OT- Vacuum Pump Oil

[rws]

Tell me the difference in vacuum pump oil? I see prices from 6 to 8 bucks a quart to 90 bucks a quart. How can there be that much difference? I borrowed a pump for my heat pump replacement and have read it's best to have clean oil in the pump.

[CCWKen]

It's all mineral oil but I'm not sure what else they could "add" to it for vacuum pumps. Perhaps it's more of what's taken out by better refining or filtering. I use the Robinair Premium for ~$28 a gallon. There's a definite change in sound and suction when running fresh oil. For automotive use, I run the pump a minimum of 30 minutes to make sure the oil gets hot. This helps burn off moisture even though it pulls <100 micron long before that.

Here's the last batch I bought: http://www.ebay.com/itm/262515793820

[Highpower]

The pump needs clean oil to work efficiently. If the pump (alone) can't pull 50 microns then I change the oil. The cost of the oil doesn't matter as long as it can meet that simple test. If the pump can't do that it's unlikely that it will be able to pull the 500 microns (minimum) needed to evacuate your system.

Some will say you need to change the oil every time you use a vacuum pump. I'm not Scrooge McDuck so I follow the above. JMO.

[EddyCurr]

Tell me the difference in vacuum pump oil? I see prices from 6 to 8 bucks a quart to 90 bucks a quart. How can there be that much difference?

Can you give examples?

My guess is the price difference will come down to 1) branding differences between the refiner's house label and the label afixed for clients refiners bottle product for; 2) pricing practices of vendors in the supply chain.

A 1qt bottle of Mobil Vacuum Pump Oil (ISO 68) from an EXXON outlet might sell at a different price/unit than a large volume retailer who gets the same product packaged under a house brand. Same deal where we are considering a guy selling pints of the same from his basement on eBay or Amazon.

... borrowed a pump for my heat pump replacement and have read it's best to have clean oil in the pump.

Talk to the owner and/or look up the manual for recommendations to determine what brand and ISO viscosity of oil has been/should be used. (You do NOT want to make the embarassing & expensive mistake of using the wrong oil in a borrowed pump.) There will only be a few refiners of the appropriate lubricant, everyone else is along for the ride at the consumer's expense.

For reference, I see Mobil Vacuum Pump Oil in qts for US$10-14 and in 5 gal pails from US$90-110 depending on vendor.

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[EddyCurr]

Incidently, while I have a bit of familiarity with the ISO-68 version of Mobil's Vacuum Pump Oil, today I am seeing an ISO-100 version appearing in search results.

As far as I can tell, the 68 is just labeled as "Vacuum Pump Oil", while the other is called "Vacuum Pump Oil 100". If you happen to settle on Mobil's offering, check the specs before ordering and inspect the product on arrival to avoid receiving/using something other than intended.

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[rws]

This is a Yellow Jacket two stage pump. I'll see if I can find the recommendations for it on line.

[fastfire]

Some will say you need to change the oil every time you use a vacuum pump. I'm not Scrooge McDuck so I follow the above. JMO.[/QUOTE]

I use a vacuum pump with the freeze drier and change the oil every use.
I just don't remember the brand but it cost about 28.00 a gallon.
I use a slightly modified automotive oil filter to clean the oil after I freeze the oil to separate the water.
To freeze use an open top container that you can spoon the frozen oil out and at the bottom will be the frozen water(ice) to discard.
Let the oil warm to room temp them filter and reuse.
https://harveyfilter.com/how-it-works/ I made the filter set-up that I use.

[macona]

Just pick up mechanical pump oil from Duniway stockroom or LDS Vacuum.

All of those are cheap compared to the oil one of my pumps use, 50ml is $150.

[CCWKen]

Just pick up mechanical pump oil from Duniway stockroom or LDS Vacuum.

All of those are cheap compared to the oil one of my pumps use, 50ml is $150.

That's what the OP is trying to determine--Why is 50ml $150? What makes it different from the cheap ones. I'd like to know also.

[macona]

Its Fomblin, a fluorinated fluid that is non reactive to just about anything. The main use is for pumping corrosives or oxygen. If you are pumping on a plasma etch unit that uses 02 then you cant use the generic mineral oil pump fluid or bad things can happen. Sometime you will see vacuum pumps marked "fomblin prepped", that means the entire pump side of the vacuum pump was taken apart and thoroughly degreased so zero hydrocarbons remain and the pump was reassembled with fomblin to lube everything.

If you are using a oil sealed rotary vacuum pump for something like a freeze dryer you are using the wrong kind of pump, you should be using something like a wet ring or scroll pump that is oil free.

[drmico60]

If all the mechanics of the pump are working well then the ultimate vacuum attainable will be set by the volatility of the oil. If the vapour pressure of the oil is 1 torr then the pump will only be able to achieve a 1 torr vacuum. If it is 1 millitorr then a vacuum of 1 millitorr should be achievable. Thus a good high vacuum oil must be highly refined in the sense that all the lighter volatile components must be removed and this costs money to do. There is no point though in producing higher vacuum than actually required so the oil must be selected to suit the purpose.

[boslab]

Just pick up mechanical pump oil from Duniway stockroom or LDS Vacuum.

All of those are cheap compared to the oil one of my pumps use, 50ml is $150.

I know what you mean, I used to replace the oil in the Edwards vacuum pumps on the spectrometers in work with new clear mineral oil from Phillips aka panalytical, a litre bottle was about $500 plus vat.
I often wondered if ordinary vacuum oil would have done just as well but was too scared to try, I didn't fancy wiping out a 400k machine, easily done.
However the oil looked the same, I used the old oil for miscilanious hinge oiling, sharpening etc, worked good on a sharpening stone
Mark

[EddyCurr]

If all the mechanics of the pump are working well then the ultimate vacuum attainable will be set by the volatility of the oil. If the vapour pressure of the oil is 1 torr then the pump will only be able to achieve a 1 torr vacuum. If it is 1 millitorr then a vacuum of 1 millitorr should be achievable. Thus a good high vacuum oil must be highly refined in the sense that all the lighter volatile components must be removed and this costs money to do. There is no point though in producing higher vacuum than actually required so the oil must be selected to suit the purpose.

Thank you for this post.

It educated me on its own and opened up lines of inquiry I have only begun to follow up on.

.

[rws]

I bought a quart of Yellow Jacket vacuum pump oil (Yellow Jacket pump) from the supplier I went to for my line set. Cost $8.60. Clear as can be. Whether good or bad, I'm changing the oil in this pump to do my unit.