§ 52.01-105 Piping, valves and fittings (modifies PG-58 and PG-159).

(a) Boiler external piping within the jurisdiction of the ASME BPVC must be as indicated in PG-58 and PG-59 of Section I of the ASME BPVC (incorporated by reference; see § 52.01-1) except as noted otherwise in this section. Piping outside the jurisdiction of the ASME BPVC must meet the appropriate requirements of part 56 of this subchapter. (b) In addition to the requirements in PG-58 and PG-59 of Section I of the ASME BPVC, boiler external piping must: (1) Meet the design conditions and criteria in § 56.07-10 of this subchapter, except § 56.07-10(b); (2) Be included in the pipe stress calculations required by § 56.35-1 of this subchapter; (3) Meet the nondestructive examination requirements in § 56.95-10 of this subchapter; (4) Have butt-welding flanges and fittings when full radiography is required; and (5) Meet the requirements for threaded joints in § 56.30-20 of this subchapter. (c) Steam stop valves, in sizes exceeding 152mm (6 inch) NPS, must be fitted with bypasses for heating the line and equalizing the pressure before the valve is opened. (d)(1) Feed water must not be discharged into a boiler against surfaces exposed to hot gases or radiant heat of the fire. (2) Feed water nozzles of boilers designed for pressures of 2758 kPa (400 psi), or over, must be fitted with sleeves or other suitable means employed to reduce the effects (e)(1) Firetube and drum type boilers must be fitted with a surface and a bottom blowoff valve or cock attached directly to the boiler or to a short distance piece. The bottom blowoff valve must be attached to the lowest part of the boiler or fitted with an internal pipe leading to the lowest point inside the boiler. Boilers equipped with a continuous blowdown valve on the steam drum are not required to be fitted with an additional surface blowoff connection. (2) Where blowoff pipes are exposed to radiant heat of the fire, they must be protected by fire brick or other suitable heat-resisting material. (f) Where dry pipes are used, they must be provided with drains at each end to prevent an accumulation of water.