Oil Filter micron

[Iceehot]

Curious what micron rating of oil filters others use.
I currently use the compressor package manufacturer's recommended micron rating on my screw compressors. I have filter salesman wanting to sell lower Micron ratings with the sales pitch of benefits. I have attended a couple of hydraulics classes and I can see the benefit of lower micron rating and cleaner oil for hydraulics which then makes me think about internal of compressor and oil on journal bearings etc.
What Micron rating do you use and thoughts of lower Micron ratings?
Thanks

[NoNickName]

10um which is also automotive standard

[tarcau mihai]

hello
few yrs ago we overhouled a grenco chiller working with r22 screw compresor...that one has a oil pump and what i remember it was that on suction side of oil pump it was 40um and on discharge side it was 25um...

[US Iceman]

If the compressor is one that has been running for a while, the particles that passed through the previous filters will already have done damage to the bearings.

So if a better filter is used, it would only prevent further particles from doing more damage.

The best time to use higher filtration filters is when the system is new. However, whatever filters you do use specify them as absolute filters for a particle size. Some filters are rated nominal particle size, which allows some by-passing to still occur in the filter.

[Iceehot]

I am planning on a few overhauls soon, want to change oil, filters and coalescers while down. Thinking of better filters on one package to do side by side tests. Need to show the extra expense of filters vs. cleaner oil to bean counters.

[US Iceman]

One thing to be aware of is; the higher filtration capacity of better filters may appear to clog up faster than the old style you are currently using. The better filters start to clean the system up and as a result plug up faster than what you might expect.

Something to watch out for...

[nh3wizard]

I am planning on a few overhauls soon, want to change oil, filters and coalescers while down. Thinking of better filters on one package to do side by side tests. Need to show the extra expense of filters vs. cleaner oil to bean counters.

Aren't oil and filter changes recommended for warranty purposes by the company doing the re-builds?

It must be tough working for a company that scrutinizes a relitively small expense as oil filters compared to having to buy a new compressor.

[Iceehot]

[quote=nh3wizard;119386]Aren't oil and filter changes recommended for warranty purposes by the company doing the re-builds?
Yes, I am planning on changing filters and oil. But want to try smaller Micron, Absolute rated filters on one of the packages to see the difference. There is big difference in price for a small micron rated filter especially if I start going through several of them as system cleans up.
It makes a lot of sense for very clean oil on a hydraulic system as everything is turned, pumped, moved with oil. On screw compressor there is a lot of oil used for journal bearings, seal between rotors, mechanical seal etc. So I want to try it.

[RANGER1]

Why not try an oil bypass filter instead.It continually cleans the oil without main filter blocking up .
If you change oil charge , having a fresh start and a fine bypass filter taking a small quantity of oil through it off discharge of oil pump returning back into oil seperator.
Normally a nominal 20-25 micron oil filter is ok. The bypass filter could be 5-10 micron circulating oil charge every 8 hrs or so.
Sabroe recips used to use this method with very good results.

[keepitcool]

I was also going to suggest what RANGER1 did. We have done this as well. we put it in as a full time side stream filter pulling right off the bottom of the separator. It helped keep the oil clean. I can direct you to a source if you like. Just PM me.

[Magoo]

The compressor manufacturer will state what micron rated filter for oil is required. Generally in the 25 micron region.
If you are short of work try 10 >15 micron and you will be busy changing oil filters monthly.

magoo

[refteach]

I agree with Magoo, all of our filters were in a 25 micron range on our new equipment, when we switched to a 10 micron filter on smaller screws there were some instances that the filter would not last two or three days. We had to increase the surface area dramatically in order to get a decent life out of the filter. You also have to think about cold oil at a cold start, even with crankcase or separator (screws) heaters the the 100 degree oil only lasts so long and it gets real viscous fast until the machine warms up.

[NoNickName]

Wrong. The oil must always be warm even the compressor is off. If you need 25um, then it means the system is dirty. We install 10um on our compressors.

[M.Amer]

bitzer sn-6461-60 screw's 25 um

[US Iceman]

When screw compressors are shut down the sump heaters try to keep the oil warm. However, the oil in the external piping and filter housings and oil cooler can become colder. Therefore when the compressor starts with high filtration elements the cold oil can produce start-up problems due to increased viscosity along with the higher rated filters.

It's a problem to watch out for...

[gwapa]

Iceehot
I think you should first analyse you oil with a Qualify Lab. With this analisys you can predict a very nice mantenance and also you can know the size and type of partiquels that are running in the system.
According with the lab analisys you can select an oil filter por a period of time and then make another oil analisys to observe what is going on the system.
regards
Gwapa

[hendry]

hi, everyone ...
it's holiday seasons in my part of the world ... Muslim's holidays after 1-month long fasting.

coming back ...

how fine should the filter be?
what's your bearing suppliers say? that should be the 1st consideration.

2. know your source of contamination.

3. do an oil analysis.

4. bingo .... 20 micron might do the works.

;)