November 5, 2008
by Plant Staff
When equipment isn’t running, money isn’t flowing. Global competition and spiralling plant operating and maintenance costs make it imperative to do everything possible to maximize machine uptime and asset reliability. One way to achieve this is oil analysis and fluid testing. The path to success is identifying opportunities, planning procedures, justifying the associated cost to management, implementing a used lubricant analysis program, and monitoring it for occasional tweaking when necessary.
Paul Hetherington, manager of technical training and education for the Fluid Life Corp. in Burlington, Ont., says the benefits are numerous. Choosing an off-site, professional oil analysis laboratory offers a full complement of testing services, covering spectrometry, viscosity, oxidation and nitration. Contamination tests cover moisture, fuel dilution, glycol content and particle count. A high-quality off-site laboratory will also follow standard American Society for Testing Materials (ASTM) test methods while maintaining a strict quality control program to ensure results are repeatable.
Then there are the cost benefits. A study conducted at Syncrude Canada over a four-month period showed a 20:1 return on investment (ROI) with a routine oil analysis program—a $511,000 savings.
Oil contamination or degradation can cause up to 80% of component failures, so look there first. Oil analysis works hand-in-hand with other predictive maintenance practices and can provide quick and high ROI.
Hetherington says the success of any oil analysis program, either on-site or off-site, is the ability to obtain test results reliably and quickly. This process starts at the plant location by setting up a streamlined process for collecting the samples and preparing for shipment off-site.
Reducing oil consumption and using recycled oil will save money, increase equipment reliability and extend machine life.
When planning your “attack,” look for technical support from OEMs, suppliers and trade organizations. Do a plant audit of lubricant storage facilities, sample points and frequency. Then select what you want to have tested.
Samples should be taken from the same installed ports—after a pump and before filters. Dipstick or mid-stream drain samples can also be used. Primary sample points for hydraulic fluids should be on return lines before filters. Take secondary samples before or after supply filters, after cylinders and/or on valve blocks.
For suction pumps, use a new section of hose every time and flush the tubing before every sample. Two or three strokes of the plunger is usually sufficient to obtain a useful sample. Loosen the nut when the sample jar is about three-quarters full. This applies to low-pressure systems, such as gearboxes, bearings and fluid reservoirs. For high-pressure systems, sample valves are required because you need a sample of circulating oil. These valves must have removable caps for protection against external contamination.
Factors affecting sample frequency include type and age of equipment, age of the fluid and, most importantly, operating conditions, such as loads, pressures, speeds and temperatures.
When selecting an oil analysis laboratory, check for quality assurance, turnaround time, disclosure of test methods and reputation. Find out what services other plants are using.
Justifying the need and cost for lubricant analysis is often difficult. Management won’t give you a budget if you can’t present a convincing financial case for regular, competent oil analysis that covers such items as ROI and longer machine life, lower repair bills and fewer oil changes. When identifying expenses, be aware of some hidden costs of oil changes, such as paperwork, permits and cost of purchase orders, overhead, transfer and disposal costs and environmental fees.
When implementing a lubricant analysis program, specify who takes charge, who trains staff, who takes samples and who reads reports. Data interpretation depends on establishing what is considered “normal.” Beware of irregular sampling, which can lead to false assumptions, and costly unnecessary equipment shutdowns. Sample containers should be clean and leak-free. Sample tubing should never be reused—one sample, one tube.
Monitoring is very important. Regularly review your program, monitor cost savings, assess ROI, and re-evaluate sample schedules and test recommendations annually.
A successful oil analysis program also depends on tracking key performance indicators. The objective of fluid testing is to preserve and measure the health of lubricants and ensure fundamental fluid quality and properties. Oils must be tested for chemical, physical and additive properties, contamination and wear debris. This must include spectrometry, viscosity, acid number, base number and testing for oxidation, as well as for moisture, dilution, glycol content, and particle and sediment counts.
To get the most out of your investment in lubricant analysis, Hetherington suggests looking at all the data, questioning everything, understanding each result, analyzing for trends and not jumping to conclusions.