Podcast: How compressed air innovations over the last 10 years have shaped industrial maintenance

For a long time, compressed air systems were a massive time drain on stretched maintenance personnel, with plants reluctantly willing to make a tradeoff of continuous manual intervention in exchange for constant air delivery. However, things are different these days. In this episode of Great Question: A Manufacturing Podcast, Ron Marshall of Compressed Air Challenge reviews some of the key changes in the compressed air world over the past 10 years have dramatically improved things for compressed air users.

Below is an excerpt from the podcast:

PS: Ron Marshall is an independent consultant, the marketing coordinator of Compressed Air Challenge, and he recently wrote a new cover story for our July/August print issue. He tackles a look backward in the industry, looking back 10 years to identify what were some of the most important changes that we've seen over the last decade, and pointing toward what might be coming in the future. Ron, welcome back to the podcast.

RM: Thanks for having me on again.

PS: Now we don't have to walk through each of the changes that you outlined in your article. People can go ahead and click to the article if they'd like, but I appreciate you being on to talk about some of the key developments that you did mention in the article.

RM: Sure, sure. Yeah, that would be a good idea.

PS: The first one you mentioned right away are CAGI Data Sheets and what I like about that one is that, at this point, I think people in our industry know that these are pretty familiar objects. They've been around for a while, but I was with you 100% that these have made a massive change in the past 10 years. For people who aren't in the compressed air industry or who might not know about them, can you explain what these are and how they work?

RM: Basically they are sheets describing the important characteristics of air compressors. The testing is done by third party verification testers. Back in the old days, there used to be some really round numbers detailing what the rated capacity, the brake horsepower, all those things were for various different makes and models of air compressors. I would say sometimes some manufacturers didn't pay close attention to accuracy in this.

When it comes to comparing compressors, it's pretty important to be able to choose the correct one, one that may be the most efficient, if you're concerned about efficiency. So the third party verification and the CAGI sheets can be used to compare the compressors, one manufacturer versus another, or even within the manufacturers, one make of a compressor versus another. Sometimes compressor manufacturers have basic premium and super efficiency type of compressors, so you can see the flow of the compressors, the test pressure, the kilowatts, and a specific power number that's telling you how much air you get from certain kilowatts. That tells you basically how efficient the compressor is.

Now through the years, CAGI started with one sheet for fixed speed compressors. But variable speed drive compressors were developed, so now there's a sheet for variable speed drive compressors where you can see the efficiency across the full range of operation. Then there's specialized CAGI sheets for variable displacement compressors as well. Refrigerated dryers are another component, and there's CAGI sheets for those as well, so you can see the difference between the non-cycling and cycling dryers, and make a wise decision or an informed decision on the equipment you're buying, and the comparison between equipment.

PS: That's really the hub of this, is that it's a vendor driven organization, and the vendors came together to provide this information for customers to understand what the best capital equipment would be for the application they're seeking to use it on.

RM: Yeah, it's very good information. I was really excited, I was working for a power utility when they first came out, and I used those sheets all the time. They're a nice, accurate way of determining efficiency and characteristics when I'm testing compressors. You can gain good information from these sheets. I'm really very excited about the sheets still, and even more excited now, because I think I mentioned in the article about “isentropic efficiency,” a new number that's on the CAGI sheets now.

PS: You did, you called it out as specifically as a KPI which is extremely useful to plant teams. For those who don't know what it is (and when you introduced it to me, I wasn't familiar with it), could you explain what it is, and why the inclusion of this particular KPIs is an important game changer?

RM: With isentropic efficiency, what they do is they take the mathematical model of a perfect compressor, and calculate out how many kW /100 cfm is produced by that perfect compressor. Then they set that perfect compressor to 100, so that would be what to compare to. And then when you compare an actual compressor, you're comparing what percentage it is compared to a perfect compressor. So, one compressor might be 77%, the other might be 60%, the other might be 80%, right. The highest number wins in terms of efficiency.

