Code of Federal Regulations Title 46. Shipping § 46.52.01–95 Design (modifies PG–16 through PG–31 and PG–100)

(a) Requirements. Boilers required to be designed to this part shall meet the requirements of PG–16 through PG–31 of section I of the ASME Boiler and Pressure Vessel Code (incorporated by reference;  see 46 CFR 52.01–1) except as noted otherwise in this section.

(b) Superheater.

(c) Economizer. The design pressure of an economizer integral with the boiler and connected to the boiler drum without intervening stop valves shall be at least equal to 110 percent of the highest setting of the safety valves on the drum.

(d) Brazed boiler steam air heaters. Boiler steam air heaters utilizing brazed construction are permitted at temperature not exceeding 525° F. Refer to § 56.30–30(b)(1) of this subchapter for applicable requirements.

(e) Stresses. (Modifies PG–22.) The stresses due to hydrostatic head shall be taken into account in determining the minimum thickness of the shell or head of any boiler pressure part unless noted otherwise. Additional stresses, imposed by effects other than internal pressure or static head, which increase the average stress over substantial sections of the shell or head by more than 10 percent of the allowable stress shall be taken into account. These effects include the weight of the vessel and its contents, method of support, impact loads, superimposed loads, localized stresses due to the reactions of supports, stresses due to temperature gradients and dynamic effects.

(f) Cylindrical components under internal pressure. (Modifies PG–27.) The minimum required thickness and maximum allowable working pressure of boiler piping, tubes, drums and headers shall be as required by the formula in PG–27 of section I of the ASME Boiler and Pressure Vessel Code except that threaded boiler tubes are not permitted.