Machinery Lubrication


Machinery Lubrication magazine published by Noria Corporation

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ML www . | September - October 2020 | 19 ML because of the higher amount of oil-soluble varnish in the second sample, the proba- bility of sediment contamination is higher at the critical points within the second gas turbine at the thermal power plant. Importance of particle counting report: Most oil labs currently use laser particle counters calibrated in accordance with ISO4406:99 to count suspended parti- cles within the oil. In this standard, only suspended particles larger than 4 microns are examined and counted. Field observa- tions have shown that high contamination of turbine oil with particulate matter can contribute to profound errors in MPC varnish potential test results. erefore, it is important to consider particle counts when evaluating MPC values. Clearly, calculating the R index and thus removing insoluble particles from the varnish potential test results can be of great value to analysts. Conclusion: ough this article is a critique of defi- ciencies in the ASTM D7843 standard, it is still available and viable as a powerful and reliable tool. Analysts' attention to the test results and the issues mentioned in this article can help to mitigate misunder- standings and errors in the final analysis. Focusing only on the numerical value of MPC tests can be misleading and could lead to costly, inaccurate and ineffective decisions. e smart choice is to supplement your particle counting results with the R index presented here in order to ensure useful analysis of MPC value. ML REFERENCES • Dr. A. Sasaki, CPA newsletter (October 2015) • US Patent NO. 8,390,796B2 (Mar. 5, 2015) • Andy Sitton, Focuslab. • Machinery Lubrication Magazine. (6/2014) • The varnish issue: strategies for successful monitoring and acceptable level. • Dr. H. Tubisu. Dr. A. Sasaki. • Review of varnish problems of modern gas turbines. • Society of tribologists and lubrication engineers annual meeting. (2010)

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