 0.2 percent of the (ii) Head specimen. One specimen must be taken from either head on a gauge length. Elastic extension calculations must be based on an elastic cylinder when both heads are made of modulus of 30,000,000. In the event of the same material. However, if the two heads are made of differing materials, controversy, the entire stress-strain a specimen must be taken from each diagram must be plotted and the yield head. strength determined from the 0.2-per- (iii) If due to welded attachments on cent offset. the top head there is insufficient sur- (iii) For the purpose of strain measface from which to take a specimen, it urement, the initial strain reference may be taken from a representative must be set while the specimen is head of the same heat treatment as the under a stress of 12,000 psi and the test cylinder. strain indicator reading being set at (2) Specimens must conform to the the calculated corresponding strain. following: (iv) Cross-head speed of the testing (i) A gauge length of 8 inches with a machine may not exceed 1/8 inch per width not over 1½ inches, a gauge minute during yield strength deterlength of 2 inches with a width not mination. over 1½ inches, or a gauge length at (k) Elongation. Physical test specileast 24 times thickness with a width mens must show at least a 40 percent not over 6 times thickness is authorelongation for a 2-inch gauge length or ized when a cylinder wall is not over 3/16 at least a 20 percent elongation in inch thick. other cases. Except that these elon- (ii) The specimen, exclusive of grip gation percentages may be reduced nuends, may not be flattened. Grip ends merically by 2 for 2-inch specimens and may be flattened to within 1 inch of by 1 in other cases for each 7,500 psi ineach end of the reduced section. crement of tensile strength above 50,000 (iii) When size of the cylinder does psi to a maximum of four increments. not permit securing straight speci- (1) Tests of welds. Welds must be submens, the specimens may be taken in jected to the following tests: any location or direction and may be straightened or flattened cold, by pres- (1) Tensile test. A specimen must be sure only, not by blows when specicut from one cylinder of each lot of 200 mens are so taken and prepared, the inor less. The specimen must be taken spector's report must show in connecfrom across the longitudinal seam and tion with record of physical tests demust be prepared and tested in accordtailed information in regard to such ance with and must meet the requirespecimens. ments of CGA Pamphlet C-3. (iv) Heating of a specimen for any (2) Guided bend test. A root test specipurpose is not authorized. men must be cut from the cylinder (3) The yield strength in tension used for the tensile test specified in must be the stress corresponding to a paragraph (1)(1) of this section. Specipermanent strain of 0.2 percent of the mens must be taken from across the gauge length. The following conditions longitudinal seam and must be preapply: pared and tested in accordance with (i) The yield strength must be deterand must meet the requirements of mined by either the "off-set" method CGA Pamphlet C-3. 891 § 178.65 49 CFR Ch. I (10-1-06 Edition) (3) Alternate guided bend test. This tached by welding, or by brazing. The test may be used and must be as rebrazing rod is to melt at a temperature quired by CGA Pamphlet C-3. The specof 1100 °F Welding or brazing must be imen must be bent until the elongation along all the edges of the plate. at the outer surface, adjacent to the (3) On the neck, valve boss, valve proroot of the weld, between the lightly tection sleeve, or similar part permascribed gauge lines a to b, must be at nently attached to the top of the cylleast 20 percent, except that this perinder. centage may be reduced for steels hav- (4) On the footring permanently ating a tensile strength in excess of 50,000 tached to the cylinder, provided the psi, as provided in paragraph (k) of this water capacity of the cylinder does not section. exceed 25 pounds. (m) Radiographic examination. Welds (p) Inspector's report. In addition to of the cylinders must be subjected to a the information required by $178.35, the radiographic examination as follows: inspector's report must indicate the (1) Radiographic inspection must type and amount of radiography. conform to the techniques and accept- [Amdt. 178-114, 61 FR 25942, May 23, 1996, as ability criteria set forth in CGA Pamamended at 64 FR 51919. Sept. 27, 1999: 66 FR phlet C-3. When fluoroscopic inspection 45386, 45388, Aug. 28, 2001; 67 FR 51654, Aug. 6, is used, permanent film records need 2002; 67 FR 61016, Sept. 27, 2002; 68 FR 57633, not be retained. Oct. 6, 2003; 68 FR 75748, Dec. 31, 2003) (2) Should spot radiographic examination fail to meet the requirements § 178.65 Specification 39 non-reusable of paragraph (m)(1) of this section, two (non-refillable) cylinders. additional welds from the same lot of (a) Type, size, service pressure, and test 50 cylinders or less must be examined, pressure. A DOT 39 cylinder is a seamand if either of these fail to meet the less, welded, or brazed cylinder with a requirements, each cylinder must be service pressure not to exceed 80 perexamined as previously outlined; only cent of the test pressure. Spherical those passing are acceptable. pressure vessels are authorized and (n) Rejected cylinders. (1) Unless othcovered by references to cylinders in erwise stated, if a sample cylinder or this specification. specimen taken from a lot of cylinders (1) Size limitation. Maximum water cafails the prescribed test, then two addipacity may not exceed: (i) 55 pounds tional specimens must be selected from (1,526 cubic inches) for a service presthe same lot and subjected to the presure of 500 p.s.i.g. or less, and (ii) 10 scribed test. If either of these fails the pounds (277 cubic inches) for a service test, then the entire lot must be repressure in excess of 500 p.s.i.g. jected. (2) Test pressure. The minimum test (2) Reheat treatment of rejected cylpressure is the maximum pressure of inders is authorized. Subsequent therecontents at 130 °F or 180 p.s.i.g. whichto, cylinders must pass all prescribed ever is greater. tests to be acceptable. Repair of welded (3) Pressure of contents. The term seams by welding is authorized pro- "pressure of contents" as used in this vided that all defective metal is cut specification means the total pressure away and the joint is rewelded as preof all the materials to be shipped in the scribed for original welded joints. cylinder. (o) Markings. Markings must be (b) Material: steel or aluminum. The stamped plainly and permanently in cylinder must be constructed of either any of the following locations on the steel or aluminum conforming to the cylinder: following requirements: (1) On shoulders and top heads when (1) Steel. (i) The steel analysis must they are not less than 0.087-inch thick. conform to the following: (2) On a metal plate attached to the Ladle Check top of the cylinder or permanent part analysis analysis thereof; sufficient space must be left on the plate to provide for stamping at Carbon, maximum percent 0.12 0.15 least six retest dates; the plate must be Phosphorus, maximum percent .04 .05 Sulfur, maximum percent .05 .06 at least 1/16-inch thick and must be at- 892 Pipeline and Hazardous Materials Safety Admin., DOT § 178.65 (ii) For a cylinder made of seamless minimum strength of the shell matesteel tubing with integrally formed rial in the finished cylinder. ends, hot drawn, and finished, content (3) Attachments to the cylinder are percent for the following may not expermitted by any means which will not ceed: Carbon, 0.55; phosphorous, 0.045; be detrimental to the integrity of the sulfur, 0.050. cylinder. Welding or brazing of attach- (iii) For non-heat treated welded ments to the cylinder must be comsteel cylinders, adequately killed deep pleted prior to all pressure tests. drawing quality steel is required. (4) Welding procedures and operators (iv) Longitudinal or helical welded must be qualified in accordance with cylinders are not authorized for service CGA Pamphlet C-3 (IBR, see $171.7 of pressures in excess of 500 p.s.i.g. this subchapter). (2) Aluminum. Aluminum is not au- (d) Wall thickness. The minimum wall thorized for service pressures in excess thickness must be such that the wall of 500 psig. The analysis of the alustress at test pressure does not exceed minum must conform to the Aluminum the yield strength of the material of Association standard for alloys 1060, the finished cylinder wall. Calculations 1100, 1170, 3003, 5052, 5086, 5154, 6061, and must be made by the following for- 6063, as specified in its publication enmulas: titled "Aluminum Standards and (1) Calculation of the stress for cyl- Data" (IBR, see $171.7 of this subinders must be made by the following chapter). formula: (3) Material with seams, cracks, lam- S = [P(1.3D² + 0.4d2)] / (D² - d²) inations, or other injurious defects not permitted. Where: (4) Material used must be identified S = Wall stress, in psi; by any suitable method. P = Test pressure in psig: (c) Manufacture. (1) General manufac- D = Outside diameter, in inches; d = Inside diameter, in inches. turing requirements are as follows: (i) The surface finish must be uni- (2) Calculation of the stress for form and reasonably smooth. spheres must be made by the following (ii) Inside surfaces must be clean, formula: dry, and free of loose particles. S = PD / 4t (iii) No defect of any kind is permitted if it is likely to weaken a fin- Where: ished cylinder. S = Wall stress. in psi: (2) Requirements for seams: P = Test pressure 1 psig: (i) Brazing is not authorized on alu- D = Outside diameter, in inches; t = Minimum wall thickness, in inches. minum cylinders. (ii) Brazing material must have a (e) Openings and attachments. Openmelting point of not lower than 1,000 ings and attachments must conform to °F. the following: (iii) Brazed seams must be assembled (1) Openings and attachments are with proper fit to ensure complete penpermitted on heads only. etration of the brazing material (2) All openings and their reinforcethroughout the brazed joint. ments must be within an imaginary (iv) Minimum width of brazed joints circle, concentric to the axis of the cylmust be at least four times the thickinder. The diameter of the circle may ness of the shell wall. not exceed 80 percent of the outside di- (v) Brazed seams must have design ameter of the cylinder. The plane of strength equal to or greater than 1.5 the circle must be parallel to the plane times the minimum strength of the of a circumferential weld and normal shell wall. to the long axis of the cylinder. (vi) Welded seams must be properly (3) Unless a head has adequate thickaligned and welded by a method that ness, each opening must be reinforced provides clean, uniform joints with by a securely attached fitting, boss, adequate penetration. pad, collar, or other suitable means. (vii) Welded joints must have a (4) Material used for welded openings strength equal to or greater than the and attachments must be of weldable 893 $ 178.65 49 CFR Ch. I (10-1-06 Edition) quality and compatible with the mate- (4) Cylinders and test rings may not rial of the cylinder. crack when flattened so that their (f) Pressure tests. (1) Each cylinder outer surfaces are not more than six must be tested at an internal pressure times wall thickness apart when made of at least the test pressure and must of steel or not more than ten times be held at that pressure for at least 30 wall thickness apart when made of aluseconds. minum. (i) The leakage test must be con- (5) If any cylinder or ring cracks ducted by submersion under water or when subjected to the specified flatby some other method that will be tening test, the lot of cylinders repequally sensitive. resented by the test must be rejected (ii) If the cylinder leaks, evidences (see paragraph (h) of this section). visible distortion, or any other defect, (h) Rejected cylinders. Rejected cylwhile under test, it must be rejected inders must conform to the following (see paragraph (h) of this section). requirements: (2) One cylinder taken from the be- (1) If the cause for rejection of a lot ginning of each lot, and one from each is determinable, and if by test or in- 1,000 or less successively produced spection defective cylinders are elimiwithin the lot thereafter, must be nated from the lot, the remaining cylhydrostatically tested to destruction. inders must be qualified as a new lot The entire lot must be rejected (see under paragraphs (f) and (g) of this secparagraph (h) of this section) if: tion. (i) A failure occurs at a gage pressure (2) Repairs to welds are permitted. less than 2.0 times the test pressure; Following repair, a cylinder must pass (ii) A failure initiates in a braze or a the pressure test specified in paragraph weld or the heat affected zone thereof; (f) of this section. (iii) A failure is other than in the (3) If a cylinder made from seamless sidewall of a cylinder longitudinal with steel tubing fails the flattening test deits long axis; or scribed in paragraph (g) of this section, (iv) In a sphere. a failure occurs in suitable uniform heat treatment must any opening, reinforcement. or at a be used on each cylinder in the lot. All point of attachment. prescribed tests must be performed (3) A "lot" is defined as the quantity subsequent to this heat treatment. of cylinders successively produced per (i) Markings. (1) The markings reproduction shift (not exceeding 10 quired by this section must be durable hours) having identical size, design, and waterproof. The requirements of construction, material, heat treat- $178.35(h) do not apply to this section. ment, finish, and quality. (2) Required markings are as follows: (g) Flattening test. One cylinder must (i) DOT-39. be taken from the beginning of produc- (ii) NRC. tion of each lot (as defined in para- (iii) The service pressure. graph (f)(3) of this section) and sub- (iv) The test pressure. jected to a flattening test as follows: (v) The registration number (M****) (1) The flattening test must be made of the manufacturer. on a cylinder that has been tested at (vi) The lot number. test pressure. (vii) The date of manufacture if the (2) A ring taken from a cylinder may lot number does not establish the date be flattened as an alternative to a test of manufacture. on a complete cylinder. The test ring (viii) With one of the following statemay not include the heat affected zone ments: or any weld. However, for a sphere, the (A) For cylinders manufactured prior test ring may include the circumferento October 1, 1996: "Federal law forbids tial weld if it is located at a 45 degree transportation if refilled-penalty up to angle to the ring, ±5 degrees. $25,000 fine and 5 years imprisonment (3) The flattening must be between 60 (49 U.S.C. 1809)" or "Federal law fordegrees included-angle, wedge shaped bids transportation if refilled-penalty knife edges, rounded to a 0.5 inch raup to $500,000 fine and 5 years imprisondius. ment (49 U.S.C. 5124)." 894 Pipeline and Hazardous Materials Safety Admin., DOT § 178.68 (B) For cylinders manufactured on or TABLE 1-AUTHORIZED MATERIALS-Continued after October 1, 1996: "Federal law for- Chemical analysis-limits in bids transportation if refilled-penalty Designation percent 5154 up to $500,000 fine and 5 years imprisonment (49 U.S.C. 5124)." Aluminum remainder. (3) The markings required by para- 1 Analysis must regularly be made only for the elements graphs (i)(2)(i) through (i)(2)(v) of this specifically mentioned in this table. If, however, the presence of other elements is indicated in the course of routine analsection must be in numbers and letters ysis, further analysis should be made to determine conformat least 1/8 inch high and displayed seance with the limits specified for other elements. quentially. For example: (c) Identification. Material must be DOT-39 NRC 250/500 M1001. identified by any suitable method that will identify the alloy and manufactur- (4) No person may mark any cylinder er's lot number. with the specification identification (d) Manufacture. Cylinders must be "DOT-39" unless it was manufactured manufactured using equipment and in compliance with the requirements of this section and its manufacturer has a processes adequate to ensure that each registration number (M****) from the cylinder produced conforms to the re- Associate Administrator. quirements of this subpart. No defect is permitted that is likely to weaken the [Amdt. 178-114, 61 FR 25942, May 23, 1996, as finished cylinder appreciably. A reaamended at 65 FR 58631, Sept. 29. 2000; 66 FR sonably smooth and uniform surface 45389, Aug. 28. 2001; 67 FR 51654, Aug. 8, 2002: finish is required. All welding must be 68 FR 75748, 75749, Dec. 31, 2003] by the gas shielded arc process. § 178.68 Specification 4E welded alu- (e) Welding. The attachment to the minum cylinders. tops and bottoms only of cylinders by (a) Type, size and service pressure. A welding of neckrings or flanges, DOT 4E cylinder is a welded aluminum footrings, handles, bosses and pads and cylinder with a water capacity (nomivalve protection rings is authorized. nal) of not over 1,000 pounds and a serv- However, such attachments and the ice pressure of at least 225 to not over portion of the cylinder to which it is 500 psig. The cylinder must be conattached must be made of weldable alustructed of not more than two seamless minum alloys. drawn shells with no more than one (f) Wall thickness. The wall thickness circumferential weld. The circumferenof the cylinder must conform to the tial weld may not be closer to the point following: of tangency of the cylindrical portion (1) The minimum wall thickness of with the shoulder than 20 times the the cylinder must be 0.140 inch. In any cylinder wall thickness. Cylinders or case, the minimum wall thickness shells closed in by spinning process and must be such that calculated wall cylinders with longitudinal seams are stress at twice service pressure may not authorized. not exceed the lesser value of either of (b) Authorized material. The cylinder the following: must be constructed of aluminum of (i) 20,000 psi. uniform quality. The following chem- (ii) One-half of the minimum tensile ical analyses are authorized: strength of the material as required in TABLE 1-AUTHORIZED MATERIALS paragraph (j) of this section. (2) Calculation must be made by the Designation Chemical analysis-limits in percent 51541 following formula: S = [P(1.3D² + 0.4d²)] / (D² - d²) Iron plus silicon 0.45 maximum. Copper 0.10 maximum. Where: Manganese 0.10 maximum. Magnesium 3.10/3.90. S = wall stress in psi; Chromium 0.15/0.35. P = minimum test pressure prescribed for Zinc 0.20 maximum. water jacket test; Titanium 0.20 maximum. D = outside diameter in inches; Others, each 0.05 maximum. d - inside diameter in inches. Others, total 0.15 maximum. 895 § 178.68 49 CFR Ch. I (10-1-06 Edition) (3) Minimum thickness of heads and (i) At least one cylinder selected at bottoms may not be less than the minrandom out of each lot of 200 or less imum required thickness of the side must be tested in accordance with wall. paragraphs (h)(1). (h)(2), and (h)(3) of (g) Opening in cylinder. Openings in this section. cylinders must conform to the fol- (ii) All cylinders not tested as prolowing: vided in paragraph (h)(4)(i) of this sec- (1) All openings must be in the heads tion must be examined under pressure or bases. of at least 2 times service pressure and (2) Each opening in cylinders, except show no defect. those for safety devices, must be pro- (5) One finished cylinder selected at vided with a fitting, boss, or pad, serandom out of each lot of 1,000 or less curely attached to cylinder by welding must be hydrostatically tested to 4 by inert gas shielded arc process or by times the service pressure without threads. If threads are used, they must bursting. Inability to meet this recomply with the following: quirement must result in rejection of (i) Threads must be clean-cut, even, the lot. without checks and cut to gauge. (i) Flattening test. After hydrostatic (ii) Taper threads to be of length not testing, a flattening test is required on less than as specified for American one section of a cylinder, taken at ran- Standard taper pipe threads. dom out of each lot of 200 or less as fol- (iii) Straight threads, having at least lows: 4 engaged threads, to have tight fit and (1) If the weld is not at midlength of calculated shear strength at least 10 the cylinder, the test section must be times the test pressure of the cylinder; no less in width than 30 times the cylgaskets required, adequate to prevent inder wall thickness. The weld must be leakage. in the center of the section. Weld rein- (3) Closure of a fitting, boss, or pad forcement must be removed by machinmust be adequate to prevent leakage. ing or grinding so that the weld is flush (h) Hydrostatic test. Each cylinder with the exterior of the parent metal. must successfully withstand a hydro- There must be no evidence of cracking static test, as follows: in the sample when it is flattened be- (1) The test must be by water jacket, tween flat plates to no more than 6 or other suitable method, operated so times the wall thickness. as to obtain accurate data. The pres- (2) If the weld is at midlength of the sure gauge must permit reading to an cylinder, the test may be made as specaccuracy of 1 percent. The expansion ified in paragraph (i)(f) of this section gauge must permit a reading of the or must be made between wedge shaped total expansion to an accuracy either knife edges (60° angle) rounded to a 1/2 of 1 percent or 0.1 cubic centimeter. inch radius. There must be no evidence (2) Pressure of 2 times service presof cracking in the sample when it is sure must be maintained for at least 30 flattened to no more than 6 times the seconds and sufficiently longer to inwall thickness. sure complete expansion. Any internal (j) Physical test. A physical test must pressure applied previous to the official be conducted to determine yield test may not exceed 90 percent of the strength, tensile strength, elongation, test pressure. If, due to failure of the and reduction of area of material as test apparatus, the test pressure canfollows: not be maintained, the test may be re- (1) The test is required on 2 specipeated at a pressure increased by 10 mens cut from one cylinder or part percent over the pressure otherwise thereof taken at random out of each specified. lot of 200 or less. (3) Permanent volumetric expansion (2) Specimens must conform to the may not exceed 12 percent of total volfollowing: umetric expansion at test pressure. (i) A gauge length of 8 inches with a (4) Cylinders having a calculated wall width not over 1½ inches, a gauge stress of 18,000 psi or less at test preslength of 2 inches with a width not sure may be tested as follows: over 1½ inches. 896 Pipeline and Hazardous Materials Safety Admin., DOT § 178.69 (ii) The specimen, exclusive of grip ments, the entire lot represented must ends, may not be flattened. Grip ends be rejected. may be flattened to within 1 inch of (2) Guided bend test. A bend test specieach end of the reduced section. men must be cut from the cylinder (iii) When size of cylinder does not used for the physical tests specified in permit securing straight specimens, paragraph (j) of this section. Specimen the specimens may be taken in any lomust be taken across the seam, must cation or direction and may be be 1½ inches wide, edges must be parstraightened or flattened cold, by presallel and rounded with a file, and backsure only, not by blows; when speciup strip, if used, must be removed by mens are so taken and prepared, the inmachining. The specimen must be bent spector's report must show in connecto refusal in the guided bend test jig iltion with record of physical test delustrated in paragraph 6.10 of CGA tailed information in regard to such Pamphlet C-3 (IBR, see § 171.7 of this specimens. subchapter). The root of the weld (in- (iv) Heating of a specimen for any side surface of the cylinder) must be lopurpose is not authorized. cated away from the ram of the jig. No (3) The yield strength in tension specimen must show a crack or other must be the stress corresponding to a open defect exceeding 1/8 inch in any dipermanent strain of 0.2 percent of the rection upon completion of the test. gauge length. The following conditions Should this specimen fall to meet the apply: requirements, specimens may be taken (i) The yield strength must be deterfrom each of 2 additional cylinders mined by the "offset" method as prefrom the same lot and tested. If either scribed in ASTM E 8 (IBR, see $171.7 of of the latter specimens fail to meet rethis subchapter). quirements, the entire lot represented (ii) Cross-head speed of the testing must be rejected. machine may not exceed 1/8 inch per (m) Rejected cylinders. Repair of weldminute during yield strength detered seams is authorized. Acceptable cylmination. inders must pass all prescribed tests. (k) Acceptable results for physical tests. (n) Inspector's report. In addition to An acceptable result of the physical the information required by $178.35, the test requires an elongation to at least record of chemical analyses must also 7 percent and yield strength not over 80 include applicable information on iron, percent of tensile strength. titanium, zinc, and magnesium used in (1) Weld tests. Welds of the cylinder the construction of the cylinder. are required to successfully pass the following tests: [Amdt. 178-114, 61 FR 25942, May 23, 1996, as (1) Reduced section tensile test. A speciamended at 62 FR 51561, Oct. 1, 1997; 66 FR men must be cut from the cylinder 45386, Aug. 28, 2001: 67 FR 51654, Aug. 8, 2002; used for the physical tests specified in 68 FR 75748. Dec. 31. 2003; 69 FR 54046, Sept. paragraph (j) of this section. The speci- 7. 