The Evolution Of Vibration Monitoring
This month we sat down with Chad Dyson to have a discussion about how vibration monitoring has progressed over the years and where it is heading. In this Q&A Chad offers great insight to some important questions you might have if you are considering starting a vibration program, or getting your existing vibration program into the next gear.
Can you tell me a little bit about yourself, your current position and a brief history of your career and experience?
I’m a vibration analyst of over 18 years. I spent a lot of time in oil and gas, but have also been exposed to a lot of other industries, pulp and paper, chemical and some manufacturing. I have worked multiple roles in the vibration analysis space. I have worked in many roles in the vibration field, from sole analyst on site to lead analyst of a team for a contractor, to sales of vibration hardware and reliability solutions.
Can you explain what vibration monitoring is for people that are not familiar with it?
Typically, we perform vibration monitoring on rotating equipment, although you can monitor vibration on stationary equipment, but for the purpose of this call we’ll discuss rotating equipment. What we’re trying to do is monitor the frequencies of the vibration that are occurring on a piece of rotating equipment. We accomplish this either with a handheld device, a wireless device, or some type of full time online monitor. What we do with that is we take a waveform, which is the raw vibration data, and run it through an FFT (Fast Fourier Transform) that converts the waveform to a spectrum to see what frequencies and amplitudes are present.
From there, we can use a little bit of math, some knowledge of the components inside the machine we are monitoring, and speed of the equipment to come up with some diagnostics about the equipment faults. So, we’re able to determine whether a machine is out of balance, if there are bearing defects present, if there’s misalignment, or if there’s process events occurring in the system that are causing our machine vibration as well, like cavitation. The goal is to take all of this information and make an accurate prediction of how long this machine will run in its current state with the defects that are present. From there, we’re able to effectively plan when to do the maintenance. You want to perform the right maintenance, at the right time. In doing this we can reduce downtime and costs. If we only need to repair the bearings, then we will only repair the bearings. We typically don’t want to run a piece of equipment to failure, because then we may have to replace more than just bearings. Things like shafts, impellers, pump casings and bearing housings will get damaged. The repair scope, cost, and downtime are likely to increase greatly. What we want to do is make the right call at the right time and take action at that point. We want to maximize runtime, but we don’t want to maximize it by just running it to failure, that’s not cost or time effective. We take all of that information from the vibration signal, process variables, and temperatures as well, to paint a nice picture of the health of the machine.
You mentioned FFT, what’s FFT?
FFT stands for Fast Fourier Transform. It’s an algorithm by two mathematicians, Cooley and Turkey based on a tool created by Fourier who was himself a talented mathematician. A vibration waveform is made up of many different frequencies at different amplitudes and even phases. The FFT algorithm takes the data in the waveform and converts it to a spectrum. The spectrum is represented as frequency and amplitude. This allows us to see all the different frequencies occurring in the waveform and diagnose the defects present on the machine in question.
What is driving the need for vibration monitoring?
Unfortunately the mindset of just running equipment to failure is expensive. Failures become an issue because the repair is going to take longer, is more costly, and unexpected. If we’re able to actively predict how long and what the actual defect is, we can make a more accurate prediction of when to repair. Basically, at the end of the day, it’s a cost reduction. Everything comes back down to dollars and safety. If we can see a machine that’s going to have a failure soon, we’ll catch it and repair it. We won’t let it catch on fire possibly, right? That’s always a risk as well, so it’s safety, dollars and maintenance budget driven. They’re all savings.
What are the advantages and disadvantages of vibration monitoring?
The advantage is that there’s plenty of upside. We’re able to make an accurate prediction on a defect and take the right action. Right action at the right time. We can use vibration levels as a KPI for plant maintenance activities. Those are some of the positives, those are the upsides. As far as you know, you’re getting a look into the future. Some of the downsides of it is that it can be labor intensive. What I mean by that is we have to send someone out with a portable analyzer to collect this data. This person is now out in the elements, next to online process equipment. There is a certain level of safety risk associated with the collection of the vibration task. We are able to collect a lot of data with a Triaxial sensor now, but in the past, we used to only have access to single or maybe even dual channels. So, data collection was a big part of it, where you didn’t have that much time to analyze. Now we’re getting to the point where we have access to a lot of data and now we need the time to analyze. Another of the downsides is the length of time to collect data. Our analysts are better off spending their time actually analyzing than to go out and physically collect the data.
