HDPE and PVC are both plastic materials. While they share similarities, they have significant key differences. HDPE is a strong and flexible thermoplastic–ideal for water and wastewater pipelines as well as oil and gas transfer systems. PVC has a higher tensile strength, but stronger doesn’t always mean tougher. While PVC’s tensile strength is higher than HDPE, it’s also more brittle and susceptible to fatigue cracking and failures.

In this episode of ISCO Insights, V.P. of Engineering and QA, Dustin Langston of WL Plastics, Chief Engineer at the City of Duluth, Eric Shaffer, and ISCO Hosts, Garry Bouvet and Chelsea Rabideau break it down for you.

We’ll cover:

• Commercialization of HDPE and PVC
• Properties and performance
• Standards and ratings
• Installation
• City of Duluth project

Chelsea 

Hello everybody, I’m Chelsea rabidly one of the hosts of ISCO insights, I’ll be guiding you through this conversation today we’re having about HDPE, and PVC. So with increasing resin prices and shortages in supply, they’ve impacted availability of products all over the map. And so it’s really important that we have this conversation today about different materials, and what’s available on the market. So I’m really excited for what we have today for you. First, we want to go over some instructions throughout the presentation. If you have any technical difficulties, you can enter those in the chat box at the bottom of your screen at that bar. If you have any questions for any of our presenters, whether that’s Gary Boothbay, or either the other guests presenters we have today, you can just enter those in the q&a box. We’ll be monitoring that throughout the presentation. So go ahead and enter those in there and we’ll make sure that it gets to the right person. For our presentation today. As I said, I’ll be helping move the conversation along but we also have Gary bluebay, who’s our in house HDPE guru, Dusty Langston, who’s the VP of Engineering and QA with WL plastics and Eric Schaeffer, who’s the chief engineer of utilities, with the city of Duluth, and he’s going to talk to us a little bit a little bit about his personal experience, working with the city of Duluth on solving some watermain issues. So without any further ado, we have Gary, Dusty and Eric. Gary, why don’t you tell us a little bit about yourself. We’ll

Garry 

Chelsea, great to be with you again here. My name is Gary Boothbay. I’m with ISCO industry’s been with ISCO for 25 years, I’ve been in the HDPE business for nearly 30 years. Can’t hard to believe looking at me, right that I can be in that long. But doing a lot of different roles with ISCO talking about HDP educating, training, fusion all around the world. So glad to be here with you today.

Chelsea 

Great, Gary, thank you so much. And next let’s go to Dusty Langston. Dusty, tell us a little bit about yourself.

Dusty Langston 

Yeah, Dusty Langston with WL plastics. We’re a pipe manufacturer for HDPE pipe. I have been with wo plastics for 17 years coming up in August in many capacities from engineering to quality assurance production. Pretty much a little bit of everything. So excited to be here on ISCO insight. This is great stuff I love Have these these programs? Well,

Chelsea 

we are so excited to have you here. And finally, let’s go to Eric. Eric, tell us a little bit about your background.

Eric Schaeffer 

I’ve been with the city of Duluth here about 14 years, mostly working in water, sanitary sewer and natural gas. Prior to that, I was in consulting for about 20 years doing water and wastewater projects.

Chelsea 

Awesome. Thank you so much, Eric. Well, now I’ll hand things over to Gary, and he’ll get us kicked off with this presentation today.

Garry 

Thank you, Chelsea. And I’m really glad everybody’s joining us today. We treat this as a learning education. Presentation, we want to if you’ve got questions, we want you to answer them. We’ve got people, as Chelsea said, monitoring those questions, and we’ll get to him as best we can to get an answer. But we’re going to start off a little bit with history of PVC and HDPE. And a lot of people HDPE may be very new to you, especially some on this audience today. Polyethylene is as old as PVC pipe, they were both created in the late 50s. And they both started their commercialization in the different markets in the mid 60s. Both of the pipes took different paths. HDP went the route of oil and gas and gas distribution, where PVC took the municipal route water and sewer applications. And so that’s kind of the difference. Now, those worlds have been coming back and colliding a little bit. And Dusty, I’ll bring you in. And if you want to add any got anything to add to that conversation piece there? Yeah, absolutely.

Dusty Langston 

So the I think it’s the most important why these different materials Chase different markets, and it really came down to HDPE. Pipe was fusible from day one, it was always joined using Fusion. And so we chase markets that would require a leak free joint such as gas distribution, oil and gas gathering PVC, you know, it had a bell and spigot joint just like ductile iron. So they chase ductile iron, water and sewer markets. And over the last 50 years, we’ve completely dominated both of those markets, TVs, thermoplastic materials has both of those markets. And

Chelsea 

just to note, before we go on, I just launched a little poll here seeing what people are more familiar with HDPE, or PVC, about 70% of our audience is more familiar with PVC. So I think this is a great conversation to be having right now. Gary,

Garry 

fantastic. Yep. And hopefully will shed some light on HDPE and expose them to a product that can be very beneficial to them, especially in current marking market conditions that we’re all facing. So let’s dive a little bit into properties here. And again, Dusty, you know, you and I will talk about these, in particular. But let’s start with the the pipe property comparison. And this, this is a chart that kind of actually compares three products HDPE, PVC, and ductile iron. And if you notice looking at this at this graph, the blocks that are in green, those would signify things that HDPE and PVC are very similar with, right, they’re both about the same. The red ones are the difference makers and Dusty if you want to elaborate on this, appreciate that.

