Sec.29-232-38. Hydrostatic pressure tests

A hydrostatic pressure test, when applied to boilers of riveted or welded construction, except locomotive boilers, shall not exceed one and one-half times the maximum allowable working pressure. Hydrostatic pressure applied to locomotive boilers shall not exceed one and one-quarter times the maximum allowable working pressure. During the hydrostatic pressure test, the safety valve or valves shall be removed or each valve disc shall be held down by means of a testing clamp and not by applying additional load to the spring with the compression screw. It is suggested that the minimum temperature of the water used to apply a hydrostatic test be not less than 70°F., but the maximum temperature shall not exceed 160°F. When a hydrostatic test is to be applied to existing installations, the pressure shall be as follows: (1) For all cases involving the question of tightness, the pressure shall be equal to the release pressure of the safety valve or valves having the lowest release setting; (2) for all cases involving the question of safety, the pressure shall be equal to one and one-half times the maximum allowable working pressure, except for locomotive boilers, in which case it shall be one and one-quarter times the maximum allowable working pressure.

(Effective August 25, 1987)