Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/468007
14 January - February 2015 | www.machinerylubrication.com Finally, the best scenario is to use an ultrasound instrument with data storage and data management software to create routes. Data such as decibel levels and sound fi les can be recorded periodically. How often the readings are taken should be based on an asset criticality assessment. Once a baseline has been established, a low-level alarm can be set for when a lack of lubrication condition has been detected for a bearing. A high-level alarm is also set to indicate when a bearing has reached the point of initial failure. If lubrication is not the solution to the problem, a more detailed test would be required to identify the specifi c defect, such as an inner or outer race bearing fault. When a point along a route has been determined to be lacking lubrication, an inspector can go to that point and apply lubricant until the decibel level drops back down to the baseline level. Other Ultrasound Applications Ultrasound imaging or recording is a new concept that involves using a special instrument to analyze ultrasounds, which are then viewed in spectrum analysis software. Although this is a fairly new technique, the use of ultrasound for both mechanical and electrical inspections is growing. The spectrum analysis of recorded ultra- sounds can enhance diagnostic accuracy and reduce the subjectivity of only comparing decibel levels or simply what is heard by the inspector in the headset. Adding ultrasound to mechanical inspections can also allow for better use of other tools such as vibration analysis. If there are too many assets to monitor with vibration, ultrasound can be included to complement the vibration analysis program. Critical assets can benefi t from having both vibration and ultrasound data collected. For noncritical assets, which may not necessitate the time to collect vibration data but still need to be monitored, ultrasound data can quickly and easily be used. Another reason to complement a vibration program with ultra- sound is if the vibration analyst's time is limited. A vibration route can be very time-consuming, but ultrasound can help reduce the time it takes to collect vibration data. Ultrasound can be used fi rst, and once the decibel level has risen to trigger an alarm, vibration can further diagnose the problem and the reason for the increase in noise level. The beauty of adding ultrasound to an existing predictive main- tenance and reliability program is that it can be used for many different applications. Typically, those who are starting out on a reliability journey or are just beginning to utilize the technology will employ ultrasound for compressed air and gas leak detection. Tremendous energy savings can be realized through the use of ultra- sound for both steam trap and compressed air/gas inspections. Based on these savings, the maintenance and reliability department can gain buy-in from both management and fl oor personnel. The savings associated with the energy-conservation efforts can then be reinvested in the program by means of additional tools, training, certifi cation courses or even manpower. The same method for energy-conservation applications can also be used for electrical and mechanical applications. This is what makes ultrasound a versatile and easy-to-use tool for both the well-established maintenance and reliability programs, and those that are just beginning their journey. COVER STORY This overlay shows recorded ultrasound files of four motor outboard points on identical motors. One has an obvious bearing defect.