2004] men must be taken from across the § 178.69 Responsibilities and requireseam, edges must be parallel for a disments for manufacturers of UN tance of approximately 2 inches on eipressure receptacles. ther side of the weld. The specimen must be fractured in tension. The ap- (a) Each manufacturer of a UN presparent breaking stress calculated on sure receptacle marked with "USA" as the minimum wall thickness must be a country of approval must comply at least equal to 2 times the stress calwith the requirements in this section. culated under paragraph (f)(2) of this The manufacturer must maintain a section, and in addition must have an quality system, obtain an approval for actual breaking stress of at least 30,000 each initial pressure receptacle design psi. Should this specimen fail to meet type, and ensure that all production of the requirements, specimens may be UN pressure receptacles meets the aptaken from 2 additional cylinders from plicable requirements. the same lot and tested. If either of the (1) Quality system. The manufacturer latter specimens fails to meet requireof a UN pressure receptacle must have 897 § 178.70 49 CFR Ch. I (10-1-06 Edition) its quality system approved by the Asity system as approved by the Assosociate Administrator. The quality sysciate Administrator. The manufacturer tem will initially be assessed through shall notify the Associate Adminisan audit by the Associate Administrator of any intended changes to the trator or his or her representative to approved quality system prior to makdetermine whether it meets the Γe- ing the change. The Associate Adminisquirements of this section. The Assotrator will evaluate the proposed clate Administrator will notify the change to determine whether the manufacturer in writing of the results amended quality system will satisfy of the audit. The notification will conthe requirements. The Associate Adtain the conclusions of the audit and ministrator will notify the manufacany corrective action required. The Asturer of the findings. sociate Administrator may perform (b) Design type approvals. The manuperiodic audits to ensure that the manfacturer must have each pressure reufacturer operates in accordance with ceptacle design type reviewed by an IIA the quality system. Reports of periodic and approved by the Associate Adminaudits will be provided to the manufacistrator in accordance with $178.70. A turer. The manufacturer must bear the cylinder is considered to be of a new cost of audits. design, compared with an existing ap- (2) Quality system documentation. The proved design, as stated in the applicamanufacturer must be able to demble ISO design, construction and testonstrate a documented quality system. ing standard. Management must review the adequacy (c) Production inspection and certifiof the quality system to assure that it cation. The manufacturer must ensure is effective and conforms to the rethat each UN pressure receptacle is inquirements in $178.70. The quality sysspected and certified in accordance tem records must be in English and with $178.71. must include detailed descriptions of [71 FR 33885, June 12, 2006] the following: (i) The organizational structure and § 178.70 Approval of UN pressure reresponsibilities of personnel with receptacles. gard to design and product quality; (a) Initial design-type approval. The (ii) The design control and design manufacturer of a UN pressure recepverification techniques, processes, and tacle must obtain an initial design procedures used when designing the type approval from the Associate Adpressure receptacles; ministrator. The initial design type ap- (iii) The relevant procedures for presproval must be of the pressure recepsure receptacle manufacturing, quality tacle design as it is intended to be procontrol, quality assurance, and process duced. The manufacturer must arrange operation instructions; for an IIA, approved by the Associate (iv) Inspection and testing meth- Administrator in accordance with subodologies, measuring and testing equippart I of part 107 of this chapter, to ment, and calibration data; perform a pre-audit of its pressure re- (v) The process for meeting customer ceptacle manufacturing operation prior requirements; to having an audit conducted by the (vi) The process for document control Associate Administrator or his desand document revision; ignee. (vii) The system for controlling non- (b) IIA pre-audit. The manufacturer conforming material and records, inmust submit an application for initial cluding procedures for identification, design type approval to the IIA for resegregation, and disposition; view. The IIA will examine the manu- (viii) Production, processing and fabfacturer's application for initial design rication, including purchased compotype approval for completeness. An innents, in-process and final materials; complete application will be returned and to the manufacturer with an expla- (ix) Training programs for relevant nation. If an application is complete, personnel. the IIA will review all technical docu- (3) Maintenance of quality system. The mentation, including drawings and calmanufacturer must maintain the qualculations, to verify that the design 898 Pipeline and Hazardous Materials Safety Admin., DOT § 178.70 meets all requirements of the applica- (4) Details of any refusal of approval ble UN pressure receptacle standard of a similar application by a designated and specification requirements. If the approval agency of another country. technical documentation shows that (5) The name and address of the prothe pressure receptacle prototype deduction IIA that will perform the funcsign conforms to the applicable standtions prescribed in paragraph (e) of this ards and requirements in $178.70, the section. The IIA must be approved in manufacturer will fabricate a protowriting by the Associate Administrator type lot of pressure receptacles in conin accordance with subpart I of part 107 formance with the technical docuof this chapter. mentation representative of the design. (6) Documentation on the manufac- The IIA will verify that the prototype turing facility as specified in $178.69. lot conforms to the applicable require- (7) Design specifications and manuments by selecting pressure receptacles facturing drawings, showing compoand witnessing their testing. After pronents and subassemblies if relevant, detotype testing has been satisfactorily sign calculations, and material specicompleted, showing the pressure recepfications necessary to verify complitacles fully conform to all applicable ance with the applicable pressure respecification requirements, the certiceptacle design standard. fying IIA must prepare a letter of rec- (8) Manufacturing procedures and any applicable standards that describe ommendation and a design type apin detail the manufacturing processes proval certificate. The design type apand control. proval certificate must contain the (9) Design type approval test reports name and address of the manufacturer detailing the results of examinations and the ILA certifying the design type, and tests conducted in accordance with the test results, chemical analyses, lot the relevant pressure receptacle standidentification, and all other supporting ard, to include any additional data, data specified in the applicable ISO desuch as suitability for underwater apsign, construction and testing standplications or compatibility with hydroard. The IIA must provide the certifigen embrittlement gases. cate and documentation to the manu- (d) Modification of approved pressure facturer. receptacle design type. Modification of (c) Application for initial design type an approved UN pressure receptacle deapproval. If the pre-audit is found satissign type is not authorized without the factory by the IIA, the manufacturer approval of the Associate Adminiswill submit the letter of recommendatrator. A manufacturer seeking modition from the IIA and an application fication of an approved UN pressure refor design type approval to the Assoceptacle design type may be required clate Administrator. An application for to submit design qualification test initial design type approval must be data to the Associate Administrator submitted for each manufacturing fabefore production. An audit may be recility. The application must be in quired as part of the process to modify English and, at a minimum, contain an approval. the following information: (e) Responsibilities of the production (1) The name and address of the man- IIA. The production IIA is responsible ufacturing facility. If the application is for ensuring that each pressure recepsubmitted by an authorized representatacle conforms to the design type aptive on behalf of the manufacturer, the proval. The production IIA must perform the following functions: application must include the represent- (1) Witness all inspections and tests ative's name and address. specified in the UN pressure receptacle (2) The name and title of the indistandard to ensure compliance with the vidual responsible for the manufacturstandard and that the procedures er's quality system, as required by adopted by the manufacturer meet the $178.69. requirements of the standard; (3) The designation of the pressure (2) Verify that the production inspecreceptacle and the relevant pressure retions were performed in accordance ceptacle standard. with this section; 899 § 178.70 49 CFR Ch. I (10-1-06 Edition) (3) Select UN pressure receptacles (g) Recordkeeping. The production IIA from a prototype production lot and and the manufacturer must retain a witness testing as required for the decopy of the design type approval cersign type approval; tificate and certificate of compliance (4) Ensure that the various design records for at least 20 years. type approval examinations and tests (h) Denial of design type application. If are performed accurately; the design type application is denied, (5) Verify that each pressure recepthe Associate Administrator will notacle is marked in accordance with the tify the applicant in writing and proapplicable requirements in $178.72; and vide the reason for the denial. The (6) Furnish complete test reports to manufacturer may request that the Asthe manufacturer and upon request to sociate Administrator reconsider the the purchaser. The test reports and decision. The application request certificate of compliance must be remust- tained by the IIA for at least 20 years (1) Be written in English and filed from the original test date of the preswithin 60 days of receipt of the decisure receptacles. sion; (f) Production inspection audit and cer- (2) State in detail any alleged errors tification. (1) If the application, design of fact and law; and drawing and quality control documents (3) Enclose any additional informaare found satisfactory, PHMSA will tion needed to support the request to schedule an on-site audit of the presreconsider. sure receptacle manufacturer's quality (i) Appeal. (1) A manufacturer whose system, manufacturing processes, inreconsideration request is denied may spections, and test procedures. appeal to the PHMSA Administrator. (2) During the audit, the manufac- The appeal mustturer will be required to produce pres- (i) Be written in English and filed sure receptacles to the technical standwithin 60 days of receipt of the Assoards for which approval is sought. clate Administrator's decision on re- (3) The production IIA must witness consideration; the required inspections and verifications on the pressure recep- (ii) State in detail any alleged errors of fact and law; tacles during the production run. The IIA selected by the manufacturer for (iii) Enclose any additional informaproduction inspection and testing may tion needed to support the appeal; and be different from the IIA who per- (iv) State in detail the modification formed the design type approval of the final decision sought. verifications. (2) The PHMSA Administrator will (4) If the procedures and controls are grant or deny the relief and inform the deemed acceptable, test sample presappellant in writing of the decision. sure receptacles will be selected at ran- PHMSA Administrator's decision is the dom from the production lot and sent final administrative action. to a laboratory designated by the Asso- (j) Termination of a design type apciate Administrator for verification proval certificate. (1) The Associate Adtesting. ministrator may terminate an approval (5) If the pressure receptacle test certificate issue under this section if it samples are found to conform to all the is determined that, because of a change applicable requirements, the Associate in circumstances, the approval no Administrator will issue approvals to longer is needed or no longer would be the manufacturer and the production granted if applied for; information IIA to authorize the manufacture of upon which the approval was based is the pressure receptacles. The approved fraudulent or substantially erroneous; design type approval certificate will be or termination of the approval is necreturned to the manufacturer. essary to adequately protect against (6) Upon the receipt of the approved risks to life and property. design type approval certificate from (2) Before an approval is terminated, the Associate Administrator, the presthe Associate Administrator will prosure receptacle manufacturer must vide the manufacturer and the apsign the certificate. proval agency- 900 Pipeline and Hazardous Materials Safety Admin., DOT § 178.71 (i) Written notice of the facts or con- (1) Following the final heat treatduct believed to warrant the withment, all cylinders, except those sedrawal; lected for batch testing must be sub- (ii) Opportunity to submit oral and jected to a hydraulic volumetric expanwritten evidence, and sion test. (iii) Opportunity to demonstrate or (2) The standard requirements appliachieve compliance with the applicacable to UN pressure receptacles may tion requirement. be varied only if approved in writing by (3) If the Associate Administrator dethe Associate Administrator. termines that a certificate of approval (3) The test pressure of UN cylinders, must be withdrawn to preclude a sigtubes, and bundles of cylinders must nificant and imminent adverse affect conform to the requirements in part on public safety, the procedures in 178 of this subchapter. paragraph (j)(2)(ii) and (iii) of this sec- (d) Service equipment. (1) Except for tion need not be provided prior to withdrawal of the approval, but shall be pressure relief devices, UN pressure receptacle equipment, including valves, provided as soon as practicable thereafter. piping, fittings, and other equipment subjected to pressure must be designed [71 FR 33886, June 12, 2006, as amended at 71 and constructed to withstand at least FR 54397, Sept. 14, 2006) 1.5 times the test pressure of the pressure receptacle. § 178.71 Specifications for UN pressure receptacles. (2) Service equipment must be configured or designed to prevent damage (a) General. Each UN pressure recepthat could result in the release of the tacle must meet the requirements of pressure receptacle contents during this section. Requirements for apnormal conditions of handling and proval, qualification, maintenance, and transport. Manifold piping leading to testing are contained in $178.70, and shut-off valves must be sufficiently subpart C of part 180 of this subchapter. flexible to protect the valves and the (b) Definitions. The following definipiping from shearing or releasing the tions apply for the purposes of design pressure receptacle contents. The filland construction of UN pressure receping and discharge valves and any protacles under this subpart: tective caps must be secured against Alternative arrangement means an approval granted by the Associate Adunintended opening. The valves must ministrator for a MEGC that has been conform to ISO 10297 (IBR, see $171.7 of designed, constructed or tested to the this subchapter) and be protected as technical requirements or testing specified in § 173.301b(f) of this submethods other than those specified for chapter. UN pressure receptacles in part 178 or (3) UN pressure receptacles that canpart 180 of this subchapter. not be handled manually or rolled, Bundle of cylinders. See $171.8 of this must be equipped with devices (e.g. subchapter. skids, rings, straps) ensuring that they Design type means a pressure recepcan be safely handled by mechanical tacle design as specified by a particular means and so arranged as not to impair pressure receptacle standard. the strength of, nor cause undue Design type approval means an overall stresses, in the pressure receptacle. approval of the manufacturer's quality (4) Pressure receptacles filled by volsystem and design type of each presume must be equipped with a level insure receptacle to be produced within dicator. the manufacturer's facility. (e) Bundles of cylinders. UN pressure UN tube. See $171.8 of this subreceptacles assembled in bundles must chapter. be structurally supported and held to- (c) General design and construction. gether as a unit and secured in a man- UN pressure receptacles and their cloner that prevents movement in relasures must be designed, manufactured, tion to the structural assembly and tested and equipped in accordance with movement that would result in the the requirements contained in this secconcentration of harmful local tion. stresses. The frame design must ensure 901 $ 178.71 49 CFR Ch. I (10-1-06 Edition) stability under normal operating conother means that will not become disditions. lodged by operational impact loads. (1) The frame must securely retain Valves that need to be operated in norall the components of the bundle and mal service or in an emergency must must protect them from damage during be accessible. conditions normally incident to trans- (f) [Reserved] portation. The method of cylinder re- (g) Design and construction requirestraint must prevent any vertical or ments for UN refillable seamless steel cylhorizontal movement or rotation of the inders. In addition to the general recylinder that could cause undue strain quirements of this section, UN refillon the manifold. The total assembly able seamless steel cylinders must conmust be able to withstand rough hanform to the following ISO standards, as dling, including being dropped or overapplicable: turned. (1) ISO 9809-1: Gas cylinders-Refill- (2) The frame must include features able seamless steel gas cylinders-Dedesigned for the handling and transporsign, construction and testing-Part 1: tation of the bundle. The lifting rings Quenched and tempered steel cylinders must be designed to withstand a design with tensile strength less than 1 100 load of 2 times the maximum gross MPa. (IBR, see $171.7 of this subweight. Bundles with more than one chapter). lifting ring must be designed such that (2) ISO 9809-2: Gas cylinders-Refill- a minimum sling angle of 45 degrees to able seamless steel gas cylinders-Dethe horizontal can be achieved during sign, construction and testing-Part 2: lifting using the lifting rings. If four Quenched and tempered steel cylinders lifting rings are used, their design with tensile strength greater than or must be strong enough to allow the equal to 1 100 MPa. (IBR, see $171.7 of bundle to be lifted by two rings. Where this subchapter). two or four lifting rings are used, dia- (3) ISO 9809-3: Gas cylinders-Refillmetrically opposite lifting rings must able seamless steel gas cylinders-Debe aligned with each other to allow for sign, construction and testing-Part 3: correct lifting using shackle pins. If Normalized steel cylinders. (IBR, see the bundle is filled with forklift pock- $171.7 of this subchapter). ets, it must contain two forklift pock- (h) Design and construction requireets on each side from which it is to be ments for UN refillable seamless aluminum lifted. The forklift pockets must be poalloy cylinders. In addition to the gensitioned symmetrically consistent with eral requirements of this section, UN the bundle center of gravity. refillable seamless aluminum cylinders (3) The frame structural members must conform to ISO 7866: Gas cylmust be designed for a vertical load of inders-Refillable seamless aluminum 2 times the maximum gross weight of alloy gas cylinders-Design, constructhe bundle. Design stress levels may tion and testing. (IBR, see $171.7 of this not exceed 0.9 times the yield strength subchapter). The use of Aluminum of the material. alloy 6351-T6 or equivalent is prohib- (4) The frame may not contain any ited. protrusions from the exterior frame (i) Design and construction requirestructure that could cause a hazardous ments for UN non-refillable metal cylcondition. inders. In addition to the general re- (5) The frame design must prevent quirements of this section, UN non-recollection of water or other debris that fillable metal cylinders must conform would increase the tare weight of bunto ISO 11118: Gas cylinders-Non-refilldles filled by weight. able metallic gas cylinders-Specifica- (6) The floor of the bundle frame tion and test methods. (IBR, see $ 171.7 must not buckle during normal operof this subchapter.) ating conditions and must allow for the (j) Design and construction requiredrainage of water and debris from ments for UN refillable seamless steel around the base of the cylinders. tubes. In addition to the general re- (7) If the frame design includes movquirements of this section, UN refillable doors or covers, they must be caable seamless steel tubes must conform pable of being secured with latches or to ISO 11120: Gas cylinders-Refillable 902 Pipeline and Hazardous Materials Safety Admin., DOT § 178.71 seamless steel tubes of water capacity in the UN pressure receptacle design between 150 L and 3000 L-Design, conand construction ISO standards, and struction and testing. (IBR, see $171.7 any restrictions specified in part 173 of this subchapter). for the gases to be transported, the re- (k) Design and construction requirequirements of the following standards ments for UN acetylene cylinders. In admust be applied with respect to matedition to the general requirements of rial compatibility: this section, UN acetylene cylinders (1) ISO 11114-1: Transportable gas cylmust conform to the following ISO inders-Compatibility of cylinder and standards, as applicable: valve materials with gas contents- (1) For the cylinder shell: Part 1: Metallic materials. (IBR, see (i) ISO 9809-1: Gas cylinders-Refillable seamless steel gas cylinders-De- $171.7 of this subchapter). sign, construction and testing-Part 1: (2) ISO 11114-2: Transportable gas cyl- Quenched and tempered steel cylinders inders-Compatibility of cylinder and with tensile strength less than 1 100 valve materials with gas contents- MPa. Part 2: Non-metallic materials. (IBR, (ii) ISO 9809-3: Gas cylinders-Refillsee § 171.7 of this subchapter). able seamless steel gas cylinders-De- (n) Protection of closures. Closures and sign, construction and testing-Part 3: their protection must conform to the Normalized steel cylinders. requirements in $173.301(f) of this sub- (2) The porous mass in an acetylene chapter. cylinder must conform to ISO 3807-2: (o) Marking of UN refillable pressure re- Cylinders for acetylene-Basic requireceptacles. UN refillable pressure recepments-Part 2: Cylinders with fusible tacles must be marked clearly and legplugs. (IBR, see $171.7 of this subibly. The required markings must be chapter). permanently affixed by stamping, en- (1) Design and construction requiregraving, or other equivalent method, ments for UN composite cylinders. (1) In on the shoulder, top end or neck of the addition to the general requirements of pressure receptacle or on a permathis section, UN composite cylinders nently affixed component of the presmust be designed for unlimited service life and conform to the following ISO sure receptacle, such as a welded colstandards, as applicable: lar. Except for the "UN" mark, the minimum size of the marks must be 5 (i) ISO 11119-1: Gas cylinders of composite construction-Specification and mm for pressure receptacles with a ditest methods-Part 1: Hoop-wrapped ameter greater than or equal to 140 mm composite gas cylinders. (IBR, see and 2.5 mm for pressure receptacles $171.7 of this subchapter). with a diameter less than 140 mm. The (ii) ISO 11119-2: Gas cylinders of comminimum size of the "UN" mark must posite construction-Specification and be 5 mm for pressure receptacles with a test methods-Part 2: Fully-wrapped diameter less than 140 mm and 10 mm fibre reinforced composite gas cylfor pressure receptacles with a diameinders with load-sharing metal liners. ter of greater than or equal to 140 mm. (IBR, see $171.7 of this subchapter). The depth of the markings must not (iii) ISO 11119-3: Gas cylinders of create harmful stress concentrations. composite construction-Specification A refillable pressure receptacle conand test methods-Part 3: Fully forming to the UN standard must be wrapped fibre reinforced composite gas marked as follows: cylinders with non-load sharing metal- (1) The UN packaging symbol. lic or non-metallic liners. (IBR, see $171.7 of this subchapter). (2) ISO 11119-2 and ISO 11119-3 gas cylinders of composite construction manufactured in accordance with the requirements for underwater use must bear the "UW" mark. (m) Material compatibility. In addition to the material requirements specified 903 $ 178.71 49 CFR Ch. I (10-1-06 Edition) to the last digit. For acetylene cylinders, the tare weight must be marked on the cylinders in kilograms (KG). The tare weight is the sum of the empty weight, mass of the valve, any coating and all permanently attached parts (e.g. fittings and accessories) that are not removed during filling. The tare weight must be expressed to two significant figures rounded down to the last digit. The tare weight does not include the cylinder cap or any outlet cap or plug not permanently attached to the cylinder. (2) The ISO standard, for example (8) The minimum wall thickness of ISO 9809-1, used for design, constructhe pressure receptacle in millimeters tion and testing. Acetylene cylinders followed by the letters "MM". This must be marked to indicate the porous mark is not required for pressure remass and the steel shell, for example: ceptacles with a water capacity less "ISO 3807-2/ISO 9809-1." than or equal to 1.0 L or for composite (3) The mark of the country where cylinders. the approval is granted. The letters (9) For pressure receptacles intended "USA" must be marked on UN pressure for the transport of compressed gases receptacles approved by the United and UN 1001 acetylene, dissolved, the States. The manufacturer must obtain working pressure in bar, proceeded by an approval number from the Associate the letters "PW". Administrator. The manufacturer ap- (10) For liquefied gases, the water caproval number must follow the country pacity in liters expressed to three sigof approval mark, separated by a slash nificant digits rounded down to the (for example, USA/MXXXX). Pressure last digit, followed by the letter "L". If receptacles approved by more than one the value of the minimum or nominal national authority may contain the water capacity is an integer, the digits mark of each country of approval, sepafter the decimal point may be omitarated by a comma. ted. (4) The identity mark or stamp of the (11) Identification of the cylinder IIA. thread type (e.g., 25E). (5) The date of the initial inspection, (12) The country of manufacture. The the year (four digits) followed by the letters "USA" must be marked on cylmonth (two digits) separated by a inders manufactured in the United slash, for example "2006/04". States. (6) The test pressure in bar, preceded (13) The serial number assigned by by the letters "PH" and followed by the manufacturer. the letters "BAR". The test pressure must be obtained from the results of a (14) For steel pressure receptacles, hydraulic volumetric expansion test. the letter "H" showing compatibility (7) The empty or tare weight. Except of the steel, as specified in ISO 11114-1. for acetylene cylinders, empty weight (15) Identification of aluminum alloy, is the mass of the pressure receptacle if applicable. in kilograms, including all integral (16) Stamp for nondestructive testparts (e.g., collar, neck ring, foot ring, ing, if applicable. etc.), followed by the letters "KG". The (17) Stamp for underwater use of empty weight does not include the composite cylinders, if applicable. mass of the valve, valve cap or valve (p) Marking sequence. The marking reguard or any coating. The empty quired by paragraph (o) of this section weight must be expressed to three sigmust be placed in three groups as nificant figures rounded up to the last shown in the example below: digit. For cylinders of less than 1 kg, (1) The top grouping contains manuthe empty weight must be expressed to facturing marks and must appear contwo significant figures rounded down secutively in the sequence given in 904 Pipeline and Hazardous Materials Safety Admin., DOT $ 178.71 paragraphs (o)(11) through (17) of this (3) The bottom grouping contains section. certification marks and must appear (2) The middle grouping contains consecutively in the sequence given in operational marks described in paraparagraph (o)(1) through (5) of this secgraphs (o)(6) through (10) of this section. tion. (11) (12) (13) (14) (15) (16) (17) 25E USA 765432 H UW (9) (6) (7) (10) (8) PW200 PH300BAR 62.1KG 50L 5.8MM (1) (2) (3) (4) (5) u n ISO 9809-1 USA/MXXXX IB 2005/12 (q) Other markings. Other markings graphs (o)(7), (8), (11) and (17) are not are allowed in areas other than the side applicable. The required serial number wall, provided they are made in low marking in paragraph (o)(13) may be stress areas and are not of a size and replaced by the batch number. depth that will create harmful stress (2) Each receptacle must be marked concentrations. Such marks must not with the words "DO NOT REFILL" in conflict with required marks. letters of at least 5 mm in height. (r) Marking of UN non-refillable pres- (3) A non-refillable pressure recepsure receptacles. Unless otherwise specitacle, because of its size, may subfied in this paragraph, each UN non-restitute the marking required by this fillable pressure receptacle must be paragraph with a label. Reduction in clearly and legibly marked as premarking size is authorized only as prescribed in paragraph (o) of this section. scribed in ISO 7225, Gas cylinders-Pre- In addition, permanent stenciling is cautionary labels. (IBR, see $171.7 of authorized. Except when stenciled, the this subchapter). marks must be on the shoulder, top end (4) Each non-refillable pressure reor neck of the pressure receptacle or on ceptacle must also be legibly marked a permanently affixed component of by stenciling the following statement: the pressure receptacle, for example a "Federal law forbids transportation if welded collar. refilled-penalty up to $500,000 fine and 5 (1) The marking requirements and seyears in imprisonment (49 U.S.C. quence listed in paragraphs (o)(1) 5124)." through (17) of this section are re- (5) No person may mark a non-refillquired, except the markings in paraable pressure receptacle as meeting the 905 § 178.74 49 CFR Ch. I (10-1-06 Edition) requirements of this section unless it ing all drawings and calculations, to was manufactured in conformance with ensure that the design of the MEGC this section. meets all requirements of the relevant [7] FR 33887, June 12, 2006, as amended at 71 specification and to determine whether FR 54397, Sept. 14, 2006) it is complete and conforms to the requirements of this section. An incom- § 178.74 Approval of MEGCs. plete application will be returned to (a) Application for design type apthe applicant with the reasons why the proval. (1) Each new MEGC design type application was returned. If the applimust have a design approval certification is complete and all applicable cate. An owner or manufacturer must requirements of this section are met, apply to an approval agency that is apthe approval agency must prepare a proved by the Associate Administrator MEGC design approval certificate conin accordance with subpart E of part taining the manufacturer's name and 107 of this chapter +to obtain approval address, results and conclusions