Dusty Langston 

Absolutely. So for HDPE pipe, restrain joint leaf prefusion joint is, is standard. You get that with every bite, joining with both fusion electro fusion and kind of fusion, you get that leak free joint. And I actually the screen went away there so I can’t see the table anymore. But if I remember correctly, let’s talk about permeation as well permeability, the pipe Yes, pipe and gaskets for PVC ductile iron gaskets, funnily enough, EPA actually did a study on this. Sorry, no, it was the water Research Foundation to look at permeation in water systems of hydrocarbons. And even though you know HDPE pipe is a permeable product. They were found non in the field. They had no actual complaints that were noted in that study of polyethylene, but they had tons that were gaskets of both PVC and duct liner materials. Corrosion, plastics don’t grow. So that’s not an issue with us. We’re not going to rush we’re not going to grow. Freeze HDPE pipe will expand with a freeze, it will not break the pipe. It’ll actually expand with that ice and it will not break the pipe bend radius. We’ll get to this a little bit more in a future slide but we are by far the most flexible pipe material out there, which lends itself to you know ease of installation, both in trench and trenchless installation methods. flow resistance C factor of 150 stainless PVC ductile iron 140 new 120 is actually what ASCE The pipeline handbook recommends production line for New, and then it gets less as a corrosion gets older. Joint leakage again, ACP pipe doesn’t leak, it is a fuse joint. And you can get it in much longer lengths 50 foot versus 20 foot for our competition. So it’s that many fewer joints in a system to begin with.

Garry 

And with those joints of both PVC and ductile, iron dusty, you’re talking about, you know, right restraints, you’re talking about additional thrust blocks associated with more of those joints, and none of those with the HDPE. So again, this is a great side by side comparison. They all, you know, do the job, but it’s just great to point out some of the differences between the different materials. Let’s talk about temperature operation range, Dusty, and, you know, this is one that I think not really understanding for some people, right about the PVC, they’re both plastics. How do they differentiate when it comes to the temperature? Yeah,

Dusty Langston 

so this is the question we all get, you know, is it plastic, plastic and very much now, the molecular orientation of these two pipe materials is very different. So for HDPE pipe, it remains a ductile product, all the way down to negative 130. Negative 130. F is its last transition period. But for PVC pipe, it’s always operating in its last transition period, it actually becomes a ductile product at about 221 degrees Fahrenheit, which is much much higher, you’re obviously not going to be running that pipe anywhere near 220 degrees. So it will always be acting as the glass or brittle material in any application, any temperature range where HDPE pipe will always be flexible and ductile material in its entire operating range. Right.

Garry 

And that brittleness that you’re talking about really comes into play when we’re thinking about things like impact resistance, right? Durability and being a lot, right. Yeah. Even tapping, right I mean, when you’re when you’re tapping a what you would classify as a brittle material, or putting in a service. There’s there’s a lot of care that needs to go in right and preventing any type of, of crack or split it

Dusty Langston 

most of the people on this call have had the experience in their life. And they’ve actually been out in the trench on multiple pipe material installations, not just polyethylene. This is a very well rounded group on pipe materials. And every one of us I’m sure has seen, you know, a PVC pipe kind of come apart during the tap, whether it was an inappropriate tap, how it was actually, the tap was performed. But that’s just not something that happens with polyethylene pipe, there’s never going to be a scenario where you go to tap a polyethylene pipe, and it’ll unzip or crack or do anything like that it just is too ductile material for that to happen.

Garry 

Right? Fantastic. Another big aspect of differences between HDPE pipe and PVC is its UV resistance polyethylene pipe has to per two to 3% Carbon Black in the resin makeup, that’s why it’s black in color that provides that UV protection, so there’s no degradation to the pipe when exposed to ultraviolet versus PVC dust and PVC has a limited exposure life with it, isn’t that correct? Yeah,

Dusty Langston 

they don’t recommend that you store PVC outdoors for really any extended period of time. For HDPE pipe you had to run on the head below UV protected. A lot of our customers oil and gas gathering mining, those pipes are installed above ground for for day one from day one all the way through their entire life. That PVC pile that’s actually a picture I took just in our local municipal yard. Probably every municipality has a stack of pipe PVC that looks like this. This is just leftover remnants from other pipe jobs. This blackening of the pipe is actually called dehydrate chlorination. And that’s a self propagating effect. So once it becomes UV burnt, we’ll call it that’ll continue to proceed. Even once it’s out of UV will even once it’s in the ground, and that dehydrate chlorination actually creates a very low impact resistance. It reduces impact resistance, I want to say the PVC guy study was like 30% impact resistance because of that. Are you promoting damage?

Chelsea 

Thank you. Just a quick question here from the audience who would like to know are the pipe characteristics you’re presenting applicable to all sizes?

Garry 

Oh, yes. So with the HDPE. It’s a great question with the HDPE. All of these characteristics that we’re talking about regardless if it’s half inch, all the way up to 88 inch is going to exhibit and have the same basic characteristics when we’re done. Talking about exposure and brittleness, ductility, all those things that Dusty is touched on. Thank you.

Dusty Langston 

The only thing that would change slightly is going to be bend radius, which we’re talking about right now. This is perfect segue. So bend radius, the thicker the pipe is, it’s a little counterintuitive. The thicker the pipe is for polyethylene, the tighter you can actually bend it, the more force it’ll require to bend. But you can bend it tighter because you’re have more wall thickness to to make sure the pipe doesn’t kink or bend too much. So the thicker the wall, you can see Dr. Nines, it’s 20 times OD, Dr. 30 to five, you know, very thin polyethylene pipe is 42 times VOD. So it’s still very flexible no matter what the standard claim to fame as you can stand, you can wrap an eight inch waterline water main around a standard 40 foot full stack with zero fittings. That sounds like Yep, absolutely.

Garry 

And that that really is a big difference. That diagram there on the right really shows the differences in that bend radius that you’ve mentioned, Dusty, you mentioned on going around a cul de sac not having to put an elbow just taking strings of HDPE pipe fuse together and bent around that cul de sac versus, you know, 275 foot radius on that 12 inch pipe. Because their bend radius on PVC is I think about 200 times the OD, is that correct?

Dusty Langston 

That’s correct. And then feasible PVC, all that bending and normal PVC takes place inside the bones to get joint. Same with ductile iron, it’s exact same bend radius 200 times DOD. And then on the fusible PVC, where you don’t have that balance being a joint anymore, it actually increases it’s 250 times the diameter.

Garry 

And here’s what I think what you were talking about Dusty on that deflection taking place inside, you know, the bell and spigot. So that’s where their deflection is allowed to occur inside that bell and spigot but it’s under three degrees, is that correct?

