MACHINERY LUBRICATION- INDIA NOVEMBER-DECEMBER 2019 | Page 27

MLI replacement parts are selected and installed prior to the machine being placed back into service, which is especially critical when replacing bearings. While the same size bearing normally is put back into service, the bearing’s configuration may change. Using a bearing that is different from the type listed on the equipment tag can result in a maintenance-induced failure. An example of this would be switching from a bearing that must be periodically regreased to one that is sealed and should not be greased. If this sealed bearing is installed and there is no indication of it now being a maintenance-free bearing, someone may apply grease to the housing and pressurize the cavity, forcing grease into places where it shouldn’t be. Over time, the grease can build up and cause a failure or contribute to a failure mechanism due to increased heat or drag. Therefore, whenever the replaced bearings are not the same as those that were installed initially, every effort should be made to document this in the computerized maintenance management system (CMMS) or on the equipment. When repairs are made by an outside company, such as a rebuild shop, documentation should be provided detailing which bearing was replaced and what is now in the machine. Many shops can also make new equipment tags so the information on the tag can be kept up to date and accurate. Otherwise, an additional tag must be added to the machine stating it has been rebuilt and offering a shorthand 55% of lubrication professionals can read a bearing number and understand what infor- mation it indicates, based on a recent survey at Machinery­ Lubrication.com account of what was done or where to find information regarding the rebuild. Working with the shop to create an efficient process for performing and documenting each rebuild will be key to knowing which replacement parts have been installed in your equipment. When I serviced compressors, the work usually was completed after an equipment breakdown. The goal was to get it operating again as quickly as possible. This frequently led to corners being cut and broken parts being replaced with ones that weren’t quite the same as the originals. When the machine would break down again, another technician might replace the part with something slightly different. This often resulted in a significant deviation from what the manufacturer intended or what was required for the machine to run at its peak efficiency. The same thing can happen when bearings are replaced. Although changing certain bearings or their configurations may produce some improvements, if it is done in a silo with no information disseminated to the rest of the organization, it can cause problems in the machine. Replacement parts should be documented on a work order and recorded in the CMMS. While you likely won’t want to update a bill of materials for a piece of equipment if you can’t use the original parts, there should at least be some notes regarding whether a part has changed and why. This will require diligence by all parties involved. These documents have largely been converted to electronic forms, so it is much easier to get the information into the hands of the people who need it. Finally, if you replace a bearing with one that doesn’t require periodic relubrication, you can ensure greasing will not create an issue by replacing the grease fittings. This can be achieved during a rebuild and will involve pulling the current fitting and replacing it with a plug. Not only will SKF Bearing Numbers this reduce the risk of someone applying grease where it isn’t needed, but it can also be used by both in-house and contracted teams alike. With some attention and effort, you won’t have to play a guessing game to know which bearings are inside your equipment and what that means to your organization. By doing a little homework, you can unlock a wide array of information to improve your lubrication program as well as your overall reliability. ML About the Author Wes Cash is the director of technical services for Noria Corporation. He serves as a senior technical consultant for Lubrication Program Development projects and as a senior instructor for Noria’s Oil Analysis II and Machinery Lubrication I and II training courses. Wes holds a Machine Lubrication Technician (MLT) Level II certification and a Machine Lubricant Analyst (MLA) Level III certification through the International Council for Machinery Lubrication (ICML). Contact Wes at [email protected] to learn how Noria can help you determine the best way to lubricate the bearings in your machines. www.machinerylubricationindia.com | November - December 2019 | 25