Blower Relief Valve Vacuum Capabilities Vacuum Preset Limit 150 in wc Outside Diameter 5 in Inlet Size 2 in Inlet Type NPT Compatible Manufacturer Part Number VFD5-H VFD5-L VFD6-H Compatible Grainger Part Number 22NX92 22NX93 22NX95 Maximum Operating Pressure 28 in Hg Minimum Operating Pressure 1 in Hg Maximum Operating Temperature 400 Degrees F Minimum Operating Temperature -20 Degrees F Overall Length 5.81 in