Blower Relief Valve Vacuum Capabilities Vacuum Preset Limit 163 in wc Outside Diameter 5 in Inlet Size 2 in Inlet Type NPT Compatible Manufacturer Part Number 2VFB40-3.42-7W Compatible Grainger Part Number 38UW83 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