Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/1470959
www.machinerylubrication.com | May - June 2022 | 17 ML ML ML ML it also makes the equipment run at an elevated temperature. e increase in operating temperature reduces the fluid's life, so more frequent oil changes are necessary. It's important to also consider the increased energy costs required to churn through the added volume. Compare Factors Not all lubricants are created equal; some provide additional protection in specific areas, and some perform better in terms of longevity. When selecting lubricants, compare factors such as base oils, additive packages and performance-related tests. Commonly, people refer to tests such as the Rotating Pressure Vessel Oxidation Test (RPVOT) and Turbine Oil Oxidation Stability Test (TOST) to glean insight into how long a lubricant's life might be. While these tests do provide insight into oxidative stability, you must determine the most likely means of lubricant failure for your equipment and then look at the appropriate test results. For instance, if your fluid is more likely to fail due to hydrolysis (water contamination), then select lubricants that perform better in hydrolytic stability tests. Choosing more stable lubricants may cost extra on the front-end, but you will reduce the number of changes and thus the number of gallons needed on-hand overall. To dial in frequencies, the use of condition-based maintenance techniques tends to be the gold standard. For greasing, tools such as ultrasound and grease analysis are very common. By performing this analysis, we can make sure bearings, gears and other components are getting greased in the appropriate timeframe (analysis also helps determine appropriate volumes). Oil analysis serves a similar purpose to help change fluids only when the need arises. Also, the condition of the oil can be monitored so that action can be taken when contam- inant levels rise, which, in turn, extends the life of the oil. In some cases, based upon the condition of the oil, you could avoid a complete changeout and potentially opt for a bleed-and-feed or partial changing of the oil. This can be done to extend the current charge of oil until such time that a full change can be performed. Lubricant analysis is a powerful tool, especially when it comes to helping you identify ways to extend intervals and change lubri- cants only when prescribed. Proper Storage Another place in the program where good lubricants can go bad is storage. Oils that sit in packaged options or bulk tanks can become contaminated, shortening their lifespan. Additives can separate in storage as well. To help minimize either of these from occurring, proper storage activities should be followed. This includes keeping lubricants sealed and in climate-con- trolled areas as much as possible. For bulk storage tanks, this may also include the use of kidney-loop filters. Periodically circulating the stored oil helps remove any contam- inants that ingress, keeps additives in solution, and generally helps maintain the lubricant in a better condition prior to use. Lubricants that are stored outside and allowed to breathe in dirty, wet air often aren't fit for service and need to be disposed of before ever being used. In the case that inventory levels can't be maintained, plan ahead for any oil changes. Work with your supplier to find an oil or grease that is compatible and whose operating characteristics are as similar as possible. Doing compatibility tests ahead of time allows you to quickly make the transition and lets you know if you need to flush the systems or simply do rolling changeouts. With the way the market exists right now, having a couple of candidate options available can save headaches that may arise later. ML About the Author Wes Cash is the Vice President of Services for Noria Corporation. He serves as a senior technical consultant for Lubrication Program Development projects and as a senior instructor for Noria's Oil Analysis I and Machinery Lubrication I and II training courses. He holds a Machinery Lubrication Engineer (MLE) Machine Lubri- cation Technician (MLT) Level II certification and a Machine Lubricant Analyst (MLA) Level III certification through the International Council for Machinery Lubrication (ICML). Contact Wes at wcash@noria.com.