Vacuum and Pressure Relief Valve, Body Material Brass, Cracking Pressure - Maximum 14.7 psi, Cracking Pressure - Minimum 0 in Hg, Flow Rate - Maximum 2 cfm, Inlet Port Connection Gender Male, Inlet Port Connection Size 1/4 in, Inlet Port Connection Type NPT, Maximum Compatible Vacuum Pump 1/4 hp, Operating Pressure - Maximum 14.7 psi, Operating Temperature - Maximum 250 Degrees F, Operating Temperature - Minimum 33 Degrees F, Poppet Material Stainless Steel, Relief Type Proportional Relief WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov - Nickel (Metallic)