Machinery Lubrication

Machinery Lubrication May-June 2021

Machinery Lubrication magazine published by Noria Corporation

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38 | May - June 2021 | www . Why Gearboxes Hate Water Contamination David Dise | Noria Corporation CONTAMINATION CONTROL & LUBRICANT RECONDITIONING Factor: C3M Learn More: Factor: C3M – Contamination Control Objectives Level: Management and Training(M) Stage: Contamination Control & Lubricant Reconditioning About: Implementing contamination control objectives and goals increases machine reli- ability. More stringent objectives should be set for machines with high criticality. More about this ASCEND ™ Factor Water is the second m o s t d e s t r u c t i v e c ont a m i n a nt a nd is often ignored as the primary root cause of gearbox failure. e metal parts inside the gearbox will always be susceptible to rusting and varnish when water is present. When you add a slight amount of heat, air and water together, you will have oxidation, acid numbers will rise and rust will start forming, causing a plethora of other problems. As the additives in the oil start working in overdrive to combat the water contamination, they get consumed or used up. Addi- tive polarity is defined as the natural directional attraction of additive molecules to other polar materials in contact with the oil. ese polar materials include water, sponges, glass, dirt, metal surfaces and wood pulp. In effect, additives hitch a ride on particles or water droplets. Over time the oil loses its ability to protect metal surfaces, viscosity changes and eventually failure will occur. Let's ta lk about the three different states, or phases, of water contamination you might see inside a gear-box oil reservoir. You can have dissolved water, free water or emulsified water. It is important to know the different states of water contamination and what they look like to not only determine how bad a problem is, but to identify what action needs to be taken to fix it. When talking about gearbox reser- voirs, all three states of water can cause serious damage. Free water and emulsified water specifically are the most harmful states in any lubricated system. Dissolved Water Dissolved water is like humidity in the air. e water or moisture is present but dispersed throughout the oil, molecule by molecule, making it almost impossible to detect with the human eye. You can have a high concentration of dissolved water without being able to see it with the naked eye. With a high concentra- tion of dissolved water, you might see condensation start to build. Having a high concentration of water and adding heat will make it react like when you leave a water bottle almost empty in the sun. e heat pulls the moisture out of the oil in a fog or cloud and sticks the moisture to the inside walls of the reservoir not being splashed with oil. As the satu- ration level goes up, condensation builds and eventually forms into a condensation droplet waiting to become heavy enough to slide or drip

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