Current through Register Vol. 54, No. 50, December 14, 2024
Section 3a.115 - Hydrostatic pressure test(a) A hydrostatic pressure test must comply with the following requirements: (1) A hydrostatic pressure test may not exceed the following pressures:(i) For boilers or unfired pressure vessels in the field, 1.5 times the maximum allowable working pressure.(ii) For boilers of locomotives, 1.25 times the maximum allowable working pressure.(iii) For glass-lined unfired pressure vessels, the maximum allowable working pressure.(iv) For unfired pressure vessels fabricated to ASME section VIII, division 1 after January 1, 2000, 1.3 times the maximum allowable working pressure.(v) For unfired pressure vessels fabricated to ASME Section VIII, Divisions 2 and 3, the pressure that was preapproved by an inspector.(2) Pressure must be controlled at all times and may not be more than 106% of the test pressure allowed by the ASME Code at the time of construction.(3) The temperature of the water used to apply the test must be between 70° and 120°F.(4) A safety valve must be removed or each valve shall be held to its seat by a testing clamp. Screwing down the compression screw upon the spring is prohibited. A VR stamp holder must reseal the valves.(5) Pressure must be equal to or below the release pressure of the safety valve having the highest release setting when a test is applied to an existing installation to determine tightness.(b) An inspector may require a hydrostatic test after the completion of a repair to insure the pressure containing boundaries hold design pressure.