Summary

Jack Walker and Paul Atzemis discuss the AWWA C222 standard. This standard relates to the use of polyurethanes and polyurea for the interior and exterior of steel water pipe, valves, and fittings.

Timestamps

Click to follow along with the transcript:

•  0:00 - Intro
•  3:39 - Introduction to AWWA C222 - Polyurethane Coatings and Linings for Steel Water Pipe and Fittings
•  4:40 - AWWA C222 for the exterior of steel pipe
•  5:44 - History of polyurethane use within the AWWA C222 standard
•  6:53 - Use of polyurethanes for the interior of water pipes
•  8:03 - NSF/ANSI/CAN 600 - Health Effects Evaluation and Criteria for Chemicals in Drinking Water
•  9:31 - Chemical resistance required per AWWA C222
•  10:45 - Repairs of the polyurethane coating per AWWA C222
•  11:36 - Performance requirements per AWWA C222
•  14:16 - Wrap up

Transcript

Introduction to AWWA C222 - Polyurethane Coatings and Linings for Steel Water Pipe and Fittings

Jack Walker: Today, I kind of want to talk about, you know, we've been kind of in standard land, and I think we're going to stay there. We want to talk a little bit about AWWA C222, and that is "Polyurethane Coatings and Linings for Steel Water Pipe and Fittings."

Paul Atzemis: So, you know, Jack, this really does fit in well with some of the topics that we've had lately because we've covered some other areas that have kind of dove into some standards. And we did a whole series of episodes on the water/wastewater market. Now, AWWA C222 does not play a real big effect in the water/wastewater transmission area, but it can because it is suitable for potable or non-potable water pipes. So, you can use it, it's just you don't find a lot of people who actually reference it for the wastewater side of it.

Jack: Correct. Yeah. You typically see this referenced in potable water piping. So, it can be used for the exterior and the interior. There's a couple different requirements here.

AWWA C222 for the exterior of steel pipe

Jack: You know, one of the reasons why you would use one of these coatings on the exterior is if you're doing any kind of directional drilling or doing buried pipe service does really well with impact. It dries quickly. You can get it back into service, bury it quickly with these products. So, that's a lot of the times why they look at the C222 polyurethanes for buried pipe.

Paul: That's right. And when you get into the C222 document, it's a 30-page or so, 35-page document. It's really ominous when you first start looking at it. But then you realize there's a lot in there about history. There's a lot in there about how it came to being in the form that it's in. They go into great detail about some of the references or updates that were made in the recent, because this standard was just updated in 2018. It goes through all of those histories, but when you get to the real nuts and bolts of what it is that this standard talks about, there's a really easy table. It's really straightforward, and you're able to just look at it and say, "Does this material that I'm looking to use meet this qualification of testing?"

History of polyurethane use within the AWWA C222 standard

Jack: And I do appreciate the history and the standard. I'm not going to lie. Basically, in the 70s, they started using these high solids polyurethanes for underground fuel storage tanks. And so, like I said, they used them because they do well with impact, damage, those kind of things. And anybody who's backfilled anything in dirt, I don't care if it's in the industrial world. If you've dug in dirt, you understand what kind of things you're dealing with. And if you've dug deep in dirt, like if you've ever set a fence or anything, you've had to go down deep, you learn really quickly how across most of the United States, you get into rock. Pretty quickly. That can be extremely damaging to a coating. And then, on top of that, when you bury that, you don't want to have to wonder whether or not your coating survived, right?

Paul: That's right. This standard really does a good job of pointing out some impact-resistant figures and some abrasion resistance that are really important, specifically for the outside of a pipe when you're doing these types of buried services or directional drilling, like you mentioned earlier.

Jack: Yeah, I think I should be clear, though, these coatings are not just for buried pipe. However, that's where their strength is when we come to the exterior of the coatings.

Use of polyurethanes for the interior of water pipes

Jack: One of the things that I find interesting when we move over to the interior side of this coating. So, obviously, we can use the same type of coatings as the interior lining. A lot of the times, this is for water pipes, so like we said, raw water versus potable water. And one thing that the standard does do, it does not give you any qualifications for whether or not the coating can be used in potable or raw. It defers to the NSF testing for potable water. It tells you you have to pass NSF 61 in order to be put into potable water service.

Paul: That's right. That way they can allow that end of the testing and the verification and the validation to be done under a standard that can be more controlled. You can control that locally. A local municipality can have a different set of requirements or a state or a country. So, they allow those to be a separate part so that you're not having to complicate the matters of the durability of it. In this standard, you can look at it and say, "Okay, does it do all this? And is it NSF 61?" If you're doing the inside of the pipe because, again, you don't need the NSF requirement if you're doing the outside of the pipe.

NSF/ANSI/CAN 600 - Health Effects Evaluation And Criteria For Chemicals In Drinking Water

Jack: And remember, like we talked about with Brian Cheshire a few weeks, we talked about how NSF 600 is coming in replacing NSF 61, and a lot of these coatings that we're talking about today in the C222 are 100% solids or high solids. So, they're all going to still be valid under that NSF 600 qualification. So, these C222 products, the ones Carboline carries, are all 100% solids, and they will all still continue to be NSF-approved under that newer, tighter, more restrictive standard.

Paul: That's right. One of the things that's stated in this standard is the type of urethane that it needs to be is an ASTM D16 Type V, which specifically states they are typically 100%, but maybe as low as 90%. So, you're really up there in the high solids range. And like you said, Jack, most of the manufacturers who make things in this category are hitting that 98, 99, 100% solids product.

