Machinery Lubrication

Machinery Lubrication May-June 2019

Machinery Lubrication magazine published by Noria Corporation

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Page 12 of 82

e January-February 2017 issue of Machinery Lubrication detailed how the Seminole Electric Cooperative near Jacksonville, Florida, was able to extend the life of the lubricants used in its electro-hydraulic control (EHC) systems. is follow-up article will explain the unintended consequences of going 30 years without an oil change. After 30 years, the facility's phosphate-ester fl uid became unmanageable, and a high- velocity chemical fl ush was completed on the system with a rinse fl uid and a new fl uid fi ll. is turned out to be an eye-opening expe- rience, as the fl uid became dark soon after the fl ush. Some believed this was due to the generation of new debris or problems within the system. Others thought the new oil was cleaning the system. Whatever the reason, the new fl uid was quickly getting worse, and when you have 2,500 gallons per unit, it must be treated as an asset rather than a commodity. New Pr oblems e problems began shortly after the fi rst chemical fl ush was completed on the second unit and it was returned to service. e new fl uid turned black fast. It was so dark that a fl ashlight could not be seen through the fl uid in a sample bottle. e fi nal fi lter was changed from a 3-micron element to a 1-micron varnish-removal type element. e hope was this fi lter would help clean up the problems occurring after the chemical fl ush. is proved to be a problem of its own, as the element could not last even one month before the terminal diff erential pressure was reached. One of the high diff erential pressure elements was sent for analysis to identify the composition of the debris that was plugging the element. Once this was determined, a plan of action could be developed to correct the issue. e fi lter analysis detected fi ve distinct categories of materials. More than 86 percent was derived from the EHC fl uid, which was comprised of phosphate esters and their breakdown products (varnish). Another 8.63 percent was reported as metal/metalloid By Brian Thorp 8 | May - June 2019 | www . COVER STORY

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