Machinery Lubrication

Reliable Plant | www . reliableplant.com Machinery Lubrication | www . machinerylubrication.com 2025 Annual 51 ML Our job is to control each of these and reduce their interactions with the lubricant as much as possible. Some are more easily controlled than others though. While most lubricants will oxidize eventually, we do have help in delaying the process or at least managing the results of oxidation to a point. e vast majority of lubricants will be formulated with antioxidant additives that function in multiple ways to minimize the impact of oxidation. ese additives deplete as they work to slow or delay oxidation. Some of these additives can neutralize or decompose some of the highly reactive free radicals and hydroperoxides associated with oxidation. Monitoring these additives has become an important aspect of lubricant analysis, especially for equipment utilizing large volumes of lubri- cants, such as turbines and other machinery with circulating oil systems. e lyrics in the song "Wake Me Up Before You Go-Go" definitely apply to the monitoring aspect of these additives. In many cases, we want to carefully consider the additive levels to help determine our next course of action. As they deplete to an unsafe level, we may focus on our next full oil change or perhaps even a partial change, known as a bleed-and-feed, to buy us time until a scheduled outage occurs, at which point a more thorough change could occur. Oxidation causes a dual course of devas- tation. On one hand, oxidizing promotes the formation of acids, which, if left unchecked, can lead to corrosion. is is especially true in equipment with softer metallurgy, where the acid can pit surfaces, leading to significant damage. e other aspect of oxidation is the production of larger molecules that eventually increase viscosity and, ultimately, the sludge, tars, and varnish that appear inside the equipment. Varnish has become especially problematic in the industry as it creates surface deposits that reduce dynamic tolerances, reduce heat transfer ability, and produce sticky surfaces that can trap abrasive particles, leading to increased wear. Regardless of the path of destruction, neither is beneficial, and we can delay them from becoming problematic with diligence. To do this, we need to focus on WHAM! Water Water can impact the lubricant in many ways but increases the oxidation rate. Water promotes the formation of acids and free radi- cals, which oxidizes the oil quicker. It also leads to the formation of emulsions, which increases the fluid's surface area, creating more interac- tions with oxygen. Keeping water out of the lubricant requires multiple efforts. Most oils are hygroscopic, meaning that they absorb moisture from the air, so any air in contact with oil needs to be as dry as possible. Dry air purge systems or desiccant breathers can be used to do this. Sanitation activities such as washdowns can be a source of water ingression, and care should be taken to seal equipment against ingression by properly outfitting the machine with seals, sight glasses, quick connects, breathers, or any other accessories that reduce the need to open the equipment during maintenance. Water can be removed from the oil, and depending on the quantity and the state of coexistence, this can be straightforward. Free water, water that has separated completely from the oil, can simply be drained out and removed. If the water is emulsified, utilizing water-removing filter elements can be a simple

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