Significance of Lubricant Testing
Significance of Lubricant Testing
(OP)
I am attempting to modify our testing procedures to eliminate routine QA testing for lubricating oils, greases, hydraulic oils, etc. Typically, these products are purchased by our maintenance sections for use in Department vehicles and equipment. We typically run flashpoint, viscosity / viscosity index, and pour point.
On a typical product, will these tests really give any good information? Can a company manipulate these numbers (mainly viscosity and pour point) to pass specifications while using cheaper materials? My speculation is that the testing we perform won't make much of a difference if we specify products listed on the API website of licensed products. If we eliminate testing of these products, we will have more room for other, more important testing equipment.
Also, for large diesel engines (ferry boats) will something like Total Base Number, possible TBN after 500 hours of use, give a good indication of quality for these harsh engine uses?
Thanks.
On a typical product, will these tests really give any good information? Can a company manipulate these numbers (mainly viscosity and pour point) to pass specifications while using cheaper materials? My speculation is that the testing we perform won't make much of a difference if we specify products listed on the API website of licensed products. If we eliminate testing of these products, we will have more room for other, more important testing equipment.
Also, for large diesel engines (ferry boats) will something like Total Base Number, possible TBN after 500 hours of use, give a good indication of quality for these harsh engine uses?
Thanks.
Jason Davis
Louisiana Dept. of Transportation
Materials Laboratory





RE: Significance of Lubricant Testing
one other thing to bear in mind is that these tests are only simple checks to see whether the product conforms to some simple measurements - and they are certainly not an alternative to the extensive (and very costly!) bench engine testing that is required for API or ACEA approval.
In other words: what you are testing now will very rarely show any anormality, and is no indication of quality whatsoever.
RE: Significance of Lubricant Testing
Materialsguy,
Quality assurance, aka QA, is an expression used by oil manufacturers operating under the ISO 9000 regulations. If the supplier is accredited under one of the QA systems, and most are, one could trust in that the purchased products answer to reported specs and avoid re-checking them in one's labs.
However, we should remember that even "functional" lab bench tests, although valuable as predicting tools on how a specific lubricant will perform under variable operating conditions in full-size machinery, are not infallible or foolproof.
In fact, it is usually on the basis of the lube behaviour in the end-use item that many OEM will "recommend" a brand name to be used in their equipment.
Having said that, I agree with your lab bench testing suggestion in addition to the more conventional tests to be carried out on "used" oil samples. I've read elsewhere that even ASTM recommends carrying out TBN testing on samples of oil taken from the crankcase to check the level of remaining alkalinity in marine diesel engine oils particularly when high sulphur fuels are used. Same samples could be submitted to testing of viscosity, flash point, sulphated ash, pentane and benzene insolubles to verify the suitability of the oil for further service. Good luck.
RE: Significance of Lubricant Testing
Thanks again!
Jason Davis
Louisiana Dept. of Transportation
Materials Laboratory
RE: Significance of Lubricant Testing
RE: Significance of Lubricant Testing
RE: Significance of Lubricant Testing
Used oil testing is critical in expensive and critical components.
Speak to your lube supplier as to what tests should be performed to give you the information you need.
As a guide test engine oils for viscosity @100 deg C, wear metals by ICP, TBN, Soot level, PQ and fuel dilution by flash point or GC.
TBN retention is important but more so if using high sulfur fuels.
RE: Significance of Lubricant Testing
RE: Significance of Lubricant Testing
RE: Significance of Lubricant Testing
But oil analisis is really about determining maintenance intervals and proactive maintenance opportunities, discovering problems before they become major issues or stop production.
RE: Significance of Lubricant Testing
Testing used oil quality is one thing. Testing oil quality as it is received is another. If you are talking about ferry boats etc then how is your oil delivered? if it is in factory sealed drums, testing may not reveal much useful data. If it is delevered from a fuelling barge, from tanks on board, then testing as received may be valuable simply to confirm that what you have ordered is what has been delivered.
Other than that, if you have been testing oils on receipt then you should have plenty of historical data to tell you whether this information has brought any greater benefit than relying on the original oil specification.