Industrial applications will most likely experience a growth in oil analysis testing and monitoring, especially power-generation equipment. Companies with mechanical maintenance needs might be familiar with used-oil testing, but many haven’t fully grasped the relevance of and the value derived by implementing an oil-testing program. Even companies that use testing services might have questions about test reporting and its applicability to plant-floor fixes. This article provides an overview of the practice of testing in-service lubricants and clarifies how testing and analysis benefit companies that have a significant investment in operating equipment.
Diagnosing equipment condition and evaluating in-service lubricant test results include looking at both the equipment health and oil integrity. Trending the test data over a period of time is a valuable tool to monitor ongoing equipment condition and predict corrective action before interruption to operations or increased maintenance costs occur. Effective trend analysis minimizes downtime, permits more efficient maintenance scheduling, protects your warranty claims and increases equipment resale value.
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Predictive maintenance is a key advantage of analyzing in-service lubricants. Scheduled maintenance alone, without in-service lubricant testing, might occur too frequently or might not detect problems between services. Optimizing maintenance schedules reduces costs and improves return on investment. Companies that take in-service lubricant analysis seriously concentrate on root cause analysis. Testing allows for monitoring of contaminants, such as dirt or water, so that root causes are controlled and kept at a level that minimizes detrimental effects.
Evaluating a used lubricant sample isn’t always based on a single physical or chemical property. Equipment or lubricant problems might be flagged by a range of acceptable limits for multiple variables. In addition, it might not be necessary to wait for test results to reach a condemning or warning limit across the board, because changes in a combination of them also might lead to condemning the oil or flagging an equipment condition. Trained diagnosticians understand equipment application and design, oil formulation and costs involved in draining and replacing in-service oil. A diagnostician also recognizes the integrity or applicability of the data to make judgments regarding the oil’s condition.
Do what needs to be done
Testing in-service lubricants normally includes a check for wear, contaminants, oil physical properties and degradation. When establishing your testing program, consult with a laboratory and your lubricant supplier for the most cost-effective test package relevant to your needs. More isn’t always better. Acquire information that can be used effectively. Decide how the testing relates to and complements your maintenance needs. List the tests that meet your particular needs. An important consideration is working with your laboratory to optimize the service to obtain the most cost-effective results and produce successes that lead to increased equipment reliability. Typical testing programs include standard routine tests that can meet most service requirements. Laboratories providing your testing service also should provide specialized testing and technical services to address non-routine needs.
Good sampling procedures also are important to obtain reliable test data. Minimize the time that elapses between taking the sample and the lab testing to ensure you receive current equipment-condition information. Tag the sample with complete and accurate information. Document your procedures to ensure that proper and timely sampling occurs, proper information is entered, and samples are shipped to the testing laboratory on time. Testing laboratories can provide sampling supplies and tools, generally at an added cost. Good service providers are willing to work with end users to develop best-practices sampling procedures and to provide material applicable to an end user’s needs.
*Survey of 227 incidents from
April 2004 to July 2008
| Variable | Savings per incident* |
| Wear detected | $2,600 |
| Coolant contamination | $2,800 |
| Dirt detected | $2,900 |
| Water detected | $2,900 |
| Fuel dilution detected | $4,600 |
| Improper viscosity | $2,300 |
| High engine soot | $2,300 |
| High insolubles | $1,000 |
Report for action
One of the biggest challenges to getting the maximum benefit from testing in-service lubricants is getting the test results back to where they can be used and follow-up action can be scheduled. Providing clear instructions to the testing laboratory and to in-house personnel for report routing is important. The data needs to go where it can be used effectively and needs to be received in a timely manner.
Data reports are available in several formats, but electronic, Web-based reporting provides significant advantages for recordkeeping, data management and maintenance integration. Companies with multiple sites, large equipment or fleet inventories can manage information more effectively if it’s provided digitally. An effective Web-based reporting system can integrate in-service lubricant analysis with other maintenance processes.
Effective follow-up on your part can maximize your return on investment. Expect a testing laboratory to provide accessible communication between you and the lab experts. The value of the test report sometimes can be enhanced tenfold after a conversation with the testing laboratory. Alarming results might require following little trends before they morph into larger problems. A well-tuned analysis program is expected to complement your other maintenance practices. It’s good practice to document and build on successes to improve maintenance, operating efficiency and cost savings.
Eye the future
Difficult economic conditions have made used oil analysis an important tool for business viability. The service complements and optimizes other maintenance practices. Therefore, the industry strives to present more value in the information provided to customers, whether it’s through electronic reporting, new testing technology, or keeping up with changes in equipment design and oil formulations. In some applications, inline lubricant monitoring sensors and on-site analyzer instrumentation might become more prevalent. Sensors and analyzers have a specific niche that can work well for remote locations, continuous monitoring, and screening before sending to a commercial laboratory.
- Use safe sample extraction methods
- Use consistent practices
- Use optimal sampling points and choose a representative location
- Minimize sources of garbage data
- Never sample directly from a filter
- Take samples before the oil is changed and before adding make-up oil
- Have the oil warmed up and thoroughly mixed before sampling
- Don’t overfill sample bottles, but provide a sufficient sample to perform all tests
- Cool the samples before sealing the sample containers
- Use inline sample ports on circulating systems for best results
- Sample in areas of turbulence, such as bends, and avoid sampling from straight sections of pipe
- Use clean sample containers and equipment
- Use containers that won’t leak after replacing the caps
- Provide required sample information
- Keep unused sample bottles sealed and clean
- Keep paperwork clean
- Establish procedures for forwarding samples to the laboratory
- Send samples immediately to the testing lab to ensure applicable test results
New testing technology is constantly under review. Improved analytical instrumentation provides advances in wear particle analysis, either through quicker and less-expensive analysis, or more detailed inspection of wear particles. Also, new methodology has been developed to monitor lubricant degradation and varnish formation in industrial applications.
Equipment technology always is changing, which provides a challenge for commercial testing laboratories to keep up with equipment design changes and new demands on lubricants. New fuel formulations affect in-service lubricants differently. Engine design changes require updating the evaluation criteria for both equipment and lubricants.
Electronic data reporting opens up opportunities to provide more useful data management. Laboratories now can work with customers to target maintenance and equipment reliability improvements. Equipment reliability can be more easily compared to various sites, applications and designs.
See the payoff
An effective program is measured by one thing: Cost savings that improve your bottom line. End users have documented cost savings of $25,000 or more from a single oil analysis on a single piece of equipment. Though the numbers in Table 1 are considered conservative savings per detected incident, they signify the return on investment you can realize through testing in-service lubricants.
It’s important to note that these savings demonstrate the ROI that in-service lubricant analysis can provide. The technique has proved to be a cost-effective predictive maintenance tool that enhances equipment reliability and produces cost savings. This might explain why so many Fortune 500 companies with significant investments in operating equipment use lubricant-testing services in one form or another.
David Doyle, CLS, OMA I, OMA II, is vice president and operations manager, North America tribology division, ALS Staveley Services Fluids Analysis, Houston (www.alstribology.com). Contact him at [email protected] and (877) 835-8437.