of the of a new design. When a series of examination and necessary data for MEGCs is manufactured without identification of the design type. If the change in the design, the certificate is Associate Administrator approves the valid for the entire series. The design Design Type Approval Certificate apapproval certificate must refer to the plication, the approval agency and the prototype test report, the materials of manufacturer must each maintain a construction of the manifold, the copy of the approved drawings, calculastandards to which the pressure receptions, and test data for at least 20 tacles are made and an approval numyears. ber. The compliance requirements or (c) Approval agency's responsibilities. test methods applicable to MEGCs as The approval agency is responsible for specified in this subpart may be varied ensuring that the MEGC conforms to when the level of safety is determined the design type approval. The approval to be equivalent to or exceed the reagency must: quirements of this subchapter and is (1) Witness all tests required for the approved in writing by the Associate approval of the MEGC specified in this Administrator. A design approval may section and $ 178.75. serve for the approval of smaller (2) Ensure, through appropriate in- MEGCs made of materials of the same spection, that each MEGC is fabricated type and thickness, by the same fabin all respects in conformance with the rication techniques and with identical approved drawings, calculations, and supports, equivalent closures and other test data. appurtenances. (3) Determine and ensure that the (2) Each application for design ap- MEGC is suitable for its intended use proval must be in English and contain and that it conforms to the requirethe following information: ments of this subchapter. (i) Two complete copies of all engi- (4) Apply its name, identifying mark neering drawings, calculations, and or identifying number, and the date the test data necessary to ensure that the approval was issued, to the metal idendesign meets the relevant specificatification marking plate attached to tion. the MEGC upon successful completion (ii) The manufacturer's serial number of all requirements of this subpart. that will be assigned to each MEGC. Any approvals by the Associate Admin- (iii) A statement as to whether the istrator authorizing design or condesign type has been examined by any struction alternatives (Alternate Arapproval agency previously and judged rangements) of the MEGC (see paraunacceptable. Affirmative statements graph (a) of this section) must be indimust be documented with the name of cated on the metal identification plate the approval agency, reason for non-acas specified in $178.75(j). ceptance, and the nature of modifica- (5) Prepare an approval certificate tions made to the design type. for each MEGC or, in the case of a se- (b) Actions by the approval agency. The ries of identical MEGCs manufactured approval agency must review the applito a single design type, for each series cation for design type approval, includof MEGCs. The approval certificate 906 Pipeline and Hazardous Materials Safety Admin., DOT $ 178.74 must include all of the following infor- (e) Denial of application for approval. mation: If the Associate Administrator finds (i) The information displayed on the that the MEGC will not be approved for metal identification plate required by any reason, the Associate Adminis- $178.75(j): trator will notify the applicant in writ- (ii) The results of the applicable ing and provide the reason for the deframework test specified in ISO 1496-3 nial. The manufacturer may request (IBR, see $171.7 of this subchapter); that the Associate Administrator re- (iii) The results of the initial inspecconsider the decision. The application tion and test specified in paragraph (h) request mustof this section; (1) Be written in English and filed (iv) The results of the impact test within 90 days of receipt of the decispecified in § 178.75(i) (4): sion; (v) Certification documents verifying (2) State in detail any alleged errors that the cylinders and tubes conform of fact and law; and to the applicable standards; and (3) Enclose any additional informa- (vi) A statement that the approval tion needed to support the request to agency certifies the MEGC in accordreconsider. ance with the procedures in this sec- (f) Appeal. (1) A manufacturer whose tion and that the MEGC is suitable for reconsideration request is denied may its intended purpose and meets the reappeal to the PHMSA Administrator. quirements of this subchapter. When a The appeal mustseries of MEGCs is manufactured with- (i) Be in writing and filed within 90 out change in the design type, the ceΓ- days of receipt of the Associate Admintificate may be valid for the entire seistrator S decision on reconsideration; ries of MEGCs representing a single de- (ii) State in detail any alleged errors sign type. The approval number must of fact and law; consist of the distinguishing sign or (iii) Enclose any additional informamark of the country ("USA" for the tion needed to support the appeal; and United States of America) where the (iv) State in detail the modification approval was granted and a registraof the final decision sought. tion number. (2) The Administrator will grant or (6) Retain on file a copy of each apdeny the relief and inform the appelproval certificate for at least 20 years. lant in writing of the decision. The Ad- (d) Manufacturers' responsibilities. The ministrator's decision is the final admanufacturer is responsible for compliministrative action. ance with the applicable specifications (g) Modifications to approved MEGCs. for the design and construction of (1) Prior to modification of any ap- MEGCs. The manufacturer of a MEGC proved MEGC that may affect conformmust: ance and safe use, and that may in- (1) Comply with all the requirements volve a change to the design type or afof the applicable ISO standard specified fect its ability to retain the hazardous in $178.71; material in transportation. the (2) Obtain and use an approval agen- MEGC's owner must inform the apcy to review the design, construction proval agency that prepared the initial and certification of the MEGC; approval certificate for the MEGC or, if (3) Provide a statement in the manuthe initial approval agency is unavailfacturers' data report certifying that able, another approval agency, of the each MEGC manufactured complies nature of the modification and request with the relevant specification and all certification of the modification. The the applicable requirements of this owner must supply the approval agency subchapter; and with all revised drawings, calculations, (4) Retain records for the MEGCs for and test data relative to the intended at least 20 years. When required by the modification. The MEGC's owner must specification, the manufacturer must also provide a statement as to whether provide copies of the records to the apthe intended modification has been exproval agency, the owner or lessee of amined and determined to be unacceptthe MEGC, and to a representative of able by any approval agency. The writ- DOT, upon request. ten statement must include the name 907 § 178.75 49 CFR Ch. I (10-1-06 Edition) of the approval agency, the reason for (iii) Termination of the approval is non-acceptance, and the nature of necessary to adequately protect changes made to the modification since against risks to life and property: or its original rejection. (iv) The MEGC does not meet the (2) The approval agency must review specification. the request for modification. If the ap- (2) Before an approval is terminated, proval agency determines that the prothe Associate Administrator will proposed modification does not conform to vide the personthe relevant specification, the approval (i) Written notice of the facts or conduct believed to warrant the termiagency must reject the request in acnation; cordance with paragraph (d) of this sec- (ii) An opportunity to submit oral tion. If the approval agency determines and written evidence; and that the proposed modification con- (3) An opportunity to demonstrate or forms fully with the relevant specificaachieve compliance with the applicable tion, the request is accepted. If modirequirements. fication to an approved MEGC alters (i) Imminent Danger. If the Associate any information on the approval cer- Administrator determines that a certificate, the approval agency must pretificate of approval must be terminated pare a new approval certificate for the to preclude a significant and imminent modified MEGC and submit the certifiadverse effect on public safety, the Ascate to the Associate Administrator for sociate Administrator may terminate approval. After receiving approval the certificate immediately. In such from the Associate Administrator, the circumstances, the opportunities of approval agency must ensure that any paragraphs (h)(2) and (3) of this section necessary changes are made to the need not be provided prior to termimetal identification plate. A copy of nation of the approval, but must be each newly issued approval certificate provided as soon as practicable theremust be retained by the approval agenafter. cy and the MEGC's owner for at least [71 FR 33890, June 12, 2006] 20 years. The approval agency must perform the following activities: § 178.75 Specifications for MEGCs. (i) Retain a set of the approved re- (a) General. Each MEGC must meet vised drawings, calculations, and data the requirements of this section. In a as specified in § 178.69(b) (4) for at least MEGC that meets the definition of a 20 years; "container" within the terms of the (ii) Ensure through appropriate in- International Convention for Safe Conspection that all modifications containers (CSC) must meet the requireform to the revised drawings, calculaments of the CSC as amended and 49 tions, and test data; and CFR parts 450 through 453, and must (iii) Determine the extent to which have a CSC approval plate. retesting of the modified MEGC is nec- (b) Alternate Arrangements. The techessary based on the nature of the pronical requirements applicable to posed modification, and ensure that all MEGCs may be varied when the level of required retests are satisfactorily persafety is determined to be equivalent formed. to or exceed the requirements of this (h) Termination of Approval Certificate. subchapter. Such an alternate arrangement must be approved in writing by (1) The Associate Administrator may the Associate Administrator. MEGCs terminate an approval issued under approved to an Alternate Arrangement this section if he or she determines must be marked as required by parathat--- graph (j) of this section. (i) Because of a change in cir- (c) Definitions. The following definicumstances, the approval no longer is tions apply: needed or no longer would be granted if Leakproofness test means a test using applied for; gas subjecting the pressure receptacles (ii) Information upon which the apand the service equipment of the MEGC proval was based is fraudulent or subto an effective internal pressure of not stantially erroneous; less than 20% of the test pressure. 908 Pipeline and Hazardous Materials Safety Admin., DOT § 178.75 Manifold means an assembly of piping Quenched and tempered steel cylinders and valves connecting the filling and/or with tensile strength greater than or discharge openings of the pressure reequal to 1 100 MPa. (IBR, see $171.7 of ceptacles. this subchapter); Maximum permissible gross mass or (iii) ISO 9809-3: Gas cylinders-Refill- MPGM means the heaviest load authorable seamless steel gas cylinders-Deized for transport (sum of the tare sign, construction and testing-Part 3: mass of the MEGC, service equipment Normalized steel cylinders. (IBR, see and pressure receptacle). $171.7 of this subchapter); or Service equipment means manifold sys- (iv) ISO 11120: Gas cylinders-Refilltem (measuring instruments, piping able seamless steel tubes of water caand safety devices). pacity between 150 L and 3000 L-De- Shut-off valve means a valve that sign, construction and testing. (IBR, stops the flow of gas. see $171.7 of this subchapter). Structural equipment means the rein- (4) Pressure receptacles of MEGCs, forcing, fastening, protective and stabifittings, and pipework must be conlizing members external to the presstructed of a material that is compatsure receptacles. ible with the hazardous materials in- (d) General design and construction retended to be transported, as specified quirements. (1) The MEGC must be capain this subchapter. ble of being loaded and discharged (5) Contact between dissimilar metwithout the removal of its structural als that could result in damage by galequipment. It must possess stabilizing vanic action must be prevented by apmembers external to the pressure repropriate means. ceptacles to provide structural integ- (6) The materials of the MEGC, inrity for handling and transport. MEGCs cluding any devices, gaskets, and acmust be designed and constructed with cessories, must have no adverse effect supports to provide a secure base duron the gases intended for transport in ing transport and with lifting and tiethe MEGC. down attachments that are adequate (7) MEGCs must be designed to withfor lifting the MEGC including when stand, without loss of contents, at loaded to its maximum permissible least the internal pressure due to the gross mass. The MEGC must be decontents, and the static, dynamic and signed to be loaded onto a transport vethermal loads during normal condihicle or vessel and equipped with skids, tions of handling and transport. The mountings or accessories to facilitate design must take into account the efmechanical handling. fects of fatigue, caused by repeated ap- (2) MEGCs must be designed, manuplication of these loads through the exfactured and equipped to withstand, pected life of the MEGC. without loss of contents, all normal (8) MEGCs and their fastenings must, handling and transportation condiunder the maximum permissible load, tions. The design must take into acbe capable of withstanding the folcount the effects of dynamic loading lowing separately applied static forces and fatigue. (for calculation purposes, acceleration (3) Each pressure receptacle of a due to gravity (g) = 9.81 m/s2): MEGC must be of the same design type, (1) In the direction of travel: 2g seamless steel, and constructed and (twice the MPGM multiplied by the actested according to one of the following celeration due to gravity); ISO standards: (ii) Horizontally at right angles to (1) ISO 9809-1: Gas cylinders-Refillthe direction of travel: 1g (the MPGM able seamless steel gas cylinders-Demultiplied by the acceleration due to sign, construction and testing-Part 1: gravity. When the direction of travel is Quenched and tempered steel cylinders not clearly determined. the forces must with tensile strength less than 1 100 be equal to twice the MPGM); MPa. (IBR, see $171.7 of this sub- (iii) Vertically upwards: 1g (the chapter); MPGM multiplied by the acceleration (ii) ISO 9809-2: Gas cylinders-Refilldue to gravity): and able seamless steel gas cylinders-De- (iv) Vertically downwards: 2g (twice sign, construction and testing-Part 2: the MPGM (total loading including the 909 § 178.75 49 CFR Ch. I (10-1-06 Edition) effect of gravity) multiplied by the acsion 2.3 liquefied gases must be deceleration due to gravity. signed so that each pressure receptacle (9) Under each of the forces specified can be filled separately and be kept in paragraph (d)(8) of this section, the isolated by a valve capable of being stress at the most severely stressed closed during transit. For Division 2.1 point of the pressure receptacles must gases, the pressure receptacles must be not exceed the values given in the apisolated by an individual shut-off valve plicable design specifications (e.g., ISO into assemblies of not more than 3,000 11120). L. (10) Under each of the forces specified (3) For MEGC filling and discharge in paragraph (d)(8) of this section, the openings: safety factor for the framework and (i) Two valves in series must be fastenings must be as follows: placed in an accessible position on each (i) For steels having a clearly defined discharge and filling pipe. One of the yield point, a safety factor of 1.5 in revalves may be a backflow prevention lation to the guaranteed yield valve. (ii) The filling and discharge destrength; or vices may be equipped to a manifold. (ii) For steels with no clearly defined (iii) For sections of piping which can yield point, a safety factor of 1.5 in rebe closed at both ends and where a liqlation to the guaranteed 0.2 percent uid product can be trapped, a pressureproof strength and, for austenitic relief valve must be provided to presteels, the 1 percent proof strength. vent excessive pressure build-up. (11) MEGCs must be capable of being (iv) The main isolation valves on a electrically grounded to prevent elec- MEGC must be clearly marked to inditrostatic discharge when intended for cate their directions of closure. All flammable gases. shutoff valves must close by a clock- (12) The pressure receptacles of a wise motion of the handwheel. MEGC must be secured in a manner to (v) Each shut-off valve or other prevent movement that could result in means of closure must be designed and damage to the structure and conconstructed to withstand a pressure centration of harmful localized equal to or greater than 1.5 times the stresses. test pressure of the MEGC. (e) Service equipment. (1) Service (vi) All shut-off valves with screwed equipment must be arranged so that it spindles must close by a clockwise mois protected from mechanical damage tion of the handwheel. For other shutby external forces during handling and off valves, the open and closed positransportation. When the connections tions and the direction of closure must between the frame and the pressure rebe clearly shown. ceptacles allow relative movement be- (vii) All shut-off valves must be detween the subassemblies, the equipsigned and positioned to prevent uninment must be fastened to allow movetentional opening. ment to prevent damage to any work- (viii) Ductile metals must be used in ing part. The manifolds, discharge fltthe construction of valves or accestings (pipe sockets, shut-off devices), sories. and shut-off valves must be protected (4) The piping must be designed, confrom damage by external forces. Manistructed and installed to avoid damage fold piping leading to shut-off valves due to expansion and contraction, memust be sufficiently flexible to protect chanical shock and vibration. Joints in the valves and the piping from sheartubing must be brazed or have an ing, or releasing the pressure recepequally strong metal union. The melttacle contents. The filling and dising point of brazing materials must be charge devices, including flanges or no lower than 525 °C (977 °F). The rated threaded plugs, and any protective caps pressure of the service equipment and must be capable of being secured of the manifold must be not less than against unintended opening. two-thirds of the test pressure of the (2) Each pressure receptacle intended pressure receptacles. for the transport of Division 2.3 gases (f) Pressure relief devices. Each presmust be equipped with an individual sure receptacle must be equipped with shut-off valve. The manifold for Divione or more pressure relief devices as 910 Pipeline and Hazardous Materials Safety Admin., DOT § 178.75 specified in $ 173.301(f) of this subcaping gas must be directed away from chapter. When pressure relief devices the pressure receptacle in such a manare installed, each pressure receptacle ner that it cannot impinge upon the or group of pressure receptacles of a other pressure receptacles. Heat resist- MEGC that can be isolated must be ant protective devices that deflect the equipped with one or more pressure reflow of gas are permissible provided the lief devices. Pressure relief devices required pressure relief device capacity must be of a type that will resist dyis not reduced. Arrangements must be namic forces including liquid surge and made to prevent access to the pressure must be designed to prevent the entry relief devices by unauthorized persons of foreign matter, the leakage of gas and to protect the devices from damage and the development of any dangerous caused by rollover. excess pressure. (g) Gauging devices. When a MEGC is (1) The size of the pressure relief deintended to be filled by mass, it must vices: CGA S-1.1, 2003 edition (IBR, see be equipped with one or more gauging $171.7 of this subchapter) must be used devices. Glass level-gauges and gauges to determine the relief capacity of inmade of other fragile material are prodividual pressure receptacles. hibited. (2) Connections to pressure-relief de- (h) MEGC supports, frameworks, lifting vices: Connections to pressure relief and tie-down attachments. (1) MEGCs devices must be of sufficient size to enmust be designed and constructed with able the required discharge to pass un- a support structure to provide a secure restricted to the pressure relief device. base during transport. MEGCs must be A shut-off valve installed between the protected against damage to the prespressure receptacle and the pressure resure receptacles and service equipment lief device is prohibited, except where resulting from lateral and longitudinal duplicate devices are provided for impact and overturning. The forces maintenance or other reasons, and the specified in paragraph (d)(8) of this secshut-off valves serving the devices action, and the safety factor specified in tually in use are locked open, or the paragraph (d)(10) of this section must shut-off valves are interlocked so that be considered in this aspect of the deat least one of the duplicate devices is sign. Skids, frameworks, cradles or always operable and capable of meeting other similar structures are acceptthe requirements of paragraph (f)(1) of able. If the pressure receptacles and this section. No obstruction is perservice equipment are so constructed mitted in an opening leading to or as to withstand impact and overleaving from a vent or pressure-relief turning, additional protective support device that might restrict or cut-off structure is not required (see parathe flow from the pressure receptacle graph (h)(4) of this section). to that device. The opening through all (2) The combined stresses caused by piping and fittings must have at least pressure receptacle mountings (e.g. the same flow area as the inlet of the cradles, frameworks, etc.) and MEGC pressure relief device to which it is lifting and tie-down attachments must connected. The nominal size of the disnot cause excessive stress in any prescharge piping must be at least as large sure receptacle. Permanent lifting and as that of the pressure relief device. tie-down attachments must be (3) Location of pressure-relief deequipped to all MEGCs. Any welding of vices: For liquefied gases, each presmountings or attachments onto the sure relief device must, under maxpressure receptacles is prohibited. imum filling conditions, be in commu- (3) The effects of environmental cornication with the vapor space of the rosion must be taken into account in pressure receptacles. The devices, when the design of supports and frameworks. installed, must be arranged to ensure (4) When MEGCs are not protected the escaping vapor is discharged upduring transport as specified in parawards and unrestrictedly to prevent graph (h)(1) of this section, the presimpingement of escaping gas or liquid sure receptacles and service equipment upon the MEGC, its pressure recepmust be protected against damage retacles or personnel. For flammable, sulting from lateral or longitudinal impyrophoric and oxidizing gases, the espact or overturning. External fittings 911 § 178.75 49 CFR Ch. I (10-1-06 Edition) must be protected against release of transport. A listing of acceptable the pressure receptacles' contents upon methods for performing the impact test impact or overturning of the MEGC on is provided in the UN Recommendaits fittings. Particular attention must tions (IBR. see $171.7 of this subbe paid to the protection of the manichapter). fold. Examples of protection include: (j) Marking. (1) Each MEGC must be (i) Protection against lateral impact, equipped with a corrosion resistant which may consist of longitudinal bars; metal plate permanently attached to (ii) Protection against overturning. the MEGC in a conspicuous place readwhich may consist of reinforcement ily accessible for inspection. The presrings or bars fixed across the frame; sure receptacles must be marked ac- (iii) Protection against rear impact, cording to this section. Affixing the which may consist of a bumper or metal plate to a pressure receptacle is frame; prohibited. At a minimum, the fol- (iv) Protection of the pressure receplowing information must be marked on tacles and service equipment against the plate by stamping or by any other damage from impact or overturning by equivalent method: use of an ISO frame according to the relevant provisions of ISO 1496-3. (IBR, Country of manufacture see $171.7 of this subchapter). UN (i) Initial inspection and test. The pressure receptacles and items of equipment of each MEGC must be inspected and tested before being put into service for the first time (initial inspection and test). This initial inspection and test of an MEGC must include the following: (1) A check of the design characteristics. (2) An external examination of the MEGC and its fittings, taking into account the hazardous materials to be transported. (3) A pressure test performed at the Approval Country test pressures specified in Approval Number §173.304b(b)(1) and (2) of this subchapter. The pressure test of the mani- Alternate Arrangements (see $178.75(b)) fold may be performed as a hydraulic MEGC Manufacturer's name or mark test or by using another liquid or gas. MEGC's serial number A leakproofness test and a test of the satisfactory operation of all service Approval agency (Authorized body for equipment must also be performed bethe design approval) fore the MEGC is placed into service. Year of manufacture When the pressure receptacles and Test pressure: bar gauge their fittings have been pressure-tested Design temperature range °C to separately, they must be subjected to a °C leakproof test after assembly. (4) An MEGC that meets the defini- Number of pressure receptacles tion of "container" in the CSC (see 49 Total water capacity liters CFR 450.3(a) must be subjected to an Initial pressure test date and identiimpact test using a prototype repfication of the Approval Agency resenting each design type. The prototype MEGC must be shown to be capa- Date and type of most recent periodic tests ble of absorbing the forces resulting from an impact not less than 4 times (4 Year Month Type g) the MPGM of the fully loaded (e.g. 2004-05, AE/UE, where "AE" rep- MEGC, at a duration typical of the meresents acoustic emission and "UE" chanical shocks experienced in rail represents ultrasonic examination) 912 Pipeline and Hazardous Materials Safety Admin., DOT Pt. 178, Subpt. C, App. A Stamp of the approval agency who Maximum permissible load mass performed or witnessed the most recent kg test Working pressure at 15 °C: bar (2) The following information must gauge be marked on a metal plate firmly se- Maximum permissible gross mass cured to the MEGC: (MPGM) kg Name of the operator Unladen (tare) mass kg [71 FR 33892, June 12. 