Behind the Scenes of Oil Analysis

Matt Spurlock, Noria Corporation
Tags: oil analysis

Commercial use of oil analysis began in the mid 1970s, and since then, there have been numerous advances in oil testing and manufacturing. These advances helped provide additional knowledge in the areas of machinery and lubricant health monitoring. They have also created new jobs for thousands of individuals across the world. With more than 200 commercial oil analysis laboratories in North America, the need for analyzing used oil samples has become a booming industry.

Knowledge is Key
Generally, when an individual fills the role of a laboratory technician or lube oil analyst, he or she should possess advanced knowledge regarding the intended position. Several certification organizations can help identify an individual’s overall understanding of a specific lubrication-related subject. The Society of Tribologists and Lubrication Engineers (STLE) offers the Oil Monitoring Analyst (OMA), Certified Lubrication Specialist (CLS) and Certified Metalworking Fluids Specialist (CMFS) certification exams. The International Council for Machinery Lubrication (ICML) offers the Machinery Lubrication Technician (MLT), Machinery Lubrication Analyst (MLA) and the Laboratory Lubricant Analyst (LLA) exams. While not every individual involved in the machinery lubrication and oil analysis fields should be required to hold all of these certifications, some type of education and certification is highly recommended and is increasingly expected.

The Dangers of Jumping Ahead
While performing the job that I do on a daily basis – that of a data analyst – I sometimes forget the need to take things back to a basic level. I attempt to make my oil analysis reports easily readable and as complete as possible. To date, I’ve yet to have a client call as a result of not understanding my evaluations and recommendations. I mention this because a recent phone conversation made me realize just how new and misunderstood oil analysis truly is. Although present since the 1940s and commercialized in the 1970s, there is still widespread misunderstanding of the concept of oil analysis; both the reasons why we perform oil analysis and the reasons why we may not perform oil analysis. Overall, it is a new technology in the predictive maintenance world. Many believe oil needs to be sampled only to determine if it should be changed.

Case in Point
I recently received sample data from a commercial laboratory for evaluation. The data contained only the equipment identifier and name … abbreviated. This was it; no other information was readily available on the sample label. I contacted the client to inquire about the details of the sample and the question that was immediately asked was, “Was the sample dirty?” This initially surprised me because I had not taken a detailed look at the sample due to the lack of information.

While discussing this particular gearbox, it became clear to me the complete misunderstanding regarding oil sampling. I learned this particular gearbox was critical to the overall process of the site. If it fails, the plant shuts down. The gearbox was fitted with no breather, no filter and no means for offline filtration. The sampling method is performed via drop tube. Additionally, the lubrication technician onsite stated that visible wear debris was observed in the sample.

This sample was taken only because of the visible appearance of wear debris. The client simply wanted to know if the oil should be changed.

Testing Parameters
The basics of oil analysis suggest oil is tested to measure three main categories: machinery wear, contamination and lubricant health. Each of these categories represents multiple parameters that are monitored depending on the goals of the local oil program. For the example above, the client was concerned whether or not to change the oil due to the apparent wear debris. Changing lubricant will usually not solve a wear-related problem when the wear debris is large enough to be visibly observed.

For this case, I explained that further testing would be required to determine the mode of wear for this gearbox. Given the criticality of the gearbox, the added cost of analytical ferrography is justified by the savings of what appears to be an incipient failure.

Escaping Shutdown
I recommended to the client to install a proper sampling valve that will ensure the drawing of a representative sample. Contamination control measures were also recommended to reduce external ingress while helping to remove any condensation buildup within the component. It was also noted that the lubricant used in this gearbox was not equivalent to what was recommended by the manufacturer. Therefore, a full lubricant change, flush and refill with the correct lubricant was recommended.

In the end, the lube tech was correct in assuming the lubricant needed to be changed. The error and misunderstanding resulted from the reason why the lubricant needed changing as well as the reason why oil analysis needed to be performed. I look forward to working with this client down the road and helping to improve the overall site reliability effort.


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