Vacuum / Pressure Relief Valve Valve Inlet Port 1/4 in NPT Preset Setting (PSI) 0 to 14.7 Valve Vacuum Range 0 to 30 in Hg Max CFM - Valves 2 cfm Max Temp 250 Degrees F Operational Pressure Range 0 to 20 psi Brass Body Material Stainless Steel Ball Poppet Nitrite Seal Material Stainless Steel Spring Material Hex (In.) 9/16 in Length (In.) 1 3/4 in Easily Convert from Vacuum to Pressure Relief by Reversing Poppet and Spring Vacuum / Pressure Relief Valve