2006] APPENDIX A TO SUBPART C OF PART 178-ILLUSTRATIONS: CYLINDER TENSILE SAMPLE The following figures illustrate the recommended locations for test specimens taken from welded cylinders: 913 Pt. 178, Subpt. C, App. A 49 CFR Ch. I (10-1-06 Edition) 1 4 2 SEAMLESS BODY SECTIONS REQUIRE ONLY 3 ONE PARENT METAL TEST 5 OPTIONAL CONVEX HEAD PARENT MATERIAL TEST SAMPLE 1 & 3 & 5 WELD TENSILE TEST И SAMPLE 4 WELD BEND TEST SAMPLE 2 THIS FIGURE ILLUSTRATES THE PROPER TENSILE LOCATION FOR A 3 PIECE CYLINDER WITH THE HEADS HAVING STRAIGHT SIDEWALL. FIGURE #1 914 Pipeline and Hazardous Materials Safety Admin., DOT Pf. 178, Subpt. C, App. A 1 4 2 3 OPTIONAL CONVEX HEAD PARENT MATERIAL TEST SAMPLE 1 & 3 WELD TENSILE TEST a SAMPLE 4 WELD BEND TEST SAMPLE 2 THIS FIGURE ILLUSTRATES THE PROPER TENSILE LOCATION FOR A 2 PIECE CYLINDER WITH THE HEADS HAVING STRAIGHT SIDEWALLS. FIGURE #2 915 Pt. 178, Subpt. C, App. A 49 CFR Ch. I (10-1-06 Edition) 1 1 3 ALTERNATIVE LOCATIONS 2 5 4 5 OPTIONAL, CONVEX HEAD SAMPLE TO BE TAKEN FROM HEAD PARENT MATERIAL TEST SAMPLE 1 & 3 & 5 WELD TENSILE TEST SAMPLE 4 WELD BEND TEST SAMPLE 2 THIS FIGURE ILLUSTRATES THE PROPER TENSILE LOCATION FOR A 2 PIECE CYLINDER THAT HAVE DEEP DRAWN HEADS. FIGURE #3 916 Pipeline and Hazardous Materials Safety Admin., DOT Pt. 178, Subpt. C, App. A 1 4 1 3 2 3 SEAMLESS SIDEWALL TWO PIECE CONSTRUCTION CONSTRUCTION PARENT MATERIAL TEST SAMPLE 1 & 3 WELD TENSILE TEST И SAMPLE 4 WELD BEND TEST SAMPLE 2 THIS FIGURE ILLUSTRATES THE PROPER TENSILE LOCATION FOR A 2 PIECE CYLINDER THAT HAVE DEEP DRAWN HEADS. FIGURE #4 917 Pt. 178, Subpt. C, App. A 49 CFR Ch. I (10-1-06 Edition) 1 4 2 3 PARENT MATERIAL TEST SAMPLE 1 & 3 WELD TENSILE TEST a SAMPLE 4 WELD BEND TEST SAMPLE 2 THIS FIGURE ILLUSTRATES THE PROPER TENSILE LOCATION FOR A 2 PIECE CYLINDER. FIGURE #5 [67 FR 51654, Aug. 8, 2002] 918 Pipeline and Hazardous Materials Safety Admin., DOT $ 178.255-6 Subparts D-G [Reserved] § 178.255-3 Expansion domes. (a) Expansion domes, if applied, must Subpart H-Specifications for have a minimum capacity of one per- Portable Tanks cent of the combined capacity of the tank and dome. SOURCE: 29 FR 18972, Dec. 29, 1964, unless (b) [Reserved] otherwise noted. Redesignated at 32 FR 5606, Apr. 5, 1967. § 178.255-4 Closures for manholes and domes. §§ 178.251-178.253-5 [Reserved] (a) The manhole cover shall be de- § 178.255 Specification 60; steel portsigned to provide a secure closure of able tanks. the manhole. All covers, not hinged to the tanks, shall be attached to the out- § 178.255-1 General requirements. side of the dome by at least 1/8 inch chain or its equivalent. Closures shall (a) Tanks must be of fusion welded be made tight against leakage of vapor construction, cylindrical in shape with and liquid by use of gaskets of suitable seamless heads concave to the presmaterial. sure. Tank shells may be of seamless construction. (b) [Reserved] (b) Tanks must be designed, con- § 178.255-5 Bottom discharge outlets. structed, certified, and stamped in accordance with Section VIII of the (a) Bottom discharge outlets prohib- ASME Code (IBR, see § 171.7 of this subited, except on tanks used for shipchapter). ments of sludge acid and alkaline cor- (c) Tanks including all permanent atrosive liquids. tachments must be postweld heat (b) If installed, bottom outlets or treated as a unit. bottom washout chambers shall be of (d) Requirements concerning types of metal not subject to rapid deterioravalves, retesting. and qualification of tion by the lading, and each shall be portable tanks contained in §§ 173.32 provided with a valve or plug at its and 173.315 of this chapter must be obupper end and liquid-tight closure at it served. lower end. Each valve or plug shall be designed to insure against unseating [29 FR 18972, Dec. 29, 1964. Redesignated at 32 due to stresses or shocks incident to FR 5606. Apr. 5, 1967. and amended by Amdt. 178-7, 34 FR 18250, Nov. 14, 1969; 68 FR 75750, transportation. Bottom outlets shall be Dec. 31, 2003) adequately protected against handling damage and outlet equipment must not § 178.255-2 Material. extend to within less than one inch of the bottom bearing surface of the skids (a) Material used in the tank must be steel of good weldable quality and conor tank mounting. form with the requirements in Sections [29 FR 18972, Dec. 29, 1964. Redesignated at 32 V, VIII, and IX of the ASME Code (IBR, FR 5606, Apr. 5, 1967. as amended by Amdt. see $171.7 of this subchapter). 178-104, 59 FR 49135, Sept. 26, 1994] (b) The minimum thickness of metal, exclusive of lining material, for shell § 178.255-6 Loading and unloading accessories. and heads of tanks shall be as follows: (a) When installed, gauging, loading Minimum and air inlet devices, including their Tank capacity thickness (inch) valves, shall be provided with adequate means for their secure closure; and Not more than 1,200 gallons 1/4 Over 1,200 to 1,800 gallons 5/16 means shall also be provided for the Over 1,800 gallons 3/8 closing of pipe connections of valves. (b) Interior heater coils, if installed, [29 FR 18972. Dec. 29, 1964. Redesignated at 32 must be of extra heavy pipe and so con- FR 5606, Apr. 5, 1967, and amended by Amdt. structed that breaking off of exterior 178-7, 34 FR 18250, Nov. 14, 1969; 68 FR 75750, connections will not cause leakage of Dec. 31, 2003) tanks. 919 § 178.255-7 49 CFR Ch. I (10-1-06 Edition) § 178.255-7 Protection of valves and devices shall be deemed to comply with accessories. this requirement. (a) All valves, fittings, accessories, (b) All tank mountings such as skids, safety devices, gauging devices, and the fastenings, brackets, cradles, lifting like shall be adequately protected lugs, etc., intended to carry loadings against mechanical damage by a housshall be permanently secured to tanks ing closed with a cover plate. in accordance with the requirements (b) Protective housing shall comply under which the tanks are fabricated, with the requirements under which the and shall be designed with a factor of tanks are fabricated with respect to desafety of four, and built to withstand sign and construction, and shall be deloadings in any direction equal to two signed with a minimum factor of safety times the weight of the tanks and atof four to withstand loadings in any ditachments when filled to the maximum rection equal to two times the weight permissible loaded weight. of the tank and attachments when (c) Lifting lugs or side hold-down filled with water. lugs shall be provided on the tank mountings in a manner suitable for at- § 178.255-8 Safety devices. taching lifting gear and hold-down de- (a) See § 173.315(i) of this subchapter. vices. Lifting lugs and hold-down lugs (b) [Reserved] welded directly to the tank shall be of the pad-eye type. Doubling plates weld- [Amdt. 178-83, 50 FR 11066, Mar. 19, 1985] ed to the tank and located at the § 178.255-9 Compartments. points of support shall be deemed to comply with this requirement. (a) When the interior of the tank is (d) All tank mountings shall be so dedivided into compartments, each comsigned as to prevent the concentration partment shall be designed, conof excessive loads on the tank shell. structed and tested as a separate tank. Thickness of shell and compartment § 178.255-12 Pressure test. heads shall be determined on the basis of total tank capacity. (a) Each completed portable tank (b) [Reserved] prior to application of lining shall be tested before being put into transpor- § 178.255-10 Lining. tation service by completely filling the (a) If a lining is required, the matetank with water or other liquid having rial used for lining the tank shall be a similar viscosity, the temperature of homogeneous, nonporous, imperforate which shall not exceed 100 °F during when applied, not less elastic than the the test, and applying a pressure of 60 metal of the tank proper. It shall be of psig. The tank shall be capable of holdsubstantially uniform thickness, not ing the prescribed pressure for at least less than 1/32 inch thick if metallic, and 10 minutes without leakage, evidence not less than 1/16 inch thick if nonof impending failure, or failure. All clometallic, and shall be directly bonded sures shall be in place while the test is or attached by other equally satisfacmade and the pressure shall be gauged tory means. Rubber lining shall be not at the top of the tank. Safety devices less than 3/16 inch thick. Joints and and/or vents shall be plugged during this test. seams in the lining shall be made by fusing the material together or by (b) [Reserved] other equally satisfactory means. The [29 FR 18972. Dec. 29, 1964. Redesignated at 32 interior of the tank shall be free from FR 5606, Apr. 5, 1967, as amended by Amdt. scale, oxidation, moisture and all for- 178-104, 59 FR 49135, Sept. 26, 1994] eign matter during the lining operation. § 178.255-13 Repair of tanks. (b) [Reserved] (a) Tanks failing to meet the test may be repaired and retested, provided § 178.255-11 Tank mountings. that repairs are made in complete com- (a) Tanks shall be designed and fabpliance with the requirements of this ricated with mountings to provide a sespecification. cure base in transit. "Skids" or similar (b) [Reserved] 920 Pipeline and Hazardous Materials Safety Admin., DOT § 178.270-12 $ 178.255-14 Marking. § 178.270-12 Valves, nozzles, piping, (a) In addition to markings required and gauging devices. by Section VIII of the ASME Code (a) All tank nozzles, except those pro- (IBR, see $171.7 of this subchapter), vided for filling and discharge connecevery tank shall bear permanent marks tions below the normal liquid level of at least 1/8-inch high stamped into the the tank, relief devices, thermometer metal near the center of one of the wells, and inspection openings, must be tank heads or stamped into a plate perfitted with manually operated stop manently attached to the tank by valves located as near the shell as pracmeans of brazing or welding or other ticable either internal or external to suitable means as follows: the shell. Each filling and discharge Manufacturer's name Serial connection located below the normal No. liquid level of the tank must be DOT specification equipped with an internal discharge Nominal capacity (gallons) valve. A tank nozzle installed in the Tare weight (pounds) Date of manufacture vapor space to provide a filling or cleaning opening, which is closed by a (b) [Reserved] blank flange or other suitable means, [29 FR 18972, Dec. 29, 1964. Redesignated at 32 need not be provided with a manually FR 5606, Apr. 5, 1967, and amended by Amdt. operated stop valve. A tank nozzle in- 178-67, 46 FR 49906, Oct. 8. 1981; 68 FR 75750, stalled for a thermometer well or in- Dec. 31, 2003] spection opening need not be provided § 178.255-15 Report. with a manually operated stop valve. (b) Each valve must be designed and (a) A copy of the manufacturer's data report required by Section VIII of the constructed to a rated pressure not less ASME Code (IBR, see $171.7 of this subthan the MAWP of the tank. Each stop chapter) under which the tank is fabvalve with a screwed spindle must be ricated must be furnished to the owner closed by a clockwise motion of the for each new tank. handwheel. All valves must be constructed to prevent unintentional Place opening. Date Portable tank (c) Each internal discharge valve Manufactured for Company shall be self-closing, located inside the Location tank, within the welded flange or with- Manufactured by Company in its companion flange. Location (d) A shear section must be located Consigned to Company Location outboard of each internal discharge Size feet outside diameter by valve seat and within 10.2 cm (4 inches) long. of the vessel. The shear section must Marks on tank as prescribed by $178.255-14 of break under strain without affecting this specification are as follows: the product retention capabilities of Manufacturer's name Serial number the tank and any attachments. Owner's serial number (e) All piping must be of suitable ma- DOT specification terial. Welded joints must be used ASME Code Symbol (par U-201) wherever practicable. The bursting Date of manufacture strength of all piping and pipe fittings Nominal capacity gallons. must be at least 4 times the MAWP of It is hereby certified that this tank is in complete compliance with the requirements the tank. Piping must be supported in of DOT specification No. 60. such a manner as to prevent damage (Signed) due to thermal stresses, jarring or vi- Manufacturer or owner bration. (b) [Reserved] (f) All nozzles and tank shell penetrations for nozzles shall be designed and [29 FR 18972, Dec. 29, 1964. Redesignated at 32 FR 5606, Apr. 5, 1967, and amended by Amdt. constructed in accordance with Section 178-83, 50 FR 11066, Mar. 19, 1985; 68 FR 75750, VIII of the ASME Code (IBR, see § 171.7 Dec. 31, 2003) of this subchapter). 921 § 178.270-13 49 CFR Ch. I (10-1-06 Edition) (g) Glass liquid level gauges, or port at the lower end of the base strucgauges of other easily destructible mature providing vertical and lateral reterial, which are in direct communicastraint and by support at the upper end tion with the contents of the tank are of the base structure providing lateral prohibited. restraint only. [Amdt. 178-65, 46 FR 9898. Jan. 29. 1981; 46 FR (2) Lateral inertia. The tank loaded to 24184, Apr. 30, 1981, as amended by Amdt. 178- its maximum gross weight must be po- 117. 61 FR 50628. Sept. 26, 1996; 66 FR 45386, sitioned for five minutes with its trans- Aug. 28. 2001; 68 FR 75751, Dec. 31, 2003) verse axis vertical. It shall be held in this position for five minutes by sup- § 178.270-13 Testing. port at the lower side of the base struc- (a) Hydrostatic test. Each portable ture providing vertical and lateral retank and all piping. valves, and other straint and by support at the upper attachments which are subject to the side of the base structure providing latpressure of the contents of the tank, eral restraint only. except pressure relief devices, must be (d) Approval of smaller tanks of the hydrostatically tested by completely same design. Design approval must infilling the tank (including domes, if clude the prototype testing of at least any) with water or other liquid having one tank of each design and each size; a similar density and viscosity and aphowever, a set of tests made on a tank plying a pressure of at least 150 percent of one size may serve for the approval of the MAWP. The pressure shall be of smaller tanks with equal or lesser maintained for at least 10 minutes. diameter and length) made of the same While under pressure, the tank shall be material and thickness by the same inspected for leakage, undue distorfabrication technique and with idention, or other conditions which inditical supports and equivalent closures cate weakness or which might render and other appurtenances. the tank unsafe for transportation (e) Pressure and vacuum relief devices. service. Failure to successfully meet Each spring loaded relief device must the test criteria shall be deemed evibe tested for the accuracy of the setdence of failure to meet the requireting prior to installation on a tank and ments of this specification. Tanks failmust be effectively sealed to maintain ing to pass the test shall be suitably the required setting. repaired and must successfully pass the (Amdt. 178-65, 46 FR 9898, Jan. 29, 1981; 46 FR prescribed tests prior to use for trans- 24184, Apr. 30, 1981, as amended by 66 FR porting any hazardous material. 45387, Aug. 28, 2001] (b) Testing of internal coils. Internal coils, if installed, must be § 178.270-14 Marking of tanks. hydrostatically tested to an internal (a) General. Each tank must bear a pressure of 13.8 bar (200 psig) or 150 percorrosion resistant metal identificacent of the rated pressure of the coils, tion plate that is permanently atwhichever is greater. tached to the portable tank and readily (c) Tank container qualification test. accessible for inspection. The informa- For each tank design, a prototype tion required in paragraph (b), and, tank, using a framework for containerwhen appropriate, paragraph (c) of this ized transport, must fulfill the requiresection must be stamped, embossed or ments of parts 450-453 of this title for otherwise marked by an equally duracompliance with the requirements of ble method on the plate in characters Annex II of the International Convenat least 3 mm (0.118 inches) high. The tion for Safe Containers. In addition, plate must not be painted. the following tests must be completed (b) Required information. At least the without leakage or deformation that following information must appear on would render the tank unsuitable for the metal identification plate for each use: tank: (1) Longitudinal inertia. The tank (1) US DOT Specification number. loaded to its maximum gross weight (2) Country of manufacture. must be positioned with its longitu- (3) Manufacturer's name. dinal axis vertical. It shall be held in (4) Date of manufacture. this position for five minutes by sup- (5) Manufacturer's serial number. 922 Pipeline and Hazardous Materials Safety Admin., DOT § 178.273 (6) Identification of USA/DOT apapproval agency previously and judged proval agency and approval number. unacceptable. Affirmative statements (7) MAWP, in bar or psig. must be documented with the name of (8) Test pressure, in bar or psig. the approval agency, reason for non- (9) Total measured water capacity at acceptance, and the nature of modifica- 20 °C (68 °F), in liters or gallons. tions made to the design type. (10) Maximum allowable gross (b) Action by approval agency. The apweight, in kg or lbs. proval agency must perform the fol- (11) Equivalent minimum shell thicklowing activities: ness in mild steel, in mm or Inches. (12) Tank material and specification (1) Review the application for apnumber. proval to determine whether it is com- (13) Metallurgical design temperature plete and conforms with the requirerange, in °C or °F. ments of paragraph (a) of this section. (c) Additional information. The fol- If an application is incomplete, it will lowing additional information must apbe returned to the applicant with an pear on the metal identification plate explanation as to why the application when applicable: is incomplete. (1) Lining material. (2) Review all drawings and calcula- (2) Heating coil MAWP in bar and tions to ensure that the design is in psig. compliance with all requirements of (3) Corrosion allowance, in mm or in. the relevant specification. If the appli- (d) In addition to the markings recation is approved, one set of the apquired above, each tank used in interproved drawings, calculations, and test national transport must have a Safety data shall be returned to the applicant. Approval Plate containing the informa- The second (inspector's copy) set of aption required in §§ 451.21 through 451.25 proved drawings, calculations, and test of this title. data shall be retained by the approval (e) Nothing in this section shall be agency. Maintain drawings and apdeemed to preclude the display of other proval records for as long as the portpertinent information on the required able tank remains in service. The drawmetal identification plate. ings and records must be provided to the Department of Transportation [Amdt. 178-65, 46 FR 9899, Jan. 29, 1981, as (DOT) upon request. amended at 62 FR 51561, Oct. 1. 1997; 66 FR 45387, Aug. 28, 2001] (3) Witness all tests required for the approval of the portable tank specified § 178.273 Approval of Specification IM in this section and part 180, subpart G portable tanks and UN portable of this subchapter. tanks. (4) Ensure, through appropriate in- (a) Application for approval. (1) An spection that each portable tank is fabowner or manufacturer of a portable ricated in all respects in conformance tank shall apply for approval to a deswith the approved drawings, calculaignated approval agency authorized to tions, and test data. approve the portable tank in accord- (5) Determine and ensure that the ance with the procedures in subpart E, portable tank is suitable for its inpart 107 of this subchapter. tended use and that it conforms to the (2) Each application for approval requirements of this subchapter. must contain the following informa- (6) For UN portable tanks intended tion: for non-refrigerated and refrigerated (i) Two complete copies of all engiliquefied gases and Division 6.1 liquids neering drawings, calculations, and which meet the inhalation toxicity critest data necessary to ensure that the teria (Zone A or B) as defined in design meets the relevant specifica- $173.132 of this subchapter, or that are tion. designated as toxic by inhalation mate- (ii) The manufacturer's serial number rials in the $172.101 Table of this subthat will be assigned to each portable chapter, the approval agency must entank. sure that: (iii) A statement as to whether the (i) The portable tank has been dedesign type has been examined by any signed, constructed, certified, and 923 § 178.273 49 CFR Ch. I (10-1-06 Edition) stamped in accordance with the retype, the certificate may be valid for quirements in Division 1 of Section the entire series of portable tanks rep- VIII of the ASME Code (IBR, see $171.7 resenting a single design type. For UN of this subchapter). Other design codes portable tanks, the certificate must may be used if approved by the Assorefer to the prototype test report, the ciate Administrator (see §178.274(b)(1); hazardous material or group of haz- (ii) All applicable provisions of the ardous materials allowed to be transdesign and construction have been met ported, the materials of construction of to the satisfaction of the designated the shell and lining (when applicable) approval agency in accordance with the and an approval number. The approval rules established in the ASME Code number must consist of the distinand that the portable tank meets the guishing sign or mark of the country requirements of the ASME Code and all ("USA" for the United States of Amerthe applicable requirements specified ica) where the approval was granted in this subchapter; and a registration number. (iii) The inspector has carried out all (iii) Retain a copy of each approval the inspections specified by the rules certificate. established in the ASME Code; and (8) For UN portable tanks, the ap- (iv) The portable tank is marked proval certificate must also include the with a U stamp code symbol under the following: authority of the authorized independent inspector. (i) The results of the applicable (7) Upon successful completion of all framework and rail impact test specirequirements of this subpart, the apfied in part 180, subpart G, of this subproval agency must: chapter; and (i) Apply its name, identifying mark (ii) The results of the initial inspecor identifying number, and the date tion and test in $178.274(j). upon which the approval was issued, to (9) The approval agency shall be indethe metal identification marking plate pendent from the manufacturer. The attached to the portable tank. Any apapproval agency and the authorized inprovals for UN portable tanks authorspector may be the same entity. izing design or construction alter- (c) Manufacturers' responsibilities. The natives (Alternate Arrangements) apmanufacturer is responsible for compliproved by the Associate Administrator ance with the applicable specifications (see $178.274(a)(2)) must be indicated on for the design and construction of portthe plate as specified in $ 178.274(i). able tanks. In addition to responsi- (ii) Issue an approval certificate for bility for compliance, manufacturers each portable tank or, in the case of a are responsible for ensuring that the series of identical portable tanks mancontracted approval agency and auufactured to a single design type, for thorized inspector, if applicable, are each series of portable tanks. The apqualified, reputable and competent. proval certificate must include all the The manufacturer of a portable tank information required to be displayed on shallthe required metal identification plate (1) Comply with all the applicable Γe- required by $178.270-14 of this subquirements of the ASME Code and of chapter for IM portable tanks, $178.245- this subpart including, but not limited 6 for Specification 51 steel portable to, ensuring that the quality control, tanks, or $178.274(i) for UN portable design calculations and required tests tanks. The approval certificate must are performed and that all aspects of certify that the approval agency desthe portable tank meet the applicable ignated to approve the portable tank requirements. has approved the portable tank in ac- (2) Obtain and use a designated apcordance with the procedures in subproval agency, If applicable, and obtain part E of part 107 of this subchapter and use a DOT-designated approval and that the portable tank is suitable agency to approve the design, construcfor its intended purpose and meets the tion and certification of the portable requirements of this subchapter. When tank. a series of portable tanks is manufac- (3) Provide a statement in the manutured without change in the design facturers' data report certifying that 924 Pipeline and Hazardous Materials Safety Admin., DOT § 178.273 each portable tank that is manufacapproved and the approval agency shall tured complies with the relevant speciperform the following activities: fication and all the applicable require- (i) Return one set of the approved rements of this subchapter. vised drawings, calculations, and test (4) Maintain records of the qualificadata to the applicant. The second and tion of portable tanks for at least 5 third sets of the approved revised drawyears and provide copies to the apings, calculations, and data shall be reproval agency, the owner or lessee of tained by the approval agency as rethe tank. Upon request, provide these quired in § 107.404(a)(3) of this subrecords to a representative of DOT. chapter. (d) Denial of application for approval. (ii) Ensure through appropriate in- If an approval agency finds that a portspection that all modifications conable tank cannot be approved for any form to the revised drawings, calculareason, it shall notify the applicant in tions, and test data. writing and shall provide the applicant (iii) Determine the extent to which with the reasons for which the apretesting of the modified tank is necproval is denied. A copy of the notificaessary based on the nature of the protion letter shall be provided to the Asposed modification, and ensure that all sociate Administrator. An applicant required retests are satisfactorily peraggrieved by a decision of an approval formed. agency may appeal the decision in (iv) If modification to an approved writing, within 90 days of receipt, to tank alters any information on the apthe Associate Administrator. proval certificate, issue a new approval (e) Modifications to approved portable certificate for the modified tank and tanks. (1) Prior to modification of any ensure that any necessary changes are approved portable tank which may afmade to the metal identification plate. fect conformance and the safe use of an A copy of each newly issued approval IM or UN portable tank, which may incertificate shall be retained by the apvolve a change to the design type or proval agency and by the owner of each which may affect its ability to retain portable tank. the hazardous material in transpor- (4) If the approval agency determines tation, the person desiring to make that the proposed modification is not such modification shall inform the apin compliance with the relevant DOT proval agency that issued the initial specification, the approval agency approval of the portable tank (or if unshall deny the request in accordance available another approval agency) of with paragraph (d) of this section. the nature of the modification and re- (f) Termination of Approval Certificate. quest approval of the modification. The (1) The Associate Administrator may person desiring to modify the tank terminate an approval issued under must supply the approval agency with this section if he determines thatthree sets of all revised drawings, cal- (i) Information upon which the apculations, and test data relative to the proval was based is fraudulent or subintended modification. stantially erroneous; or (2) A statement as to whether the in- (ii) Termination of the approval is tended modification has been examined necessary to adequately protect and determined to be unacceptable by against risks to life and property; or any approval agency. The written (iii) The approval was not issued by statement must include the name of the approval agency in good faith; or the approving agency, the reason for (iv) The portable tank does not meet nonacceptance, and the nature of the specification. changes made to the modification since (2) Before an approval is terminated, its original rejection. the Associate Administrator gives the (3) The approval agency shall review interested party(ies): the request for modification, and If it (i) Written notice of the facts or conis determined that the proposed modiduct believed to warrant the termification is in full compliance with the nation; relevant DOT specification, including a (ii) Opportunity to submit oral and UN portable tank, the request shall be written evidence; and 925 § 178.274 49 CFR Ch. I (10-1-06 Edition) (iii) Opportunity to demonstrate or Alternate Arrangement portable tank achieve compliance with the applicable means a UN portable tank that has requirements. been approved to alternative technical (3) If the Associate Administrator derequirements or testing methods other termines that a certificate of approval than those specified for UN portable must be terminated to preclude a sigtanks in part 178 or part 180 of this subnificant and imminent adverse affect chapter. on public safety, he may terminate the Approval agency means the descertificate immediately. In such cirignated approval agency authorized to cumstances, the opportunities of paraapprove the portable tank in accordgraphs (f)(2) (ii) and (iii) of this section ance with the procedures in subpart E need not be provided prior to termiof part 107 of this subchapter. nation of the approval, but shall be Design pressure is defined according provided as soon as practicable thereto the hazardous materials intended to after. be transported in the portable tank. See SS 178.275, 178.276 and 178.277, as ap- [66 FR 33439, June 21, 2001, as amended at 67 plicable. FR 61016, Sept. 27, 2002; 68 FR 75748, 75751, Design type means a portable tank or Dec. 31, 2003] series of portable tanks made of mate- § 178.274 Specifications for UN portrials