Which oil or grease will work the best?
Which oil or grease will work the best?
(OP)
We are building an air amplifier for a customer that runs 24 hours a day 7 days a week in an environment that has temperature variations from 0°F to 150°F. This unit pumps 450 psi air, which generates temperatures of about 400°F at the high pressure seal. Our original testing was done with Chevron Supreme 30 Wt motor oil wiped on the seals and bearings. The unit ran 1.2 million cycles, and was dissembled. The Viton high pressure seals and the filled nylon bearing showed significant wear and little oil was left. There was evidence of varnish and carbon at the top of the high pressure barrel. We assumed the oil was burning. The low pressure urethane seals and filled nylon bearing showed little wear and still had oil present.
A group decision was made to use Dow 111 grease, used by another pneumatic valve manufacture, this grease migrated into other areas and caused a functional failure.
The customer wants us to use Mobil DTE oil or Magnalube-g, a grease. We would like to use a 2 stroke motor oil. Our thoughts on choosing the 2 stroke oil is, clean burning, low varnishing, good high temperature stability, and will not cause functional failures if it migrates out of the area needing lubrication.
Our customer is concerned with the detergents in motor oils causing seal failures.
Please give reasons to support any of these lubricants, of suggest another.
Thanks in advance,
Ed Danzer
A group decision was made to use Dow 111 grease, used by another pneumatic valve manufacture, this grease migrated into other areas and caused a functional failure.
The customer wants us to use Mobil DTE oil or Magnalube-g, a grease. We would like to use a 2 stroke motor oil. Our thoughts on choosing the 2 stroke oil is, clean burning, low varnishing, good high temperature stability, and will not cause functional failures if it migrates out of the area needing lubrication.
Our customer is concerned with the detergents in motor oils causing seal failures.
Please give reasons to support any of these lubricants, of suggest another.
Thanks in advance,
Ed Danzer





RE: Which oil or grease will work the best?
I believe that synthetic will work the best. If you are interested in using Amsoil, email the Technical Dept. at tech@amsoil.com and I'm sure somone there will give the credentialed reply you are looking for. (I'm at www.lubedealer.com/hiebert if you need it)
RE: Which oil or grease will work the best?
400 F for any sump oil is quite high. Varnish and carbon are sure signs of oil oxidation.
A custom lubricant might be in order. As previously suggested, synthetic base stocks outperform mineral oils at these high temperatures. However, the additives in motor oil or grease may be unnecessary for the air amplifier and you may create problems. One very capable grease manufacturer is William F Nye. (No, I don't work for Nye.)
It is interesting that one air amplifier manufacturer, Haskel, notes that they don't use lubricants!
RE: Which oil or grease will work the best?
RE: Which oil or grease will work the best?
RE: Which oil or grease will work the best?
I can supply info on a 85% bronze filled nylon that might eliminate the need for oil, but I am commercially involved with it's manufacture and supply, so I should not use this site for promotion.
If you need more info contact me directly
Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Which oil or grease will work the best?
Your material is interesting, but the air valve must be lubricated and the people we have designed this for don’t want to do anymore material experimentation. We tried a bronze filled Teflon seal and it failed quickly.
But for other projects please send material information to ed@danzcoinc.com
RE: Which oil or grease will work the best?
RE: Which oil or grease will work the best?
If my role was lube only, I'd be thinking that at one time garden variety ATF had some pretty impressive hi-temp characteristics compared to motor oil of the same vintage. The Turbo era may have changed that. I'd guess Mobil synthetic ATF might be the high mark.
I'd also call Kluber. http://kluberna.com/
I'd drip a little DTE , few regular and synthetic motor oils and ATFs on an aluminum plate at 400, 500, and 600 F to see where they smoke and char.
Sure would be nice to be able to cool that area off a bit.
With compressed air close by maybe some would be available for cooling.
I have little love for "bronze" as a bearing. In order to make it survive in marginal lube conditions the recipe has to be chock full of lead. It expands when hot, so when mounted in a substantial housing the ID shrinks and grabs the spinning shaft "until the sparkles come out."
RE: Which oil or grease will work the best?
The current operation is to inject a small amount of motor oil in the air stream. It will be several months before more details are available.
RE: Which oil or grease will work the best?
RE: Which oil or grease will work the best?
RE: Which oil or grease will work the best?
Is she worried about the Viton seal? I think Viton will explain they have no fear of motor oil.
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Is there a way to run another line to apply minimal oil to the seal directly? Or are ther other areas that need the bulk oil ?
RE: Which oil or grease will work the best?