Oklahoma Administrative Code
Title 380 - Department of Labor
Chapter 25 - Boiler and Pressure Vessel Rules
Subchapter 7 - General Requirements
Section 380:25-7-6 - Pressure tests

(a) A hydrostatic pressure test, when applied to boilers or pressure vessels, shall not exceed 1.5 times the maximums 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 6%

(b) During a hydrostatic test the safety 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. A plug device designed for this purpose may be used.

(c) The minimum temperature of the water used to apply a hydrostatic test shall be not less than 60° F, but the maximum temperature during inspection shall not exceed 120° F.

(d) When a hydrostatic test is applied to determine tightness, the pressure shall be equal to the normal operating pressure but need not exceed the release pressure of the safety valve having the lowest release setting.

(e) When the contents of the vessel prohibit contamination by any other medium or when a hydrostatic test is not possible, other testing media may be used providing the precautionary requirements of the applicable section of the ASME Code are followed. In such cases, there shall be agreement between the owner, the Inspector, and the jurisdiction.