This specification covers spring-loaded, angle style, pressure relief valves for steam, gas, and liquid system applications. Pressure relief valves shall be of the following types and material grades: Type I, Grades A and B; Type II, Grades C and D; and Type III, Grades E and F. Hydrostatic shell test and set pressure, blowdown, and seat tightness test shall be performed to meet the specified requirements.

1.1 This specification covers spring-loaded, angle style, pressure relief valves for steam, gas, and liquid system applications (excluding boiler safety and hydraulic system relief valves).

1.2 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.