Vacuum Pump Isolation Valve (VPI)
Agilent TechnologiesAgilent vacuum pump isolation (VPI) valves are inlet protection valves that electrically connect with the mechanical pump. The valves close rapidly when power is interrupted to prevent oil backstreaming or particle migration into the vacuum system. They also vent the pump from the inlet side, pushing any debris towards the outlet, and preventing it from being swept into the system when pumping is restarted.