This episode of the Pipeliners Podcast features Russel Treat and first-time guest Jon Naylor discussing the process of securing pipelines in the field.
Listen for the historical and current technology used to secure joints, the different types of methods used, the current testing standards, the importance of the three t’s of industrial joint integrity, and more valuable insight.
We also want to hear from you if you have expertise in this field. Let us know if you are aware of regulatory governance in the U.S. or internationally covering the frequency of checking industrial joint integrity.
Fundamentals of Industrial Joint Integrity: Show Notes, Links, and Insider Terms
- Jon Naylor is the Managing Director of JNCS, a business development agency. Jon has three decades of experience in the global pipeline sector. Jon has worked in pipeline pigging, valves, and most extensively in industrial bolting. [Connect with Jon on LinkedIn]
- ECITB (Engineering Construction Industry Training Board) is the skills, standards, and qualifications body for the development of the engineering construction workforce of Great Britain. ECITB is an extension of the U.K. government, reporting to the Department for Education.
- ASME (American Society of Mechanical Engineers) is an international developer of codes and standards that support the practice of mechanical engineering.
- The structure of a pipeline consists of many different parts that are secured together to ensure the integrity of the pipe.
- Joints are used to secure separate pieces of pipe together to help create one larger structure.
- Flange is the location where joints are bolted together to secure the pipe.
- Gasket is used to seal the space between two parts bolted together to help prevent leakage.
- Bolts are used in flange connections to fasten the parts together.
- BOPs (blowout preventers) help seal, control, and monitor flow in the pipe.
- There are common methods used to secure joints that run along the pipeline.
- Spanner is a form of adjustable wrench that dates back to the 1800s.
- Hydraulic Torque Wrench is a modern, industrial power tool used to secure bolts.
- Hydraulic Bolt Tensioning is an industrial tension tool that helps accurately tighten large bolts.
- Hydraulic cylinder is a mechanical actuator used to provide unidirectional force through a unidirectional stroke.
- Power head consists of a piston and ratchet attached to a socket that tightens the bolt in a controlled manner.
- Daisy chain is the design of system used to connect the product flowing through the system, tied back to a central location.
- Pigging refers to using devices known as “pigs” to perform maintenance operations. This tool associated with inline pipeline inspection has now become known as a Pipeline Inspection Gauge (PIG).
- Temperature cycling is the process of cycling through temperature extremes at high rates of change to determine the integrity of the pipe.
- Expansion loop helps absorb temperature expansion and contraction in pipes. Expansion loops can be fabricated from standard pipes and elbows.
- Pressure cycling captures the fluctuations that occur during the course of operations, such as starting and stopping pumps and moving product with varying densities and viscosities.
Fundamentals of Industrial Joint Integrity: Full Episode Transcript
Russel Treat: Welcome to the Pipeliners Podcast, episode 70, sponsored by EnerSys Corporation, providers of POEMS, the Pipeline Operation Excellence Management System, compliance, and operations software for the pipeline control center. Find out more about POEMS at enersyscorp.com.
Announcer: The Pipeliners Podcast, where professionals, Bubba geeks, and industry insiders share their knowledge and experience about technology, projects, and pipeline operations. And now, your host, Russel Treat.
Russel: Thanks for listening to the Pipeliners Podcast. I appreciate you taking the time. To show that appreciation, we’re giving away a customized YETI tumbler to one listener each episode. This week, our winner is Sadie Goodrum with Oasis Petroleum. Congratulations, Sadie, your YETI is on its way. To learn how you can win this signature prize pack, stick around to the end of the episode.
This week, we’re very fortunate to have with us Jon Naylor. Jon is an expert in industrial joint integrity. That’s what we’re going to be talking about on this week’s episode. Jon, welcome to the Pipeliners Podcast.
Jon Naylor: Hey, Russel. Thanks for having me.
Russel: What part of the planet are you sitting on today?
Jon: Well, I’m not in the United States, that’s for sure. I’m actually in England. I’m about 12 miles north of Newcastle in the northeast of England.
Russel: Perfect. Well, that’s just the marvels of technology that allow us to capture a podcast, being that far apart from one another.
Jon: Yeah, isn’t it wonderful?
Russel: It’s awesome. I’ve asked you to come on and talk about the fundamentals of joint integrity. I’ll be honest, this topic’s new to me. I’m probably a bit misinformed, because I might be of the mindset, you just put the bolts on, tighten them up, and that’s good enough. Maybe you could tell us, what is joint integrity, and why should I care?