of the same material specificaable tanks. tions and thicknesses, manufactured by a single manufacturer, using the (a) General. (1) Each UN portable same fabrication techniques (for examtank must meet the requirements of ple, welding procedures) and made with this section. In addition to the requireequivalent structural equipment, cloments of this section, requirements sures, and service equipment. specific to UN portable tanks used for Fine grain steel means steel that has a liquid and solid hazardous materials, ferritic grain size of 6 or finer when denon-refrigerated liquefied gases and retermined in accordance with ASTM E frigerated liquefied gases are provided 112-96 (IBR, see $171.7 of this subin $ 178.275, 178.276 and 178.277, respecchapter). tively. Requirements for approval, Fusible element means a non-reclosing maintenance, inspection, testing and pressure relief device that is thermally use are provided in 178.273 and part activated and that provides protection 180, subpart G, of this subchapter. Any against excessive pressure buildup in portable tank which meets the definithe portable tank developed by expotion of a "container" within the terms sure to heat, such as from a fire (see of the International Convention for $178.275(g)). Safe Containers (CSC) must meet the Jacket means the outer insulation requirements of the CSC as amended cover or cladding which may be part of and 49 CFR parts 450 through 453 and the insulation system. must have a CSC safety approval plate. Leakage test means a test using gas to (2) In recognition of scientific and subject the shell and its service equiptechnological advances, the technical ment to an internal pressure. requirements applicable to UN portable Maximum allowable working pressure tanks may be varied if approved by the (MAWP) is defined according to the Associate Administrator and the porthazardous materials intended to be able tank is shown to provide a level of transported in the portable tank. See safety equal to or exceeding the re- SS 178.275, 178.276 and 178.277, as applicaquirements of this subchapter. Portble. able tanks approved to alternative Maximum permissible gross mass technical requirements must be (MPGM) means the sum of the tare marked "Alternative Arrangement" as mass of the portable tank and the specified in paragraph (i) of this secheaviest hazardous material authorized tion. for transportation. (3) Definitions. The following defini- Mild steel means a steel with a guartions apply for the purposes of design anteed minimum tensile strength of 360 and construction of UN portable tanks N/mm2 to 440 N/mm2 and a guaranteed under this subpart: minimum elongation at fracture as 926 Pipeline and Hazardous Materials Safety Admin., DOT § 178.274 specified in paragraph (c)(10) of this ture must not be less than the maxsection. imum temperature of the hazardous Offshore portable tank means a portmaterial during filling, discharge or able tank specially designed for retransportation. More severe design peated use in the transportation of haztemperatures must be considered for ardous materials to, from and between portable tanks subjected to severe clioffshore facilities. An offshore portable matic conditions (for example, portable tank is designed and constructed in actanks transported in arctic regions). cordance with the Guidelines for the Shells must be designed and con- Approval of Containers Handled in structed in accordance with the re- Open Seas specified in the IMDG Code quirements in Section VIII of the (IBR, see $171.7 of this subchapter). ASME Code (IBR, see $171.7 of this sub- Reference steel means a steel with a chapter), except as limited or modified tensile strength of 370 N/mm2 and an in this subchapter. For portable tanks elongation at fracture of 27%. used for liquid or solid hazardous mate- Service equipment means measuring rials, a design code other than the instruments and filling, discharge, ASME Code may be used if approved by venting, safety, heating, cooling and the Associate Administrator. Portable insulating devices. tanks used for non-refrigerated and re- Shell means the part of the portable frigerated liquified compressed gases tank which retains the hazardous marequire an ASME certification and U terials intended for transportation, instamp. Shells must be made of metallic cluding openings and closures, but does materials suitable for forming. Nonnot include service equipment or extermetallic materials may be used for the nal structural equipment. attachments and supports between the Structural equipment means the reinshell and jacket, provided their mateforcing, fastening, protective and stabirial properties at the minimum and lizing members external to the shell. maximum design temperatures are Test pressure means the maximum proven to be sufficient. For welded gauge pressure at the top of the shell shells, only a material whose during the hydraulic pressure test weldability has been fully demequal to not less than 1.5 times the deonstrated may be used. Welds must be sign pressure for liquids and 1.3 for liqof high quality and conform to a level uefied compressed gases and refrigof integrity at least equivalent to the erated liquefied gases. In some inwelding requirements specified in Secstances a pneumatic test is authorized tion VIII of the ASME Code for the as an alternative to the hydraulic test. welding of pressure vessels. When the The minimum test pressures for portmanufacturing process or the materials able tanks intended for specific liquid make it necessary, the shells must be and solid hazardous materials are specsuitably heat-treated to guarantee adeified in the applicable portable tank T quate toughness in the weld and in the codes (such as T1-T23) assigned to heat-affected zones. In choosing the these hazardous materials in the material. the design temperature range § 172.101 Table of this subchapter. must be taken into account with re- (b) General design and construction respect to risk of brittle fracture, stress quirements. (1) The design temperature corrosion cracking, resistance to imrange for the shell must be -40 °C to -50 pact, and suitability for the hazardous °C (-40 °F to 122 °F) for hazardous matematerials intended for transportation rials transported under normal condiin the portable tank. When fine grain tions of transportation, except for steel is used, the guaranteed value of portable tanks used for refrigerated the yield strength must be not more liquefied gases where the minimum dethan 460 N/mm2 and the guaranteed sign temperature must not be higher value of the upper limit of the tensile than the lowest (coldest) temperature strength must be not more than 725 N/ (for example, service temperature) of mm² according to the material specithe contents during filling, discharge fication. Aluminum may not be used as or transportation. For hazardous mate- a construction material for the shells rials handled under elevated temperaof portable tanks intended for the ture conditions, the design temperatransport of non-refrigerated liquefied 927 $ 178.274 49 CFR Ch. I (10-1-06 Edition) gases. For portable tanks intended for (6) The construction materials of the the transport of liquid or solid hazportable tank, including any devices, ardous materials, aluminum may only gaskets, linings and accessories, must be used as a construction material for not adversely affect or react with the portable tank shells if approved by the hazardous materials intended to be Associate Administrator. Portable transported in the portable tank. tank materials must be suitable for the (7) Portable tanks must be designed external environment where they will and constructed with supports that be transported. taking into account the provide a secure base during transpordetermined design temperature range. tation and with suitable lifting and tie- Portable tanks shall be designed to down attachments. withstand, without loss of contents, at (c) Design criteria. (1) Portable tanks least the Internal pressure due to the and their fastenings must, under the contents and the static, dynamic and maximum permissible loads and maxthermal loads during normal condiimum permissible working pressures, tions of handling and transportation. be capable of absorbing the following The design must take into account the separately applied static forces (for effects of fatigue, caused by repeated calculation purposes, acceleration due application of these loads through the to gravity (g) =9.81m/s²): expected life of the portable tank. (i) In the direction of travel: 2g (2) Portable tank shells, fittings, and (twice the MPGM multiplied by the acpipework shall be constructed from celeration due to gravity); materials that are: (ii) Horizontally at right angles to (i) Compatible with the hazardous the direction of travel: 1g (the MPGM materials intended to be transported; multiplied by the acceleration due to or gravity): (ii) Properly passivated or neutral- (iii) Vertically upwards: 1g (the ized by chemical reaction, if applica- MPGM multiplied by the acceleration ble; or due to gravity); and (iii) For portable tanks used for liq- (iv) Vertically downwards: 2g (twice uid and solid materials, lined with corthe MPGM multiplied by the accelerarosion-resistant material directly tion due to gravity). bonded to the shell or attached by (2) Under each of the forces specified equivalent means. in paragraph (c)(1) of this section, the (3) Gaskets and seals shall be made of safety factor must be as follows: materials that are compatible with the (i) For metals having a clearly dehazardous materials intended to be fined yield point, a design margin of 1.5 transported. in relation to the guaranteed yield (4) When shells are lined, the lining strength: or must be compatible with the hazardous (ii) For metals with no clearly dematerials intended to be transported, fined yield point, a design margin of 1.5 homogeneous, non-porous, free from in relation to the guaranteed 0.2% perforations, sufficiently elastic and proof strength and, for austenitic compatible with the thermal expansion steels. the 1% proof strength. characteristics of the shell. The lining (3) The values of yield strength or of every shell, shell fittings and piping proof strength must be the values acmust be continuous and must extend cording to recognized material standaround the face of any flange. Where ards. When austenitic steels are used, external fittings are welded to the the specified minimum values of yield tank, the lining must be continuous strength or proof strength according to through the fitting and around the face the material standards may be inof external flanges. Joints and seams in creased by up to 15% for portable tanks the lining must be made by fusing the used for liquid and solid hazardous mamaterial together or by other equally terials, other than toxic by inhalation effective means. liquids meeting the criteria of Hazard (5) Contact between dissimilar met- Zone A or Hazard Zone B (see § 173.133 als which could result in damage by of this subchapter), when these greater galvanic action must be prevented by values are attested in the material inappropriate measures. spection certificate. 928 Pipeline and Hazardous Materials Safety Admin., DOT § 178.274 (4) Portable tanks must be capable of the construction of welded shells. The being electrically grounded to prevent values of Re and Rm to be used in dedangerous electrostatic discharge when termining this ratio must be the values they are used for Class 2 flammable specified in the material inspection gases or Class 3 flammable liquids, incertificate. cluding elevated temperature mate- (10) Steels used in the construction of rials transported at or above their shells must have an elongation at fracflash point. ture, in percentage, of not less than (5) For shells of portable tanks used 10,000/Rm with an absolute minimum of for liquefied compressed gases, the 16% for fine grain steels and 20% for shell must consist of a circular cross other steels. section. Shells must be of a design ca- (11) For the purpose of determining pable of being stress-analyzed matheactual values for materials for sheet matically or experimentally by resistmetal, the axis of the tensile test speciance strain gauges as specified in UGmen must be at right angles (trans- 101 of Section VIII of the ASME Code, versely) to the direction of rolling. The or other methods approved by the Aspermanent elongation at fracture must sociate Administrator. be measured on test specimens of rec- (6) Shells must be designed and contangular cross sections in accordance structed to withstand a hydraulic test with ISO 6892 (IBR, see $171.7 of this pressure of not less than 1.5 times the subchapter), using a 50 mm gauge design pressure for portable tanks used length. for liquids and 1.3 times the design (d) Minimum shell thickness. (1) The pressure for portable tanks used for liqminimum shell thickness must be the uefied compressed gases. Specific regreatest thickness of the following: quirements are provided for each haz- (i) the minimum thickness deterardous material in the applicable T mined in accordance with the require- Code or portable tank special provision ments of paragraphs (d)(2) through specified in the $172.101 Table of this (d)(7) of this section; subchapter. The minimum shell thick- (ii) the minimum thickness deterness requirements must also be taken mined in accordance with Section VIII into account. of the ASME Code or other approved (7) For metals exhibiting a clearly pressure vessel code: or defined yield point or characterized by (iii) the minimum thickness specified a guaranteed proof strength (0.2% proof in the applicable T code or portable strength, generally, or 1% proof tank special provision indicated for strength for austenitic steels). the prieach hazardous material in the $172.101 mary membrane stress σ (sigma) in the Table of this subchapter. shell must not exceed 0.75 Re or 0.50 (2) Shells (cylindrical portions, heads Rm, whichever is lower, at the test and manhole covers) not more than 1.80 pressure, where: m in diameter may not be less than 5 mm thick in the reference steel or of Re = yield strength in N/mm2, or 0.2% proof strength or, for austenitic equivalent thickness in the metal to be used. Shells more than 1.80 m in diamesteels, 1% proof strength; Rm = minimum tensile strength in N/ ter may not be less than 6 mm (0.2 inches) thick in the reference steel or mm². of equivalent thickness in the metal to (8) The values of Re and Rm to be be used. For portable tanks used only used must be the specified minimum for the transportation of powdered or values according to recognized mategranular solid hazardous materials of rial standards. When austenitic steels Packing Group II or III, the minimum are used, the specified minimum values thickness requirement may be reduced for Re and Rm according to the mateto 5 mm in the reference steel or of rial standards may be increased by up equivalent thickness in the metal to be to 15% when greater values are atused regardless of the shell diameter. tested in the material inspection cer- For vacuum-insulated tanks, the agtificate. gregate thickness of the jacket and the (9) Steels which have a Re/Rm ratio shell must correspond to the minimum of more than 0.85 are not allowed for thickness prescribed in this paragraph, 929 § 178.274 49 CFR Ch. I (10-1-06 Edition) with the thickness of the shell itself (d)(3) and (d)(4) of this section. This not less than the minimum thickness thickness must be exclusive of any corprescribed in paragraph (d)(3) of this rosion allowance. section. (7) There must be no sudden change (3) When additional protection of plate thickness at the attachment of against shell damage is provided in the the heads to the cylindrical portion of case of portable tanks used for liquid the shell. and solid hazardous materials requir- (e) Service equipment. (1) Service ing test pressures less than 2.65 bar equipment must be arranged so that it (265.0 kPa), subject to certain limitais protected against the risk of metions specified in the UN Recommendachanical damage by external forces tions (IBR, see $171.7 of this subduring handling and transportation. chapter), the Associate Administrator When the connections between the may approve a reduced minimum shell frame and the shell allow relative thickness. movement between the sub-assemblies, (4) The cylindrical portions, heads the equipment must be fastened to and manhole covers of all shells must allow such movement without risk of not be less than 3 mm (0.1 inch) thick damage to any working part. The exregardless of the material of constructernal discharge fittings (pipe sockets, tion, except for portable tanks used for shut-off devices) and the internal stopliquefied compressed gases where the valve and its seating must be protected cylindrical portions, ends (heads) and manhole covers of all shells must not against mechanical damage by external forces (for example, by using shear be less than 4 mm (0.2 inch) thick regardless of the material of construcsections). Each internal self-closing tion. stop-valve must be protected by a shear section or sacrificial device lo- (5) When steel is used, that has charcated outboard of the valve. The shear acteristics other than that of reference section or sacrificial device must break steel, the equivalent thickness of the at no more than 70% of the load that shell and heads must be determined acwould cause failure of the Internal selfcording to the following formula: closing stop valve. The filling and dis- 21.4e₀d₁ charge devices (including flanges or e₁ = threaded plugs) and any protective X A1 caps must be capable of being secured Where: against unintended opening. e₁ = required equivalent thickness (in mm) of (2) Each filling or discharge opening the metal to be used; of a portable tank must be clearly eo = minimum thickness (in mm) of the refmarked to indicate its function. erence steel specified in the applicable T (3) Each stop-valve or other means of code or portable tank special provision inclosure must be designed and condicated for each material in the $172.101 structed to a rated pressure not less Table of this subchapter; di = 1.8m, unless the formula is used to dethan the MAWP of the shell taking termine the equivalent minimum thickinto account the temperatures exness for a portable tank shell that is repected during transport. All stopquired to have a minimum thickness of valves with screwed spindles must 8mm or 10mm according to the applicable close by a clockwise motion of the T code indicated in the $172.101 Table of handwheel. For other stop-valves, the this subchapter. When reference steel position (open and closed) and directhicknesses of 8mm or 10mm are specified, d, is equal to the actual diameter of the tion of closure must be clearly indishell but not less than 1.8m; cated. All stop-valves must be designed Rm, = guaranteed minimum tensile strength to prevent unintentional opening. (in N/mm²) of the metal to be used; (4) Piping must be designed, con- A, = guaranteed minimum elongation at structed and installed to avoid the risk fracture (in %) of the metal to be used acof damage due to thermal expansion cording to recognized material standards. and contraction, mechanical shock and (6) The wall and all parts of the shell vibration. All piping must be of a suitmay not have a thickness less than able metallic material. Welded pipe that prescribed in paragraphs (d)(2), joints must be used wherever possible. 930 Pipeline and Hazardous Materials Safety Admin., DOT § 178.274 (5) Joints in copper tubing must be use. There must be no obstruction in brazed or have an equally strong metal an opening leading to a vent or presunion. The melting point of brazing sure relief device which might restrict materials must be no lower than 525 °C or cut-off the flow from the shell to (977 °F). The joints must not decrease that device. Vents or pipes from the the strength of the tubing, such as may pressure relief device outlets, when happen when cutting threads. Brazed used, must deliver the relieved vapor or joints are not authorized for portable liquid to the atmosphere in conditions tanks intended for refrigerated liqueof minimum back-pressure on the refied gases. lieving devices. (6) The burst pressure of all piping (3) Location of pressure relief devices. and pipe fittings must be greater than (i) Each pressure relief device inlet the highest of four times the MAWP of must be situated on top of the shell in the shell or four times the pressure to a position as near the longitudinal and which it may be subjected in service by transverse center of the shell as reathe action of a pump or other device sonably practicable. All pressure relief (except pressure relief devices). device inlets must, under maximum (7) Ductile metals must be used in filling conditions, be situated in the the construction of valves and accesvapor space of the shell and the devices sories. must be so arranged as to ensure that (f) Pressure relief devices-(1) Marking any escaping vapor is not restricted in of pressure relief devices. Every pressure any manner. For flammable hazardous relief device must be clearly and permaterials, the escaping vapor must be manently marked with the following: directed away from the shell in such a (i) the pressure (in bar or kPa) or manner that it cannot impinge upon temperature for fusible elements (in the shell. For refrigerated liquefied °C) at which it is set to discharge; gases, the escaping vapor must be di- (ii) the allowable tolerance at the rected away from the tank and in such discharge pressure for reclosing de- a manner that it cannot impinge upon vices; the tank. Protective devices which de- (iii) the reference temperature corflect the flow of vapor are permissible responding to the rated pressure for provided the required relief-device cafrangible discs; pacity is not reduced. (iv) the allowable temperature toler- (ii) Provisions must be implemented ance for fusible elements; to prevent unauthorized persons from (v) The rated flow capacity of the access to the pressure relief devices spring loaded pressure relief devices, and to protect the devices from damage frangible disc or fusible elements in caused by the portable tank overstandard cubic meters of air per second turning. (m³/s). For spring loaded pressure relief (g) Gauging devices. Unless a portable device the rated flow capacity shall be tank is intended to be filled by weight, determined according to ISO 4126-1 it must be equipped with one or more (IBR, see § 171.7 of this subchapter); and gauging devices. Glass level-gauges and (vi) when practicable, the device gauges made of other fragile material, must show the manufacturer's name which are in direct communication and product number. with the contents of the tank are pro- (2) Connections to pressure relief dehibited. A connection for a vacuum vices. Connections to pressure relief degauge must be provided in the jacket of vices must be of sufficient size to en- a vacuum-insulated portable tank. able the required discharge to pass un- (h) Portable tank supports, frameworks, restricted to the safety device. No stoplifting and tie-down attachments. (1) valve may be installed between the Portable tanks must be designed and shell and the pressure relief devices exconstructed with a support structure to cept where duplicate devices are proprovide a secure base during transport. vided for maintenance or other reasons The forces and safety factors specified and the stop-valves serving the devices in paragraphs (c)(1) and (c)(2) of this actually in use are locked open or the section, respectively, must be taken stop-valves are interlocked so that at into account in this aspect of the deleast one of the devices is always in sign. Skids, frameworks, cradles or 931 $ 178.274 49 CFR Ch. I (10-1-06 Edition) other similar structures are acceptof reinforcement rings or bars fixed able. across the frame; (2) The combined stresses caused by (iii) Protection against rear impact portable tank mountings (for example, which may consist of a bumper or cradles, framework, etc.) and portable frame; tank lifting and tie-down attachments (iv) Protection of the shell against must not cause stress that would damdamage from impact or overturning by age the shell in a manner that would use of an ISO frame in accordance with compromise its lading retention capa- ISO 1496-3 (IBR, see § 171.7 of this subbility. Permanent lifting and tie-down chapter); and attachments must be fitted to all port- (v) Protection of the portable tank able tanks. Preferably they should be from impact or damage that may refitted to the portable tank supports sult from overturning by an insulation but may be secured to reinforcing jacket. plates located on the shell at the (i) Marking. (1) Every portable tank points of support. Each portable tank must be fitted with a corrosion resistmust be designed so that the center of ant metal plate permanently attached gravity of the filled tank is approxito the portable tank in a conspicuous mately centered within the points of place and readily accessible for inspecattachment for lifting devices. tion. When the plate cannot be perma- (3) In the design of supports and nently attached to the shell, the shell frameworks, the effects of environmust be marked with at least the informental corrosion must be taken into mation required by Section VIII of the account. ASME Code. At a minimum, the fol- (4) Forklift pockets must be capable lowing information must be marked on of being closed off. The means of closthe plate by stamping or by any other ing forklift pockets must be a permaequivalent method: nent part of the framework or perma- Country of manufacture nently attached to the framework. Sin- UN gle compartment portable tanks with a Approval Country length less than 3.65 m (12 ft.) need not Approval Number have forklift pockets that are capable Alternative Arrangements (see $178.274(a)(2)) of being closed off provided that: "AA" Manufacturer's name or mark (i) The shell, including all the fit- Manufacturer's serial number tings, are well protected from being hit Approval Agency (Authorized body for the by the forklift blades; and design approval) (ii) The distance between forklift Owner's registration number pockets (measured from the center of Year of manufacture each pocket) is at least half of the Pressure vessel code to which the shell is demaximum length of the portable tank. signed (5) During transport, portable tanks Test pressure bar gauge. MAWP bar gauge. must be adequately protected against External design pressure (not required for damage to the shell, and service equipportable tanks used for refrigerated liquement resulting from lateral and longified gases) bar gauge. tudinal impact and overturning, or the Design temperature range °C shell and service equipment must be to °C. (For portable tanks used for constructed to withstand the forces rerefrigerated liquefied gases, the minimum sulting from impact or overturning. design temperature must be marked.) Water capacity at 20 °C/ liters. External fittings must be protected so Water capacity of each compartment at 20 as to preclude the release of the shell °C liters. contents upon impact or overturning of Initial pressure test date and witness identithe portable tank on its fittings. Exfication. amples of protection include: MAWP for heating/cooling system bar (i) Protection against lateral impact gauge. which may consist of longitudinal bars Shell material(s) and material standard reference(s). protecting the shell on both sides at Equivalent thickness in reference the level of the median line; steel mm. (ii) Protection of the portable tank Lining material (when applicable). against overturning which may consist Date and type of most recent periodic test(s). 