$Vacuum/Pressure Relief Valve OUR Part# FF5Z764 INLET SIZE: 3/8" N.P.T. MALE PIPE THREAD Flow Capacity 0-15 CFM Pressure Range 0 to 20 PSI Vacuum Range 0 to 30 Inches Hg Max Temp 250 F Brass Body Material POPPET WITH SEAL Stainless Steel Spring Material Hex 11/16" Length 2" Easily Convert from Vacuum to Pressure Relief by Reversing Poppet and Spring. Item Vacuum/Pressure Relief Valve (M)NPT Inlet (In.) 3/8 Flow Capacity (CFM) 0 to 15 Pressure Range (PSI) 0 to 20 Vacuum Range (Inches Hg) 0 to 30 Max. Temp. (F) 250 Body Material Brass Poppet POPPET WITH SEAL Spring Material Stainless Steel Hex (In.) 11/16 Length (In.) 2 Function Easily Convert from Vacuum to Pressure Relief by Reversing Poppet and Spring On Oct-11-11 at 01:17:10 PDT, the following: On Oct-11-11 at 01:17:15 PDT, the following:.