Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/544388
MAINTENANCE & RELIABILITY Standard operating procedures (SOPs) were developed for bearing installation practices, belt tensioning and laser alignments. Currently, the technicians are being trained on how to perform these functions correctly and effi ciently. They have come to under- stand that making something as simple as possible will assist with the permanent implementation of a new methodology. Fine-tuning Lubrication and Oil Analysis The plant continues to fi ne-tune its lubrication practices. This has been the hardest part of the transformation. Methods have been developed to alert personnel when there is possible overgreasing of a bearing, but the details are still being worked out for achieving the right amount of grease at precise intervals. Another major step at Allendale was the implementation of a condition monitoring program. In the past, the plant experienced limited success with predictive tools including a vibration meter, outsourced infrared imaging and oil analysis. This was a great fi rst step, but it was limited for a number of reasons. The infrared imaging agreement was restricted to twice a year. The technicians were tasked with making repairs, with some more successful than others. The effectiveness of the repairs wouldn't be known for another six months. Electrical problems occurred as a direct result of these missed opportunities. Two 100-horsepower motor failures and three large AC drive failures were experienced in one year. The failure modes were elec- trical and could have been avoided if infrared routes had been developed for these areas. The vibration routes were based on a total root mean square (RMS) meter, which simply looks at total vibration in a system. If the system's vibration increased, the tech- nician generated a work order to investigate. While the oil analysis program functioned well, rarely did anyone pay attention to it. Samples were pulled and sent to the lab, but the plant seldom acted on the results. Reports noted contamination and gear wear with suggestions to "replace oil" and "investigate gear wear." Unfortunately, the majority of the recommended actions were not completed. If the planner/scheduler had time, he would occasionally look at some of the issues and create work orders, but there was no consistency. Streamlining Condition Monitoring The fi rst step to correct this was to reduce the amount of equip- ment being monitored. Previously, everything was monitored, including a $100 gearbox that wouldn't shut down the process. The plant's CMMS contained an ABC indicator with a cost-of-failure descriptor. Any asset ranked from six to nine was considered a crit- ical piece of equipment. Of course, this would change over time, but it was a good starting point. Specifi cation sheets were created, and critical failure modes were determined for the equipment to be monitored. A large portion of the machines to be tested had some redundancy. However, just because a piece of equipment was to take the place of another didn't mean it couldn't be considered critical. Many of these setups weren't cycled or maintained properly. Once all the logistics were accomplished, such as determining routes, developing predictive maintenance work orders and installing vibration pads on machines, the training portion of the program began. The budget included thermography and vibra- tion analysis certifi cations as well as Machine Lubrication Technician Level I certifi cation through the International Council for Machinery Lubrication. The main focus for the condition monitoring program was the development of the vibration analysis program. At fi rst, no one at the plant knew how to analyze anything. Testing equipment was researched, and a piece of vibration equipment was purchased that could diagnose most of the plant's issues without in-house analysis. The analysis equipment would also produce vibration spectrums and time waveforms. Two factors prevented success with this program. The fi rst was the lack of repeatability in data acquisition. The second was not having a solid grasp of how the equipment worked in the processes. Plant personnel set out to gain this knowledge. They spent a great deal of time learning how to collect data, realizing that vibration pads worked best. Installing brass pads in the mounting locations allowed for repeatable data collection. The accelerometer screwed right into the mount, allowing for the same placement every time. Techniques were also developed to place systems into manual mode during the test in order to control loading. This wasn't always perfect, and not every system could be switched to manual mode when needed. The work order was rescheduled for a later date if this was the case. Initially, the plant adhered to the diagnosis from the testing equipment until it was noticed that some of the diagnoses weren't always accurate. To continue the program's progress, the decision was made to develop the ability to analyze spectrums. Certifi cation training began soon afterward. This was a huge step. While personnel were accustomed to the idea of using test equipment to monitor machines for failures, they didn't realize how important it would be to rule out certain repairs. They have since successfully used the equipment to identify fl ow noise and particular attributes of a system such as eccentric rotors. Frequently, work orders are generated to have a gearbox or motor repaired, only to discover that isn't the issue at all. In one recent example, the work order stated, "There is a loud vibration and noise, which seems to be coming from the primary gearbox." This wasn't on the critical equipment list, so it wasn't regularly monitored at this point. However, the gearboxes were expensive to replace, and a considerable amount of labor was required to complete the repair. A vibration test was performed. After analysis, Water ingression was also an issue. 26 July-August 2015 | www.machinerylubrication.com