Vacuum pump oil

[NovaMan]

I work in a chemistry lab at Western Michigan University. To make a long story short, we have been given a nice old vacuum pump. It's a Cenco Hyvac, with a plate on the pump that reads M27922. It consists of a GE 1/6 HP electric motor and the pump unit, both bolted to a heavy iron base. It's all black, and there is no guard for the belt. (Back then, people had enough common sense that a belt guard wasn't necessary.) The oil in it looks good (clear and amber) and everything turns freely, but the pump needs a top up or an oil change. It requires Cenco 11023 vacuum pump oil, which doesn't seem to exist these days. We have lots of Edwards Supergrade A for the newer 2 stage pumps, but I hate that stuff because it's almost impossible to clean up. I sent an email to HyVac, but I thought I'd post here since it's kinda interesting, and I know we have some chemists here.

Anybody know what solvent to use to clean up these new pump oils? Are they silicone based?

 

[Kestas]

Pump oils are typically petroleum based. I use pump oil for the vacuum pump in my lab. Mine is supplied by JEOL. I'm not sure where they get it from. It can be cleaned with regular mineral spirits.

I have a feeling any vacuum pump oil will work in your Cenco Hyvac pump. I rebuilt one once. It may have once had a guard. Somebody probably tossed it when the pump started leaking and needed attention. I don't know what oil Edwards Supergrade A is.

I'm no expert on vacuum pump oils, but I know they are different from your garden variety oils in that it dosen't have short-carbon chain molecules that are volatile under low pressures.

 

[chenobylite]

Fomblin or Krytox are the king of vacuum pump oils. You know something must be special when they charge by weight instead of volume. KInda like illegal drugs. A kilo of Fomblin ain't cheap though. 100% inert PFPE based, Fomblin is made in Italy while Krytox is a Dupont product. Back in my semiconductor days we used to joke that it took a lot of pizzas to make a kilo of Fomblin.

Seriously, they're a total waste unless you're pumping corrosives but you'll feel good in true BITOG fashion

If all you're pumping is ATM then just use a good oil like Inland 19, Technical White, or any pump fluid with a decent vapor pressure.