Vacuum Relief Valves, Vacuum Flow ValvesRelief Valves for Regenerative Vacuum Pumps Model No.: VRV-112-EA Part No. Use with Vacuum Pump Model Number Overall Height in. (mm) Diameter in. (mm) Thread Size VRV-112-EA VB3HF, VB4HF,VB7HV, VB8HF,VB9HV 3.50 – 4.38 (88.9 – 111.3) 2.50 (63.5) 1½” FNPT