D4521 Safety Relief Valve Body Material Bronze Inlet Type MNPT Outlet Type FNPT Inlet Size 1 1/4 in Outlet Size 1 1/2 in Factory Set Pressure 225 psi Pressure Range 0 to 300 psi Disc Material Bronze Overall Height 8 1/2 in Application Air Gas Seat Material Bronze Spring Material 316 Stainless Steel Temp Range 0 Degrees to 406 Degrees F Test Lever No Standards ASME Section VIII / CRN