Dusty Langston 

Correct. So three degrees is going to be your maximum bend allowance with inside that bell failures can occur and just five degrees. So it’s a pretty tight window to stay inside up. But all the bending again takes place inside that bell and spigot joint, you’re not allowed to bend the barrel of the pipe.

Garry 

Okay. So with HDPE being a fused, you know, but fusion joint, it’s one continuous piece. That’s why the bend radius is so much better. You know, if you use 1000 foot of pipe, you’ve got 1000 foot piece that functions as one piece of pipe. That’s

Dusty Langston 

correct. And again, it’s fully restrained joint, there’s no reason for thrust blocks or anything like that. For directional changes, unlike, you know, other balance big pipes, right.

Garry 

So now let’s we got a lot of engineers participating in viewing this presentation, Dusty, and I want to talk a little bit about specific standards and some ratings that they can hear about and and start looking at when they’re looking at designs. Start with PVC pipe, right, the two primary aw wa standards that familiar with are the C 905. And C 900. Why don’t you elaborate a little bit more if you would on on those particular standards and how they’ve kind of changed over the last few years.

Dusty Langston 

Yep, and for most people on the call that are very familiar with PVC, we all know the scene on oh five no longer even exists, it has gone away completely. So back in 1986, PVC industry changed see 905 C 905 used to be for transmission lines, and C nine, C 900 was for distribution lines. Because they were transmissions, their argument was, hey, we really don’t see a lot of search cycles and transmission lines. So we’re going to change the pressure ratings on these pipes. There was no material change, there was no new cell classification. They just decided that, hey, we don’t see a lot of surge in these applications. So we’re going to change all the pressure classes. So for example, a DRA teen went from PC 150 to a PC 235 overnight. Again, no changes in you know material or strength or anything like that. In 2007, they actually changed C 900 to make those exact same changes in pressure class, even though C 900 deals with distribution systems, which sees tons of searches, you know, 6580 searches a day in some systems. And their justification in that move was hey, we’ve been doing it in C 905. For a lot of years now with these higher pressure classes and we haven’t seen any issues. So we’re going to change make the same change in C 900. But at the same time, we’re going to put a little blurb in the back a little annex that talks about surge and how to design for surge. And we’re just going to put that responsibility onto the design engineer. And so a lot of engineers will see that those pressure classes, those increased pressure classes and not know how to properly D rate PVC for potential surge effect, because surgeon fatigue is the ultimate failure method for PVC. And then like I mentioned before 2018 C 905 was dropped, and everything was put into one standard for C 900.

Garry 

So, now it’s just C 900. Pretty much moving forward. That is correct. Okay. Well, HDPE, on the other hand, has a bevy of standards that apply to all different aspects of the of the design and setup right, so you can see that there’s a ASTM standards in the design D 3350, which covers the resin the makeup materials of the pipe, F 714, which is a dimensional od control specification, and then F 2206. If you’re looking at, for example, fabricated fittings, right, these are just a few that apply on the design side. And then there’s a training site we talk we’ll talk more a little bit about fusion but F 3190 is a certification for folks who are training operators how to install how to fuse join HDPE pipe together and then on the installation F 2624. The Fusion procedure F 1290 For electrofusion. Even aw WA has come out with an M 55 manual specifically for installation of HDPE mains for a WWE a project so those are all available very defined for the market. Then there’s also the to a HDPE standards for the pipe itself. Aw WC 90143 inch and smaller basically service lines and a WWE ac 90644 inch and larger which we would consider more of the distribution transmission mains. Dusty I want to dive into cyclical pressure a little bit and and know this is near and dear to your heart to you talk about this quite a bit when we’re talking about the ability of HDPE to handle, you know, surges and so forth. And it kind of starts here. So why don’t you take this on a little bit, if you would, yeah,

Dusty Langston 

so this is just a log of stress over a longer time on cyclic fatigue. So BBC industry, polyethylene industry, we’ve all done this testing to see how our pipes would respond to pressure spikes. The one for ACP pipe is quite famous at this point, we send it out to dozens of people a month. It was actually University of Texas, Arlington did that study where they went over two and a half million cycles on some Dr. 17. So 125 psi rated pipe pressure tested up to 250 psi, again, over two and a half million times. And no failures. Not only were the no failures, the pipe that was that was taken off test was tested, and met all the requirements of the brand new pipe, PVC, the ultimate failure method is going to be fatigue, fatigue cracking, and they have about 100,000 cycle pressure surge resistance. So depending on where you’re pulling your data from, again, the American Water Works Association put out a study that talked about how many searches happen per day in a typical water distribution system. Those numbers actually came out I believe 55 searches a day. You can see here we have just 5.5 for PVC, and if you run into pressure class that’ll last you 55 years, but if you’re getting actually 55 per day, which is what aw WA says is typical for a US water system, you can have failures very, very premature. So it is very very important to understand fatigue and sick like design for PVC to make sure that you do not get those those premature counts.

Garry 

Well, that leads us then Dusty into this slide here and talking about pressure class and I know HDPE has bounced around from working pressure rating pressure class, you know, trying to figure out which which is the best designation I’d say for for choosing a pipe material in a pipe der, but pressure classes are not all the same when we’re talking about these two products. And this slide here, I think really, really depicts it very well. You’ve got you know, Dr. 18. pipe which is very common pipe der and PVC as a pressure class to 35. Right. But one of the that is at zero feet per second, right? That’s it static, static flow. As your velocities increase, then essentially, you have to detract the working pressure off of that to 35. And what is common Dusty in standard water applications if you’ve got a fire protection like a hydrant.

