(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.