Machinery Lubrication magazine published by Noria Corporation
Issue link: http://www.e-digitaleditions.com/i/629709
THE "LUBE-TIPS" SECTION OF MACHINERY LUBRICATION MAGAZINE FEATURES INNOVATIVE ideas submitted by our readers. Additional tips can be found in our Lube-Tips email newsletter. If you have a tip to share, email it to editor@noria.com. To receive the Lube-Tips newsletter, subscribe now at www.MachineryLubrication.com/page/subscriptions. Oil Sampling Tips for Critical Equipment For critical gearboxes, consider taking a reference sample of clean oil when performing an oil change and mark it with the equipment iden- tification, lubricant information and the date of the oil change. After the gearbox has been drained, flushed (if necessar y) and charged with lubricant, run the unit for a period of time to allow for thorough mixing of the lubricant. Then a reference sample of the actual gearbox oil can be taken and marked with the same information. When the next oil change occurs, the sample of the old lubri- cant, the clean reference sample and the mixed reference sample can be sent to the laboratory together. This gives the analyst a basis for comparison of the clean oil, the actual initial charge and the final sample, eliminating erroneous trends caused by partial or incomplete flushing or change-out. It costs a little more, but for critical equipment, it is worth the expense to track gearbox conditions and prevent unscheduled outages. Writing Better Lubrication Procedures When writing preventive maintenance (PM) procedures that require multiple grease guns to be taken up ladders and stairs, add a stop point in the PM that states, for example, "Before ascending these stairs, make sure you have guns A, C and D." This prevents technicians from having to carry too much equipment up flights of stairs or ladders, which is a safety benefit. It also keeps them from reaching the top of the stairs with the incorrect guns and mixing grease in the equipment, which can lead to premature failures. Bearing Installation Advice for Optimal Lubrication Spherical roller bearings with a lubrication groove and three lubrication holes in the outer ring should be oriented correctly when mounting inside the machine. This helps to ensure that there is an adequate amount of lubricant in the outer ring raceway of the bearing. Make sure the lubrication hole is not located at the 6 o'clock position. Otherwise, the lubricant will drain out from the bearing and reduce the lubricant level inside. This tip is very important for bearing lubrication with grease, oil spray or oil drop lubrication. How to Estimate Reservoir Capacity To estimate the capacity in a rectangular oil reservoir, measure the length, width and height (from the tank bottom to the oil level) in inches. Multiply these dimensions together to get the cubic inches of oil. Divide this number by 231 for gallons. Now label the tank with the capacity so you won't have to do this calculation again. Why You Should Inspect Rebuilt Electric Motors When receiving electric motors that have been rebuilt, inspect the grease tube to the bearings to ensure that contamination is not present (metal shavings, dirt, etc.) and to verify that the grease path to the bearings is full of grease. If the grease path is empty, it could take two to three years before any grease reaches the bearing, since regreasing amounts are typically very small (0.3 to 0.7 ounces per year). Stop Turbine Oil from Cooking in Outages If you have an outage in a turbine and your lube oil pumps are locked out, be sure to turn off the tank heaters. Most heaters and resistance thermometers are located in two different places that heat and read flowing oil. This can result in overcooking the oil in the non-flowing/heated area. How Filter Changes Can Disrupt Particle Counts Have you ever seen a sudden spike in the particle count for a stable circulating oil system where no oil has been added or lost? Check to see if the oil filter was changed just prior to the oil sample date. It is not uncommon to see a spike in the particle count after changing oil filters due to the "disturbance" to the system. There- fore, don't be too zealous in changing filter elements purely on a calendar basis. Take full advantage of the operating life of your elements and only change them when they have reached their load capacity or have been in the system up to their manufacturer's recommended service life. 40 | January - February 2016 | www.machinerylubrication.com