Check Valve In Line Inlet (In.) 1/2 in (F)NPT Outlet (In.) 1/2 in (F)NPT Brass Hold Back Pressure (PSI) 450 psi Max Pressure (PSI) 450 psi Cracking Pressure (PSI) 0.1 psi Hex Size (In.) 1 1/4 in Flow Range Free Air (CFM) 0 to 20 cfm Max Temp (F) 400 Degrees F Vertical or Horizontal Mounting Tap Size 1/8 in for Pressure Switch Unloader Connection Length (In.) 2 7/8 in Stainless Steel Spring Material PTFE Poppet In-Line Check Valve