A valve whose sealing plate slides across the bore and presses against a seat, leaving an unobstructed opening when open. Gate valves sit between a chamber and its high vacuum pump, so a turbo or cryo can keep running while the chamber is vented, and between load locks and process chambers on cluster tools. Production versions are pneumatic with position switches and have a maximum pressure difference they may be opened against.
Close the gate valve before you vent, I don't want to crash another turbo this month.
Check the pressure difference before opening; a gate valve opened against a big pressure difference can damage its seal and send a gas slug into the pump.
Also heard as
- gate
- hi-vac valve
Related terms
Crossover
Point in a pump-down where pumping switches from the roughing pump to the high vacuum pump.
Turbomolecular pump
High vacuum pump whose rotor blades spin at tens of thousands of rpm and bat molecules toward the exhaust.
Load lock
Small chamber that is pumped and vented to pass parts in and out without venting the main process chamber.
Crash a turbo
To wreck a turbo pump's rotor by letting it hit the stator, most often by venting it hard while it spins.
Effective pumping speed
The pumping speed actually delivered at the chamber after losses in the connecting pipes and valves.