CSST tubing for potable water

Plumbing Forums

Help Support Plumbing Forums:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Nukedaddy

Well-Known Member
Joined
Oct 21, 2013
Messages
85
Reaction score
26
Location
St. Louis, IL
I have found a couple of makers supplying CSST tubing from 3/8” nominal through 2””. The tube runs has female gasketed threaded nuts on each end and can be field fabricated. The fittings are brass with male threads to match the nuts on the tubing. (These appear to be “G” type metric cylinder threads)
Has anyone knowledge of such a piping system being approved by a State or Model code in the US?
 
What is CSST tubing used for?


Corrugated Stainless Steel Tubing (CSST) is a flexible, stainless steel pipe used to supply natural gas in residential, commercial and industrial structures. CSST is often coated with a yellow, or in some cases, a black exterior plastic coating.

DO NOT USE THIS PIPE FOR DOMSECTIC WATER
 
If you search on the easy flex website you will see that there is a section on certifications and approvals for their water flexible tubing.
 
If you search on the easy flex website you will see that there is a section on certifications and approvals for their water flexible tubing.
Yes, the website says it has UPC approval but the phone and email address don’t seem to work so I cannot confirm any other approvals. (Like in my state, Illinois, which has its own code.)
 
You couldn’t give me that stuff if they were giving it away.
We used to say that about PVC back in the 1960s. But then came along polybutylene and if you are old enough you remember what a debacle that turned out to be. There are new technologies and materials coming out all the time. PEX has 2 different types, A and B, with 5 or more ways to join it. Buttweld and socketweld plastics are in use worldwide. CSST water connectors have been in use for water heaters in the states for 20 years. Who is to say what the next best thing is?
 
We used to say that about PVC back in the 1960s. But then came along polybutylene and if you are old enough you remember what a debacle that turned out to be. There are new technologies and materials coming out all the time. PEX has 2 different types, A and B, with 5 or more ways to join it. Buttweld and socketweld plastics are in use worldwide. CSST water connectors have been in use for water heaters in the states for 20 years. Who is to say what the next best thing is?

Why would I want a corrugated tube that would cause pipe wall erosion, noise and naturally drop my pressure ?

It’s a stupid idea. I’ve been doing this work for 35 years and my father did it for 50 years and my grandfather did it before him. I’m well aware of the evolution of new materials and different methods since modern plumbing has been being installed in America. I kinda feel qualified to have professional opinion.

There are more than two types of pex.
 
I just called them. The phone number works. The product does not have any local jurisdictional certifications beyond UPC. So, specialized approvals for YOUR state/county/parish/town or whatever that deviates from UPC? Not approved. [And, might I add, they answered the phone quickly. The person in sales listened to my question, and routed me to the person best positioned to answer it. HE answered the phone quickly, and answered my questions. So, that's pretty darn good support when most companies now don't want to talk to humans and make it difficult to get support.]

Normally, in the evolution of products used to build houses, such as plumbing and electrical products, the "evolution" is often used to cut costs. So, yes, PB was a huge debacle but the thought was it was less costly and easier to install than copper. It wasn't devised with the homeowner in mind, ONLY for ease of installation and saving a buck. Shall we talk about aluminum wiring in houses? Yeah, didn't think anyone wanted to talk about that either. Another idea: save money by saving copper...but I digress. The history of plumbing and electrical (and some structural components too) is littered with "new ideas" used to save money that have turned out to be disasters. Three words I cringe when hearing..."new and improved".

CSST is by its very nature considerably more expensive "per foot" than copper equivalent and geometrically more costly than PEX. So, if you are thinking that this is some kind of replacement for domestic plumbing applications that would normally use PEX (or in the past, CPVC, PB, Copper) you'd be wrong. It's primary application is in the solar industry where it used in solar collectors and to and from heat exchangers used in solar. At least that's what their sales team told me. They knew that it would be cost prohibitive in domestic use where PEX rules.
 
I just called them. The phone number works. The product does not have any local jurisdictional certifications beyond UPC. So, specialized approvals for YOUR state/county/parish/town or whatever that deviates from UPC? Not approved. [And, might I add, they answered the phone quickly. The person in sales listened to my question, and routed me to the person best positioned to answer it. HE answered the phone quickly, and answered my questions. So, that's pretty darn good support when most companies now don't want to talk to humans and make it difficult to get support.]

Normally, in the evolution of products used to build houses, such as plumbing and electrical products, the "evolution" is often used to cut costs. So, yes, PB was a huge debacle but the thought was it was less costly and easier to install than copper. It wasn't devised with the homeowner in mind, ONLY for ease of installation and saving a buck. Shall we talk about aluminum wiring in houses? Yeah, didn't think anyone wanted to talk about that either. Another idea: save money by saving copper...but I digress. The history of plumbing and electrical (and some structural components too) is littered with "new ideas" used to save money that have turned out to be disasters. Three words I cringe when hearing..."new and improved".