Dusty Langston 

So this is, you hit it right on the head, there’s so much confusion out there of pressure class, the pressure class, what is the working pressure, we throw in DRS as well instead of pressure classes. So polyethylene is very common for Dr. Now the PVC guys are getting into more specifically Dr. So there is a lot of confusion out there as to how this works. But your typical water system for fire flow is around five feet per second. And sometimes up to seven, I’ve actually seen some up to 11 to 13 feet per second. Again, it really ranges where you’re out in the country. But for a typical system that’s about five to five and a half feet per second, the best takeaway is here, you should be sticking the same Dr for DR, as you would a PVC line. So most jobs that we come across that they’re wanting to flip over to polyethylene, were originally designed with PVC or ductile iron. And they come to us and say, Hey, we would like to use polyethylene pipe on this line. And they’ll throw out two requirements, you have to have the same inside diameter and the same pressure class. And the same pressure class is ridiculous because again, the pressure classes we’re putting on our pipe, that’s the working pressure, that is what we want to be running that pressure at and I’m sorry, if you guys are getting feedback, I’ve got a ton of noise here around me. So I’m very sorry about that. But at five feet per second, the big takeaway here is that five and a half feet per second, you should be spec specifying Dr for Dr. Polyethylene versus PVC pipe. Some systems are lower flow rate, you know, ductile iron is often designed to two feet per second. And that’s because just two feet per second will result in 100 PSI pressure spike and ductile iron. For polyethylene pipe though two feet per second, there’s like 14 PSI pressure spike, it’s very, very little just because the material is so ductile and acts like a giant shock absorber for flow. But that’s the big takeaway here is you do not need to be specifying a DR nine for example, polyethylene that’s rated at 250 psi as an equivalent to a Dr 18 PVC working pressures are not created equal that D hard nine, for example, the dreaded 250 psi can handle surges up to 500 psi, and can handle flow velocities over 15 feet per second. So again, we’re not created equal here. Fatigue design is not something with polyethylene you need to worry about it’s not a failure method for polyethylene. So you can handle much higher flow velocities in HDPE pipe.

Garry 

Very well stated, Dusty, I know this, this is a big one. And it can be confusing. And, you know, that’s, you know, one of the things that ISCO can bring to anybody on this call is if you’re looking at designs, and you’re trying to figure out what is the pipe that I need? What is the best design for our system, that you get experts to like yes, go involved, that can help you make that determination, and help you make sure you get exactly what you need for your system requirements. So you were talking about that that comparison, Dusty, and I think this is a great tool that really helps a lot of engineers that they can go and do that. This is called the PPI pays calculators created by plastic pipe Institute. And it is an n way to input this specific data for your system requirements. The surges, the velocities that you’re running, the working pressure that you need to maintain the temperature of your line, depending on what part of the country you’re in, and you’re your life expectancy. One of the neat things about polyethylene, is it 100 year design life. Okay, we can state that we’ve got the test data, Dusty talked about those lifecycle tests earlier, we’ve got the data to back that up 100 year design life. So let’s compare how ductile iron and PVC match up. We were looking at those and what’s going to work best for your system. And this is a great tool. Dusty. I I think you use this quite a bit though. Yep.

Dusty Langston 

Oh, I live on this tool. I absolutely love it side by side comparisons of hey, here’s my flow velocity, here’s my pressures. Here’s how many cycles I’m gonna see. And side by side comparison if it’s going to work or not. So I use this app or this calculator all the time.

Garry 

right and the left information that it really generates to you. It shows you what der is going to work, specifically for HDPE based on your system design, and it’s going to show you where what the failure points are for any of the pipes, in particular, based on the parameters that are loaded. Right. And you touched on it earlier, I think you said the main takeaway is, you know, HDPE over PVC, the failure mode is fatigue, right, not an issue with polyethylene. Let’s talk briefly about the joining process. As I think there’s a lot of people who may not be familiar at all with Fusion, we’ve talked about it, you know, with the way polyethylene is joined. So I want to take a moment and just walk through the basic fusion procedure for HDPE pipe. So I’ve got two sections of pipe, we’re getting ready to get the fusion machine there. We’re clamping that pipe in this clamping step is necessary to hold the pipe in place so it doesn’t move while other fusion procedures are being completed, but also aids in rerouting the pipe making sure they’re fully lined up with each side. And so once that pipe is clamped in and secure, we’re going to bring in a facer has blades on both sides of that planer block, and those blades rotate around, and it trims the ends of the pipe removes any oxidation layer squares those pipes up making them essentially mirror images of each other. Once the facing has been completed, its tool is removed out of the air out of the fusion zone. And we’re going to remove those shavings of trimmings of pipe that we that we took off. Now, checking alignment just to again double check to make sure those pipes are lined up, there’s no gap there square the high low side to side everything in place. And since the oily hands on the glove touch the pipe ends, just a brief wipe of the ends before we put the heater plate in position. That heater is about 425 degrees. And it’s designed to heat and melt the ends of the pipe, we bring those pipe ends in contact with the heater and then we reduce pressure we just essentially have surface contact with those pipe ends to the heater. Once the proper time and melt bead has been achieved, heaters removed and those melted ends are pushed together under a predetermined pressure. And that pressure is held until that joint is cool. Once that has been cooling has been completed and the proper time, we can remove the pipe ends and you can see a well completed but fusion joint there. That is the basic process for fusion joining of HDPE pipe and that those steps are the same whether you’re doing half inch pipe or 88 inch pipe, the only thing that will be different is the mechanics of the equipment. You know some machines small diameter will be manually operated machines like I used on that one are what we call semi automatic. And then when we get into larger pipe, the future machines become fully automated processes. But those same steps are done throughout. So that gives the audience a little bit of insight into how a fusion is done what it looks like and how it’s performed. Now there’s a standard also with that procedure, F 2620 ASTM dust and PVC pipe can also be fused. There’s called fusible PVC some people in the audience may have some experience with it. One of the big differences between HDPE fusion and PVC fusion is that there’s no ASTM standard for the PVC fusion, it is a patented joining process that is done by the manufacturer, the single manufacturer of the PVC pipe. So that is kind of a proprietary process. Not everybody has the knowledge and has the ability to fuse that pipe like we would with HDPE pipe want to dive a little bit now into some installation methods. And this shows some distinct differences between HDPE and PVC as well. Most common method everybody’s done, Dusty is open cut. And if you look at these pictures and you see a distinct difference between between the two materials, with the PVC pipe on the left You’ve got your operators in the ditch, they have to line those Bell and spigot ends up, making sure they’re square, making sure they you know, lubricate the gasket properly, but they’re down working in the trench. So you’re now talking about trench boxes and shoring, maybe you know, a wider scaled trench excavation wise, in order to safely accommodate workers being present. Now take a look at the right picture, that is 36 inch HDPE pipe on a project. And you can see on that picture, the HDPE pipe is actually in the trench just behind the excavator equipment arm that you see there. But with the flexibility that that we talked about earlier, being able to bend that pipe out of the trench up into the fusion machine, all of that joining is done out of the trench. So you have less less excavation necessary, just enough for the pipe to fall into. And your operators are safely working outside the trench. So really two big differences in the joining methods of the two materials.

