POP Safety Relief Valve Body Material Bronze Inlet Type MNPT Outlet Type FNPT Inlet Size 1 1/2 in Outlet Size 2 1/2 in Factory Set Pressure 450 psi Pressure Range 5 to 500 psi Disc Material 316 Stainless Steel Overall Height 15 in Application Air and Gas Compressors and Dryers Pressure Vessels and Pressure Piping System etc Seat Material Metal Spring Material Stainless Steel Temp Range -320 Degrees to 422 Degrees F Test Lever Yes Standards ASME Section VIII UV CSA CRN NB