D4503 POP Safety Relief Valve Body Material Bronze Inlet Type MNPT Outlet Type FNPT Inlet Size 2 in Outlet Size 3 in Factory Set Pressure 175 psi Pressure Range 15 to 300 psi Disc Material 316 Stainless Steel Overall Height 17 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 406 Degrees F Test Lever No Standards ASME Section VIII UV CSA CRN NB