HAR §12-223.1-13. (j) Lighting

The equipment room shall be well-lit and have an emergency light source for use in the case of a power failure. (k) Emergency valves and controls. All emergency shut-off valves and controls shall be accessible from a floor, platform, walkway, or runway. Accessibility shall mean within a six (6) feet elevation of the standing space and not more than twelve (12) inches horizontally from the standing space edge. (l) Chimney or stack. Chimneys or stacks shall be installed in accordance with the department's requirements, manufacturer's recommendations, and industry standards, as applicable. (m) Ash removal. Ash removal systems shall be installed in accordance with jurisdictional and environmental requirements, manufacturer's recommendations, and industry standards, as applicable. (n) Return pipe connections. The following shall apply to return pipe connections: (1) The return pipe connections of each boiler supplying a gravity return steam heating system shall be so arranged as to form a loop so that the water in each boiler cannot be forced out below the safe water level; and (2) Provision shall be made for cleaning the interior of the return piping at or close to the boiler. Washout openings should be used for return pipe connections and the washout plug placed in a tee or a cross so that the plug is directly opposite and as close as possible to the opening in the boiler. (o) Bottom blowoff and drain valves. The following shall apply to bottom blowoff and drain valves of steam heating, hot-water heating, and hot-water supply heating boilers: (1) Each steam boiler shall have a bottom blowoff connection fitted with a valve or cock connected to the lowest water space practicable with a minimum size as shown in the NBIC. The discharge piping shall be full size to the point of discharge. Heating boilers having a capacity of twenty-five (25) gallons or less are exempt from the above 223.1-42 3559 §12-223.1-13 requirements, except that they shall have a NPS three-fourths (3/4) minimum drain valve; (2) Each steam or hot-water boiler shall have one or more drain connections, fitted with valves or cocks connecting to the lowest water containing spaces. All parts of the boiler must be capable of being drained (the boiler design will dictate the number and size of drains). The minimum size of the drain piping, valves, and cocks shall be NPS 3/4. The discharge piping shall be full size to the point of discharge. When the blowoff connection is located at the lowest water containing space, a separate drain connection is not required; and (3) The minimum pressure rating of valves and cocks used for blowoff or drain purposes shall be at least equal to the pressure stamped on the boiler but in no case less than thirty (30) psig. The temperature rating of such valves and cocks shall not be less than 250 degrees Fahrenheit. (p) Each potable water heater shall have a bottom drain pipe connection fitted with a valve or cock connected with the lowest water space practicable. The minimum size bottom valve shall be NPS three-fourths (3/4). Any discharge piping connected to the bottom drain connection shall be full size to the point of discharge. (q) Provisions for thermal expansion of expansion tanks and piping for steam heating, hot-water heating, and hot-water supply heating boilers shall comply with the following: (1) Expansion tanks for hot-water heating and hot-water supply heating boilers shall be installed so that all hot-water heating systems incorporating hot-water tanks or fluid relief columns prevent freezing under normal operating conditions; (2) Heating systems with an open expansion tank shall have an indoor overflow from the upper portion of the expansion tank in addition to an open vent, the indoor overflow shall be 223.1-43 3559 1 §12-223.1-13 carried within the building to a suitable plumbing fixture or drain; (3) In closed heating systems an expansion tank shall be installed in a closed heating system that will be consistent with the volume and capacity of the system. If the system is designed for a working pressure of thirty (30) psig or less, the tank shall be suitably designed for a minimum hydrostatic test pressure of seventy-five (75) psig. Expansion tanks for systems designed to operate above thirty (30) psig shall be constructed in accordance with an acceptable code of construction. Provisions shall be made for draining the tank without emptying the system except for pressurized tanks. The minimum capacity of the closed-type expansion tank should be determined