Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/778560
www.machinerylubrication.com | January - February 2017 | 35 metalworking fluid, as well as for applica- tions with food-grade, biodegradability or fire-resistant requirements. Phosphate esters are primarily beneficial for fire-resistant applications. They are often utilized in hydraulic turbines and compressors due to their unique properties, including high ignition temperatures, oxida- tion stability and low vapor pressures. Silicone-based synthetics are infre- quently used in industrial applications, but they can be advantageous in extremely high temperatures, when the lubricant will contact chemicals, or when exposed to radiation or oxygen. These synthetics have a very high viscosity index and are among the best options for oxidation and thermal stability because they are chemically inert. Selecting a Base Oil When you are choosing a base oil, there will be tradeoffs in the lubricant properties required for the application. A common example is viscosity. Higher viscosity provides adequate film strength, while lower viscosity offers low-temperature fluidity and lower energy consumption. In some cases, you may prefer to have a balance between the two so there isn't too much of a compro- mise on either side. The chart on page 33 shows a comparison of the most essential properties for each base oil. Although it's not necessarily important to understand the way in which the oil was manufactured, it is critical to know the available base oil options and the advantages and disadvantages they provide. Optimizing your lubricant selec- tion can help minimize the opportunities for machine failure. While synthetics are justifiably more expensive than mineral oil, the cost of equipment failure is typi- cally much higher. If cost is a key factor in your decision, be sure to choose wisely. References Wright, J. (2009). "Phosphate Ester Fluids - Benefits and Limitations." Machinery Lubrication, Vol. 9, Issue 6. Greaves, M.R. (2013). "Polyalkylene Glycols: Present and Future Applications." Webinar. Jackson, A. (1987). "Synthetic versus Mineral Fluids in Lubrication." Keynote Address to International Tribology Conference. Melbourne, Australia. Cash, W. (2015). "Understanding the Differences Between Synthetics." Machinery Lubrication, Vol. 15, Issue 3. Fitch, B. (2013). "When Are Mineral Oils Superior to Synthetics?" Reliable Plant Confer - ence Proceedings. Fitch, J.C., Scott, R., & Leugner, L. (2012). "The Practical Handbook of Machinery Lubri- cation - Fourth Edition." About the Author Bennett Fitch is a technical consultant with Noria Corporation. He is a mechanical engi- neer who holds a Machine Lubricant Analyst (ML A) Level III certification and a Machine Lubrication Technician (MLT) Level II certi- fication through the International Council for Machiner y Lubrication (ICML). Contact Bennett at bfitch@noria.com. ML 4 Things to Know About Base Oils 1. All oils from each base oil type are not the same, as the formulations can produce unique distinctions. Therefore, the properties described for each base oil type are generalized for the category as a whole. 2. Group III oils are sometimes advertised as synthetics. There is an understanding that the refining process has severely modified the original hydro- carbon, thus synthesizing the more highly pure product. 3. Water-based fluids are an alternative when fire resistance is imperative and typical lubricant properties like viscosity or lubricity are less important. 4. Be cautious when switching lubri- cants, particularly when they have different base oils, as they may be incompatible with each other.