Safety Relief Valve, Body Material Iron, Inlet Type FNPT, Outlet Type FNPT, Inlet Size 3/4 in, Outlet Size 3/4 in, Factory Set Pressure 30 psi, 550,000 BtuH, Disc Material Buna-N, Overall Height 3 5/8 in, Application For Pressure Protection of Hot Water Heating Boilers, Overall Length 2 1/2 in, Seat Material Metal, Spring Material Brass, Temp. Range 0 Degrees to 250 Degrees F, Test Lever Yes, Standards ASME, Military Spec MIL-V-18634B, Type I , Class 3A, Style A, Bronze Body