Jack: Sure. And as we evolve, you know, NSF 600's just the first version or not the first version. It's the current version of tightening down. We've tightened down throughout the whole course of this industry, and we will tighten down further. The nice thing about these products is that they should be good for a long time because they don't have any solvent in them.

Chemical resistance required per AWWA C222

Paul: That's right. When you start looking at these types of products, one of the things that's important with these types, is it going to be chemically resistant enough to tolerate the conditions that you're going to be in? So, not just a potable water, but you have to be able to tolerate the cleaning procedures or any disinfecting procedures, anything else that goes along with the whole drinking water system. You need to be able to tolerate that. And that's built into this test. So, it's frequently built into municipal requirements for, along with being potable water, can you handle these chemicals? But C222 also includes that testing as part of their protocol.

Jack: Sure. You definitely want to make sure that when you put something into service, that you can handle all the different variables that come with it. And frequently, we talk about immersion service and we talk about commodities. Back in our tank lining series early on, we talked about molecule size. But when you look at potable water tanks, it's easy to forget the other little things like the chemical resistance and things like that. The ancillary things, the cleaning, the chemicals, those things so frequently get overlooked. And so, now, they're making sure, especially in all the AWWA standards, that those cleaning and sanitizing procedures don't get overlooked.

Repairs of the polyurethane coating per AWWA C222

Paul: That's right. One of the other things that I like about this standard, particularly Jack, is it goes into a whole section on how to do repairs. It is amazing how many times documents or standards or specs get put together, and there's no reference to how repairs are going to be handled when it comes time to do it. And I know in a lot of cases you don't know, but there's not even a reference in a lot of these to say you're going to need to repair. And maybe it's because they're talking about pipes. And they know pipes are going to be welded together, so they got to get handled as they're being put into the ground and then they're being welded. So, you know that there were weld holdbacks and welding areas, and those are going to have to be touched up or repaired or painted. So, maybe that's why this standard specifically reminds people that you have to deal with it. But it's nice to see it listed.

Performance requirements per AWWA C222

Jack: As we go on, it gives some performance requirements in order to be certified to this standard. A lot of them are pretty basic, associated with this type of technology. They're pretty lenient when it comes to cathodic disbondment. They allow you up to 12 millimeters at the point. Flexibility, that's the big things with these products. They're all flexibles. That's with ASTM D522, Test Method B.

Paul: As we get into some other of the tests, impact resistance, like we said on a buried pipe, impact resistance is going to be key to helping maintain a monolithic coating system on the outside of a pipe. And they follow the standard ASTM G14 is the test method they go with. And they give the set of parameters here in the test method and it says, "Here's what you need." And again, it's nice to see a realistic set of requirements, but yet it's still stringent enough to be able to say, "Everything can't pass." There has to be a level. And that way you can make sure that you've got a quality system if you've got a coating system that passes these tests.

Jack: Sure, they want you to have less than a hundred milligram loss. In the abrasion resistant test, thousand revolutions. Yeah, that's not too hard to do. Most coatings can get that. Especially when they're designed like this to handle some abrasion. I think a big factor here is the water absorption. They want you to be less than 2% water absorption, and that's key because we've talked about it, that these coatings, they're porous. All coatings are porous. There are some sponge-like qualities at a microscopic level. And they don't want the coating to hold a bunch of water up against the substrate, causing premature corrosion. The one that really got me that is kind of interesting is adhesion, and we have talked about adhesion with these coatings, and we've talked about in the past, I think we've brought up how these high solids polyurethanes and polyurias really are more cohesive than they are adhesive. And the force required to break that film is more than the force required to remove that film from the substrate. And so, they call for a minimum PSI of 1,500, which is still again for these coatings, no problem. There is some new verbiage about making sure that you do scribe around the dolly in this test, partly because of that cohesiveness that I'm talking about. You will get significantly higher numbers if you don't scribe around the dolly. Three and 4,000 PSI pulls aren't unheard of with these products.

Wrap Up

Jack: All right. So, there you go. It's a pretty straightforward standard. It's AWWA C222, and that's polyurethanes for the use of water pipes and fittings. And so, if you're a specifier out there, you're writing specifications for water pipe, whether it's raw or potable, you want to go the polyurethane route. It would be a good idea to mandate that the polyurethane met this standard because AWWA has done so much work to identify the good properties that make a good coating. And that way, you don't have to worry about any premature failures, things like that. Go with a coating that has the certification.

Paul: That's right. And I think, Jack, I think this is going to be the first, I think we've got a few more of these to cover. So, if this is something that you're interested in or an area that you work in, we're going to have some more episodes coming up in the future over the next couple of months. We're not going to do them all at once, but we're going to mix them in to be able to just say, "Here's another standard that's relevant to this area."

Jack: Sure, yeah. I think water and wastewater will show up as a theme over the next year on the Carboline Tech Service Podcast.

Paul: I think so. Is that a little foreshadowing?

Jack: A little foreshadowing. We'll probably even get our friend Brian Cheshire to come back on. All right, guys, for Paul, I'm Jack. We'll go ahead and we'll see you next week.

Paul: And so, for the Carboline Tech Service Podcast, I'm Paul.

Jack: And I'm Jack. And…

Jack & Paul: We'd like to thank you for your support.