from NBIC Part 1, Tables 3.7.9.1-a and 3.7.9.1-b or from the following formula where the necessary information is available: US Customary: Vt = (0.00041T - 0.0466)Vs (Pa/Pf) - (Pa/Po) where, Vt = minimum volume of tanks, gallons Vs = volume of system, not including tanks, gallons T = average operating temperature, °F t1 = lower temperature t2 = higher temperature Pa = atmospheric pressure, psia Pf = fill pressure, psia Po = maximum operating pressure, psia Metric: Vt = (0.000738T - 0.3348)Vs (Pa/Pf) - (Pa/Po) where, Vt = minimum volume of tanks, liters Vs = volume of system, not including tanks, liters T = average operating temperature, °C Pa = atmospheric pressure, kPa 223.1-44 3 5 5 9 §12-223.1-13 Pf = fill pressure, kPa Po = maximum operating pressure, kPa; and (4) Hot-water supply systems. If a system is equipped with a check valve or pressure-reducing valve in the cold-water inlet line, consideration should be given to the installation of an airtight expansion tank or other suitable air cushion. Otherwise, due to the thermal expansion of the water, the safety relief valve may lift periodically. If an expansion tank is provided, it shall be constructed in accordance with an acceptable code of construction. Except for pre-pressurized tanks, which should be installed on the cold-water side, provisions shall be made for draining the tank without emptying the system (for a typical acceptable installation see Exhibit 7, titled, "Hot Water Boilers in Battery Acceptable Piping Installation", dated October 1, 2023, which is made a part of this chapter and located at the end of this chapter). (r) Piping for steam heating, hot-water heating, and hot-water supply boilers. Provisions shall be made for the expansion and contraction of steam and hot water mains connected to boiler(s) so there will be no undue strain transmitted to the boiler(s) (for typical schematic arrangements of piping incorporating strain absorbing joints for steam and hot-water heating boilers see Exhibit 5, titled, "Steam Boilers in Battery - Pumped Return Acceptable Piping Installation", dated October 1, 2023, which is made a part of this chapter and located at the end of this chapter, Exhibit 6, titled, "Steam Boilers in Battery - Gravity Return Acceptable Piping Installation", dated October 1, 2023, which is made a part of this chapter and located at the end of this chapter, and Exhibit 7, titled, "Hot Water Boilers in Battery Acceptable Piping Installation", dated October 1, 2023, which is made a part of this chapter and located at the end of this chapter). (s) Expansion tanks and piping for potable water heaters. The following shall apply to expansion tanks and piping for potable water heaters: 223.1-45 3559 §12-223.1-13 (1) If a system is equipped with a check valve or pressure-reducing valve in the cold-water inlet line, consideration should be given to the installation of an airtight expansion tank or other suitable air cushion. Otherwise, due to the thermal expansion of the water, the safety relief valve may lift periodically. If an expansion tank is provided, it shall be constructed in accordance with an acceptable code of construction. Except for pre-pressurized diaphragm-type tanks, which should be installed on the cold-water side, provisions shall be made for draining the tank without emptying the system; and (2) Piping. Provisions shall be made for the expansion and contraction of hot water mains connected to potable water heater(s) so that there will be no undue stress transmitted to the potable water heater(s). TABLE 3.7.9.1-a EXPANSION TANK CAPACITIES FOR GRAVITY HOT-WATER SYSTEMS | Based on a two-pipe system with average operating water temperature 170°F (77°C), using cast-iron column radiation with heat emission rate 150 Btu/hr/ft² (473 W/m²) equivalent direct radiation. | | | | --- | --- | --- | | Installed Equivalent Direct Radiation, ft² (m²) (Note) | No. | Tank Capacity, gallon (l) | | up to 350 (33) | 1 | 18 (68) | | up to 450 (42) | 1 | 21 (79) | | up to 650 (60) | 1 | 24 (91) | | up to 900 (84) | 1 | 30 (114) | | up to 1,100 (102) | 1 | 35 (132) | | up to 1,400 (130) | 1 | 40 (151) | | up to 1,600 (149) | 2 | 60 (227) | | up to 1,800 (167) | 2 | 60 (227) | | up to 2,000 (186) | 2 | 70 (265) | | up to 2,400 (223) | 2 | 80 (303) | Note: For systems with more than 2,400 ft² (223 m²) of installed equivalent direct water radiation, the required capacity of the cushion tank shall be increased on the basis of 1 gallon (3.79 l) tank capacity/33 ft² (3.1 m²) of additional equivalent direct radiation. 223.1-46 3559