Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/1449093
16 | January - February 2022 | www . machinerylubrication.com Important Properties for Lubricant Selection in the Presence of Water Base Oil — As previously mentioned, hydro- lysis is the degradation of the base oil's molecules due to water. Hydrophilic polyglycols and some esters readily absorb water without any mechan- ical action needed. However, others like mineral, polyalphaolefins, silicone and PFAE require a mechanical action by the lubricated part to cause water absorption and the formation of a water-oil emulsion. Be sure to take this into account when selecting a water-resistant lubricant. Demulsibility — When selecting a lubricant that needs to be highly resistant to water, one property that needs to be taken into account is demulsibility. Demulsibility is a lubricant's ability to release water. Most of the paper mills, food-processing facilities and steel mill opera- tions that I have encountered in the field often incorporate a lot of water into their processes. Most of our recommendations to these types of facilities are centered around water resistance and demulsibility. ickeners (Grease) — Grease is normally chosen where adhesion properties are required. But, if a grease absorbs water, it becomes softer, loses adhesion, and washes out of the lubricated part. In greases, there are certain types of thick- eners that allow for better water resistance. It is commonly known among industry specialists that aluminum and sulfonate greases are partic- ularly water-resistant. Hydrolytic Stability — Hydrolytic stability is the resistance of a cured polymer material to reverting to a semisolid or liquid form when exposed to high humidity and temperatures. Generally, a lubricant will perform better in wet/humid or high-temperature environments when it has good hydrolytic stability. Although I have pointed out a few ways to assist in lubricant selection in the pres- ence of water, I would like to conclude by saying that the main factor in any of this is preventing water contamination and keeping all other types of contamination to an absolute minimum. Fitting leaks are high on the list of reasons why water ingression exists in a machine. is is why we advise against the use of Teflon tape, and instead recommend using a thread sealant like PLS 2 to prevent micro leaks. Lastly, when preventing contaminant ingression, we highly recommend modifying machinery with preventative measures such as desiccant breathers and quick connects. ML About the Author Paul Farless is an industrial service technician for Noria Corporation. His duties include collecting data and preparing reports for the engineering team. Prior to joining Noria, Paul worked as an automotive maintenance techni - cian for an auto-repair service company. He also served four years in the U.S. Navy as a gunner's mate third-class petty officer and as a seaman deckhand, where he was responsible for the troubleshooting and maintenance of electrome- chanical and hydraulic systems. A detail-oriented team player, Paul works well in fast-paced envi- ronments and uses his military background to excel and maximize efficiency. LUBRICANT SELECTION