What are the different ways in which vibration monitoring can be implemented in a facility today?
One way you can do it is to grab an analyzer, head out to the field and actually collect data on every single piece of equipment that’s running in a manual data collection route. With a manual route, depending on how your program is set up, your vibration analyst may only have a chance to get out there to collect the data once a month. If you are in a facility with spared pieces of equipment, you may only catch one pump running in a month and you won’t make a round back out there until the next month.
Some other systems are machinery protection systems, like a wired solution on critical equipment, hardware designed to shut equipment down once it reaches a certain vibration level or a certain parameter that is configurable, but that solution is very expensive. You’re talking about a hardwired system that is very expensive to implement and can be a little complicated to operate. So, you only put it on the top 5 to 10% of your equipment in your facility, your large pieces of equipment, things that are going to cost millions of dollars if they fail and cause millions of dollars of downtime.
Another way to do it is a wireless solution. With this technology, we’re actually able to power sensors up in multiple different ways, so I don’t have to worry about building an infrastructure to haul all of this information back to a central spot. You can deploy sensors all over your balance of plant equipment and then you bring all your information back wirelessly. One downside of that is if you’re deploying a whole lot of sensors and you can have a lot of batteries to maintain, because these things typically are battery powered. Just like any battery, it’s a resource, so at some point, that battery is going to be dead and need to be changed. So, you need to look at battery life as you trade wires for batteries. It still requires some maintenance, but its deployment is easier, and you can do a lot of it very quickly.
How do you decide which equipment should be manually inspected, which should be wired, and which should be wirelessly monitored?
When I put a hardwired protection system on I’m looking at my top 10% of my plant equipment, my large compressors, my large motors, things that are million dollar losses when these things go down. From there we can do a little criticality ranking, but roughly 80% of your equipment in your plant is your balance of plant equipment. These pieces of equipment are still very important to your process, but they don’t warrant enough downtime and costs from a failure to put a hardwired system on. In the past we only had one option for balance of plant equipment, and that was to go with a handheld device and collect vibration data. But now for a balance of plant equipment we can collect the data wirelessly.
So, we’re able to get almost an always on data stream, at least get an overall levels constantly brought back to your computer and provide a really good indicator of which machines are in distress. From there, we can do a couple different things. Depending on the system you have, you may use one that just gives you an alert, “Hey, I’ve got some issue on this pump.” So I’m going to take my vibration handheld device, and I’m going to go out there and do a deep analysis on the pump. That’s a great method because what I’m doing is I’m not requiring my analysts to be in the field all day collecting data, it’s more directive driven. The wireless system suggests that I need to look at this particular pump and I’m going to go out there, take a look at my pump, and come back to do a deep analysis on it while knowing that I have a system watching all of the other equipment while I am doing my little deep dive analysis on this one pump.
That’s a great approach. How do you decide if you want to insource or outsource your vibration monitoring program?
It depends on your level of expertise in the plant. For some plants, given their size, it might not always be advantageous for some sites to have an in-house vibration analyst. It’s a very specialized trade, it can take a while for someone to get really decent at it and they’re not always around. If you have a supervisory system looking over, you can have someone remotely access it. They don’t have to be at your site and you don’t have to pay to have someone travel down. If you’ve got a nice wireless system, someone can access that remotely and send out some emails saying, “Hey, I’d take a look at these three or four pumps”. That’s one way to do it. However, if my facility is large enough and I have enough work to justify a full time analyst, I can either have a contractor come in, or I can hire my own in-house vibration analyst to look at my data every day. Those are the most popular ways to do it.
Do you see an opportunity to combine a wireless vibration system with an outsourced vibration analysts support?
I think having outside support is a great way to do it. That way, you can keep your costs down and that’s a completely viable way to do it. Some of these systems will have a dashboard that they can simplify the condition of your equipment in red, yellow, green. This particular piece is in red status, maybe I just need to go out there and take a walk and take a look at it, but if I can not figure out what is going on, having a contractor to either remotely look at the data to give a first diagnostic and recommendation is completely viable. From there the contractor might decide if he needs to come onsite to do a more detailed analysis and get more contextual information, but at all these stages you are informed and you can make a maintenance decision and manage your vibration monitoring costs better.
Changing gears, what is working well on providing value when it comes to vibration monitoring?
