Blower Relief Valve Vacuum Capabilities Vacuum Preset Limit 190 in wc Outside Diameter 6.9 in Inlet Size 3 in Inlet Type NPT Compatible Manufacturer Part Number 2EPT6 2EPT7 Compatible Grainger Part Number 2EPT6 2EPT7 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 8.2 in