Dusty Langston 

Yep, and I wanted to point out here we got a question from will, from one of our guests asking, do you need one of those pieces of equipment for each size? And luckily, no, you do not. That one piece of equipment can do a large range of sizes. The piece of equipment that you saw on the video that Gary played is, that’s actually the smallest size that we can well, that looked to be a six ATM machines. So that would do from six inches, all the way up to 18 inches. The piece of equipment there that he’s showing in the slide right now appears to be probably a TrackSTar 500. So 900 900 gusset, yeah, yeah,

Garry 

so we can go up to probably what 42 inch diameter I bet sorry, 36 inch 36 inch pipe, that’s actually what’s being fused there in the machine.

Dusty Langston 

Definitely can each piece of equipment though, can can weld a range of sizes, right,

Garry 

you simply just add inserts in and out of the machine to size down to the pipe that you need. Inside. Absolutely. So the inside bead is part of the fusion process. If you’ve got a force main that you’re installing, that fusion bead, has no impact doesn’t bother any of the flow calculations, because all of those are based on the bead being present. So it does not hinder anything in regards to flow or fluid movement through the pipe. Now in some gravity application situations, we have occasionally had the need to remove those beads, because sometimes they can form a puddle and create a bacteria area behind that bead that they want to avoid. So in in some gravity applications, we can go in and remove that beat and there are assist tools that can allow us and help us simply make that removal. And Gary,

Chelsea 

can y’all hear me out there? Okay, great. The last question was just about that insight beat if you didn’t catch by Gary’s answer. We had a lot of questions about what can be done with that Richard Pan also as a question because there is that beat on the inside and the outside is there a way to pig HCP by

Garry 

absolutely we we have done there have been pigging operations done on HDPE pipe. Now, there are some limitations as to the types of pigs and I don’t claim to be a pig expert by any means. But with the HDPE. It’s usually foam type pigs that are compressible with against the polyethylene, those beads do not hinder it. And then sometimes eventually, it it may even take the beat out. But removing that bead does not reduce anything in the strength of the fusion joint. It’s not part necessarily of the machine. So removing it internally or externally does not do anything to damage the strength of the fusion weld itself.

Dusty Langston 

Exactly. And there’s very rare occasions that again, is required remove those internal fusion beads, very low sloped, gravity sewer is one of them. But the tool is actually very simple, very straightforward to be able to reach down in there and be able to remove that internal fusion of typical beat intrusion death. Let’s see a question here again from well, we’re talking less than a quarter inch that’s even on the larger sizes. So if you’re talking, you know, even eight inch, an eighth of an inch, it’s very little.

Garry 

Alright, moving moving on about installation. Those are great questions, folks. Please keep those common. We’re glad to have those and feel those for you.

Chelsea 

And we do have quite a few A few that we’re saving, we’re saving

Garry 

No problem, fantastic. A lot of people get their first experience with HDPE. In applications of trenchless, something that’s unique that they cannot do with the other balance picket pipe materials, things like directional drilling, like you see depicted in these pictures, right? These are because of the flexibility, the durability of HDPE, the abrasion resistance, all those key benefits that it brings, lends itself well to these technologies. And it is that the pipe of choice for these procedures, there you can see in that first one, a 20 inch line, you’re going to look at that flexibility coming into the pipe. On the right hand side, that’s a dual 42 inch line that’s being pulled in place in a directional drill aspect. So a lot of times HDPE gets the toughest assignments, the ones that nobody else can do. You know, now we’re Dusty we’re talking about people using HDPE for their every day force mains outside of the the difficult ones like you see here. Another technology, open cut and directional drilling are both for new installations, right new pipelines going in. But rehabilitation is also becoming more and more prominent as these aging. water systems need to be repaired or replaced. And people are looking at, you know, price tags of open cut and tearing up roads and the disruption in service. A process it’s really growing and the last several years is pipe bursting, where you actually go in and break up the existing pipe in the ground, and you replace it with a new HDPE line directly behind it. So once that pipe is broken, pushed and displaced into the soil, a new HDPE line comes in and behind it and takes the place of that main. And this process can really be a money and a time saver. And a headache saver for a lot of utilities and Erich Schaefer, when we bring him back on here in a little bit, has some experience and done some pipe bursting with his system. So we’ll differ even a little bit more into his process. But there’s two basic, pipe bursting type static, and pneumatic. And pneumatic is for fracture elbow pipes like cast iron, Clay, concrete, those are fragile pipes to break up. A static burst is usually done on things that are not as practicable ductile iron, for example, it’s still called pipe bursting. But they actually cut and split the pipe before the expander head comes through and breaks up into bigger pieces. But both of those utilize HDPE extensively for the replacement lines that are coming in. And the last installation method I just want to touch on briefly is the plowing and or trenching operation, particularly in rural areas where you don’t have utilities and services and streets and all those other things. This is a great method for installing up to 24 inch diameter pipe, obviously, depending on the size of the flower trencher that you have. But it is a quick way to get a lot of polyethylene in the ground in a short period of time. So it’d be very, very efficient way of putting that in, particularly if you’re a rural water district, and you’re looking at, you know, an upcoming project all right now I’d like to bring on my good friend Eric Shaffer from the city of Duluth, Minnesota, Eric.

Eric Schaeffer 

Oh, good afternoon. Nice to see everybody.

