A fix for our Atlas Copco varnishing problem

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I have been fighting a varnishing problem with one and really all of our Atlas Copco rotary screw air compressors. I was getting high ISO readings in the 4 to 10 micron spectrum, as you can see in the image I uploaded. The Atlas Copco service thought I was nuts as did a private company that fixes them and is kind of a partner with Atlas Copco smaller units that I consulted in my area. I was wanting to filter with better OEM filters or even some high end Donaldson filters but zero info was or really could be given to me by Atlas for what I assume are political reasons and lack of never testing Donaldson filters for approval to work in severe case scenario. I just knew something is wrong here and I went through 3 different oils, Schaeffer's that couldn't handle the heat and broke down with some surface gelling on an older unit I tested it on and was told later by the smaller firm it varnishes right up, pull it. Pulled that before I got his info because of the outcome that was obvious.

I got ZERO help from Atlas Copco and the small private tier company on this. I found a seeping bearing cap on top of the motor when just out of warranty and was going to start to use the small company and asked them to repair it because at the time I thought I was getting air pulled in from somewhere or some kind of micro-dieseling. They completely ignored me, I then went to Atlas Copco and wanted them to fix it and they completely ignored me, even after giving PO's too fix it. No, help saying to me hey ___ this happens on all of them really you don't need to fix this we see this all the time. They both thought I was a nut job. I have one of the highest credited labs in the country with 2 MPC test stating I have a major varnishing problem. And I am ignored!! Granted I was on a learning curve but as having an ex-hobby Audi repair business I am very mechanically inclined and I am the maintenance guy at our 100 person plant. All they wanted me was to "run the shmit out of it" and ignore the problem. The problem of just not a rotary screw unit, but also a variable speed motor that gets cooled by this oil that is filled with varnish basically shot peening the bearings with this micro-fine varnish particles. The varnish is not as degrading to the bearings as wear metals, long term circulation of ultra high values will kill those bearing early. So who gets to pay for the new $8,000 assembly when it goes down early in life from dirty oil and bearing wear/heat issues. Certainly not them? My company will, and they will make the profit. I even got a Noria Corporation free 30 min consultation and 2 paragraph comment that after studying my 12 at the time analysis tests my unit is destined for a very early failure. They stated this problem needs to be dealt with ASAP.

Then I went to Summit Industrial oil earlier on in this process, a Kluber company. I was told their SH-46 would work a PAO with some Ester. That didn't work either, as far as my testing. I ran two different MPC varnish tests that proved I had an issue going on. Atlas ignored my findings as did Summit because they thought I "had too much information" overload. That all just said run the SH-46 and when you hit a certain acid level from our free lab testing change it out. They discounted my MPC tests "because we don't look at that test" I got from them,"run the [censored] out of it." Even though they have a better oil, Summit Ultima, a group 5 Ester based (POE) for $50 more per 5 gallon. He didn't think I needed that. No you don't need that our SH-46 is more then enough. "Just run the [censored] out of it."

Well, I did another cleaning with Summit Vanasolv in this problematic Atlas and used Summit Ultima. It appears to be the ticket to fixing what I can only suspect is a hot spot or hot spotting some where in the unit. Notice the Unit hour time and the oil hour time.

Test #9 and #10 is Atlas Copco Roto-Xtend OEM (PAO)

Test #11 and #12 is Summit SH-46 (PAO with some Ester)

Test #13 and #14 is Summit Ultima (POE)

 
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What size atlas copco? How many hours on the separator and is the temp probe for the separator working properly. Are there hot spots on the separator pressure tank? If the separator is defective, damaged or near EOL varnish will form quickly from the excessive heat. Is there any oil crossover into the airlines?
 
Originally Posted By: 03cvpi
What size atlas copco? How many hours on the separator and is the temp probe for the separator working properly. Are there hot spots on the separator pressure tank? If the separator is defective, damaged or near EOL varnish will form quickly from the excessive heat. Is there any oil crossover into the airlines?


GA15VSD, The machine has had about 4 oil filters and 4 separators spin-on filters in the 8,000 hrs. Temp prob appears to be working fine. I lasered everything and nothing gets passed 195 deg. Fan kicks on at 192 deg. Very little oil carryover, same with other GA22 VSD after compensating for size difference. GA15 VSD (20hp) has a 1 gallon oil tank. GA22(30 hp) has a 3 gallon tank. I have all my unit to throw warnings at 199 degs and auto shut off at 201 degs. I want people to call me or warn me we lost air if it gets to those levels. Our older 10 hp one ( partially clogged oil cooler Runs fine at 90%) I tested the schaeffer's on was set at the factory knock off which is WAy to high and that happen. That's why I revised all units to 201 degs auto stop before it can stress out the oil.
 
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We have the non VSD 15hp and 30hp with integrated dryers. 22k and 49k hours. Had the varnish problem on the 15hp at about the 10k hours mark and when we pulled the separator, we found an area that had what appeared to be flattened separator media over about 15% of it's media area. The 15hp ran about 4 degrees hotter on outlet temp than the 30hp, nominal output temps for both units is 185, the 15hp was hitting 190 1/2 way through it's oil change cycle so we pulled the separator and found that to be the cause. We have used the atlas copco oil & filters since day one and except for the one problem with the separator, we've never had a varnish problem. Our units are isolated in their own room with ventilation fans keeping the room within a couple of degrees of outside area temp. During winter months we blend the air into the room to never drop below 55 degrees.
 
How hot does the oil get..?

It might help to install a really fine offline/bypass filter that can deal with particles down to 2-3 μ and acid as well.
In northern europe filters from CC Jensen are very popular in the offshore and wind power industry. https://www.cjc.dk/system-solutions/marine-offshore/
You should be able to find a manufacturer that make similar filters in america.
 
No need for acid filtration, it is a group 5 Ester in comes that way, :"the nature of the beast." I had a killer high end custom kidney loop setup with beta 2000 Donaldson filters, the unit could be quick changed to what ever compressor was running, the CEO denied the purchase. $1,300. Remember I am the nut job ;-) ....... The plant manager says his friend's VW diesel is still going at 350,000 miles there is no need for the kidney loop, let alone me finally figuring out the oil varnishing issue.
 
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No, none of that is in #158 and there is a reason why. European rotary screws are smaller and run higher rpms then USA designed screws and tax the oil more because of it. Schaeffer's is not a "high" group 5 base stock oil company. Schaeffer's is a group 3 - group 4 company. So far, I have solved my problem using Summit Ultima. Didn't you read the oil analysis above?

http://www.technologylubricants.com/Technical/Summit Ultima.pdf

https://klsummit.com/products/lubricant/ultima-series


Before Kluber bought Summit, Summit started it's life specializing in compressor oils, Schaeffer's is not.
Summit also has a cleaner that is used worldwide and is the "go to" for compressor companies that have varnishing problems.

https://klsummit.com/products/lubricant/varnasolv

.
 
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It isn't surprising you are not getting much help from atlas. I have worked on several styles of their compressors and they all have some dumb issue that they can't fix. You are going to have a very hard time getting any go from them or finding a non atlas replacement part. They don't like to share any info with the end user.
 
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