AQUATROL Brass/Bronze (Safety Relief Valve Mnpt Inlet Type, Fnpt Outlet Type). Model: 740DF-M1A-100. More details: Safety Relief Valve, Body Material Brass/Bronze, Inlet Type MNPT, Outlet Type FNPT, Inlet Size 3/4 In., Outlet Size 1 In., Factory Set Pressure 100 psi, Disc Material Stainless Steel, Overall Height 7-3/8 In., Application Air, Gas, Overall Length 7-3/8 In., Seat Material Brass/Stainless Steel, Spring Material Stainless Steel, Temp. Range -320 Degrees to 406 Degrees F, Test Lever Yes, Standards ASME Section VIII / CRN.