Garry 

Oh, great to have you, Eric. And we were approached. Appreciate your time. And I want to start off I know a lot of people will probably have a ton of questions. And but I’m going to ask you a few. Maybe this will answer some of them for for folks. So we again we really appreciate you being here. But if you would just give us a brief description maybe of the current system, what you’re dealing with, you know the different pipe materials that you have in your system.

Eric Schaeffer 

City Duluth has about 430 miles of water made with our oldest being from the 1880s to our newest being installed today. Out of that 430 Miles about 50 of it is now HDPE or about 11% of our system. We have pretty much in the past few years, or past 20 years standardized specifically on HDPE. We use it for everything from small diameter to large up to our largest HTP watermain. Installers 24 inch.

Garry 

So so you’ve got a little bit got a mix of everything. How did you get started with HDPE pipe?

Eric Schaeffer 

Well, Duluth also owns natural gas utility, which I’m very involved in, and we started putting MDPE pipe in for gas when it came out, I never really thought about using it for watermain, even though we were experiencing many problems with ductile iron and corrosion. But we started the pipe burst project yet at one time. And in back in 2000. Pipe selected there was HDPE. And it went together so well and our staff liked it. contractor did a great job that we decided we tried again, in 2002, we went out and converted entire neighborhood, rolled steel and cast iron pipes to 100% HDPE. And from there, it’s just been everything’s been HDPE. First, we focused on smaller diameters only 810 12 inch. But then slowly, we’ve worked up to larger pipes, where now we have 20 inch distribution mains, with services connected directly to that large diameter HDPE.

Garry 

Was there a specific so since 2000, you’ve had some experience with HDPE in your water? Was there a specific feature or benefit or reason why you you went with HDPE? What was it? Is there a single driving point there?

Eric Schaeffer 

Well, one of the biggest driving points was leakage. You know, back in 2000, the city duals is probably losing 20 to 25% of their water every day through leaks, we’ve got that down around 10%. And HTP doesn’t leak when she bought fuse the joint, you’re done, there’s never going to leak there again. And it’s going to help us keep every drop of water we can within the system.

Garry 

So on your first early experiences, Eric, what were those like? I mean was, you know, were there issues that you had to deal with and overcome what kind of give the audience a sense, a lot of these people might be thinking about it for the first time? Well,

Eric Schaeffer 

there is a learning curve there. And so most people get into HTTP, like we did with their first projects being either pipe bursting or directional drilling. So our first job we did in 2000 was a pipe burst. And that’s where we put it in. After that in 2002. We started going through a neighborhood to actually drilling all the pipe in. And so of course HCP was perfect for that. But we were inexperienced and we didn’t know how to do quite everything right. And so, back in those days, we’re still using ductile iron fittings 90s Cross’s ductile iron bolted directly to the HDP. Of course, today, we put in everything 100% HDPE, fittings, connections, everything. So there is no iron in the system whatsoever to crowed. But we also had fusers on staff from our gas industry in sort of fusing with very well from us from day one. But fluid has never had a but he used joint fail in our water system. So it’s a fantastic thing. We struggled a little bit at the beginning with as many communities do with electrofusion. But it’s really just a little learning curve there. If you take the time to prep the pipe properly, clean it properly, or electrofusion failures are totally disappeared. We haven’t had a failure there. And probably a decade. So overall, we’re really, really quite happy with the product we’re putting in the ground today.

Garry 

Well, that is that’s great to hear. You mentioned electrofusion. And I think those you’re using that for like your service connections, right. A lot of people how do we tap? How do we run our service laterals off of polyethylene mains? Is that how you’re doing it there in Duluth?

Eric Schaeffer 

That’s exactly right carry on the smaller diameters. Typical service in Duluth we use one inch HDPE we have a tapping saddle so it has electric fuse to the pipe. It’s got a plastic cap that comes off the top and there’s a cutter right in there. Spin the cutter down, spin it back up and you’ve now tapped the pipe right while it’s live. Put the plastic cap back on and it’s good to go on the larger diameters. The main line through downtown Spears 20 inch, most of the buildings have a fire service. And so those were all 20 by six electrofusion saddles, wet tap some of them some of them dry tapped after we drained the pipe. And so either way electrofusion saddled on the side or top the pipe works fantastic for this services. Okay,

Garry 

you there’s a lot of debt Different varieties. And I’m sure there may be some questions coming in at different services. Some people like Corporation stops to use your, you’re using a, what you call a self tapping T sounds like for those installations.

Eric Schaeffer 

And we do use a corporation still. We buy a saddle with a threaded brass insert. If we have to go through a neighborhood that’s got all copper services, we will reuse copper service and put a corporation with the brass insert electrofusion panel right on the pipe. Yeah,

Garry 

so a lot of different options and different ways to to achieve the service connections that you need. Eric, what’s so you’ve had some HDPE Pipe Band for about 20 years. 22 years, I guess if you start in 2000? What’s kind of the been the the history of the pipeline? maintenance issues that maybe you’ve had to deal with? Can you describe that a little bit?

Eric Schaeffer 

Well, I can say generally today, the new pipes are maintenance free. Again, back in the early 2000s, we had a handful of failures and electrofusion. We’ve learned from our mistakes, contractors have to be certified by our staff before they can work on the system. And so we make sure that they’re installing the pipe correctly and doing electrofusion properly. But now that we’ve gotten over that little bit of a home, we haven’t had any failures, the I would say that HDPE is just generally 100% maintenance free.

Garry 

Well like to hear that. What’s your maintenance guys do now if you if they don’t have anything to maintain? What would you got them doing something else now?

Eric Schaeffer 

Well, unfortunately, we still have over 300 Miles will cast iron likes to break on a regular basis. And so we still fix a lot of watermain leaks on the old pipe. Our guys are anxious to get more pipe in the ground. We’ve got a target of about four miles a year, which should be 1% of our system. Right now. We’re down right around three miles, and we’re still working towards that goal.

Garry 

Yep. Fantastic. Well, that’s a great little history there. Eric. I mean, we’ve got a couple of pictures, images of a couple of your project sites. Why don’t you tell us a little bit about you know, what’s, what’s being done here or what’s going on, if you would on this on these projects.

