Hydrostatic Test Pressure Calculator

First-pass minimum test pressure = factor x design pressure. Watch the caveats: B31.3 also multiplies by the stress ratio (S at test temp / S at design temp) for hot service; B31.8 gas lines set the test level by class location as a percentage of SMYS, so 1.25x is only a starting point; ASME VIII multiplies by the stress ratio at test temperature. Never exceed the pipe or the weakest component's limits. Always verify against the governing code edition and the written test procedure.