(a) The following piping systems shall be hydrostatically leak tested in the presence of a marine inspector at a pressure of 1 1/2 times the maximum allowable working pressure of the system:
(1) Class I steam, feedwater, and blowoff piping. Where piping is attached to boilers by welding without practical means of blanking off for testing, the piping shall be subjected to the same hydrostatic pressure to which the boiler is tested. The maximum allowable working pressures of boiler feedwater and blowoff piping shall be the design pressures specified in §§ 56.50-30(a)(3) and 56.50-40(b), respectively.
(2) Fuel oil discharge piping between the pumps and the burners, but not less than 500 pounds per square inch.
(3) High-pressure piping for tank cleaning operations.
(4) Flammable or corrosive liquids and compressed gas cargo piping, but not less than 150 pounds per square inch.
(5) Any Class I, I-L, II-L piping.
(6) Cargo oil piping.
(7) Firemains, but not less than 150 pounds per square inch.
(8) Fuel oil transfer and filling piping.
(9) Class I compressed air piping.
(10) Fixed oxygen-acetylene system piping.
(b) Installation testing requirements for refrigeration, fluid power, and liquefied petroleum gas cooking and heating systems may be found in part 58 of this subchapter.
(c) Class II piping systems shall be tested under working conditions as specified in the section on initial service leak test, § 56.97-38.