COMPRESSOR OIL TEST

A color change usually indicates oxidation due to over-heating, or an inadequate lubricant. Not all oil is the same.

An oil analysis needs to be performed to check for TAN, water, viscosity, etc.

You can get oil analysis kits from WearCheck, an international testing lab.

If you want more information, please e-mail me. I can direct you to a lubricant that won't break down like you are experiencing. The oil temperature will probably be reduced 30F, extending equipment life and reducing amp draw.

sir thankyou for your reply ! we are using OEM recommended oil in HPACs and its performing satisfactory but it is also changing its colour and tends to turn black before time of oil change appears so i was wondering whether change of colour is significant in changing the oil or we need to concentrate on TAN, VISCOSITY AND WATER CONTENTS etc any practical example will be help full thanks

How can the oil be 'performing satisfactorily' when it is obviously breaking down before normal change interval? Contamination of some kind may be present, increasing rate of oxidation.

I can assist you if I had a little more information.

Could you supply me with the model and manufacturer number of the unit in question?

In addition, what is the OEM recommended oil you are speaking about?

What pressure are you operating at, and what is the ambient temperature?

If you like you can e-mail me @ rgreenwald@schaefferoil.com .

What type of compressor, application and ambient conditions?

I own rscompressors.co.uk, we do get some oils tested, they check for viscosity, water, but more importantly wear, the samples get analysed and are put under a microscope, we then give the results to our customer, this can save them a fortune as parts are changed before they fail. screw compressors such as compair can use 4000 hour oil on some compressors. really depends on application.

The discoloration is most likely oxidation as stated, thermal breakdown as stated and or contamination that includes water.

Ph will tell you if acidification is taking place. Acid is a major cause of wear.

A good oil analysis will tell you much more. Parts will leave traces in the oil that will let you know which part is wearing. It also tells you how the oil is holding up.

Many oils are only fair or even poor quality until additive packages are blended in to improve the oils performance. If the additive package fails for whatever reason you are left with the base viscosity index to protect your parts.

Smell can be a good indicator of problems. Burnt or off smells will tell you of a problem even when you don't know what the problem is.

Your oil should not be changing color.

I'm not familiar with the application so more detail would only be hit and miss.

Brad

the colour effect might be due to additives, acidity or alkalinity, corrotion, and metal content in the lubricting oil in use, so i will recommend that you should be performing lubricating oil analysis as from 100hrs or < not>300hrs using any of the following methods : (1) atomic absorption spectrometry (AAS) (2) atomic emission spectrometry (AES), with any oil analysis company around your geographical location. the second oil analysis method is very costly but it gives accurate result. you can buy an oil analysis spectrometry and do the analysis in your geographical location it is a good business.

the companies that perform the oil analysis websits are given below:

1) http://www.fugro.com

2) any Tractors and equipement head office in your area.

3)http://www.power-technology.com/contractors/condition/oil-analysis/

4) all society general surveillance (SGS) offices. you can copy item 5 and past on google search to see there websits.

laboratory-equipment.globalspec.com/Industrial-Directory/Oil_Analysis - 78k -

www.oas-online.co.uk

this sights has instructions on lubricating oil change

a)http://www.ehow.com/video_11_change-motor-oil.html

http://en.wikipedia.org/wiki/Oil_analysis

Turning dark is not a reason for changing the oil. someantioxidants in the formulation might change the color and still the oil can be in good condition.

The variables you need to look are:

TBN, a change of 0.5 mg KOH/g from fresh oil is a sign of deterioration, a change of 1 point may be a limit where you want to take action.

Water, up to 0.05% is normal, above that it may cause breakdown and carbonization of the oil. Compressors may have water condensation especially in humid climates. Change the oil when it surpasses the 0.1% mark.

Viscosity is variable with oxidation depending of the oil, it might go down first and then go up. One Viscosity Grade VG higher or lower is the limit in viscosity variation. i.e if you have a VG68 change it if it gets to 46 or to 100.

Fe as iron contamination from wear can be set at a dangerous level when it exceeds 50 ppm. The iron will erode furter the compressor. filter it or change if it gets to numbers higher than that.

Ask your supplier for the fresh oil component levels to check also for additive levels to see if there is any degradation, typically in Zn, Phosphorus, sulphur and others. Change the oil if additives degrade more than 30% to 50%

Hope this helps.

Very true, as the majority of the oil manufacturers add colorants to their formulation to "help" the customer tell when to change their oils. This is more a marketing ploy rather than a necessity.

I'd suggest looking at improving the filtration component. Oil by its very nature doesn't break down (unless overheated), but it is the additive package that should always be topped up. Change your filter more often and/or buy a better quality filter for your application. If you are doing oil analysis, your chance of success may be increased tremendously. You may also check out this website ( www.magneticfiltration.com ), this filtration product improves the delta capture rate of any filter it is applied to

Best of luck