The value is in the early prediction of the fault, or at least it’s in seeing the fault coming early enough to take an action. It’s to not run it to failure because we’re able to detect exactly what the issue is and only go after that issue, that’s the value savings. You wouldn’t throw away your car, because the tires are bad, you just replace the bad tire, same method here. With the vibration analysis, we can really pinpoint exactly what the problem is. We can say, “Hey, there’s an outer race bearing defect on this exact bearing”. Depending on the machine type, you may only go in and replace that actual bearing. Or it could be for example, “Hey, the machine alignment is off and we need to realign the machine”. Misalignment causes issues with seals, increases heat, and heat increases bearing wear. So, misalignment is something that we’re able to detect and fix, and it has a positive impact on the life of the equipment overall, and avoids the early replacement of a seal, a bearing, or the overall equipment.
What are some of the challenges that facilities are facing with their vibration monitoring program?
Some of the challenges are kind of what I talked about earlier. It does take a little while to train someone up, that’s where a contractor comes in. If you have a manual walk around program you’re only going to get a chance to make a round on a particular unit once a month. That is because of a combination of the amount of equipment you have to test, the number of vibration analysts you have, and the time it takes to collect the data. The other 29 days, you’re not looking at that piece of equipment. A lot of things can happen in 29 days. You can run a pump poorly from an operation standpoint and absolutely tear one up and a lot of things can happen quickly. So, with just a walk around program, those are some of the issues that you run into. You don’t get that always watching system, you’re going to get that with a wired or a wireless type of solution.
Who is most receptive to support the implementation of vibration monitoring in the facility, typically?
Typically, it’s going to be someone along the lines of your maintenance manager. It may even be that your plant manager is requesting it, depending if they had some high profile failure. Typically, maintenance managers, reliability engineers, and mechanical engineers are the ones who are typically going to implement and drive a program.
On the other side of the coin, who is skeptical or in opposition to adopting a vibration monitoring program?
Sometimes craft people will not understand exactly what it is we’re trying to do. When we give feedback, they’ll say, “Man, I worked on that, I know I did that alignment, it’s supposed to be good”, but the analyzer doesn’t make up these numbers. This is a tried and true method. It can even come from some level of management, where they are not seeing the value. So, in those instances, we need to increase the visibility of exactly what it is we’re doing and the catches we’re making. Those are kind of two hurdles. I don’t really have a good answer other than you kind of work with those craft people to say, “Hey, look, this is where we were before, when you went back and you changed these things, this is how they’re looking now”. That typically wins the guy over. It’s basically increased visibility for what we’re doing.
Do wireless vibration monitoring programs replace the vibration analyst?
What we’re actually talking about is taking the analysts out of the field, and we’re gonna fill that time with what we’re paying him to do, which is to analyze. That’s where the analyst is really making his value, his money and bringing value to whoever he’s working for. The collection is one part, but really we want these guys to have time to analyze. With a wireless solution, we’re going to be collecting the data for them and we’re actually going to give them more time to analyze and actually look at more data daily. You could probably make an argument to hire another analyst, because you’re going to have a constant stream of data, more visibility and more things to check and analyze. So really, it shouldn’t be a job hindrance, it should actually give them more security and ability to show off their talents better with a wireless type of system. If they’re really good at analyzing, they’re going to get to analyze, and they’re not going to spend so much time going out to the field to collect the data.
The other concern that I hear is, does the wireless vibration monitoring program replace the handheld analyzer, what’s your thought on that?
I see it as a compliment, so you can still use your handheld analyzer and a wireless sensor. Currently, some of the limitations of wireless monitoring may not be able to collect all the special readings that a handheld vibration collector can. It’s always good to go out there and actually take a look at a piece of equipment. You may see something like loose bolts, an oil leak, a seal leak, the coupling guard is loose, some gauges were broken, and flows were off, all of those are all things that are better detected in person. Those all go into determining the health of the machine, so I see them as a complementary tool to each other. Absolutely, you can grab your handheld and go out and collect some additional data to do a deep dive beyond the information your wireless system is providing. I don’t see any downside to having both.
What is your overall assessment of the state of vibration monitoring, is it a growing trend, slowing trend, an exciting opportunity, or is there some terrifying threat about it?