CSST is by its very nature considerably more expensive "per foot" than copper equivalent and geometrically more costly than PEX. So, if you are thinking that this is some kind of replacement for domestic plumbing applications that would normally use PEX (or in the past, CPVC, PB, Copper) you'd be wrong. It's primary application is in the solar industry where it used in solar collectors and to and from heat exchangers used in solar. At least that's what their sales team told me. They knew that it would be cost prohibitive in domestic use where PEX rules.

Thanks! There is the info I was searching for. I dont know why the toll free number still comes back to me as no longer in service. The website lists it as the Eastern office. The info email address on the website also bounces as undeliverable. I was searching for a source and pricing info that you have found. I did finally get a catalog from their Chicago area rep, but no pricing.
And as to code. Illinois is a stand alone code. I have a friend, one of my former apprentice students, who is on the code board. He said he had not heard of CSST for water other than as already made up short connectors for water heaters but would not discount that the system might be approved if submitted to the board.
But, if cost is the only driver, (and it often is), then CSST water systems may never catch on. But I think the mouse is not yet evolved to the point he can chew through stainless steel. Yet.
 
Why would I want a corrugated tube that would cause pipe wall erosion, noise and naturally drop my pressure ?

It’s a stupid idea. I’ve been doing this work for 35 years and my father did it for 50 years and my grandfather did it before him. I’m well aware of the evolution of new materials and different methods since modern plumbing has been being installed in America. I kinda feel qualified to have professional opinion.

There are more than two types of pex.
PEX is made by 2 methods. Engle (A) or Silane (B). The tubing may have an aluminum or other oxygen barrier but the resin is made in only those two ways.
 
...And as to code. Illinois is a stand alone code...

Yes, one of THOSE places where a bunch of former professionals sit in the state capitol thinking that "our conditions are different" and we know what we're talking about, so we are going to be make our own sets of rules...
In Chicago, what we call Romex, or NM wiring, which has been used since knob and tube went away, throughout North America, isn't good enough, apparently, for Chicago homes. They all have hard conduit and pulled THHN wire, like you'd wire a factory...very industrial. (sound of head shaking)

@Nukedaddy I called their office in Texas. Very helpful. I'm sure they'll be able to answer all your questions about their CSST products.
 
Yes, one of THOSE places where a bunch of former professionals sit in the state capitol thinking that "our conditions are different" and we know what we're talking about, so we are going to be make our own sets of rules...
In Chicago, what we call Romex, or NM wiring, which has been used since knob and tube went away, throughout North America, isn't good enough, apparently, for Chicago homes. They all have hard conduit and pulled THHN wire, like you'd wire a factory...very industrial. (sound of head shaking)

@Nukedaddy I called their office in Texas. Very helpful. I'm sure they'll be able to answer all your questions about their CSST products.
You have assessed the workings of the code in Illinois pretty accurately from where I see it. When I took the license test back in the late 1970s they had just done away with wiping a lead joint as part of the test, but it remained in the Chicago version. And no Romex doesn’t surprise me. Aluminum service entrance wire is common here, but it may also be hard to find or not allowed in Cook &Lake counties. The Illinois Plumbing Code does have some similarity to the National Standard Plumbing Code with bits and pieces added or pitched. It was only a few years back that Orangeburg pipe was removed from the approved list. One of the changes I would like to see is to remove plain old air chambers removed as the waterlog a few days or weeks after installation. Piston or diaphragm types work longer, but upsizing tube sizes to keep flow speeds under 5 fps works even better.
 
You have assessed the workings of the code in Illinois pretty accurately from where I see it...Aluminum service entrance wire is common here...

AL SE cable (for service entrance, and drops) is pretty standard most places. It is connected to the lugs which are designed for it, and used with an anti-corrosive paste. In the SE application, not an issue. In distribution systems it caused a lot of fires, so they dropped it. As an inspector we have to report on the existence of AL wiring...also, ABS DWV pipe when we see it.
 
AL SE cable (for service entrance, and drops) is pretty standard most places. It is connected to the lugs which are designed for it, and used with an anti-corrosive paste. In the SE application, not an issue. In distribution systems it caused a lot of fires, so they dropped it. As an inspector we have to report on the existence of AL wiring...also, ABS DWV pipe when we see it.
I don’t think I have seen any breaker panels that were not Aluminum screw clamp where the service comes from the meter. Same for the meter box itself. And both have Aluminum busses. NOX paste I sometimes see in meter and breaker boxes, but not often.
I was surprised to read that ABS was frowned on. Admitted, ABS was never as popular in the Midwest as PVC, but in the South and West it is very common. I remember the first time I used ABS. It came supplied with a double wide. I laid the pipe (full lengths) out in the yard by the trailer until needed. As the August sun hit it it bowed and rolled across the yard and into the street before I spotted what was up!
 
Our local code prohibits ABS in the city. Not that it matters what they say too much.
 
OK, I have heard back from Easyflex about their CSST water tubing and system of fittings. They described it as in “hiatus”. So I guess it did not sell well or met with too much resistance for code approvals or ??? Oh, well…. Sounded pretty good, and the specs looked good.
 
Back
Top