(a) The pressure relief valve requirements and the safety valve requirements for steam boilers must be as indicated in HG-400 and HG-401 of section IV of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR 53.01-1) except as noted otherwise in this section.

(b) Each steam boiler must have at least one safety valve.

[CGD 81-79, 50 FR 9435, Mar. 8, 1985, as amended by USCG-2003-16630, 73 FR 65163, Oct. 31, 2008]

(a) The relief valve requirements for hot water boilers must be as indicated in article 4 of section IV of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR 53.01-1) except as noted otherwise in this section.

(b) Hot water heating boilers. Each hot water heating boiler must have at least one safety relief valve.

(c) Hot water supply boilers. Each hot water supply boiler must have at least one safety relief valve and a temperature relief valve or a pressure-temperature relief valve. The valve temperature setting must not be more than 99 °C (210 °F).

[CGD 81-79, 50 FR 9435, Mar. 8, 1985, as amended by USCG-2003-16630, 73 FR 65163, Oct. 31, 2008]

Materials for valves must be in accordance with HG-401.2 of section IV of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR 53.01-1) except that nonmetallic materials may be used only for gaskets and packing.

[USCG-2003-16630, 73 FR 65164, Oct. 31, 2008]

The discharge capacities and valve markings must be as indicated in HG-402 of section IV of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR 53.01-1). The discharge capacities must be certified by the National Board of Boiler and Pressure Vessel Inspectors.

[USCG-2003-16630, 73 FR 65164, Oct. 31, 2008]