Things Many Vibration Analysts Don’t Do, but Should
In the previous issue of Maintworld –magazine we introduced 10 things vibration analysts can do in order to make their job easier. In this article we will take a look at six more ways to lessen the burden of the
vibration analysts’ tough job.
The 10 statements introduced in the previous issue of Maintworld –magazine and the following six are general observations of common problems that the author of this article has observed over the past 30 years. Hopefully you find these suggestions helpful in your maintenance program.
One: Don’t Rely on Vibration Alone
You should not rely solely on vibration data when diagnosing faults. Other condition monitoring technologies such as ultrasound, oil analysis, wear particle analysis, motor current and voltage testing, infrared analysis and performance data can not only detect faults that you can miss with vibration data alone, but they can help to confirm whether your diagnosis of a suspected fault condition is indeed correct. If you are not collecting that data, start collecting it. If you are ignoring it because someone else in the organization collects it, start using it.
Two: Fully Utilize Vibration Analysis
Vibration analysis is a tremendously powerful tool, however, most people only use it to detect avoidable fault conditions that require some form of corrective maintenance. That is, of course, a very important application and certainly generates an attractive return on investment. But there is so much more that can be done.
First, vibration analysis can be used to detect the root causes of machine failure. For example, by detecting unbalance, misalignment, looseness, resonance, installation problems, lubrication issues, incorrect operation, and more – and then eliminating those conditions – we can greatly reduce the likelihood of bearing faults and other conditions that will result in corrective maintenance and possibly downtime. Sure, you may already react to high vibration due to serious unbalance, but what we need to do is eliminate these conditions even when they are not severe.
Second, vibration analysis can be used as a QA tool. As described above, we can test the machine after it has been put back in service to ensure the work has been performed correctly (with precision). But we should also use vibration analysis as part of an acceptance-testing program. All new/overhauled machines should be tested based on an agreed standard in order to ensure that is “fit for purpose” at your plant. You will be surprised how many problems you detect - and therefore how many problems you avoid.
Three: Write Useful Reports
One of the most common complaints made by people in maintenance and operations is that the reports generated by vibration analysts are too heavy on data with vague suggestions of fault conditions, and too light on information and recommendations that can be acted upon. All they want to know is what to do and when they need to do it.
Four: Design the Program Correctly
After purchasing a vibration monitoring system there can be a great temptation to measure most of the rotating machinery in your plant (regardless of actual criticality), using the “default” settings, collected every 30 days to begin with but then stretching out to 90 days or even less frequently depending upon the available time to perform measurements. Unfortunately, this is a recipe for disaster. It can be a disaster because machines will still fail on your watch, and/or the warnings you provide will be too short and as a result the maintenance and operation departments will lose faith in your service.
The answer is to perform a proper criticality analysis to determine where you can justify the use of vibration analysis and the overlap of other technologies. You also need to understand failure modes in order to ensure that a) vibration analysis should be applied at all, and b) that the settings used are correct, and c) that the measurement interval matches the lead time to failure (LTTR), also known as the P-F interval. You do not need to perform a thorough reliability centred maintenance (RCM) analysis to make these decisions; a more streamlined approach can be taken. But you do need to perform some sort of analysis to ensure your program will deliver maximum value.
Five: Teach Others about VA, CBM and Reliability
There are so many companies around the world with skilled vibration analysts working with people who just don’t get it. This is tremendously frustrating for those analysts, and it is a waste of a terrific opportunity to reduce maintenance costs and downtime. It is essential that everyone in the organization understands the basic capability of vibration analysis (and the other condition monitoring tools) and the principal of condition-based maintenance and the principal of reliability improvement; eliminating the root causes of failure.
This represents a tremendous opportunity for industry. Everyone should understand these principals, from senior management down to operators and craftspeople – and that certainly includes people in maintenance and operations. And that leads to sixteen.
Six: Sell (and Re-sell) your Program to Senior Management
Some of the best vibration analysts in the world have come to work only to find that the company has shut down the condition-monitoring department because they did not appreciate the value of the service. I can tell you so many stories. Maybe you have been through this already. It is simply not enough to be a skilled vibration analyst.
When the vibration program began it was probably common for equipment to fail. These failures had everyone’s attention, including the senior plant management and the senior executive of the business. Thanks to vibration analysis, catastrophic failure becomes less common - even nonexistent. What a great job you’ve done! But what happens when someone up above decides they need to save some money. Do they think they need you anymore? Who needs vibration analysis if you don’t have machines breaking down all the time?
So you need to be proactive. You need to understand how your service adds value to the business – how your service is aligned with the goals of the business. And you need to frequently communicate the importance of your service. Document the “saves” you have made. Document the costs you have avoided and the costs you have reduced. Measure your current state and the progress that has been made since the program began. Demonstrate how the vibration program has improved safety, reduced the number of environmental incidents, reduced maintenance costs, and how your activities reduced downtime, thus, enabling operations to achieve their targets.
Or you could ignore this suggestion and instead work on your resume? Just kidding. Sort of…
Now, it should be stated that any criticisms made above are not directed to you personally. These are just general observations of common problems that the author has observed over the past 30 years. Hopefully one or two of these suggestions will help you in your program. And even if all of these suggestions apply to you, it does not mean you have not been providing an excellent service to your employer or customer. They are simply intended to reveal opportunities for providing greater efficiency and an improved service.