Maintenance Technology September 2016 - 82

21 Ultrasound is also reliable in picking up other potential bearing failure conditions. Using ultrasound, the technician can hear telltale grinding sounds and other anomalies, which are often accompanied by an amplitude increase. With regards to lubrication, the advantage of ultrasound is that it's able to isolate bearings and determine their individual needs; thus, reducing the possibility that some bearings are too "dry" and prevent others from over lubrication. There are good, better and best scenarios when it comes to using lubrication practices in facilities. A good scenario is the utilization of the manufacturer 's recommendations to the frequency, type of lubricant and amount of lubricant to be applied to a certain piece of equipment. A better scenario is to still make use of the timed interval, but instead of lubricating with just a grease gun, add an ultrasound instrument to use while greasing. This lets the technician involved in lubricating know when they've added enough grease or if too much/too little grease has been applied. The individual lubricating the equipment can also listen to the bearing while lubricating. Listening to the bearing while greasing is important in that the technician, who now also serves as an inspector, can hear if other bearing defects are present and determine if lubrication is or isn't the solution. If a bearing on a machine doesn't sound normal or has an increased decibel level noted off of the instrument that is being used for lubrication, that bearing can be documented and a complementary test such as vibration or ultrasound data can be collected to determine the issue/defect. Finally, the best scenario is to use an ultrasound i n s t r u m e n t w i t h d a t a s t o ra g e a n d d a t a management software to create routes. Data (decibel level and sound files) are recorded periodically. How often the readings are taken should be based on an asset criticality assessment. Once a baseline has been established, alarm levels are set to indicate when a bearing has reached a lack of lubrication. A high level alarm is also set to indicate when a bearing has reached the point of initial failure. At this point, lubrication would not be a solution to the problem, and a more detailed test would need to be performed to determine the specific defect that is taking place such as inner race or outer race bearing fault. When a point along the route demonstrates an insufficient lubrication, an inspector can go to that point and apply lubricant until the decibel level decreases to the baseline or normal level. Why You Should Begin Using Ultrasound - Today It's always a daunting proposition to make a new investment in technology. Will it pay off? Will my staff actually have an easy time using it? Is it a flash in the pan or a truly reliable modality that will stand the test of time? While more and more plants are using ultrasound and adopting a predictive and proactive rather than reactive mindset, there are still many that figuratively use crystal balls and outdated methodologies. The end result is poor reliability, unnecessary man-hours, downtime, and lost productivity and profit. While ultrasound can't cure all reliability ills, it has proven itself to be a valuable and powerful diagnostic tool that technicians must add to their toolkits. The spectrum analysis of recorded ultrasounds can enhance diagnostic accuracy. Using this spectrum analysis reduces the subjectivity associated with traditional decibel readings or simply what is heard by the inspector in the headset. Tremendous energy savings can also be realized through the use of ultrasound for both steam trap and compressed air/gas inspections. These are just two instances where a maintenance and reliability department can gain positive exposure and gain buy- in from management and WWW.SMRP.ORG 10127-4056 SMRP Solutions SE.indd 21 8/22/16 9:43 AM http://WWW.SMRP.ORG

Table of Contents for the Digital Edition of Maintenance Technology September 2016