Jon: You’re probably amongst the majority of people. Everyone knows what a bolt is, and we’ve all tightened one, to be honest, most of us. When you get to the large, critical joints in industry — particularly industries like the pipeline industry — those joints have to be tightened correctly and safely to ensure that the joint doesn’t leak.
That’s really where the term “industrial joint integrity” comes from.
Russel: I’m sure, like everything else, this is a technology that’s got some history and has evolved. Maybe you could talk a little bit about where does the science of joint integrity get its roots, and what is the history around all of that?
Jon: Yeah, sure, I’d be happy to. We’ll kick off by saying, in the early days, it was a long way from science. That’s for sure. Back then, you’d take a large spanner, a large hammer, and an even larger guy. He would hit the spanner with the hammer until he thought it was tight.
Some of these guys would even claim that they knew from the sound of the ring when they hit the spanner that it was tight and good to go. The truth is that that was a very uncontrolled way of tightening joints.
Maybe back in the early to late 1960s, some bright spark decided that if you could replace the big guy and the hammer with a hydraulic cylinder, you could then maybe take a bit of control of the tightening process. It just made the whole thing a bit smoother.
Really, that was the birth of the hydraulic torque wrench that we know of today. They’ve come on in leaps and bounds, but really, the basic principle is the same. You take a pump, you press your oil to up to 10,000 PSI.
That pressure leads through hoses into a power head, which is basically a piston and ratchet attached to a socket, and that will tighten your nut and bolt for you in a more controlled manner.
Russel: It’s interesting. I just did some other podcast recently, and we were talking about how a lot of the rulemaking in the U.S., it refers to things that were before 1970 and after 1970. Then here again, we get on and we talk about something. That timeframe of 1970s, this is another area where technology and approach began to change.
Jon: Certainly began to change, yes. One could safely say the bolting industry at that time was pretty gung ho. Yes, it certainly began improving in the early ’70s.
Russel: There’s still big guys doing the work, they’re just using a hydraulic wrench instead of a hammer and a spanner.
Jon: Exactly. There’s still those big guys out there, but they’re just pushing a button now.
Russel: Yeah, exactly.
Russel: What are the various methods of tightening?
Jon: I guess you could split it into three basic types or methods. The first one, probably a lot of people have seen in the garage when they’re getting their car wheel refitted, is the hand torque wrench. It’s just using the guy’s strength, and it’ll click when you reach the correct torque.
They’re okay on the small size nuts and bolts, but when you start needing bigger forces to tighten the nuts and bolts correctly, that’s when the hydraulics kick in. There’s two types of hydraulic methods for tightening nuts and bolts.
One is the one we’ve already discussed, which is hydraulic torque wrenches. I’ve described how they work, so I won’t repeat that. The other method is known as tensioning, hydraulic tensioning. In that process, basically, you fit a hydraulic ram onto the bolt stud itself, and stretch the stud with very high pressures, up to 20,000 pounds per square inch.
You then hand-tighten the nut, and then the pressure is released. That residual load in the bolt causes it to tighten. Now, there’s pros and cons to both, but I would say still 80 to 90 percent of the hydraulically tightened nuts and bolts on this planet are hydraulic torque, rather than tension.
Russel: Interesting. I just went through a whole mental loop. I grew up as a civil engineer, and I remember in university doing some stuff in the labs with pre-tensioned rebar in concrete, a similar idea.
Jon: Very, very similar, yeah.
Russel: In terms of how you build structural integrity into a system. I just connected some thoughts that are decades apart right there.
Jon: Yeah, yeah. I could hear the cogs going. [laughs]
Jon: A great way to think of a nut and bolt is more like a spring, because although it’s solid steel, when you’re turning the nut, it’s actually stretching it. A key point is that you kind of overstretch them. That’s really a very important point when you’re looking at the fundamentals of industrial joint integrity.
Russel: Yes, that’s the nature of metal, is it seems to us that it’s immovable, but you put it under enough heat and/or pressure, and all of a sudden, it’s fluid. Again, this confirms another belief of mine, that’s everything’s easy until you know enough about it.
Jon: [laughs] Yeah, absolutely. The flexibility of metal is our friend but also our enemy. It just depends where you are on that line.
Russel: Exactly, exactly. It’s knowing how to apply that flexibility well that’s part of the science, really. Obviously, our listeners are pipeliners. What would a pipeliner need to know? What would be important to a pipeliner to know about joint integrity?
Jon: I’ve listened to a great number of your podcasts. A lot of the time, I’ve heard discussions about failures of pipelines and the reasons for failures. You’ve touched on outside influences, guys digging them up, all that kind of thing.
