Mist coming from my vacuum pump.

[Nick Rocco]

I tried my Robinair 15310 vacuum pump for the first time and it is emitting a fog or mist when running. Is this normal?

 

[CREID]

I have heard of some vacuum pumps putting out an oil mist. Whether it is normal or not, or good or bad, I have no idea. Sorry I couldn't help.

 

[Jim15]

I called Robinair about that and the man I talked to said it was normal. I have heard other people on this site say they do not have that problem but I do.

 

[jsmithmarcus]

Same here...my Robinair puts out a fine mist for a bit on startup but it finally clears. I read somewhere that this is normal.

 

[endacoz]

Mine only mists when when it is "working" or getting up to full vacuum. So the first 10 minutes of me turning the pressure on and off as the mass of bubbles settle down it mists a lot, but one it is up to pressure my robinair can sit there for hours with no misting.

 

[MesquiteMan]

What are you using for a chamber, Nick? Any oil filled vacuum pump will put out an oil mist when it is moving any amount of air, primarily when you first start up. Once you get down to full vacuum, the mist should stop. If it does not, that usually indicates a leak in your system somewhere. Use shaving cream on all places where it could leak and then pull a full vacuum with the chamber empty. If you have a leak, the shaving cream will disappear at the leak.

Please disregard any of the crap about how hazardous the mist is that you may see on the net in different forums and youtube. Vacuum pump oil is simply highly refined mineral oil and the MSDS is totally benign. In other words, the mist will not hurt a thing and is not dangerous at all.

 

[Nick Rocco]

Thanks for all of the great input.

 

[robutacion]

I tried my Robinair 15310 vacuum pump for the first time and it is emitting a fog or mist when running. Is this normal?

G'day Nick,

While you already had the answer to your question, no one had given you a possible solution to prevent the oily fumes to spread around and possibly contaminate wood or something else that will react badly from light oil contact so, I have had this issue since I first started stabilizing and while not hazardous to your health, you may want to prevent those fumes to get into the air and for that, I come up with a very simple and cost free solution.

Gave a look on this thread post #93 and you will see what I mean.

Cheers
George

 

[RedBeard]

I've worked in the HVAC/R industry for quite a while and have used vacuum pumps extensively. When you take into consideration the intention of the vacuum pump then any "misting" is not only normal but to be expected.

I distinctly remember my very first pump had a carry handle that doubled as the exhaust port. That port would get oily to the point of the foam that was wrapped around it would would tend to slide off....makes for a hairy situation when you're lugging it 20 feet up onto a roof.

 

[More4dan]

I minimize this by pulling a partial vacuum with my air operated brake bleeder before kicking on the ac pump. Changing the oil that first came in my HFPump to a name brand oil also helped.