Eric Schaeffer 

These are both right downtown Duluth, its 20 inch water main being installed. The picture on the right shows two services. Those are the six or eight inch diameter. Coming off the main picture on the right also shows a temporary water that we’re using serves as fire services during construction. The contractors specifically really love the HDPE for temporary water, they can fuse it together and don’t have to worry about it coming apart while it sticks around downtown in the ground. The picture on the right is just an excavation there. Again, the trench was dug ahead of time watermain was pulled in through all everything. And that again is a 20 inch pipe fitter on your left is nice that you can see there above it, going perpendicular to it is a 12 inch ACP gas line that we just installed a few years before we redid the watermain.

Garry 

Okay, those that picture on the right, those two gate valves coming up. Are those branch saddles on there, or did you use like a reducing T?

Eric Schaeffer 

No, those are great saddles electric side of the pipe. Gotcha.

Garry 

Okay. Very good. Well, that’s some, some some great pictures, Eric and some great insight. I’m gonna turn it back to Chelsea, I’m sure we got two questions. Eric already does tender. I might need your help here.

Chelsea 

All right, let’s get rolling on this question number one coming in from anonymous attendee comparing HDPE, PVC and ductile How would you rank them based on their effects on the environment?

Garry 

Oh, wow. Environmental question. Wow. polyethylene, you know, I’d say environmentally, it’s recyclable. Right? It can be. So it doesn’t have any detriment. On the ground in the ground, there’s no corrosion, there’s no release of chemicals of any kind from the pipe. It doesn’t degrade or break down in that regard. Dusty, I might even turn to you with your engineering background. And if you want to add anything there, well,

not only my engineering background, but me being the resident hippie on the call today. I think this is definitely my question. And the biggest thing that I like to point to is energy consumed to create the product. When it’s a metallic product, you’re first either mining the material out of the ground, or you are recycling things like cars or other materials to get that metal back. The the downside of recycling cars is you’re burning off a lot of plastics in The atmosphere, because most cars are probably 50% Plastics at this point. And they don’t really use those plastics or recycle them. So they kind of burn them off to be able to get their metals. But metals have to be shaped and formed at very high temperatures. ACP pipe your 400 degree extruder is melting that material down forming it into pipe. But not only that, the biggest thing I like to point to is HDPE. pipe material is 99% made here in America, transferred in pipelines, it’s made from natural gas. So you really have no leakage, you know, you’re not leaching anything into the into the soil or anything from creating this pipe material. And again, it’s all here in North America. It’s all coming from us. So that’s a great you know, made here in America plug. But because it’s made here in America, and we’re not shipping materials overseas to create our products. Our carbon footprint is by far the smallest of any pipe material out there.

Chelsea 

you’re ready for the next one? Bring it on Bring It On is betting material required for HDPE pipe?

Garry 

Oh, good question. bedding material. There’s Dusty, I guess I’m trying to figure out the best way to answer this, I

Dusty Langston 

know the best way to put it. If you’ve ever installed PVC pipes, it’s exactly the same for polyethylene, that’s the best way to put it. The bedding requirements are going to be the same. If you get into a scenario where you want to use native backfill. Most of the time that is completely possible. You might have to do a little bit of sifting out cobbles and things like that. We don’t want huge particle sizes on the pipe. It’s the exact same for PVC, though. Yep, same standard, literally the same ASTM standards for burial.

Garry 

It is the same ASTM standard. But I will say there are times where projects, we have not had to have any bedding necessary for the pipe based on the thickness of the pipe and the soil conditions that that were present. It’s really a case by case basis in that regard.

Chelsea 

All right. So next question is should we be concerned with the expansion and contraction characteristics of HDPE pipe when installing in an urban setting?

Garry 

Another excellent question. So we didn’t really touch on expansion and contraction, Dusty. But we know HDPE has a very high thermal coefficient, but has a very low force of energy required on to restrain that movement. So if we’re talking about, you know, buried applications, we have no worries about the expansion and contraction characteristics of HDPE pipe. Our biggest concern is if we transition and connect to non restrained materials like ductile iron, ore balanced picket, PVC, those joints are unrestrained are the weak link in that system, not the polyethylene. So in that regard, we would have to account for that energy that might be on that and get exerted onto the unrestrained joints. In those cases, we may be looking at a thrust block prior to the transition point. Or you’re going to have to expose 234 joints downstream of the unrestrained and restrain those joints with mega lugs or whatever combination you use for restraint. Yep,

Dusty Langston 

you hit it right on the head. Once this pipe is buried, even though the expansion contraction rates are quite high, about five times out of PVC. It doesn’t take much to restrain the pipe, it doesn’t take a lot of friction or resistant forces to restrain that pipe material. So usually just typical backfill and burial, it will hold that pipe still with thermal expansion contraction. The only time I worry about it, and actually somebody else asked this question, maybe it’s coming up. But if you’re doing an above ground application, like a bridge crossing, something like that, you just want to make sure that that pipe is restrained mechanically, so that it doesn’t expand and possibly walk into the roadway on a bridge crossing. Yep. But below ground soil usually is more than enough to restrain. Yep,

Eric Schaeffer 

I would I would chime in and agree with that up here in Duluth, we are way north we see extreme temperatures, minus 20s are pretty regularly thing in the wintertime. And we bearer pipe down seven and a half feet. But at that depth, tried to get it out of the frost zone. We do not have any issues at all with the expansion and contraction.

Garry 

Excellent. Eric, thank you for chiming in with your experience there. All right,

Chelsea 

you guys ready for the next one? Yes. How do you repair line that is cut.