In reality, the bolted joints on a pipeline system can really be considered as the weak links. You’ll find them on the pig drops, on the compression stations, on valves. All over a piping system, you will find bolted joints. Every one, sadly, does have the potential to leak or fail. That’s mainly because there’s a lot of components there, all of which have to be working in unison.
Russel: As I’m sitting there, and I’m listening to conversation, one of the things I’m thinking about is, in large pipeline systems, where temperatures are changing, either because of the product or because of seasonal temperature changes, all that stuff is moving.
Russel: One of the places that that movement is applied is anywhere where the pipe is jointed.
Jon: You’re absolutely right. You’ll know when people build large pipelines, they put in these expansion loops to allow for the pipe to expand and contract. Now, as far as the bolted joints are concerned, it’s down to the engineers to make sure that the spec of all the relevant components is correct, so that they can take those various outward forces and influences.
The problems then come when people come along to service and maintain the pipeline. They take out the old gasket, they take out the old nuts and bolts, have to put the right ones back in. There’s all sorts of potential there for human error.
Russel: What are the kind of things that would lead to a leak or a failure in a bolted joint?
Jon: A lot of people might think that the most common reason for a leak is that it hasn’t been tightened up enough. In reality, going back to the guy with the big hammer and the spanner, the problems they were causing was that they were tightening too much.
You know we mentioned about the bolt being a spring? If you overtighten that bolt too far, it’s not going to spring back. It actually begins to stretch and narrow at the point where it’s being overstressed. You overtighten some bolts on a flange, you’ve crushed the gasket, you’ve overstretched the bolts, and the whole thing appears tight at first, but it isn’t.
When you get some pressure inside that line, the whole thing is going to relax and start leaking. Absolutely worst case, you can have some catastrophic failures, which none of us want. It doesn’t do the industry any good, as far as the image is concerned.
Russel: Sure. I guess that’s interesting, because that’s a little bit counterintuitive, if you don’t really understand metallurgy and how this stuff works. It’s a little counterintuitive to think that the primary cause would be to over tighten the bolts.
Jon: No, it’s a factor a lot of people aren’t aware of. It’s human nature, if you think, “Right, I’m going to really wind that bolt down, and then it’s never going to come apart,” but you can take it too far, particularly with hydraulic torquing. It’s got so much grunt.
Russel: Right, right. Very important that you know that it be tightened correctly. I guess the other thing, as I’m sitting here thinking about this, the other issue would be that, if I don’t have consistent tightening across all the bolts.
Jon: You’re turning into a bolting expert already, Russel. I’m very impressed.
Russel: Uh oh.
Russel: People need to be afraid. Be very afraid.
Jon: I use an analogy all the time when I’m talking to people who are interested in listening to this bolting geek. The best analogy is, when you tighten the wheel nuts on your car, you don’t go clockwise or anti-clockwise around the four, five, or six studs. You do the opposites.
The reason you do them opposite is so that the wheel sits square, and isn’t off square. Tightening a flange off square, you’re going to damage the gasket, and you’re not going to get equal tightening across the whole flange.
There’s torque wrench manufacturers out there now who are pushing the idea that you shouldn’t really be tightening with one hydraulic torque wrench, you should use four. Then what you can do — one pump, four tools — you’re getting that parallel closure, and the whole thing’s closing down. There’s no gasket here.
Russel: If you’re doing it on an x-y axis, then every time you’re tightening, you’re getting a consistent pull against the gasket.
Jon: Absolutely, yes. You’re not overstressing one part of the gasket. Going back to the hydraulic tensioning I mentioned earlier, nobody would tension a flange with one tensioner. They’ve always put them 50 percent.
If you’ve got a 24-bolt flange, you’ll have 12 tensioners on there, all daisy chain interlinked to one pump, so that you get parallel. The forces that the tensioner’s putting in, it’s taking the whole system close to its maximum, anyway.
Russel: That’s fascinating.
Jon: Yeah, that’s one of the minor downsides of tensioning, is you need a lot more equipment to tighten each flange. Also, you need extended bolts. On a two-inch bolt, you’d need eight inches of bolt extension, so that you can get hold of the threads with the hydraulic ram.
Russel: Yeah, exactly. It’s like a lot of these other episodes where I’m talking about a subject that I really don’t know a lot about, and yet it relates to education and experience that I have. I’m processing this, and I’m thinking about what would make for a good joint, versus a poor joint.