932 Pipeline and Hazardous Materials Safety Admin., DOT $ 178.274 Month Year Test (5) A test of the satisfactory operpressure bar gauge. ation of all service equipment includ- Stamp of approval agency that performed or ing pressure relief devices must also be witnessed the most recent test. performed. When the shell and its fit- For portable tanks used for refrigerated tings have been pressure-tested sepaliquefied gases: rately, they must be subjected to a Either "thermally insulated" or "vacuum inleakage test after reassembly. All sulated" welds, subject to full stress level in the Effectiveness of the insulation system (heat influx) Watts (W). shell, must be inspected during the ini- Reference holding time days or hours tial test by radiographic, ultrasonic, or and initial pressure bar/kPa gauge another suitable non-destructive test and degree of filling in kg for each method. This does not apply to the refrigerated liquefied gas permitted for jacket. transportation. (6) A UN portable tank that meets the definition of "container" in the (2) The following information must be marked either on the portable tank CSC (see 49 CFR 450.3(a) must be itself or on a metal plate firmly sesubjected to an impact test using a cured to the portable tank: prototype representing each design type. The prototype portable tank Name of the operator. must be shown to be capable of absorb- Name of hazardous materials being transing the forces resulting from an impact ported and maximum mean bulk temperanot less than 4 times (4 g) the maxture (except for refrigerated liquefied imum permissible gross mass of the gases, the name and temperature are only required when the maximum mean bulk fully loaded portable tank at a duratemperature is higher than 50 °C). tion typical of the mechanical shocks Maximum permissible gross mass experienced in rail transportation. A (MPGM) kg. listing of standards describing methods Unladen (tare) mass kg. acceptable for performing the impact test are provided in the UN Rec- NOTE TO PARAGRAPH (1)(2): For the identification of the hazardous materials being ommendations. UN portable tanks used transported refer to part 172 of this subfor the dedicated transportation of chapter. "Helium, refrigerated liquid," UN1963 and "Hydrogen, refrigerated liquid," (3) If a portable tank is designed and UN1966 that are marked "NOT FOR approved for open seas operations, such RAIL TRANSPORT" in letters of a as offshore oil exploration, in accordminimum height of 10 cm (4 inches) on ance with the IMDG Code, the words at least two sides of the portable tank "OFFSHORE PORTABLE TANK" must are excepted from the 4 g impact test. be marked on the identification plate. (7) The following tests must be com- (j) Initial inspection and test. The inipleted on a portable tank or a series of tial inspection and test of a portable portable tanks designed and contank must include the following: structed to a single design type that is (1) A check of the design characterisalso a CSC container without leakage tics. or deformation that would render the (2) An internal and external examinaportable tank unsafe for transportation tion of the portable tank and its fitand use: tings, taking into account the haz- (i) Longitudinal Inertia. The portable ardous materials to be transported. For tank loaded to its maximum gross UN portable tanks used for refrigerated weight must be positioned with its lonliquefied gases, a pressure test using an gitudinal axis vertical. It shall be held inert gas may be conducted instead of in this position for five minutes by sup- a hydrostatic test. An internal inspecport at the lower end of the base struction is not required for a portable tank ture providing vertical and lateral reused for the dedicated transportation straint and by support at the upper end of refrigerated liquefied gases that are of the base structure providing lateral not filled with an inspection opening. restraint only. (3) A pressure test as specified in (ii) Lateral inertia. The portable tank paragraph (i) of this section. loaded to its maximum gross weight (4) A leakage test. must be positioned for five minutes 933 § 178.275 49 CFR Ch. I (10-1-06 Edition) with its transverse axis vertical. It (i) The maximum effective gauge shall be held in this position for five pressure allowed in the shell during minutes by support at the lower side of filling or discharge; or the base structure providing vertical (ii) The maximum effective gauge and lateral restraint and by support at pressure to which the shell is designed the upper side of the base structure which must be not less than the design providing lateral restraint only. pressure. [66 FR 33440, June 21, 2001, as amended at 67 (c) Service equipment. (1) In addition FR 15744, Apr. 3, 2002; 68 FR 45041, July 31. to the requirements specified in 2003; 68 FR 57633, Oct. 6, 2003; 68 FR 75751, $178.274, for service equipment, all Dec. 31, 2003; 69 FR 76185, Dec. 20, 2004; 70 FR openings in the shell, intended for fill- 34399. June 14, 2005] ing or discharging the portable tank EDITORIAL NOTE: At 68 FR 57633, Oct. 6, must be fitted with a manually oper- 2003, $178.274 was amended in paragraph ated stop-valve located as close to the (b)(1); however, the amendment could not be shell as reasonably practicable. Other incorporated due to inaccurate amendatory openings, except for openings leading instruction. to venting or pressure relief devices, must be equipped with either a stop- § 178.275 Specification for UN Portable valve or another suitable means of clo- Tanks intended for the transporsure located as close to the shell as tation of liquid and solid hazardous materials. reasonably practicable. (2) All portable tanks must be fitted (a) In addition to the requirements of with a manhole or other inspection $178.274, this section sets forth definiopenings of a suitable size to allow for tions and requirements that apply to internal inspection and adequate ac- UN portable tanks intended for the cess for maintenance and repair of the transportation of liquid and solid hazinterior. Compartmented portable ardous materials. tanks must have a manhole or other (b) Definitions and requirements-(1) inspection openings for each compart- Design pressure means the pressure to ment. be used in calculations required by the (3) For insulated portable tanks, top recognized pressure vessel code. The fittings must be surrounded by a spill design pressure must not be less than collection reservoir with suitable the highest of the following pressures: drains. (i) The maximum effective gauge (4) Piping must be designed, conpressure allowed in the shell during structed and installed to avoid the risk filling or discharge; or of damage due to thermal expansion (ii) The sum ofand contraction, mechanical shock and (A) The absolute vapor pressure (in vibration. All piping must be of a suitbar) of the hazardous material at 65 °C, able metallic material. Welded pipe minus 1 bar (149 °F, minus 100 kPa); joints must be used wherever possible. (B) The partial pressure (in bar) of (d) Bottom openings. (1) Certain hazair or other gases in the ullage space, ardous materials may not be transresulting from their compression durported in portable tanks with bottom ing filling without pressure relief by a openings. When the applicable T code maximum ullage temperature of 65 °C or portable tank special provision, as (149 °F) and a liquid expansion due to referenced for materials in the $172.101 an increase in mean bulk temperature Table of this subchapter, specifies that of 35 °C (95 °F); and bottom openings are prohibited, there (C) A head pressure determined on must be no openings below the liquid the basis of the forces specified in level of the shell when it is filled to its $ 178.274(c) of this subchapter, but not maximum permissible filling limit. less than 0.35 bar (35 kPa). When an existing opening is closed, it (2) Maximum allowable working presmust be accomplished by internally sure (MAWP) means a pressure that and externally welding one plate to the must not be less than the highest of shell. the following pressures measured at (2) Bottom discharge outlets for portthe top of the shell while in operating able tanks carrying certain solid, crysposition: tallizable or highly viscous hazardous 934 Pipeline and Hazardous Materials Safety Admin., DOT § 178.275 materials must be equipped with at 6.1, PG I or II, the remote means of cloleast two serially fitted and mutually sure must be capable of thermal actiindependent shut-off devices. Use of vation. The thermal means of activaonly two shut-off devices is only aution must activate at a temperature of thorized when this paragraph is refnot more than 250 °F (121 °C). erenced in the applicable T Code indi- (e) Pressure relief devices. All portable cated for each hazardous material in tanks must be fitted with at least one the $172.101 Table of this subchapter. pressure relief device. All relief devices The design of the equipment must be to must be designed, constructed and the satisfaction of the approval agency marked in accordance with the requireand must include: ments of this subchapter. (i) An external stop-valve fitted as (f) Vacuum-relief devices. (1) A shell close to the shell as reasonably pracwhich is to be equipped with a vacuumticable; and relief device must be designed to with- (ii) A liquid tight closure at the end stand, without permanent deformation, of the discharge pipe, which may be a an external pressure of not less than bolted blank flange or a screw cap. 0.21 bar (21.0 kPa). The vacuum-relief (3) Except as provided in paragraph device must be set to relieve at a vacu- (c) (2) of this section, every bottom disum setting not greater than -0.21 bar (- charge outlet must be equipped with 21.0 kPa) unless the shell is designed three serially fitted and mutually indefor a higher external over pressure, in pendent shut-off devices. The design of which case the vacuum-relief pressure the equipment must include: of the device to be fitted must not be (i) A self-closing internal stop-valve, greater than the tank design vacuum which is a stop-valve within the shell pressure. A shell that is not fitted with or within a welded flange or its com- a vacuum-relief device must be depanion flange, such that: signed to withstand, without perma- (A) The control devices for the opernent deformation, an external pressure ation of the valve are designed to preof not less than 0.4 bar (40.0 kPa). vent any unintended opening through (2) Vacuum-relief devices used on impact or other inadvertent act; portable tanks intended for the trans- (B) The valve is operable from above portation of hazardous materials meetor below; ing the criteria of Class 3. including (C) If possible, the setting of the elevated temperature hazardous matevalve (open or closed) must be capable rials transported at or above their of being verified from the ground; flash point, must prevent the imme- (D) Except for portable tanks having diate passage of flame into the shell or a capacity less than 1,000 liters (264.2 the portable tank must have a shell cagallons), it must be possible to close pable of withstanding, without leakthe valve from an accessible position age, an internal explosion resulting on the portable tank that is remote from the passage of flame into the from the valve itself within 30 seconds shell. of actuation: and (g) Pressure relief devices. (1) Each (E) The valve must continue to be efportable tank with a capacity not less fective in the event of damage to the than 1,900 liters (501.9 gallons) and external device for controlling the opevery independent compartment of a eration of the valve; portable tank with a similar capacity, (ii) An external stop-valve fitted as must be provided with one or more close to the shell as reasonably pracpressure relief devices of the reclosing ticable; type. Such portable tanks may, in ad- (iii) A liquid tight closure at the end dition, have a frangible disc or fusible of the discharge pipe, which may be a element in parallel with the reclosing bolted blank flange or a screw cap; and devices, except when the applicable T (iv) For UN portable tanks, with botcode assigned to a hazardous material tom outlets, used for the transporrequires that the frangible disc precede tation of liquid hazardous materials the pressure relief device, according to that are Class 3, PG I or II, or PG III paragraph (g)(3) of this section, or with a flash point of less than 100 °F (38 when no bottom openings are allowed. °C); Division 5.1, PG I or II; or Division The pressure relief devices must have 935 $ 178.275 49 CFR Ch. I (10-1-06 Edition) sufficient capacity to prevent rupture temperature. The shell must not be of the shell due to over pressurization subject to undue fluctuations of presor vacuum resulting from filling, dissure during normal conditions of transcharging, heating of the contents or portation. fire. (ii) The required pressure relief de- (2) Pressure relief devices must be device must be set to start to discharge signed to prevent the entry of foreign at a nominal pressure of five-sixths of matter, the leakage of liquid and the the test pressure for shells having a development of any dangerous excess test pressure of not more than 4.5 bar pressure. (450 kPa) and 110% of two-thirds of the (3) When required for certain haztest pressure for shells having a test ardous materials by the applicable T pressure of more than 4.5 bar (450 kPa). code or portable tank special provision A self-closing relief device must close specified for a hazardous material in at a pressure not more than 10% below the $172.101 Table of this subchapter, the pressure at which the discharge portable tanks must have a pressure starts. The device must remain closed relief device consistent with the reat all lower pressures. This requirequirements of this subchapter. Except ment does not prevent the use of vacufor a portable tank in dedicated service um-relief or combination pressure rethat is fitted with an approved relief lief and vacuum-relief devices. device constructed of materials com- (h) Fusible elements. Fusible elements patible with the hazardous material, must operate at a temperature between the relief device system must include a 110 °C (230 °F) and 149 °C (300.2 °F) profrangible disc preceding (such as, bevided that the pressure in the shell at tween the lading and the reclosing the fusing temperature will not exceed pressure relief device) a reclosing presthe test pressure. They must be placed sure relief device. A pressure gauge or at the top of the shell with their inlets suitable tell-tale indicator for the dein the vapor space and in no case may tection of disc rupture, pin-holing or they be shielded from external heat. leakage must be provided in the space Fusible elements must not be utilized between the frangible disc and the on portable tanks with a test pressure pressure relief device to allow the portwhich exceeds 2.65 bar (265.0 kPa). Fusiable tank operator to check to deterble elements used on portable tanks inmine if the disc is leak free. The frantended for the transport of elevated gible disc must rupture at a nominal temperature hazardous materials must pressure 10% above the start-to-disbe designed to operate at a temperacharge pressure of the reclosable presture higher than the maximum temsure relief device. perature that will be experienced dur- (4) Every portable tank with a capacing transport and must be designed to ity less than 1,900 liters (501.9 gallons) the satisfaction of the approval agency. must be fitted with a pressure relief de- (i) Capacity of pressure relief devices. vice which, except as provided in para- (1) The reclosing pressure relief device graph (g)(3) of this section, may be a required by paragraph (g)(1) of this secfrangible disc when this disc is set to tion must have a minimum cross secrupture at a nominal pressure equal to tional flow area equivalent to an orithe test pressure at any temperature fice of 31.75 mm (1.3 inches) diameter. within the design temperature range. Vacuum-relief devices, when used. (5) When the shell is fitted for presmust have a cross sectional flow area sure discharge, a suitable pressure renot less than 284 mm² (11.2 inches2). lief device must provide the inlet line (2) The combined delivery capacity of to the portable tank and set to operate the pressure relief system (taking into at a pressure not higher than the account the reduction of the flow when MAWP of the shell, and a stop-valve the portable tank is fitted with franmust be fitted as close to the shell as gible-discs preceding spring-loaded practicable to minimize the potential pressure-relief devices or when the for damage. spring-loaded pressure-relief devices (6) Setting of pressure relief devices. (i) are provided with a device to prevent Pressure relief devices must operate the passage of the flame), in condition only in conditions of excessive rise in of complete fire engulfment of the 936 Pipeline and Hazardous Materials Safety Admin., DOT § 178.276 portable tank must be sufficient to (A) Without insulation or sun shield: limit the pressure in the shell to 20% 60 °C (140 °F); above the start to discharge pressure (B) With sun shield: 55 °C (131 °F); and limiting device (pressure relief device). (C) With insulation: 50 °C (122 °F). The total required capacity of the re- (3) Filling density means the average lief devices may be determined using mass of liquefied compressed gas per the formula in paragraph (i)(2)(i)(A) of liter of shell capacity (kg/1). this section or the table in paragraph (4) Maximum allowable working pres- (i)(2)(iii) of this section. sure (MAWP) means a pressure that (j) Approval, inspection and testing. must be not less than the highest of Approval procedures for UN portable the following pressures measured at tanks are specified in $178.273. Inspecthe top of the shell while in operating tion and testing requirements are specposition, but in no case less than 7 bar ified in § 180.605 of this subchapter. (700 kPa): [66 FR 33445, June 21, 2001, as amended at 68 (i) The maximum effective gauge FR 32414, May 30, 2003; 69 FR 76185, Dec. 20, pressure allowed in the shell during 2004) filling or discharge; or (ii) The maximum effective gauge § 178.276 Requirements for the design, pressure to which the shell is designed, construction, inspection and testing which must be: of portable tanks intended for the (A) Not less than the pressure specitransportation of non-refrigerated fied for each liquefied compressed gas liquefied compressed gases. listed in the UN Portable Tank Table (a) In addition to the requirements of for Liquefied Compressed Gases in § 178.274 applicable to UN portable § 173.313; and tanks, the following requirements (B) Not less than the sum of: apply to UN portable tanks used for (1) The absolute vapor pressure (in non-refrigerated liquefied compressed bar) of the liquefied compressed gas at gases. In addition to the definitions in the design reference temperature $178.274, the following definitions minus 1 bar; and apply: (2) The partial pressure (in bar) of air (1) Design pressure means the pressure or other gases in the ullage space to be used in calculations required by which is determined by the design refthe ASME Code, Section VIII (IBR, see erence temperature and the liquid $171.7 of this subchapter). The design phase expansion due to the increase of pressure must be not less than the the mean bulk temperature of (t, highest of the following pressures: = filling temperature, usually 15 °C, t, = (i) The maximum effective gauge 50 °C maximum mean bulk temperapressure allowed in the shell during ture). filling or discharge; or (b) General design and construction re- (ii) The sum of: quirements. (1) Shells must be of seam- (A) The maximum effective gauge less or welded steel construction, or pressure to which the shell is designed combination of both, and have a water as defined in this paragraph under capacity greater than 450 liters (118.9 "MAWP"; and gallons). Shells must be designed. con- (B) A head pressure determined on structed, certified and stamped in acthe basis of the dynamic forces specicordance with the ASME Code, Section fied in paragraph (h) of this section, VIII. but not less than 0.35 bar (35 kPa). (2) Portable tanks must be postweld (2) Design reference temperature means heat-treated and radiographed as prethe temperature at which the vapor scribed in Section VIII of the ASME pressure of the contents is determined Code, except that each portable tank for the purpose of calculating the constructed in accordance with part MAWP. The value for each portable UHT of the ASME Code must be tank type is as follows: postweld heat-treated. Where postweld (i) Shell with a diameter of 1.5 meters heat treatment is required, the port- (4.9 ft.) or less: 65 °C (149 °F); or able tank must be treated as a unit (ii) Shell with a diameter of more after completion of all the welds in than 1.5 meters (4.9 ft.): and/or to the shell and heads. The 937 § 178.276 49 CFR Ch. I (10-1-06 Edition) method must be as prescribed in the must satisfy the following require- ASME Code. Welded attachments to ments: pads may be made after postweld heat (1) consist of a shield covering not treatment is made. A portable tank less than the upper third, but not more used for anhydrous ammonia must be than the upper half of the surface of postweld heat-treated. The postweld the shell, and separated from the shell heat treatment must be as prescribed by an air space of approximately 40 mm in the ASME Code, but in no event at (1.7 inches) across; or less than 1050 °F tank metal tempera- (ii) consist of a complete cladding of ture. Additionally, portable tanks coninsulating materials. The insulation structed in accordance with part UHT must be of adequate thickness and conof the ASME Code must conform to the structed to prevent the ingress of moisfollowing requirements: ture and damage to the insulation. The (i) Welding procedure and welder perinsulation and cladding must have a formance tests must be made annually thermal conductance of not more than in accordance with Section IX of the 0.67 (W.m⁻².K⁻¹) under normal condi- ASME Code. In addition to the essentions of transportation. tial variables named therein, the fol- (c) Service equipment. (1) Each opening lowing must be considered to be essenwith a diameter of more than 1.5 mm tial variables: number of passes, thick- (0.1 inch) in the shell of a portable ness of plate, heat input per pass, and tank, except openings for pressure-remanufacturer's identification of rod lief devices, inspection openings and and flux. The number of passes, thickclosed bleed holes, must be fitted with ness of plate and heat input per pass at least three mutually independent may not vary more than 25 percent shut-off devices in series: the first from the qualified procedure. Records being an internal stop-valve, excess of the qualification must be retained flow valve, integral excess flow valve, for at least 5 years by the portable or excess flow feature (see $178.337- tank manufacturer or his designated 1(g)), the second being an external agent and, upon request, made availstop-valve and the third being a blank able to a representative of the Departflange. thread cap, plug or equivalent ment of Transportation or the owner of tight liquid closure device. the tank. (2) When a portable tank is fitted (ii) Impact tests must be made on a with an excess flow valve, the excess lot basis. A lot is defined as 100 tons or flow valve must be so fitted that its less of the same heat and having a seating is inside the shell or inside a thickness variation no greater than welded flange or, when fitted exterplus or minus 25 percent. The minimum nally, its mountings must be designed impact required for full-sized speciso that in the event of impact it mainmens shall be 20 foot-pounds (or 10 tains its effectiveness. The excess flow foot-pounds for half-sized specimens) at valves must be selected and fitted so as 0 °F (-17.8 °F) Charpy V-Notch in both to close automatically when the rated the longitudinal and transverse direcflow, specified by the manufacturer, is tion. If the lot test does not pass this reached. Connections and accessories requirement, individual plates may be leading to or from such a valve must accepted if they individually meet this have a capacity for a flow more than impact requirement. the excess flow valve's rated flow. (3) When the shells intended for the (3) For filling and discharge openings transportation of non-refrigerated liqthat are located below the liquid level, uefied compressed gases are equipped the first shut-off device must be an inwith thermal insulation, a device must ternal stop-valve and the second must be provided to prevent any dangerous be a stop-valve placed in an accessible pressure from developing in the insuposition on each discharge and filling lating layer in the event of a leak, pipe. when the protective covering is closed (4) For filling and discharge openings it must be gas tight. The thermal insulocated below the liquid level of portlation must not inhibit access to the able tanks intended for the transporfittings and discharge devices. In additation of flammable and/or toxic liquetion, the thermal insulation systems fied compressed gases, the internal 938 Pipeline and Hazardous Materials Safety Admin., DOT § 178.276 stop-valve must be a self-closing safety (ii) One plugged opening of 2-inch Nadevice that fully closes automatically tional Pipe Thread or less provided for during filling or discharge in the event maintenance purposes may be located of fire engulfment. The device shall elsewhere; fully close within 30 seconds of actu- (iii) An opening of 3-inch National ation and the thermal means of closure Pipe Size or less may be provided at must actuate at a temperature of not another location, when necessary, to more than 121 °C (250 °F). Except for facilitate installation of condensing portable tanks having a capacity less coils. than 1,000 liters (264.2 gallons), this de- (9) Filling and discharge connections vice must be operable by remote conare not required to be grouped and may trol. be installed below the normal liquid (5) In addition to filling, discharge level of the tank if: and gas pressure equalizing orifices, (i) The portable tank is permanently shells may have openings in which mounted in a full framework for congauges, thermometers and manometers tainerized transport; can be fitted. Connections for such in- (ii) For each portable tank design, a struments must be made by suitable prototype portable tank, meets the rewelded nozzles or pockets and may not be connected by screwed connections quirements of parts 450 through 453 of this title for compliance with the rethrough the shell. (6) All portable tanks must be fitted quirements of Annex II of the International Convention for Safe Conwith manholes or other inspection tainers; and openings of suitable size to allow for internal inspection and adequate ac- (iii) Each filling and discharge outlet cess for maintenance and repair of the meets the requirements of paragraph interior. (c)(4) of this section. (7) Inlets and discharge outlets on chlo- (d) Bottom openings. Bottom openings rine portable tanks. The inlet and disare prohibited on portable tanks when charge outlets on portable tanks used the UN Portable Tank Table for Liqueto transport chlorine must meet the refied Compressed Gases in $173.313 of quirements of § 178.337-1(c)(2) and must this subchapter indicates that bottom be fitted with an internal excess flow openings are not allowed. In this case, valve. In addition to the internal exthere may be no openings located cess flow valve, the inlet and discharge below the liquid level of the shell when outlets must be equipped with an exit is filled to its maximum permissible ternal stop valve (angle valve). Excess filling limit. flow valves must conform to the stand- (e) Pressure relief devices. (1) Portable ards of The Chlorine Institute, Inc. tanks must be provided with one or (IBR, see $171.7 of this subchapter) as more reclosing pressure relief devices. follows: The pressure relief devices must open (i) A valve conforming to Drawing automatically at a pressure not less 101-7, dated July 1993, must be installed than the MAWP and be fully open at a under each liquid angle valve. pressure equal to 110% of the MAWP. (ii) A valve conforming to Drawing These devices must, after discharge, 106-6, dated July 1993, must be installed close at a pressure not less than 10% under each gas angle valve. For portbelow the pressure at which discharge able tanks used to transport non-restarts and must remain closed at all frigerated liquefied gases. lower pressures. The pressure relief de- (8) External fittings must be grouped vices must be of a type that will resist together as close as reasonably pracdynamic forces including liquid surge. ticable. The following openings may be A frangible disc may only be used in seinstalled at locations other than on the ries with a reclosing pressure relief detop or end of the tank: vice. (i) The openings for liquid level gaug- (2) Pressure relief devices must be deing devices, pressure gauges, or for signed to prevent the entry of foreign safety devices, may be installed sepamatter, the leakage of gas and the derately at the other location or in the velopment of any dangerous excess side of the shell; pressure. 