Machinery Lubrication magazine published by Noria Corporation
Issue link: http://www.e-digitaleditions.com/i/680544
DOWNTIME? UPTIME! ASSET RELIABILITY through ULTRASOUND... View Video: www.uesystems.com/time R e l i a b i l i t y N e v e r S o u n d e d s o G o o d ! 1-800-223-1325 - info@uesystems.com ratory should assist you in determining exception tests that could provide more information about any concern identified by a routine test. This further analysis should include techniques like micro- scopic analysis, which can be obtained from any remaining oil from the original sample. More oil may also need to be drawn from the machine. These exception tests are intended to confirm, deny or provide more details in order to find the root cause of the issue. With this data and more in-depth examination into the recent events of the machine's operating conditions, investigation reports and other condition monitoring technologies, remediation recom- mendations can be formulated. In many cases, the laboratory may be able to provide the inves- tigative assistance you need to get to the root cause of a potential failure. Know your lab's full capabilities and set your expectations accordingly. The laboratory should be passionate about detecting and solving problems, and share your end goal of aiding in the opti- mization of plant-wide reliability by proactively monitoring various indicators within the oil of individual machines. At What Cost? Each of these oil analysis selection principles can be refined by considering the optimum reference state (ORS) of each machine or, more importantly, your plant's overall reliability objectives. If price was not a concern, you would simply choose a lab that could deliver on all of these principles. Unfortunately, price eventually must be a concern. So when does the price of oil analysis outweigh its returns? First, you must consider the impact of a potential failure for any of your machines, including the resulting cost of parts, labor and lost revenue from a production interruption. Then, depending on the magnitude of this impact, you must decide how much you would be willing to spend to avoid the average incident, regardless of whether there is a history of failure. In almost every circumstance, a single catch that avoids the average failure would more than justify the typical cost of an oil anal- ysis program for an entire plant. Oil analysis services are generally competitively priced in the market. Nevertheless, beware of the potential shortcomings of very low-cost or even free oil analysis programs, such as those provided by a lube supplier. Even if the oil analysis is free, it still costs you time and money to collect samples and manage results. If the oil analysis program isn't created with your end goal as the focus, you may not be giving yourself any sort of advantage. You may be better off spending a few extra dollars to guarantee you get the value you're trying to achieve. Asking the questions specified by the selection principles will help ensure this. As the optimum reference state suggests, there is an optimum effective- ness zone that is a balance between the cost of an investment (like oil analysis) and the cost of unreliable operation. The total cost of reli- ability will be the lowest at this optimum effectiveness zone. So while price must be taken into consideration, it should not be your top priority. Consider price only after you can verify your satisfac- tion with the level of service and quality the lab offers in each of the selection principles as it relates to your end goal. Like most things, it is often a tradeoff between price, service and quality, where two of the three are achievable at a desired level. Do not sacrifice the necessary levels of service and quality for price. The attainment of your end goal is depending on it. About the Author Bennett Fitch is a technical consultant with Noria Corporation. He is a mechanical engineer who holds a Machine Lubricant Analyst (ML A) Level III certification and a Machine Lubrication Technician (MLT) Level II certification through the International Council for Machinery Lubri- cation (ICML). Contact Bennett at bfitch@noria.com to find out how Noria can help you select an oil analysis lab. Correction In the January-February 2016 issue of Machinery Lubrication, an inaccurate statement was made regarding the self-locking ability of worm drives. The fact is, while many worm gear drives at higher ratios under specific conditions may exhibit a self-locking property, those with lower gear ratios are known to freely reverse the direction of power. This static self-locking ability may only be possible when the lead angle of the worm is less than the static friction angle of the mating materials. Nevertheless, while this can be advantageous, the need for a backstop or a brake to prevent unexpected reverse rotation is very important, as back-driving is still a possibility under certain circumstances, such as when there is sufficient vibration or when gear teeth surfaces polish over time. ML