No, it’s really taken off here. I would say where we were 10 years ago to where we are now, are completely different spaces. We were primarily focused on handhelds, but now with how the technology is improving, we’re able to get more data, and not just in vibration. We have all of these wireless technologies, even some batteryless ones, where we can get a lot of data into the hands of the analysts. You take that, along with machine learning, AI and you start to see some really slick things where you’re getting some early warnings based off of machine learning. If we can actually use that data with machine learning, it gives us insights into different things and we can actually create little ecosystems where we’re taking in vibration parameters, flow parameters, temperature, amp loads and come up with an overall system health. So, it’s not always just the bearings, we can make a more accurate prediction with all of these other parameters built in and find a root cause of where the actual issues are coming from. If we’re seeing bearing defects every time on a pump, and we have all this other information that shows we are constantly running this pump off its performance curve, then the bearing failures are coming from the fact that we’re running the pump on and off its performance curve at times, so we need to re-engineer that pump. We need to either change an impeller, increase flow through it, or some other way to get it to its best efficiency point on the pump performance curve.
What trends have you been observing in regards to vibration monitoring approaches?
The ecosystem approach. We want to gather all of this information and we don’t want to silo it, we want to get them all in the same spot. There are plenty of companies out there that make data aggregators, these are some high level dashboards with a bunch of algorithms in it, and it gives you the overall health of a system. Where we used to have even teams not really talking, process teams not talking with maintenance teams, now we can aggregate all of our information in one spot. Everybody can see that and make conscious decisions on the actual health of the equipment, not just their one piece. It’s been really great for that.
Where do you see the future of vibration monitoring going? What’s the North Star that you see, in terms of implementation?
I think it’s going to be heavily AI based, but it’s still going to require a lot of human interfacing. I don’t ever see it going completely automated. I do see us less in the field collecting data. As sensors and technology improve, we’ll be able to request whatever we want from our desk. I think there’s still a role there always for an analyst, someone to come in and make the calls, because there’s always that human nature, something that even that machine doesn’t understand about the process or just experience in general. We put experience into machine learning, into an AI but there’s always just that little bit of human factor. I don’t think you’d ever want it to be completely automated. I think the technology is getting so good, where we’re getting all of this information, and it should make analyzing and root causes easier and faster to predict and see coming, so you can do more with your limited time.
Basically, eliminating the manual data gathering, the data coming to the vibration analyst and then maybe AI becoming this sort of sous chef to the vibration analyst, helping him and then making him more effective in making that final decision that needs to be taken for the equipment?
Exactly. It is another layer of protection basically, it is another “hey, this system has my back, looking out for me even when I’m not at work”. That’s one of the other things where maybe you had a facility where you had to work a bunch of overtime and get called in, now we’re able to make those calls from home or at least on your phone. You can get the machine information out to your phone in a lot of instances and that way you can get some of your weekend back, you can have work life balance. All of those things are going to change for the better in the future here.
Why will vibration analysts or maintenance managers want to consider wireless batteryless vibration monitoring?
It’s a reduction of people in the field and we can see it as a safety improvement as well. The less time I actually have someone walking out in the environment, next to the hot equipment, tripping hazards, and all those kinds of things, the better. So, I’m going to remove the human factor of someone having to go out and collect that. That’s one of the ways. The other way is I can elevate that data to whoever wants to see it. It doesn’t have to be siloed with the vibration guy. I can now get that information to my maintenance manager, or my plant manager. I can just give him a red, yellow, green, he doesn’t necessarily need to see all the technicals but he probably likes to know that his equipment is running good. He can ask questions about the situation and provide a direction for someone to go out and collect more data to help in the final decision. It’s just another layer of visibility, that’s always going to be good. The more people we have looking the better, always.
Do you think that wireless and batteryless vibration monitoring systems might help in the retention of critical vibration analyst talent?
Sure, because now I don’t have to send that guy to the field, so I’m putting my older, seasoned guys in a comfortable environment every day. I don’t have to necessarily be worried too much about turnover, he doesn’t have to go out underneath a hot dryer section and collect data, that’s tough on someone. We’re talking about extreme temperatures there. You’re not going to be sending someone out, especially with the batteryless system, to constantly maintain batteries. We’re gonna have that always on, that always streaming data. I’m not wearing somebody out just by going after batteries all day. So yeah, those are some definite ways where that should help, especially the work life balance as well. I can give a guy his weekends back and he can look at data for a couple minutes and make a call to the plant and say, “Hey, take a look at this one piece of equipment”. He doesn’t have to go in and stop what he’s doing. He could be at his kids game or out to dinner, and he doesn’t have to stop what he’s doing and leave. Those are some of the things that would absolutely help that balance, for sure.
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