Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/136253
AS I SEE IT • Audible inspections (change in machine sound) • Temperature inspections (touch, heat guns, gauges, etc.) • Portable PdM technology inspections (vibration overalls, thermography, acoustics, motor current, etc.) • Mechanical inspections (shaft movement, seal conditions, open gear wear, etc.) • Instrument and gauge inspections (flow rates, proximity probes, pressure, bypass indicators, etc.) •Onsite oil analysis screening tests (crackle, blotter, viscosity, ferrous density, patch, etc.) Many impending and precipitous failure conditions that were first reported by scheduled oil analysis could have been detected much earlier if better and more frequent inspection methods were in place, such as those in the list above. The economics of early detection are enormously improved as well. As noted previously, failure detection and failure analysis are different concepts. Once an abnormal condition has been detected, it can be investigated further to determine where it is coming from, the probable cause of the failure, how severe and threatening it is, and the corrective action. This is where oil analysis and other predictive technologies can be very valuable. "Unscheduled" oil samples can then be forwarded to the lab for troubleshooting purposes (diagnostics and prognostics). These include samples from secondary sampling ports to help localize the source of the problem. In the laboratory, specialized qualitative and quantitative tests can be performed to characterize the nature of the condition. These might include wear particle identification (XRF, SEM-EDX, analytical ferrography and many others). The skills of a triboanalyst and a multi-technology PdM specialist can combine lab data with surveillance data for the most complete picture of the machine's condition (see Figure 2). Proactive Maintenance Still Requires Scheduled Oil Analysis Unscheduled oil analysis is not an alternative to scheduled oil sampling and analysis. Routine oil analysis is still needed for many reasons. The most important is proactive maintenance, which uses oil analysis to monitor and control the presence of failure root causes. These include verification of the lubricant's physical and chemical properties as well as contamination control. The benefits of a fine-tuned proactive maintenance program are much slower machine wear rates (longer machine service life), fewer overall machine failures and less associated downtime. When proactive maintenance is combined with EPM, a comprehensive and more efficient condition-based maintenance program results. The detection phase of EPM is continuous failure surveillance across numerous parameters. It integrates skillful and frequent human inspection tactics with other conventional monitoring technologies. 4| May - June 2013 | www.machinerylubrication.com Early predictive maintenance is about extreme vigilance. It involves the development of more effective inspection skills and a more effective means of inspection (machine modifications). It also requires a culture change and management support for remediation of machines that have not yet failed. About the Author Fitch has a wealth of "in the trenches" Jim experience in lubrication, oil analysis, tribology and machinery failure investigations. Over the past two decades, he has presented hundreds of courses on these subjects. Jim has published more than 200 technical articles, papers and publications. He serves as a U.S. delegate to the ISO tribology and oil analysis working group. Since 2002, he has been director and board member of the International Council for Machinery Lubrication. He is the CEO and a co-founder of Noria Corporation. Contact Jim at jfitch@noria.com.