ARM 36.21.640. WELL CASING

(1) All casing installed, other than plastic casing set forth in ARM 36.21.641 and 36.21.645, shall be of steel, in new or like new condition, being free of pits, breaks, or contamination, and shall meet minimum American society of testing materials (ASTM A-120) specifications for line pipe, for the following sizes: Minimum specifications for steel well casing (2) All casing having a diameter larger than 20 inches shall have a wall thickness of at least .375 inch. (3) Well casing installed in a well greater than a nominal diameter of 10 inches, may have a wall thickness of .250 inch as long as it otherwise meets ASTM A-120 specifications and does not exceed the following depth limitations: Diameter Maximum Depth 12 inches 250 feet 14-16 inches 150 feet 18-20 inches 100 feet (4) Casings of other specifications may be considered under the provisions of variances ARM 36.21.680. Nominal Size (inches Outside Diameter (inches) Wall Thickness (inches) Weight Per Foot (pounds) 2 2.375 .154 3.56 2 2.875 .203 5.79 3 3.500 .216 7.58 3 4.000 .226 9.11 4 4.500 .237 10.79 5 5.563 .244 13.70 6 6.625 .250 17.02 8 8.625 .250 22.36 10 10.750 .250 28.04 12 12.750 .312 41.45 14 14.000 .312 45.68 16 16.000 .312 52.27 18 18.000 .375 70.59 20 20.000 .375 78.60