Multi-vane throttle valve

A multi-vane throttling valve for a vacuum process chamber includes a throttle chamber body having an inside exposed to the vacuum process chamber and an outside exposed to atmospheric pressure, the chamber body defining a through-opening for controlling vacuum within the vacuum process chamber, a plurality of rotatable vanes mounted within the through-opening for controlling a flow of gases through the through-opening where each rotatable vane includes a cooling flow pathway in fluid communication with and disposed longitudinally along each rotatable vane, and a drive mechanism disposed on and connected to an outside of the throttle chamber body for rotating the plurality of rotatable vanes to vary the flow of process gases.