Sciencemadness Discussion Board

vacuum oil

soma - 26-7-2017 at 04:15

Is there a generic alternative to welch duo-seal vacuum oil?

Thanks.

XeonTheMGPony - 26-7-2017 at 04:47

I been told Hydraulic jack oil works well, I have yet not had a chance to test it, Nucalgon vac oil is pretty good quality.

Any high quality hydroshocked oil with low vapor pressure will work less the pump needs certain anti wear additives or detergents, and from what I have seen vac pumps don't

Just don't use differential oil! or the Molidium sulfide will reek up the shop fast!

NedsHead - 26-7-2017 at 06:19

I use this http://www.penriteoil.com.au/products/indus-pro-hydraulic-32

OldNubbins - 26-7-2017 at 06:20

If you are in the U.S., NAPA auto parts sells vacuum oil in their stores - I think I paid around $4-5 per quart. It appears similar to the AW32 hydraulic oil I have, just a little lighter amber and no odor.

JJay - 26-7-2017 at 12:47

I get vacuum oil at NAPA as well. They don't usually have it on the shelf, but if you call ahead they can have it ready for you in a few hours.

soma - 27-7-2017 at 13:15

I called NAPA. It seems they're using the vacuum oil for a/c comprewssors so I'm wondering if just getting a/c/ compressor oil is the same thing.

We've got a Welch 1400 rotary vane pump.

[Edited on 27-7-2017 by soma]

XeonTheMGPony - 27-7-2017 at 17:11

No the oil is for the vacuum pumps for dehydrating the AC system. Actual compressor oil for refrigerant systems use polyoether, polyglycol (PEG) Alkylebenzene for R 22 some of the 400 series will take that as well, Mineral for R-12

and some fun mixtures there of, most are hydroscopic and absorb a surprising amount of water in a short amount of time

soma - 28-7-2017 at 02:40

There's no NAPA real near where I am. With shipping it costs $2 less than the welch duoseal oil.

There's no generic source?

[Edited on 28-7-2017 by soma]

Sulaiman - 28-7-2017 at 02:59

In my inexperienced opinion,
if you need to get the absolute minimum pressure that your pump is capable of, then the care and choice of oil may be critical,

for chemistry you will neither need nor be able to achieve this vacuum level, pvc tubing is porous to air, joints leak, liquids evaporate....
and unless you have cryogenic traps etc. your oil WILL get contaminated and require replacing more often than you would wish.
So I think that you should just buy the cheapest vaccum oil that you can find.

AvBaeyer - 28-7-2017 at 19:02

I have been using Mobil Vacuum Pump Oil which I purchase from Zoro Tools. My cheap little pump will easily pull 0.1 mm Hg or less direct on the gauge and 1-1.2 mm on a properly set up distillation system. The oil is listed on Amazon or can be purchased direct.

Hope this helps.

AvB