The reason they did that is because the old way of rating compressors, the specific power of compressors, was kW /100 cfm. Now with compressors, as the pressure goes up, the kilowatts goes up; as the pressure goes down, the kilowatts goes down. Manufacturers were testing the compressors at different pressures, and you didn't really have an apples to apples comparison with different pressures, and you couldn't really accurately compare the compressors. Now with isentropic efficiency, that number is not affected by the test pressure, so you can tell right away which compressor you're comparing, which one is the most efficient by selecting the biggest number, the biggest percentage isentropic efficiency.

PS: It’s another effort by the Compressed Air and Gas Association to level the playing field and to be to be transparent about these different kinds of measurements.

RM: Yeah. Excellent change. I really like it.

PS: Terrific. Well, I know we're going to put some links to sample CAGI data sheets in the podcast notes and in the transcript. Ron, why don't we move over to the second general category which you tackled in your article, which is condition monitoring tools. For anybody familiar with some of the tools, I think they're going to know which one you might want to talk about. But there was one that jumped out to you as a huge development in the past 10 years.

RM: Yes, that's right, it's the acoustical leak detectors. They are cutting edge! With the premium price tag. But that price tag is coming down quite substantially now that more players are getting into the industry. Just about every leak detector manufacturer has acoustical imager in their portfolio, and that is really good. Before you had something that was like a gun, with a cone on the end, and you pointed it here and there and you could hear leaks and other things too – maybe electrical corona, bad bearings, or things like that. You could hear the general direction of the leakage, but it really didn't pinpoint where it was.

With these acoustical detections devices, there's a visual image generated by a camera, and there's directional microphones in the back, and it overlays a signal and detects where the leak is in your image and tells you exactly where it is. That really speeds up the leak detection process and helps you identify even through caging, even from the floor, up 20 feet in the air, you can see exactly where that leak is and what pipe it's on, and that's important.

One time I was in this manufacturer where they had more than just air, they had welding gases going in the pipes. I shone that thing up in the into the ceiling, and I found a very expensive leak, a $33,000/year leak in an argon supply. It was only 1 cfm, so if it was compressed air, not really much to worry about. But with argon much more expensive than compressed air, that would have paid for the unit right on the spot. Just that one leak.

PS: Either that or that's some way towards getting more headcount too, What could you do with 33,000 more dollars?

RM: Yeah, that's right. So that's a really exciting development in the compressed air world and there's more and more plants now that have at least one imager available to them. There's new developments in the imager field, too, where they're coupling them to infrared and all that stuff, so it’s pretty nice.

PS: I think of this as the “camera revolution” among condition monitoring. It’s the acoustical imagers. plus you've got motion amplification technologies which take high speed video of the asset and slow it down where you can see things wobble and vibrate. I’ve heard a lot of technicians who say that the data that's the convincer to get money for reliability programs is these kinds of visual data. When you see it, you tend to believe it.

You also mentioned that there's a movement in the works to develop a universal agreed-upon air compressor communication protocol. Right now, some of these devices have trouble talking to each other, and this isn't directly related to condition monitoring, it's not going to assess machine health, but it's more moving the data around when you are taking these measurements and getting signals back. Could you talk about what's happening with third party controls providers in this area?

RM: Sure, it's very important to be able to monitor air compressors, to see what their operating parameters are, if they're overheating, various things like that. Control is very important as well, to be able to control compressors, tell them to load and unload in a strategic fashion. The problem with the air compressor industry is there's different communication protocols for each manufacturer, right? One manufacturer might have Profibus, one might have Modbus, one might have CAN bus, and when you try to tie them together so that they are communicating with one another, it's impossible between manufacturers. It's not like the HVAC industry where they came up with a common protocol like BACnet, where various different manufacturers could connect to one communication bus.

So yeah these communication providers are now figuring out the various communication protocols for each different manufacturer, and they're putting them together, actually have a little box that translates the language and brings them together in, say, a web-based software package where you can monitor the compressors so the software would indicate if the compressor is overheating or what the conditions are. You can see that all in a dashboard and be able to control the compressors using that digital data rather than just sending digital signals to load and unload compressors, which is the old way of doing it, or tricking the compressors to see a different pressure than there actually is. That used to be done as well, but now you can write to the compressors and tell them to load and unload or alter the settings all through this software.