Garry 

Oh, actually, I’ll start. I’m going to start with Eric on that one. Eric, how do you repair a line on your HDPE? Well,

Eric Schaeffer 

just a simple mark. little slot in the pipe we’ve probably gotten temporary repair at first. Specifically Duluth uses ductile iron pipe size for HDPE as opposed to iron pipe size. The two are a little bit different diameter, but by using ductile iron pipe size, the clamps that we use pretty which every day to fix all the leaks on our cast iron system will fit directly onto the HDP. And so if we happen to have third party damage somebody thinks digs into our pipe, which is really not very common here because our pipes are down seven and a half feet, we’ll go out, put a clamp on it immediately get it back in service. In the rare occasion that does happen, we typically do go out and cut that clamp out and put into electrofusion couplings and short piece of pipe. And we do that specifically because of corrosion is so bad in Duluth, I don’t want to say clamp corrosion off and leak again, 20 years from now.

Garry 

Absolutely. When we know those repair clamps, there are only temporary repairs, right? I believe that stated, but I I personally know of repair clamps that have been in place for 25 years. So while they’re temporary, they do stay on a long time.

Chelsea 

And just a quick note here, guys, we’ve got about two more minutes, probably a little bit less till we’re up against the hour. And we do try to not take up too much of your time. Just know that if you entered a question, we do still have those even when the webinar ends. And so we can definitely reach out to you with answers for those questions. We have lots of resources, our entire team is prepared to any answer any other questions that you might have. And if you do want to set up webinars similar to this for a different group, you can reach out to us at insights at ISCO dash pipe.com. And we can put Gary through the wringer all over again. It’s my favorite thing to do. So we thank you guys so much for asking us all these questions. I’ll give you just a couple more. Here’s one, Gary, how do you inspect a fusion joint?

Garry 

Oh, excellent question. Inspection of fusion joints is actually done at the fusion process, you’re, when you take the heater out, you’re looking at that melt pattern, making sure it conforms properly and has the right the right size and pattern on that melt. And then when you push it together, you’re you’re looking obviously at your roll back on your bead, but you don’t see that inner fusion at that point. But there are some tools that are out there available to help ensure that that fusion procedure is done correctly, and give you pretty good confidence in the quality of the weld that’s been done. And one of those is called a data logger that gets hooked up to the fusion machine. And it monitors the temperatures, the pressures that are being applied, the the times that you’re doing for your melt, and your cooling, all those things, which are about 95% of the mistakes that can occur, creating a bad fusion. Those are all done with that data logger. So I would highly encourage anybody who’s looking at fusion to simply put a date data logger requirement, and you can get immediate feedback on how well that weld was performed.

Chelsea 

All right, great. One last question here. And this one is How does HDPE perform in the presence of soils contaminated with petroleum or chlorinated solvents? That’s another excellent question.

Garry 

That I mean, I heard a bad question. I mean, there has not been a bad question on this. Dusty, I am going to send out when I pass that question over to you, just because you’re a heck of a lot smarter than I absolutely.

Dusty Langston 

So every time I take myself off videos, it’s so I can go to the q&a section and try and type out some answers so people can get their questions here today, just as I hate leaving people hanging but again, please reach out to us if we didn’t get time to get to your questions. And we will get answered. This is a humdinger of a question though. It is perfectly placed. So if you have a permeation or a permeable material like a hydrocarbon for maybe a brownfield and old gas station that’s been leaking for decades, something like that, we will first off recommend that you avoid the area with any pipe material polyethylene PVC ductile iron any of them. If you cannot avoid the area, directional drilling is an option to get under that possibly contaminated soil. If that’s not an option, and you’re wanting to direct open cut this through, then we would recommend wrapping the HDPE pipe in a in a nylon polyamide pipe wrap. So just like the ductile iron guys like to use polyethylene pipe wraps on their product, we recommend that you use nylon or polyamid wraps on polyethylene pipe or any pipe that’s going through a hydrocarbon permit or hydrocarbon area. And because that is hydrocarbons do not permeate through nylon. So that’s a great option. If you’re going through a hydrocarbon area. If you have chlorine affected soils, that’s not really gonna affect HDPE pipe. The chlorine really has to have a carrier and also pressure to attack polyethylene. So if you have a chlorine contaminated soil, we’re not worried about that. You don’t need to do any kind of special wraps or anything like that. Yep.

Garry 

Excellent. Dusty, I know that’s a that’s a very broad question. There’s even more options available if you are in hydrocarbon permeation. situations. So we can want to just, I hate to cut off all the questions, Chelsea because I mean, I could probably spend here all day answering, these are so

Chelsea 

many. And again, just to reiterate, you don’t even have to reach out to us. We have all of your questions here. And we’ll be reaching out to you to make sure that all of these get answered, no worries there.

Garry 

Yep, I know, I’m going to be busy after this, as well. But I want to briefly touch on everybody. Eric mentioned him in his, you know, the learning curve that he had, well, ISCO is here to help shorten that learning curve for anybody on the call today that’s looking at or considering a project and looking at HDPE as an option. You know, we have local people all around the country, or all around North America, even up into Canada, who can come in, talk to you, get you and get you the help and assistance that you need, whether it be for fusion equipment for your contractors, if you’re needing any type of engineering estimates, even technical review of your specifications, this go can help you with all of that from a wide source of folks and team support team that we have with us here. And things like this education training. Again, Chelsea mentioned that you can call and have me come on and do an independent presentation for your entire team, if you’re so inclined. So we’re here to help you shorten that learning curve, get you comfortable making sure you get the right situation for your project. Absolutely.

Chelsea 

Thank you so much, Gary. And some of these questions that you may have seen in the chat box or the q&a box have answers that are available to you on ISCO dash pipe.com. And we’ve got one more slide here showing some of our social media sites that are available to you. We have lots of resources on those as well. We have a YouTube page that shows the fusion process case studies on different projects. So feel free to check that out. It’s it’s go industries on YouTube and all of our other social media sites, we’ll keep you updated on what we’ve got going on. And when we’ve got other conversations on ISCO insights coming up, we also have a podcast, you can scan that QR code right there. We’ll also be sending out an email with a link to that podcast. And it’ll also have a recording of this presentation for you available on YouTube. So thank you guys so much for joining us. I can’t tell you how much we appreciate all of your, as Gary said excellent questions that keep us thinking and we love to share information that we’ve gathered over the years of experience. So thank you so much for joining us for the latest episode of ISCO insights. We’ll see you next time may 26. Have a great day.