Fusor Forums

You method is good and how I do it. I valve off the fusor chamber to diff pump inlet. (fusor left under vacuum. I then turn off the boiler in the diff pump and monitor the diff pump boiler temp until it drops to below 80 deg C, then I valve off the diff pump outlet to the mechanical pump inlet. (diff pump left isolated and under vacuum. Last I turn off the mechanical rotary pump and immediately un-clamp the hose to the mechanical pump and foreline. I let the foreline and mechanical pump up to air for 1 second (woosh!) then immediately re-clamp the foreline to pump.

I also have a ball valve on the mechanical pump's outlet. I immediately close this valve so that no air can enter the turned off rotary mechanical pump until the next time I use it.

Naturally, the first action on any restart is to open this ball valve to allow the rotary to exhaust properly while running.

Richard Hull