Recent content by Bladestein

We pull a vacuum to approximately 200mTorr and then leak check for 1 minute. We get leaks of 20-50 which in my opinion is no good. We helium check for leaks but even if we had a leak up of 20 the helium check finds no leaks. The end result is out of spec oxygen on our final product. We could...

Air has been purged from the system in theory. System pulls vacuum to remove air then back filled with argon. But when backfilling is air being pulled in also.

Pressure line.

I have an argon line used for atomization and backfilling a VIM melting chamber. If there is a leak on the argon line (at a fitting, valve, etc), will this leak actually draw in air when gas is turned on and flowing through pipe creating a mixture of argon and air?

Not sure. I am physically using a metal stick to stir.

Why am I not shocked when I stir the molten metal bath of a 1000lb induction furnace? Alumina crucible used.