More and more of these providers are starting to do that now, and once you're hooked into those compressor controls, there's a lot of information that you can take out of them, and that tells you a lot about how that compressor is running, and maybe flags when maintenance is required or things are going out of bounds. This is on the dashboard, or you might receive an e-mail, that there's something happening. That's starting to develop now, even down to the compressor condensate drain level too, I've seen some drains that communicate with some sort of computer as well. I guess it's the IoT era, where things are starting to talk with one another.

PS: You know, there was a comment made sort of an editor to editor meeting this week where were thinking that a lot of folks who are doing IoT, if you ask them if they have IoT setups, they'll say “no, we don't have IoT in the plants.” But when you say, are you moving data around this way and that way and storing it in the cloud? “Oh yeah, we do all that!” IoT has slowly crept in one sensor at a time and one asset at a time.

RM: Yeah, that's right. In the compressed air industry, information is power, so it’s good that you get the most information possible. The software packages now gather that information and show you the important stuff and flag when things go wrong.

PS: I'm curious if you if you can give a thumbnail estimate. Clearly this something which is a gradual evolution rather than a targeted effort by any one or two manufacturers. Would you say we'll be there where the devices can talk to each other or over a common protocol within three years? five years? Or is this going to take the time it takes?

RM: Well, that's on my wish list and I really hope that the manufacturers get together and talk with a standard communication protocol. There's so many of the older compressors out there that are talking with the old protocol. I'd be very surprised if it actually happens, right? Not with the OEM's, maybe. I don't know. I don't think it's going to happen soon.

PS: I like the fact that the discussion is underway and I know a good integrator partner can help people out with these kind of challenges too, on a plant to plant basis.

RM: Yeah, that's right. The possibility is there. People out there who have received a new compressor, some of those compressors have cell phone connections on them. You see a little antenna on top of the compressor. The manufacturers are using that, sending data back to the main office or whatever to tell people that maybe the oil needs changing or there's high vibration, or things like that. People can subscribe to that service and get that information themselves; or, the manufacturers just use it for their own purposes, and that helps them as well. But I can see with some sort of interface like that you could pull things together in a room full of even different manufacturers, and come up with a really good dashboard that could help the maintenance people.

PS: Let's finish with the last category you covered in your article, which is professionalization and opportunities in that direction. You specifically called out two certifications that are setting the bar in the compressor industry. Could you describe those?

RM: Yeah, yeah. The first one is CAGI Certified Compressed Air System Specialist (CCASS). There really isn't a certification in the compressed air industry, not a common one anyway, so CAGI came up with this certification. It's really a general level of understanding of compressed air for the compressed air professionals. You write this exam, it proves that you have a general level of knowledge, and you can call yourself a certified compressed air system specialist. And that's good to have, you can put it in your e-mail signature and things like that, it lets people know that you know what you're talking about.

Then there's a second level of certification – CCASA, Certified Compressed Air System Auditor, and that is going to be for compressed air geeks like me, where we go around doing audits of compressed air systems. It's going to be quite a more difficult exam that you have to write to prove your worth, and then that'll get you a pretty nice certification to show that you are very good auditor, a knowledgeable auditor.

The problem with the certifications is CAGI really doesn't provide the training. It takes a lot of experience of course, plus some book learning. There is a body of knowledge that you have to be familiar with to be able to pass the exam. Compressed Air Challenge provides a big portion of that body of knowledge through the training that we have, the fundamentals and the advanced training. There's a new training about system assessments as well, and that information people have found really helps prepare for the examination.

There's other things, too. There's some standards that people should be familiar with, the ASME EA4, and CAGI provides an online training that you should be familiar with too. CAGI also has a handbook, a very extensive handbook that's available for free download for people, and it would be recommended to go through that and to get familiar with that. But the key is, I believe anyway, the fundamentals and advanced training from the Compressed Air Challenge. So I would recommend that for anyone that wants to write for their CCASS or CCASA examination. Now I just wanted to say that the CCASA, I just checked the website today, it's still saying “coming soon,” but I would imagine within the next few months that'll start to be active.

About the Podcast
Great Question: A Manufacturing Podcast offers news and information for the people who make, store and move things and those who manage and maintain the facilities where that work gets done. Manufacturers from chemical producers to automakers to machine shops can listen for critical insights into the technologies, economic conditions and best practices that can influence how to best run facilities to reach operational excellence.