939 § 178.277 49 CFR Ch. I (10-1-06 Edition) (3) A portable tank intended for the ery capacity must consider the additransportation of certain liquefied tional thermodynamic properties of the compressed gases identified in the UN gas, for example see CGA S-1.2 (IBR, Portable Tank Table for Liquefied see § 171.7 of this subchapter). Compressed Gases in $173.313 of this subchapter must have a pressure relief [66 FR 33448, June 21, 2001, as amended at 68 FR 75748, 75752, Dec. 31, 2003; 69 FR 54046, device which conforms to the require- Sept. 7, 2004; 69 FR 76185, Dec. 20, 2004) ments of this subchapter. Unless a portable tank, in dedicated service, is § 178.277 Requirements for the design, fitted with a relief device constructed construction, inspection and testing of materials compatible with the hazof portable tanks intended for the ardous material, the relief device must transportation of refrigerated liquebe comprised of a frangible disc prefied gases. ceded by a reclosing device. The space (a) In addition to the requirements of between the frangible disc and the de- § 178.274 applicable to UN portable vice must be provided with a pressure tanks, the following requirements and gauge or a suitable tell-tale indicator. definitions apply to UN portable tanks This arrangement must facilitate the used for refrigerated liquefied gases: detection of disc rupture, pinholing or Design pressure For the purpose of leakage which could cause a malfuncthis section the term "design pressure" tion of the pressure relief device. The is consistent with the definition for defrangible disc must rupture at a nomisign pressure in the ASME Code, Secnal pressure 10% above the start-to-distion VIII (IBR, see $171.7 of this subcharge pressure of the relief device. (4) In the case of portable tanks used chapter). for more than one gas, the pressure re- Holding time is the time, as deterlief devices must open at a pressure inmined by testing, that will elapse from dicated in paragraph (e)(1) of this secloading until the pressure of the contion for the gas having the highest tents, under equilibrium conditions, maximum allowable pressure of the reaches the lowest set pressure of the gases allowed to be transported in the pressure limiting device(s) (for examportable tank. ple, pressure control valve or pressure (f) Capacity of relief devices. The comrelief device). Holding time must be debined delivery capacity of the relief determined as specified in § 178.338-9. vices must be sufficient so that, in the Maximum allowable working pressure event of total fire engulfment, the (MAWP) means the maximum effective pressure inside the shell cannot exceed gauge pressure permissible at the top 120% of the MAWP. Reclosing relief deof the shell of a loaded portable tank in vices must be used to achieve the full its operating position including the relief capacity prescribed. In the case highest effective pressure during filling of portable tanks used for more than and discharge; gas, the combined delivery capacity of Minimum design temperature means the pressure relief devices must be the temperature which is used for the taken for the liquefied compressed gas design and construction of the shell which requires the highest delivery canot higher than the lowest (coldest) pacity of the liquefied compressed service temperature of the contents gases allowed to be transported in the during normal conditions of filling, disportable tank. The total required cacharge and transportation. pacity of the relief devices must be de- Shell means the part of the portable termined according to the requiretank which retains the refrigerated liqments in § 178.275(i). These requireuefied gas intended for transport, inments apply only to liquefied comcluding openings and their closures, pressed gases which have critical tembut does not include service equipment peratures well above the temperature or external structural equipment. at the accumulating condition. For Tank means a construction which gases that have critical temperatures normally consists of either: near or below the temperature at the (1) A jacket and one or more Inner accumulating condition, the calculashells where the space between the tion of the pressure relief device delivshell(s) and the jacket is exhausted of 940 Pipeline and Hazardous Materials Safety Admin., DOT § 178.277 air (vacuum insulation) and may incorto be sufficient. In choosing the mateporate a thermal insulation system; or rial, the minimum design temperature (2) A jacket and an inner shell with must be taken into account with rean intermediate layer of solid therspect to risk of brittle fracture, to hymally insulating material (for examdrogen embrittlement, to stress corrople, solid foam). sion cracking and to resistance to im- (b) General design and construction repact. quirements. (1) Portable tanks must be (5) Any part of a portable tank, inof seamless or welded steel construccluding fittings, gaskets and pipetion and have a water capacity of more work, which can be expected normally than 450 liters (118.9 gallons). Portable to come into contact with the refrigtanks must be designed, constructed, erated liquefied gas transported must certified and stamped in accordance be compatible with that refrigerated with Section VIII of the ASME Code. liquefied gas. (2) Portable tanks must be postweld (6) The thermal insulation system heat treated and radiographed as premust include a complete covering of scribed in Sections V and VIII of the the shell with effective insulating ma- ASME Code except that each tank conterials. External insulation must be structed in accordance with part UHT protected by a jacket so as to prevent in Section VIII of the ASME Code must the ingress of moisture and other dambe postweld heat treated. Where age under normal transport conditions. postweld heat treatment is required, (7) When a jacket is so closed as to be the tank must be treated as a unit gas-tight, a device must be provided to after completion of all the welds to the prevent any dangerous pressure from shell and heads. The method must be as developing in the insulation space. prescribed in the ASME Code. Welded (8) Materials which may react with attachments to pads may be made after oxygen or oxygen enriched postweld heat treatment is made. The atmospheres in a dangerous manner postweld heat treatment must be as may not be used in portable tanks inprescribed in Section VIII of the ASME tended for the transport of refrigerated Code, but in no event at less than 1,050 liquefied gases having a boiling point °F tank metal temperature. below minus 182 °C at atmospheric (3) Welding procedure and welder perpressure in locations with the thermal formance tests must be made annually insulation where there is a risk of conin accordance with Section IX of the tact with oxygen or with oxygen en- ASME Code (IBR, see § 171.7 of this subriched fluid. chapter). In addition to the essential variables named in the ASME Code, the (9) Insulating materials must not deteriorate to an extent that the effecfollowing must be considered as essentiveness of the insulation system, as tial variables: number of passes, thickness of plate. heat input per pass, and determined in accordance with parathe specified rod and flux. The number graph (b)(11) of this section, would be reduced in service. of passes, thickness of plate and heat input per pass may not vary more than (10) A reference holding time must be 25% from the procedure qualification. determined for each refrigerated lique- Records of the qualification must be fied gas intended for transport in a retained for at least 5 years by the portable tank. The reference holding portable tank manufacturer and made time must be determined by testing in available to the approval agency and accordance with the requirements of the owner of the portable tank as spec- § 178.338-9, considering the following ified in § 178.273. factors: (4) Shells and jackets must be made (i) The effectiveness of the insulation of metallic materials suitable for formsystem, determined in accordance with ing. Jackets must be made of steel. paragraph (b)(11) of this section; Non-metallic materials may be used (ii) The lowest set pressure of the for the attachments and supports bepressure limiting device; tween the shell and jacket, provided (iii) The initial filling conditions; their material properties at the min- (iv) An assumed ambient temperaimum design temperature are proven ture of 30 °C (86 °F); 941 § 178.277 49 CFR Ch. I (10-1-06 Edition) (v) The physical properties of the inclosest to the jacket must be a selfdividual refrigerated liquefied gas inclosing device, which is capable of tended to be transported. being closed from an accessible posi- (11) The effectiveness of the insulation on the portable tank that is retion system (heat influx in watts) may mote from the valve within 30 seconds be determined by type testing the portof actuation. This device must actuate able tank in accordance with a proceat a temperature of not more than 121 dure specified in 178.338-9(c) or by °C (250 °F). using the holding time test in § 178.338- (2) Each filling and discharge opening 9(b). This test must consist of either: in portable tanks used for the trans- (i) A constant pressure test (for export of non-flammable refrigerated liqample, at atmospheric pressure) when uefied gases must be fitted with at the loss of refrigerated liquefied gas is least two mutually independent shutmeasured over a period of time; or off devices in series: the first being a (ii) A closed system test when the stop-valve situated as close as reasonrise in pressure in the shell is measured ably practicable to the jacket and the over a period of time. (12) When performing the constant second a blank flange or equivalent device. pressure test, variations in atmospheric pressure must be taken into ac- (3) For sections of piping which can count. When performing either test, be closed at both ends and where liquid corrections must be made for any variproduct can be trapped, a method of ation of the ambient temperature from automatic pressure relief must be prothe assumed ambient temperature refvided to prevent excess pressure builderence value of 30 °C (86 °F). up within the piping. (13) The jacket of a vacuum-insulated (4) Each filling and discharge opening double-wall tank must have either an on a portable tank must be clearly external design pressure not less than marked to indicate its function. 100 kPa (1 bar) gauge pressure cal- (5) When pressure-building units are culated in accordance with Section used, the liquid and vapor connections VIII of the ASME Code or a calculated to that unit must be provided with a critical collapsing pressure of not less valve as close to the jacket as reasonthan 200 kPa (2 bar) gauge pressure. Inably practicable to prevent the loss of ternal and external reinforcements contents in case of damage to the presmay be included in calculating the sure-building unit. A check valve may ability of the jacket to resist the exterbe used for this purpose if it is located nal pressure. on the vapor side of the pressure build- NOTE TO PARAGRAPH (b): For the deterup coil. mination of the actual holding time, as indi- (6) The materials of construction of cated by paragraphs (b)(10), (11), (12), and valves and accessories must have satis- (13). before each journey. refer to $178.338- factory properties at the lowest oper- 9(b). ating temperature of the portable (c) Design criteria. For shells with tank. vacuum insulation, the test pressure (7) Vacuum insulated portable tanks must not be less than 1.3 times the sum are not required to have an inspection of the MAWP and 100 kPa (1 bar). In no opening. case may the test pressure be less than (e) Pressure relief devices. (1) Every 300 kPa (3 bar) gauge pressure. shell must be provided with not less (d) Service equipment. (1) Each filling than two independent reclosing presand discharge opening in portable sure relief devices. The pressure relief tanks used for the transport of flamdevices must open automatically at a mable refrigerated liquefied gases must pressure not less than the MAWP and be fitted with at least three mutually be fully open at a pressure equal to independent shut-off devices in series: 110% of the MAWP. These devices the first being a stop-valve situated as must, after discharge, close at a presclose as reasonably practicable to the sure not lower than 10% below the presjacket, the second being a stop-valve sure at which discharge starts and and the third being a blank flange or must remain closed at all lower presequivalent device. The shut-off device sures. The pressure relief devices must 942 Pipeline and Hazardous Materials Safety Admin., DOT § 178.318-2 be of the type that will resist dynamic § 178.318 Specification MC 201; conforces including surge. tainer for detonators and percus- (2) Except for portable tanks used for sion caps. oxygen, portable tanks for non-flam- § 178.318-1 Scope. mable refrigerated liquefied gases (except oxygen) and hydrogen may in ad- (a) This specification pertains to a dition have frangible discs in parallel container to be used for the transporwith the reclosing devices as specified tation of detonators and percussion in paragraphs (e)(4)(ii) and (e)(4)(iii) of caps in connection with the transporthis section. tation of liquid nitroglycerin, desen- (3) Pressure relief devices must be desitized liquid nitroglycerin or signed to prevent the entry of foreign diethylene glycol dinitrate, where any matter, the leakage of gas and the deor all of such types of caps may be used velopment of any dangerous excess for the detonation of liquid nitroglycerin, desentitized liquid nitroglycerin pressure. or diethylene glycol dinitrate in blast- (4) Capacity and setting of pressure relief devices. (i) In the case of the loss of ing operations. This specification is not intended to take the place of any vacuum in a vacuum-insulated tank or shipping or packing requirements of of loss of 20% of the insulation of a this Department where the caps in portable tank insulated with solid maquestion are themselves articles of terials, the combined capacity of all commerce. pressure relief devices installed must (b) [Reserved] be sufficient so that the pressure (including accumulation) inside the shell [29 FR 18975, Dec. 29, 1964. Redesignated at 32 does not exceed 120% of the MAWP. FR 5606, Apr. 5, 1967. and amended by Amdt. 178-60, 44 FR 70733, Dec. 10. 1979] (ii) For non-flammable refrigerated liquefied gases (except oxygen) and hy- § 178.318-2 Container. drogen, this capacity may be achieved by the use of frangible discs in parallel (a) Every container for detonators with the required safety-relief devices. and percussion caps coming within the Frangible discs must rupture at nomiscope of this specification shall be constructed entirely of hard rubber, nal pressure equal to the test pressure of the shell. phenolresinous or other resinous material, or other nonmetallic, nonsparking (iii) Under the circumstances dematerial, except that metal parts may scribed in paragraphs (e)(4)(i) and be used in such locations as not in any (e)(4)(ii) of this section, together with event to come in contact with any of complete fire engulfment, the comthe caps. Space shall be provided so bined capacity of all pressure relief dethat each detonator of whatever nature vices installed must be sufficient to may be inserted in an individual cell in limit the pressure in the shell to the the body of the container, into which test pressure. each such cap shall snugly fit. There (iv) The required capacity of the reshall be provided no more than twenty lief devices must be calculated in ac- (20) such cellular spaces. Space may be cordance with CGA Pamphlet S-1.2 provided into which a plurality of per- (IBR, see § 171.7 of this subchapter). cussion caps may be carried, provided [66 FR 33450, June 21, 2001, as amended at 68 that such space may be closed with a FR 75748, 75752, Dec. 31, 2003] screw cap, and further provided that each or any such space is entirely sepa- Subpart I [Reserved] rate from any space provided for any detonator. Each cellular space into which a detonator is to be inserted and Subpart J-Specifications for Concarried shall be capable of being covtainers for Motor Vehicle ered by a rotary cover so arranged as Transportation to expose not more than one cell at any time, and capable of rotation to such a SOURCE: 29 FR 18975, Dec. 29, 1964, unless place that all cells will be covered at otherwise noted. Redesignated at 32 FR 5606, the same time, at which place means Apr. 5, 1967. shall be provided to lock the cover in 943 § 178.318-2 49 CFR Ch. I (10-1-06 Edition) place. Means shall be provided to lock tion of moisture, such treatment shall in place the cover for the cells provided be applied as shall be necessary in for the carrying of detonators. The reorder to provide against the penetraquirement that not more than one cell tion of water by permeation. A suitable be exposed at one time need not apply carrying handle shall be provided, exin the case of detonators, although cept for which handle no part of the spaces for such caps and detonators container may project beyond the exteshall be separate. Sufficient annular rior of the body. space shall be provided inside the cover (b) Exhibited in plates I and II are for such detonators that, when the line drawings of a container for detocover is closed, there will be sufficient nators and percussion caps, illustrative space to accommodate the wires cusof the requirements set forth in tomarily attached to such caps. If the $178.318-2(a). These plates shall not be material is of such a nature as to reconstrued as a part of this specificaquire treatment to prevent the absorption. 944 Pipeline and Hazardous Materials Safety Admin., DOT § 178.320 Fuse cop container end Electric cop container end Section A-B-C BLASTING CAP CONTAINER PLATE 1 Spot for index button of close position "F" Spot for center holes at "G" C 2020 F Engrave and fill in white C E Percussion cap pocket 2 required Section E-E PLAN Handie removed PLATE Il [29 FR 18975, Dec. 29, 1964. Redesignated at 32 FR 5606, Apr. 5, 1967, and amended by Amdt. 178-60, 44 FR 70733, Dec. 10, 1979) § 178.318-3 Marking. tention or containment function and Each container must be marked as provides no structural support to the prescribed in $178.2(b). cargo tank. Baffle means a non-liquid-tight trans- [Amdt. 178-40, 41 FR 38181, Sept. 9, 1976. as verse partition device that deflects, amended at 66 FR 45185, Aug. 28, 2001] checks or regulates fluid motion in a tank. § 178.320 General requirements appli- Bulkhead means a liquid-tight transcable to all DOT specification cargo verse closure at the ends of or between tank motor vehicles. cargo tanks. (a) Definitions. For the purpose of this Cargo tank means a bulk packaging subchapter: that: Appurtenance means any attachment (1) Is a tank intended primarily for to a cargo tank that has no lading rethe carriage of liquids, gases, solids, or 945 § 178.320 49 CFR Ch. I (10-1-06 Edition) semi-solids and includes appurvariations in piping that do not affect tenances, reinforcements, fittings, and the lading retention capability of the closures (for tank, see SS 178.337-1, cargo tank; 178.338-1, or 178.345-1, as applicable); (4) Of the same materials of construc- (2) Is permanently attached to or tion; forms a part of a motor vehicle, or is (5) To the same cross-sectional dinot permanently attached to a motor mensions; vehicle but that, by reason of its size, (6) To a length varying by no more construction, or attachment to a than 5 percent; motor vehicle, is loaded or unloaded (7) With the volume varying by no without being removed from the motor more than 5 percent (due to a change in vehicle; and length only); and (3) Is not fabricated under a speci- (8) For the purposes of § 178.338 only, fication for cylinders, intermediate with the same insulation system. bulk containers, multi-unit tank car External self-closing stop valve means a tanks, portable tanks, or tank cars. self-closing stop valve designed so that Cargo tank motor vehicle means a the self-stored energy source is located motor vehicle with one or more cargo tanks permanently attached to or outside the cargo tank and the welded forming an integral part of the motor flange. vehicle. Extreme dynamic loading means the Cargo tank wall means those parts of maximum loading a cargo tank motor the cargo tank that make up the privehicle may experience during its exmary lading retention structure, inpected life, excluding accident loadings cluding shell, bulkheads, and fittings resulting from an accident, such as overturn or collision. and, when closed, yield the minimum volume of the cargo tank assembly. Flange means the structural ring for Charging line means a hose, tube, guiding or attachment of a pipe or fitpipe, or a similar device used to presting with another flange (companion surize a tank with material other than flange), pipe, fitting or other attachment. the lading. Companion flange means one of two Inspection pressure means the presmating flanges where the flange faces sure used to determine leak tightness are in contact or separated only by a of the cargo tank when testing with thin leak-sealing gasket and are sepneumatic pressure. cured to one another by bolts or Internal self-closing stop valve means a clamps. self-closing stop valve designed so that Connecting structure means the structhe self-stored energy source is located ture joining two cargo tanks. inside the cargo tank or cargo tank Constructed and certified in accordance sump, or within the welded flange, and with the ASME Code means a cargo the valve seat is located within the tank is constructed and stamped in accargo tank or within one inch of the cordance with Section VIII of the external face of the welded flange or ASME Code (IBR, see $171.7 of this subsump of the cargo tank. chapter), and is inspected and certified Lading means the hazardous material by an Authorized Inspector. contained in a cargo tank. Constructed in accordance with the Loading/unloading connection means ASME Code means a cargo tank is conthe fitting in the loading/unloading structed in accordance with Section line farthest from the loading/unload- VIII of the ASME Code with authorized ing outlet to which the loading/unloadexceptions (see $178.346 through ing hose, pipe, or device is attached. 178.348) and is inspected and certified Loading/unloading outlet means a by a Registered Inspector. cargo tank outlet used for normal load- Design type means one or more cargo ing/unloading operations. tanks that are made- Loading/unloading stop valve means (1) To the same specification: the stop valve farthest from the cargo (2) By the same manufacturer; tank loading/unloading outlet to which (3) To the same engineering drawings the loading/unloading connection is atand calculations, except for minor tached. 946 Pipeline and Hazardous Materials Safety Admin., DOT § 178.320 Manufacturer means any person enfabricated to more than one cargo tank gaged in the manufacture of a DOT specification. specification cargo tank, cargo tank Normal operating loading means the motor vehicle, or cargo tank equiploading a cargo tank motor vehicle ment that forms part of the cargo tank may be expected to experience rouwall. This term includes attaching a tinely in operation. cargo tank to a motor vehicle or to a Nozzle means a subassembly conmotor vehicle suspension component sisting of a pipe or tubular section with that involves welding on the cargo or without a welded or forged flange on tank wall. A manufacturer must regone end. ister with the Department in accord- Outlet means any opening in the shell ance with subpart F of part 107 in subor head of a cargo tank, (including the part A of this chapter. means for attaching a closure), except Maximum allowable working pressure that the following are not outlets: a or MAWP means the maximum presthreaded opening securely closed dursure allowed at the top of the tank in ing transportation with a threaded its normal operating position. The plug or a threaded cap. a flanged open- MAWP must be calculated as preing securely closed during transporscribed in Section VIII of the ASME tation with a bolted or welded blank Code. In use, the MAWP must be greatflange, a manhole, a gauging device, a er than or equal to the maximum ladthermometer well, or a pressure relief ing pressure conditions prescribed in device. $173.33 of this subchapter for each ma- Outlet stop valve means the stop valve terial transported. at a cargo tank loading or unloading Maximum lading pressure. See outlet. 173.33(c). Pipe coupling means a fitting with in- Minimum thickness means the minternal threads on both ends. imum required shell and head (and baf- Rear bumper means the structure defle and bulkhead when used as tank resigned to prevent a vehicle or object inforcement) thickness needed to meet from under-riding the rear of another the specification. The minimum thickmotor vehicle. See $393.86 of this title. ness is the greatest of the following val- Rear-end tank protection device means ues: (1)(i) For MC 330, MC 331, and MC the structure designed to protect a 338 cargo tanks, the specified minimum cargo tank and any lading retention thickness found the applicable specipiping or devices in case of a rear end fication(s): or collision. (ii) For DOT 406, DOT 407 and DOT Self-closing stop valve means a stop 412 cargo tanks, the specified minimum valve held in the closed position by thickness found in Tables I and II of means of self-stored energy, that opens the applicable specification(s); or only by application of an external force (iii) For MC 300, MC 301, MC 302, MC and that closes when the external force 303, MC 304, MC 305, MC 306, MC 307, MC is removed. 310, MC 311, and MC 312 cargo tanks, Shell means the circumferential porthe in-service minimum thickness pretion of a cargo tank defined by the scribed in Tables I and II of basic design radius or radii excluding $ 180.407(i)(5) of this subchapter, for the the bulkheads. minimum thickness specified by Tables Stop valve means a valve that stops I and Il of the applicable specificathe flow of lading. tion(s); or Sump means a protrusion from the (2) The thickness necessary to meet bottom of a cargo tank shell designed with the structural integrity and accito facilitate complete loading and undent damage requirements of the appliloading of lading. cable specification(s); or Tank means a container, consisting (3) The thickness as computed per of a shell and heads, that forms a presthe ASME Code requirements (if applisure tight vessel having openings decable). signed to accept pressure tight fittings Multi-specification cargo tank motor veor closures, but excludes any appurhicle means a cargo tank motor vehicle tenances, reinforcements. fittings, or equipped with two or more cargo tanks closures. 947 § 178.337 49 CFR Ch. I (10-1-06 Edition) Test pressure means the pressure to compliance with certain paragraphs of which a tank is subjected to determine the ASME Code, compliance with those structural integrity. paragraphs is not prohibited. Toughness of material means the capa- [Amdt. 178-89, 55 FR 37055, Sept. 7. 1990, as bility of a material to absorb energy amended by Amdt. 178-98, 58 FR 33306, June represented by the area under a stress 16, 1993; Amdt. 178-118, 61 FR 51339, Oct. 1. strain curve (indicating the energy ab- 1996: 68 FR 19277, Apr. 18, 2003; 68 FR 52370, sorbed per unit volume of the material) Sept. 3, 2003: 68 FR 75752, Dec. 31, 2003) up to the point of rupture. Vacuum cargo tank means a cargo § 178.337 Specification MC 331; cargo tank that is loaded by reducing the tank motor vehicle primarily for transportation of compressed gases pressure in the cargo tank to below atas defined in subpart G of part 173 mospheric pressure. of this subchapter. Variable specification cargo tank means a cargo tank that is constructed § 178.337-1 General requirements. in accordance with one specification, (a) ASME Code construction. Tanks but that may be altered to meet anmust beother specification by changing relief (1) Seamless or welded construction, device, closures, lading discharge deor a combination of both; vices, and other lading retention de- (2) Designed, constructed, certified, vices. and stamped in accordance with Sec- Void means the space between tank tion VIII of the ASME Code (IBR, see heads or bulkheads and a connecting $171.7 of this subchapter); structure. (3) Made of steel or aluminum; how- Welded flange means a flange atever, if aluminum is used, the cargo tached to the tank by a weld joining tank must be insulated and the hazthe tank shell to the cylindrical outer ardous material to be transported must surface of the flange, or by a fillet weld be compatible with the aluminum (see joining the tank shell to a flange §§ 178.337-1(e)(2), 173.315(a) table, and shaped to fit the shell contour. 