Like a lot of other things, it’s not just about what you do and the tools you use. There’s also a process involved. Maybe you could talk a little bit about what would be the appropriate process from I’ve got a joint, and I need to get it bolted up and connected. What would be a good process for doing that?
Jon: I tend to call it the three t’s of industrial joint integrity. The three t’s are this.
One is training, so that the guy who’s got the equipment knows what he’s doing. There are recognized standards. There’s one in the U.K. called ECITB, mechanical joint integrity training. That’s now recognized globally. The other one, ASME, they’re also doing a bolting training course so that the guys can be certified to show that they actually know what they’re doing. Frighteningly, it’s not that long ago that a guy off the street could walk onto a site, and tighten a bolt, a flange, really with no training at all. That’s been a step in the right direction. People are now getting correctly trained.
The second t is tooling. We’ve already touched on the various types of torque and tension tools available. It’s important that you have the right tool for the application. There’s a number of issues that you need to consider when you’re looking at a bolting application. One is obviously the size of the nut and bolt. Another is access. There is lots of applications out there — BOPs, for example, where access is very tight. You have to make sure that you have the right tool.
Then, thirdly, the tool has to be of the right power output, because we’re taking ourselves right back to that overtighten we were talking about. Too big a tail of the job, jack up the pressure too much, you’re stretching your bolts, and you’re setting yourself up for a leaking flange.
The final T is traceability. I say traceability, but it’s a bit more than that. This is really where the bolting industry is catching up. It’s as far as creating work instructions for the guy, how that work instruction is fed to him.
How the data on what he’s done, with what tool, when, on what flange, is all collected and stored, correctly stored so that it can be accessed in the event of an issue or a question on a particular flange. If you put those three together — the tooling, the training, and the traceability — you’re mitigating a lot of the potential for human error and for a failure of a joint.
Russel: This is interesting to me for another reason. When you talk about pipeline integrity, one of the big things that’s been evolving rapidly in our world is the ability and the tools available for capturing huge amounts of data that these smart tools collect.
Then being able to overlay that and look at it. I’m not a pipeline integrity guy. I know some pretty smart pipeline integrity guys, and I’ve been learning from them. I haven’t even considered how bolting and the joints go into all this.
You certainly consider when you’re running a tool, you’re looking at every weld. You’re trying to locate every weld. You’re trying to understand the health of every weld, but you’ve got the same issue every place you have a joint. It’s a similar issue, I should say. It’s not the same.
Jon: It’s not the same issue, and I think there are, again, I’m no pipeline inspection expert. I have a bit of a pigging background, but I would imagine checking the integrity of a joint from the inside, as opposed to a weld, would probably be a different process.
Russel: I think that’s right. I’ll have to talk to Mark Lamontagne and ask him this question, because I’m sure he’ll have an answer. It might take me 15 or 20 minutes to understand his answer, but he’ll have one.
Jon: [laughs] Yes, that’s true. I’ll be interested to hear what you find out.
Russel: I know that the tools will locate pipe components like valves and other things that are fixtures mounted on the pipeline. I know the tools will locate that, but I don’t think they do any analysis of that.
Russel: I think that’s typically done more…most joints are accessible. They don’t require a dig to get to a joint, typically. There are exceptions, but typically, there’s not a dig required to get to a joint.
Jon: No, you’re right.
Russel: I guess that does raise the question, what kind of ongoing inspection or recertification of a joint’s required? How often do you need to go back, and look and see? That joint is moving over time as it’s temperature cycling and such, and pressure cycling. How often do you need to go back and look and make sure the joints are healthy?
Jon: Russel, that’s a bit of a “how long is a piece of string” question, because every pipeline system is different. I think part of the challenge for the regulators is coming up with a sensible set of instructions to follow as to what should be done.
Now, most pipeline systems, the operators will have a regular service process. Part of that process really must be checking the integrity of the flanges and the joints, make sure that they are still doing what they’re supposed to be doing.
Russel: I have no idea if there’s any regulatory governance in the U.S. around any requirements for that.
Jon: My knowledge of U.S. is limited, but I am not aware of any. I’m not aware of any in the U.K., either, to be honest.
Russel: I will make a shout-out to the listeners and just say, if any of you guys are listening to this, and you have some feedback on this question, drop me a message on LinkedIn, or go to the Contact Us page at pipelinepodcastnetwork.com. Drop us a note, and we’ll incorporate that in the show notes. I think that’s something that would be of interest to the people that are listening.
Jon: It is, and it’s a key point, Russel. The frequency of checking these joints is critical.
