For compressed air to fill breathing apparatus, we would want an oil-free compressed air. I have asked above what is the specified allowable limit of oil content in the compressed air for plant air usage. I think for instrument air usage, the alowable oil content in the compressed air is tighter. I think answering this question may lead to the root cause of the high oil consuption regardless whether to change the oil or not.

Allowable limit of oil in compressed plant air?
Does this exist? In general we need to add lubricators to prevent air operated equipment to seize.
The moisture contained in the air is a far more bigger concern.

James, you made us very curious, what type of equipment is this, power consumption, is it water cooled, etc..
I could think of the cooling system not functioning properly, carrying oil and water out of the compressor. Do you have an oil cooler, knock-out box etc..

james do yo have oil recovery on your drains - this could indicate excessive oil carry over - or else check for oily fish!

Mike.

James F.
If the product you are talking about is the PAG/Ester blend then that is that particular compressor manufactures selling cost. There is a direct replacement for that product from Summit lubricants (down in your neck of the woods) You might want to contact them. The cost differential for us was around a 45% decrease is base cost.
The product meets the OEM compressor manufactures specifications and hence warrantee cannot be witheld (legaly)

BTW we eventually changed out this manufacturers rotary screws and no longer require this very expensive lube.

regards.......

Sorry. I've been away on a few trips this month, and also training.

svanels: I don't want to give anyone the manufacturer, or the lube since it is proprietary, and I would rather not give anyone a bias against the manufacturer. That of course is not my goal. My goal is to make sure that our equipment is cost effective, and is reliable. Your Q's on water cooled and knock out box I'll have to get back to you on....

Mike66: We do not have oil recovery on our drains. Obviously, we have the oil separator on the system, to take the excess oil from the process, instead of sending it down the line.

Alan Wallace: The product is a silicone based oil. That is the reason for the high cost. I just don't see the value in paying more for oil than gold, when you could get by with an equivalent PAO or PAG/Ester blend as you mentioned. If it provides the same lubricity, then why spend your life savings on that kind of gold, oops, sorry, I meant to say oil. :-)

My ability to concentrate on this air compressor oil issue has dwindled due to other significant issues in our plant. Not only that, I have a baby coming and a new house to move into that will suck time as most of you know. The comments and questions are great! Please, don't stop them from coming. I will look into your questions when I get a chance.

James,

Silicone based lubricants are indeed expensive, and the price you noted seems typical. However, you have a wide variety of options available that can work in typical screw service. PAO, Ester and Blends have been used successfully for many years in screw service. When (if) you make a change be REAL careful to flush the system down completely. Some of the silicone based fluids aren't miscible with lubricants of any sort.

RE: Advice provided earlier suggesting that the OEM's select the lubricants from small 'performacne lubricant manufacturers': I would agree. Compressor OEM purchase 're-sale' based on a perforamcne standard at a price. As such, there are a good many folks that make products that will fit the bill, even if you can't purchase directly from the same exact supplier.

RE: comment provided earlier suggested that the volume seemed high: Again, I agree. I would sure have an engineer verify demister performance and make sure my service agent was maintaining the system according to OEM specs. I would also have a leak check conducted on the machines. These tend to shake fitting loose over time. Lots of the leaks are easily ID'd and stopped with routine inspection.

One last thought: if you want to extend power head lifecycle, improve the quality of the filtraion on the intake. The OEM intake and oil filters are overwhelmed with the dirt load passed in/through the air stream, and as such, leaves the lubrication system in a perpetual state of elevated contamination. Bring the ISO code down and you can add appreciably to bearing life.

Regards.

M. Johnson
mjohnson@amrri.com