Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/1449093
Lubricant Water Handling Ability: Why it Matters Condition Monitoring, Lubricant Analysis & Troubleshooting LUBRICANT SELECTION Factor: S1P No matter the product being manufactured, I would say most facil- ities have some sort of water being introduced during the process. Some of the uses for water in the manufacturing processes include washing, diluting, trans- porting, cooling, etc. Knowing that these processes involve water, we often recommend that the lubricant purchaser considers a lubricant's ability to handle or resist water; what follows is a few reasons why. Effects of Water Contamination in a Lubricant Rust and Corrosion — Water induces oxidation which produces rust when in contact with iron and steel surfaces for extended amounts of time. Rust can cause abrasive wear, which is when a hard, rough surface slides across a softer surface. Once an oil starts to oxidize, you may see an increase in the acid number as well. Hydrogen Embrittlement — is is when water finds its way into the microscopic cracks in the metal surfaces of the component. When water is introduced to excessive pres- sure, it will actually decompose into its components, and the hydrogen will be released. is can force those microscopic cracks to open wider, making them larger and thus more dangerous to the machine. Cavitation — Vaporous cavitation is when the vapor pressure of water is met in a low-pressure area of the machine, which induces expansion of the vapor bubbles. Eventually, this expansion will cause the vapor bubbles to implode and condense back to the liquid state. When this occurs, it causes a sort of micro-jet that causes surface fatigue and erosion. Lubrica nt Degradation — Water not only accelerates oxidation of metal surfaces, but also of the oil by depleting oxidation inhibitors and demulsifiers within the lubricant. When oxidation occurs, acid forma- tion can occur soon after. ere is also the obvious change in viscosity which is the most important factor of any lubricating oil. Add water to any other fluid, and the viscosity will decrease when hydrolyzed; conversely, if the water is emulsified into the oil, it can produce sludge, which will actually increase the viscosity. Decrea sed L oad Ca rr ying Capacity — In the presence of water, the film strength of the oil becomes impaired. The pressure-viscosity coefficient is disrupted, which means the lubricant's ability to solidify or increase viscosity in relation to load is impaired, and the appropriate lubricating film may not be produced. Water is extremely detrimental to this process within the lubricant. Learn More: noria.com/ascend/ Factor: S1P — Lubricant Selection Process Level: Platform (P) Stage: Lubricant Selection About: Lubricant selection is a paramount first step, but many factors such as machinery requirements, opera - tional context, available technologies, environ- mental impact, energy consumption and technological advances must be considered beforehand. More about this ASCEND ™ Factor Paul Farless | Noria Corporation