Russel: We’ve talked about the history, the methods of tightening, and some things about what can cause leaks or failures, how you mitigate that, and the process for bolting and tightening. If you were talking to someone who…in the U.S. right now, there are a lot of midstream operators that are building pipelines and building facilities around pipeline plants and such.
If you were talking to one of these young engineers, what guidance would you give them as they’re looking at doing their projects around how they’re constructing their joints, and what kind of construction inspection ought to be happening around those joints?
Jon: I tell you what, Russel, over the years, I’ve found myself crawling around very tight spots in pipeline systems. I wished I’d had the opportunity to talk to the guy who designed them. First and foremost is access.
It’s quite clear that, in many systems, the ability to access the joint to check it, tighten it up, and then close it hasn’t really been given a lot of consideration. That causes quite a lot of consternation for the bolting guys.
What I would also say to the design guys is, maybe packing your flange joints into a couple of different packages, one being what you would class as a standard joint, and the other which you would class as a hyper critical joint.
On the critical joints, it’s always advisable to fit them with extended studs and enough space to get the tensioners in. Really, that’s when tensioners come into their own.
Russel: Talk about that a little bit more. What kind of joints would be non-standard joints?
Jon: Rather than non-standard, it’s a joint that you really need to guarantee is going to be, go above and beyond the normal levels of acceptable tightness. Joints that have particularly high pressure, particularly noxious products. All of these, you need to consider how they’re going to be closed and opened, and the most appropriate method.
Russel: I would also think that joints between critical processes that have additional stresses due to temperature changes, either in the process, ambient, or things where vibration is a consideration, would also be areas where you might want to consider those critical joints. Would that be right?
Jon: That would be absolutely right, yes. Particularly in refineries, for example. There’s a lot more going on than just a normal pipeline, as you rightly said. There’s pressure variations or more vibration. Refineries are usually moving more explosive, sometimes high temperature. You’re absolutely right on that.
Russel: To what degree does corrosion play a role in all this?
Jon: As far as joint failure is concerned, not a lot, is my opinion and experience. Like you rightly said earlier, these bolted are generally topside. They’re not buried. They’re visible, and the pipework is, on big launches, open stations, the pipework is generally visible, painted, and well protected.
Russel: Actually, “painted” is a bit of a misnomer. “Coated” is a more accurate way to say that.
Jon: I beg your pardon. I am not a coating expert. [laughs]
Russel: Neither am I, but I’ve seen pipe that was painted, and I’ve seen pipe that was coated. It’s not the same thing. [laughs]
Jon: No, you’re absolutely right. I’ll stand corrected. [laughs]
Russel: All right. Jon, this has been really educational for me. Frankly, I’ve taken quite a lot away about joints that I hadn’t even thought about. Oftentimes, I try to summarize something down to three key takeaways. I’m going to try and do that, and then maybe you could give me a letter grade on my three key takeaways from this conversation.
Jon: I’d be happy to grade you, yes. No problem at all, Russel.
Russel: Takeaway number one, joints are critical to any kind of piping. That’s where I would start. I think the second thing is that the reason for joint failure is more about overtightening or improperly tightening than it is about under tightening.
Russel: Then lastly, the process of tightening needs to be done according to a standard and a practice that maximizes your opportunity for a good joint. Basically, multiple points of tightening at the same time. To press the two pieces together equally, versus unequally. I think that’s my three key takeaways. What do you think? How’d I do?
Jon: I think you’re an A-star student, to be honest, Russel. That was top notch. You picked up the key points, bang on. [laughs]
Russel: Very good, very good. Jon, if somebody was interested in learning more or talking to you about some jointing issues, how might they best get in touch with you?
Russel: Great. We’ll put all that in the show notes, so if anybody is listening to this, all you got to do is go to Pipeliners Podcast, just do a search for Jon, and you will find this episode. Jon, thank you so much for being our guest. I’m certain I’m going to have more questions for you, and there’s more opportunity for me to learn. We’ll do that again at a future date.
Jon: That would be great, Russel. Thanks very much for having me. It’s been a real pleasure.
Russel: I hope you enjoyed this week’s episode of the Pipeliners Podcast and our conversation about joint integrity with Jon Naylor. Just a reminder before you go, you should register to win our customized Pipeliners Podcast YETI tumbler. Simply visit pipelinepodcastnetwork.com/win to enter yourself in the drawing.
Russel: If you have ideas, questions, or topics you’d be interested in, please let us know on the Contact Us page at pipelinepodcastnetwork.com, or reach out to me on LinkedIn. Thanks for listening. I’ll talk to you next week.
Transcription by CastingWords