Vacuum Relief Valve Body Material Lead Free Copper Silicon Alloy Inlet Type MNPT Outlet Type MNPT Inlet Size 3/4 in Outlet Size 3/4 in Factory Set Pressure 15 psi Pressure Range 0 to 200 psi Disc Material Silicone Overall Height 2 in Application Supply Tanks Water Heater Overall Length 2 in Spring Material Stainless Steel Temp Range 0 Degrees to 250 Degrees F Standards ANSI Z21.22 CSA