178.337-2(a)(1) of this subchapter); and (b) Design certification. (1) Each cargo (4) Covered with a steel jacket if the tank or cargo tank motor vehicle decargo tank is insulated and used to sign type, including its required accitransport a flammable gas (see dent damage protection device, must $ 173.315(a) table Note 11 of this subbe certified to conform to the specificachapter). tion requirements by a Design Certi- (b) Design pressure. The design presfying Engineer who is registered in acsure of a cargo tank authorized under cordance with subpart F of part 107 of this specification shall be not less than this title. An accident damage protecthe vapor pressure of the commodity tion device is a rear-end protection, contained therein at 115 °F. or as preoverturn protection, or piping protecscribed for a particular commodity in tion device. $173.315(a) of this subchapter, except (2) The Design Certifying Engineer that in no case shall the design presshall furnish to the manufacturer a sure of any cargo tank be less than 100 certificate to indicate compliance with p.s.i.g. nor more than 500 p.s.i.g. the specification requirements. The certificate must include the sketches, NOTE 1: The term design pressure as used in drawings, and calculations used for certhis specification. is identical to the term MAWP as used in the ASME Code. tification. Each certificate, including sketches, drawings, and calculations, (c) Openings. (1) Excess pressure relief shall be signed by the Design Certivalves shall be located in the top of the fying Engineer. cargo tank or heads. (3) The manufacturer shall retain the (2) A chlorine cargo tank shall have design certificate at his principal place only one opening. That opening shall of business for as long as he manufacbe in the top of the cargo tank and tures DOT specification cargo tanks. shall be fitted with a nozzle that meets (c) Exceptions to the ASME Code. Unthe following requirements: less otherwise specified, when excep- (i) On a cargo tank manufactured on tions are provided in this subpart from or before December 31, 1974, the nozzle 948 Pipeline and Hazardous Materials Safety Admin., DOT § 178.337-1 shall be protected by a dome cover as a unit after completion of all the plate which conforms to either the welds in and/or to the shells and heads. standard of The Chlorine Institute, The method must be as prescribed in Inc., Dwg. 103-3, dated January 23, 1958, Section VIII of the ASME Code. Welded or to the standard specified in paraattachments to pads may be made after graph (c) (2) (ii) of this section. postweld heat treatment. A cargo tank (ii) On a cargo tank manufactured on used for anhydrous ammonia must be or after January 1, 1975. the nozzle postweld heat treated. The postweld shall be protected by a manway cover heat treatment must be as prescribed which conforms to the standard of The in Section VIII of the ASME Code, but Chlorine Institute, Inc., Dwg. 103-4, in no event at less than 1,050 SF cargo dated September 1, 1971. tank metal temperature. (d) Reflective design. Every (g) Definitions. The following definiuninsulated cargo tank permanently tions apply to §§ 178.337-1 through attached to a cargo tank motor vehicle 178.337-18: shall, unless covered with a jacket Emergency discharge control means the made of aluminum, stainless steel, or ability to stop a cargo tank unloading other bright nontarnishing metal, be operation in the event of an unintenpainted a white, aluminum or similar tional release. Emergency discharge reflecting color on the upper two-thirds control can utilize passive or off-truck of area of the cargo tank. remote means to stop the unloading (e) Insulation. (1) Each cargo tank reoperation. A passive means of emerquired to be insulated must conform gency discharge control automatically with the use and performance requireshuts off the flow of product without ments contained in 173.315(a) table the need for human intervention withand 178.337-1 (a)(3) and (e)(2) of this in 20 seconds of an unintentional resubchapter. lease caused by a complete separation (2) Each cargo tank intended for of the liquid delivery hose. An offchlorine; carbon dioxide, refrigerated truck remote means of emergency disliquid; or nitrous oxide, refrigerated charge control permits a qualified perliquid service must have suitable insuson attending the unloading operation lation of such thickness that the overto close the cargo tank's internal selfall thermal conductance is not more closing stop valve and shut off all mothan 0.08 Btu per square foot per °F diftive and auxiliary power equipment at ferential per hour. The conductance a distance from the cargo tank motor must be determined at 60 °F. Insulation vehicle. material used on cargo tanks for ni- Excess flow valve, integral excess flow trous oxide, refrigerated liquid must be valve, or excess flow feature means a noncombustible. Insulating material component that will close automatiused on cargo tanks for chlorine must cally if the flow rate of a gas or liquid be corkboard or polyurethane foam, through the component reaches or exwith a minimum thickness of 4 inches, ceeds the rated flow of gas or liquid or 2 inches minimum thickness of cespecified by the original valve manuramic fiber/fiberglass of 4 pounds per facturer when piping mounted directly cubic foot minimum density covered by on the valve is sheared off before the 2 inches minimum thickness of fiber. first valve, pump, or fitting down- (f) Postweld heat treatment. Postweld stream from the valve. heat treatment must be as prescribed Internal self-closing stop valve means a in the ASME Code except that each primary shut off valve installed in a cargo tank constructed in accordance product discharge outlet of a cargo with Part UHT of Section VIII of the tank and designed to be kept closed by ASME Code must be postweld heat self-stored energy. treated. Each chlorine cargo tank must Primary discharge control system be fully radiographed and postweld means a primary shut-off installed at a heat treated in accordance with the product discharge outlet of a cargo provisions in Section VIII of the ASME tank consisting of an Internal self-clos- Code under which it is constructed. ing stop valve that may include an in- Where postweld heat treatment is retegral excess flow valve or an excess quired, the cargo tank must be treated flow feature, together with linkages 949 § 178.337-2 49 CFR Ch. I (10-1-06 Edition) that must be installed between the ferential orientation of the cargo tank valve and remote actuator to provide shell. manual and thermal on-truck remote (b) For a chlorine cargo tank. Plates, means of closure. the manway nozzle, and anchorage [Order 59-B. 30 FR 579, Jan. 16, 1965. Redesigshall be made of carbon steel which nated at 32 FR 5606, Apr. 5. 1967] meets the following requirements: (1) For a cargo tank manufactured on EDITORIAL NOTE: For FEDERAL REGISTER cltations affecting 178.337-1, see the List of or before December 31, 1974- CFR Sections Affected which appears in the (i) Material shall conform to ASTM A Finding Aids section of the printed volume 300, "Steel Plates for Pressure Vessels and on GPO Access. for Service at Low Temperatures" (IBR, see § 171.7 of this subchapter); § 178.337-2 Material. (ii) Material shall be Class 1, Grade (a) General. (1) All material used for A, flange or firebox quality: construction of the cargo tank and ap- (iii) Plate impact test specimens, as purtenances must be suitable for use required under paragraph (a) of this with the commodities to be transsection, shall be of the Charpy keyhole ported therein and must conform to notch type; and the requirements in Section II of the (iv) Plate impact test specimens ASME Code (IBR, see $171.7 of this subshall meet the impact test requirechapter) and/or requirements of the ments in paragraph (a) of this section American Society for Testing and Main both the longitudinal and transverse terials in all respects. directions of rolling at a temperature (2) Impact tests are required on steel of minus 45.5 C. °F.). used in the fabrication of each cargo (2) For a cargo tank manufactured on tank constructed in accordance with or after January 1, 1975- part UHT in Section VIII of the ASME (i) Material shall conform to ASTM A Code. The tests must be made on a lot 612 (IBR, see $171.7 of this subchapter), basis. A lot is defined as 100 tons or less Grade B or A 516/A 516M (IBR, see 171.7 of the same heat treatment processing of this subchapter), Grade 65 or 70; lot having a thickness variation no (ii) Material shall meet the Charpy greater than plus or minus 25 percent. V-notch test requirements of ASTM A The minimum impact required for full 20/A 20M (IBR, see $171.7 of this subsize specimens must be 20 foot-pounds chapter); and in the longitudinal direction at -30 (iii) Plate impact test specimens °F., Charpy V-Notch and 15 foot-pounds shall meet the impact test requirein the transverse direction at -30 °F., ments in paragraph (a) of this section Charpy V-Notch. The required values in both the longitudinal and transverse for subsize specimens must be reduced directions of rolling at a temperature in direct proportion to the cross-secof minus 40 °C. (-40 °F.). tional area of the specimen beneath the (c) A cargo tank in anhydrous ammonotch. If a lot does not meet this renia service must be constructed of quirement, individual plates may be steel. The use of copper, silver, zinc or accepted if they individually meet this their alloys is prohibited. Baffles made requirement. from aluminum may be used only if (3) The fabricator shall record the joined to the cargo tank by a process heat, and slab numbers, and the ceΓ- not requiring postweld heat treatment tified Charpy impact values, where reof the cargo tank. quired, of each plate used in each cargo [Order 59-B, 30 FR 579, Jan. 16. 1965. Redesigtank on a sketch showing the location nated at 32 FR 5606, Apr. 5, 1967] of each plate in the shell and heads of EDITORIAL NOTE: For FEDERAL REGISTER cithe cargo tank. Copies of each sketch tations affecting $178.337-2, see the List of shall be provided to the owner and re- CFR Sections Affected which appears in the tained for at least five years by the Finding Aids section of the printed volume fabricator and made available to duly and on GPO Access. identified representatives of the Department of Transportation. $ 178.337-3 Structural integrity. (4) The direction of final rolling of (a) General requirements and acceptthe shell material shall be the circumance criteria. (1) Except as provided in 950 Pipeline and Hazardous Materials Safety Admin., DOT § 178.337-3 paragraph (d) of this section, the maxthroughout the cargo tank motor vehiimum calculated design stress at any cle. The vertical, longitudinal, and latpoint in the cargo tank may not exceed eral normal operating loadings can the maximum allowable stress value occur simultaneously and must be prescribed in Section VIII of the ASME combined. The vertical, longitudinal Code (IBR, see $171.7 of this suband lateral extreme dynamic loadings chapter), or 25 percent of the tensile occur separately and need not be comstrength of the material used. bined. (2) The relevant physical properties (1) Normal operating loadings. The folof the materials used in each cargo lowing procedure addresses stress in tank may be established either by a the tank shell resulting from normal certified test report from the material operating loadings. The effective stress manufacturer or by testing in conform- (the maximum principal stress at any ance with a recognized national standpoint) must be determined by the folard. In either case, the ultimate tensile lowing formula: strength of the material used in the de- S = 0.5(S, + Sx) ±[0.25(Sy - Sx)2 + S,2]0.5 sign may not exceed 120 percent of the ultimate tensile strength specified in Where: either the ASME Code or the ASTM (i) S = effective stress at any given standard to which the material is manpoint under the combination of static ufactured. and normal operating loadings that can (3) The maximum design stress at occur at the same time, in psi. any point in the cargo tank must be (ii) S, = circumferential stress gencalculated separately for the loading erated by the MAWP and external presconditions described in paragraphs (b). sure, when applicable, plus static head, (c), and (d) of this section. Alternate in psi. test or analytical methods, or a com- (iii) Sx = The following net longitubination thereof, may be used in place dinal stress generated by the following of the procedures described in parastatic and normal operating loading graphs (b), (c), and (d) of this section, if conditions, in psi: the methods are accurate and (A) The longitudinal stresses resultverifiable. ing from the MAWP and external pres- (4) Corrosion allowance material may sure, when applicable, plus static head, not be included to satisfy any of the in combination with the bending stress design calculation requirements of this generated by the static weight of the section. fully loaded cargo tank motor vehicle, (b) Static design and construction. (1) all structural elements, equipment and The static design and construction of appurtenances supported by the cargo each cargo tank must be in accordance tank wall; with Section VIII of the ASME Code. (B) The tensile or compressive stress The cargo tank design must include resulting from normal operating longicalculation of stresses generated by detudinal acceleration or deceleration. In sign pressure, the weight of lading, the each case, the forces applied must be weight of structure supported by the 0.35 times the vertical reaction at the cargo tank wall, and the effect of temsuspension assembly, applied at the perature gradients resulting from ladroad surface, and as transmitted to the ing and ambient temperature extremes. cargo tank wall through the suspension When dissimilar materials are used, assembly of a trailer during deceleratheir thermal coefficients must be used tion; or the horizontal pivot of the in calculation of thermal stresses. truck tractor or converter dolly fifth (2) Stress concentrations in tension, wheel, or the drawbar hinge on the bending and torsion which occur at fixed dolly during acceleration; or anpads, cradles, or other supports must choring and support members of a be considered in accordance with aptruck during acceleration and decelerapendix G in Section VIII of the ASME tion, as applicable. The vertical reac- Code. tion must be calculated based on the (c) Shell design. Shell stresses resultstatic weight of the fully loaded cargo ing from static or dynamic loadings, or tank motor vehicle, all structural elecombinations thereof, are not uniform ments, equipment and appurtenances 951 $ 178.337-3 49 CFR Ch. I (10-1-06 Edition) supported by the cargo tank wall. The sembly of a trailer, applied at the road following loadings must be included: surface, and as transmitted to the (1) The axial load generated by a cargo tank wall through the suspension decelerative force; assembly of a trailer, and the hori- (2) The bending moment generated by zontal pivot of the upper coupler (fifth a decelerative force; wheel) or turntable; or anchoring and (3) The axial load generated by an acsupport members of a truck, as applicacelerative force; and ble. The vertical reaction must be cal- (4) The bending moment generated by culated based on the static weight of an accelerative force; and the fully loaded cargo tank motor vehi- (C) The tensile or compressive stress cle, all structural elements, equipment generated by the bending moment reand appurtenances supported by the sulting from normal operating vertical cargo tank wall; and accelerative force equal to 0.35 times (D) The torsional shear stress genthe vertical reaction at the suspension erated by the same lateral forces as deassembly of a trailer; or the horizontal scribed in paragraph (c)(1)(iv)(C) of this pivot of the upper coupler (fifth wheel) section. or turntable; or anchoring and support (2) Extreme dynamic loadings. The folmembers of a truck, as applicable. The lowing procedure addresses stress in vertical reaction must be calculated the tank shell resulting from extreme based on the static weight of the fully dynamic loadings. The effective stress loaded cargo tank motor vehicle, all (the maximum principal stress at any structural elements, equipment and appoint) must be determined by the folpurtenances supported by the cargo lowing formula: tank wall. S = 0.5(Sy + Sx) ±[0.25(S, - Sx)2 + S,2]0.5 (iv) S, = The following shear stresses generated by the following static and Where: normal operating loading conditions, (i) S = effective stress at any given in psi: point under a combination of static (A) The static shear stress resulting and extreme dynamic loadings that can from the vertical reaction at the susoccur at the same time, in psi. pension assembly of a trailer, and the (ii) Sy = circumferential stress genhorizontal pivot of the upper coupler erated by MAWP and external pressure, (fifth wheel) or turntable; or anchoring when applicable, plus static head, in and support members of a truck, as appsi. plicable. The vertical reaction must be (iii) Sx = the following net longitucalculated based on the static weight dinal stress generated by the following of the fully loaded cargo tank motor static and extreme dynamic loading vehicle, all structural elements, equipconditions, in psi: ment and appurtenances supported by (A) The longitudinal stresses resultthe cargo tank wall; ing from the MAWP and external pres- (B) The vertical shear stress gensure, when applicable, plus static head, erated by a normal operating accelerain combination with the bending stress tive force equal to 0.35 times the generated by the static weight of the vertical reaction at the suspension asfully loaded cargo tank motor vehicle, sembly of a trailer; or the horizontal all structural elements, equipment and pivot of the upper coupler (fifth wheel) appurtenances supported by the tank or turntable; or anchoring and support wall; members of a truck, as applicable. The (B) The tensile or compressive stress vertical reaction must be calculated resulting from extreme longitudinal based on the static weight of the fully acceleration or deceleration. In each loaded cargo tank motor vehicle, all case the forces applied must be 0.7 structural elements, equipment and aptimes the vertical reaction at the suspurtenances supported by the cargo pension assembly, applied at the road tank wall; surface, and as transmitted to the (C) The lateral shear stress generated cargo tank wall through the suspension by a normal operating lateral acceleraassembly of a trailer during decelerative force equal to 0.2 times the tion; or the horizontal pivot of the vertical reaction at each suspension astruck tractor or converter dolly fifth 952 Pipeline and Hazardous Materials Safety Admin., DOT § 178.337-3 wheel, or the drawbar hinge on the loaded cargo tank motor vehicle, all fixed dolly during acceleration; or the structural elements, equipment and apanchoring and support members of a purtenances supported by the cargo truck during acceleration and deceleratank wall; tion, as applicable. The vertical reac- (C) The lateral shear stress generated tion must be calculated based on the by an extreme lateral accelerative static weight of the fully loaded cargo force equal to 0.4 times the vertical retank motor vehicle, all structural eleaction at the suspension assembly of a ments, equipment and appurtenances trailer, applied at the road surface, and supported by the cargo tank wall. The as transmitted to the cargo tank wall following loadings must be included: through the suspension assembly of a (1) The axial load generated by a trailer, and the horizontal pivot of the decelerative force; upper coupler (fifth wheel) or turn- (2) The bending moment generated by table; or anchoring and support mem- a decelerative force; bers of a truck, as applicable. The (3) The axial load generated by an acvertical reaction must be calculated celerative force; and based on the static weight of the fully (4) The bending moment generated by loaded cargo tank motor vehicle, all an accelerative force; and structural elements, equipment and ap- (C) The tensile or compressive stress purtenances supported by the cargo generated by the bending moment retank wall; and sulting from an extreme vertical accel- (D) The torsional shear stress generative force equal to 0.7 times the erated by the same lateral forces as devertical reaction at the suspension asscribed in paragraph (c)(2)(iv)(C) of this sembly of a trailer, and the horizontal section. pivot of the upper coupler (fifth wheel) (d) In order to account for stresses or turntable; or the anchoring and supdue to impact in an accident, the deport members of a truck, as applicable. sign calculations for the cargo tank The vertical reaction must be calshell and heads must include the load culated based on the static weight of resulting from the design pressure in the fully loaded cargo tank motor vehicombination with the dynamic prescle, all structural elements, equipment sure resulting from a longitudinal deand appurtenances supported by the celeration of "2g". For this loading cargo tank wall. condition the stress value used may (iv) Ss = The following shear stresses not exceed the lesser of the yield generated by static and extreme dystrength or 75 percent of the ultimate namic loading conditions, in psi: tensile strength of the material of con- (A) The static shear stress resulting struction. For cargo tanks constructed from the vertical reaction at the susof stainless steel the maximum design pension assembly of a trailer, and the stress may not exceed 75 percent of the horizontal pivot of the upper coupler ultimate tensile strength of the type (fifth wheel) or turntable: or anchoring steel used. and support members of a truck, as ap- (e) The minimum metal thickness for plicable. The vertical reaction must be the shell and heads on tanks with a decalculated based on the static weight sign pressure of 100 psig or more must of the fully loaded cargo tank motor be 4.75 mm (0.187 inch) for steel and 6.86 vehicle, all structural elements, equipmm (0.270 inch) for aluminum, except ment and appurtenances supported by for chlorine and sulfur dioxide tanks. the cargo tank wall; In all cases, the minimum thickness of (B) The vertical shear stress genthe tank shell and head shall be detererated by an extreme vertical acceleramined using structural design requiretive force equal to 0.7 times the ments in Section VIII of the ASME vertical reaction at the suspension as- Code or 25% of the tensile strength of sembly of a trailer, and the horizontal the material used. For a cargo tank pivot of the upper coupler (fifth wheel) used in chlorine or sulfur dioxide servor turntable; or anchoring and support ice, the cargo tank must be made of members of a truck, as applicable. The steel. A corrosion allowance of 20 pervertical reaction must be calculated cent or 2.54 mm (0.10 inch), whichever based on the static weight of the fully is less, must be added to the thickness 953 § 178.337-4 49 CFR Ch. I (10-1-06 Edition) otherwise required for sulfur dioxide thickness of the mounting pad may not and chlorine tank material. In chlorine be less than that of the shell wall or cargo tanks, the wall thickness must head wall to which it is attached, and be at least 1.59 cm (0.625 inch), includnot more than 1.5 times the shell or ing corrosion allowance. head thickness. However, a pad with a (f) Where a cargo tank support is atminimum thickness of 0.25 inch may be tached to any part of the cargo tank used when the shell or head thickness wall, the stresses imposed on the cargo is over 0.25 inch. If weep holes or telltank wall must meet the requirements tale holes are used, the pad must be in paragraph (a) of this section. drilled or punched at the lowest point (g) The design, construction, and inbefore it is welded to the tank. Each stallation of an attachment, appurpad musttenance to the cargo tank, structural (i) Be fabricated from material detersupport member between the cargo mined to be suitable for welding to tank and the vehicle or suspension both the cargo tank material and the component, or accident protection dematerial of the appurtenance or strucvice must conform to the following retural support member; a Design Certiquirements: fying Engineer must make this deter- (1) Structural members, the suspenmination considering chemical and sion sub-frame, accident protection physical properties of the materials structures, and external circumferenand must specify filler material contial reinforcement devices must be forming to the requirements in Section used as sites for attachment of appur- VIII of the ASME Code (IBR, see $ 171.7 tenances and other accessories to the of this subchapter). cargo tank, when practicable. (2) A lightweight attachment to the (ii) Be preformed to an inside radius cargo tank wall such as a conduit clip, no greater than the outside radius of brake line clip, skirting structure, the cargo tank at the attachment location. lamp mounting bracket, or placard holder must be of a construction hav- (iii) Extend at least 2 inches in each ing lesser strength than the cargo tank direction from any point of attachment wall materials and may not be more of an appurtenance or structural supthan 72 percent of the thickness of the port member. This dimension may be material to which it is attached. The measured from the center of the atlightweight attachment may be setached structural member. cured directly to the cargo tank wall if (iv) Have rounded corners, or otherthe device is designed and installed in wise be shaped in a manner to minisuch a manner that, if damaged, it will mize stress concentrations on the shell not affect the lading retention integor head. rity of the tank. A lightweight attach- (v) Be attached by continuous fillet ment must be secured to the cargo welding. Any fillet weld discontinuity tank shell or head by a continuous may only be for the purpose of preweld or in such a manner as to preclude venting an intersection between the filformation of pockets which may belet weld and a tank or jacket seam come sites for corrosion. Attachments weld. meeting the requirements of this para- (Amdt. 178-89, 55 FR 37056, Sept. 7, 1990, as graph are not authorized for cargo amended by Amdt. 178-104, 59 FR 49135, Sept. tanks constructed under part UHT in 26, 1994; Amdt. 178-105, 60 FR 17401. Apr. 5, Section VIII of the ASME Code. 1995; Amdt. 178-118, 61 FR 51340. Oct. 1. 1996; (3) Except as prescribed in para- 65 FR 58631, Sept. 29, 2000; 68 FR 19279, Apr. graphs (g) (1) and (g)(2) of this section, 18, 2003; 68 FR 52370, Sept. 3, 2003; 68 FR 75753, the welding of any appurtenance to the Dec. 31, 2003] cargo tank wall must be made by attachment of a mounting pad so that § 178.337-4 Joints. there will be no adverse effect upon the (a) Joints shall be as required in Seclading retention integrity of the cargo tion VIII of the ASME Code (IBR, see tank if any force less than that pre- $171.7 of this subchapter), with all unscribed in paragraph (b)(1) of this secdercutting in shell and head material tion is applied from any direction. The repaired as specified therein. 954 Pipeline and Hazardous Materials Safety Admin., DOT § 178.337-8 (b) Welding procedure and welder per- § 178.337-6 Closure for manhole. formance must be in accordance with Section IX of the ASME Code. In addi- (a) Each cargo tank marked or certion to the essential variables named tified after April 21, 1994, must be protherein, the following must be considvided with a manhole conforming to ered as essential variables: Number of paragraph UG-46(g) (1) and other applipasses; thickness of plate; heat input cable requirements in Section VIII of the ASME Code (IBR, see § 171.7 of this per pass; and manufacturer's identification of rod and flux. When fabricasubchapter), except that a cargo tank tion is done in accordance with part constructed of NQT steel having a ca- UHT in Section VIII of the ASME Code, pacity of 3,500 water gallons or less filler material containing more than may be provided with an inspection 0.08 percent vanadium must not be opening conforming to paragraph UGused. The number of passes, thickness 46 and other applicable requirements of the ASME Code instead of a manhole. of plate, and heat input per pass may not vary more than 25 percent from the (b) The manhole assembly of cargo tanks constructed after June 30, 1979, procedure or welder qualifications. Records of the qualifications must be may not be located on the front head of retained for at least 5 years by the the cargo tank. cargo tank manufacturer and must be [Amdt. 178-7. 34 FR 18250, Nov. 14, 1969, as made available to duly identified repamended by Amdt. 178-52, 43 FR 58820, Dec. resentatives of the Department and the 18, 1978; Amdt. 178-89. 54 FR 25017. June 12, owner of the cargo tank. 1989; 55 FR 21038, May 22, 1990; 56 FR 27876, (c) All longitudinal shell welds shall June 17, 1991; 58 FR 12905, March 8, 1993; Amdt. 178-118, 61 FR 51340, Oct. 1, 1996; 68 FR be located in the upper half of the 75753, Dec. 31, 2003] cargo tank. (d) Edge preparation of shell and § 178.337-7 Overturn protection. head components may be by machine (a) See § 178.337-10. heat processes, provided such surfaces (b) [Reserved] are remelted in the subsequent welding process. Where there will be no subse- [Order 59-B, 30 FR 580, Jan. 16, 1965. Redesigquent remelting of the prepared surface nated at 32 FR 5606, Apr. 5, 1967] as in a tapered section, the final 0.050 inch of material shall be removed by $ 178.337-8 Openings, inlets, and outlets. mechanical means. (e) The maximum tolerance for mis- (a) General. The requirements in this alignment and butting up shall be in paragraph (a) apply to MC 331 cargo accordance with the requirement in tanks except for those used to trans-