Hydrostatic Pressure Tests

Hydrostatic Pressure Tests 1. A hydrostatic pressure test, when applied to boiler or pressure vessels, shall not exceed 1 1/2 times the maximum allowable working pressure. the pressure shall be under proper control so that in no case shall the required test pressure be exceeded by more than two percent. 2. See Article III, Section I, Item 1(d), for temperature limitations on particular power boiler installations. 3. Note: When a hydrostatic test is to be applied to existing installations, the pressure shall be as follows: a. For all cases involving the question of tightness, the pressure shall be equal to the working pressure. b. For all cases involving the question of safety, the pressure shall be equal to 1 1/2 times the maximum allowable working pressure. During such test the safety valve or valves shall be removed or each valve disk shall be held to its seat by means of a testing clamp and not by screwing down the compression screw upon the spring.