Section VIII Division 1 of The ASME Boiler and Pressure Vessel Code (Code)i[i]
requires testing the integrity of pressure vessels by subjecting them to a
hydrostatic pressure test of 1.3 times the maximum allowable working pressure
(MAWP) corrected for the difference between allowable stress at the test
temperature and the design temperature. The Code provides for testing at higher
hydrostatic test pressures but most pressure tests are at the 1.3 multiple. For
shell-and-tube heat exchangers built to the TEMA Standards, Paragraph RCB-
1.31 Standard Test, the holding period is at least 30 minutes. The TEMA
Standards require testing the shell and tube sides separately in such a manner
that leaks at the tube joints can be detected at least from one side.