My house has Kitec plumbing. I would like to replace my main runs which are 3/4 inch hot and cold water; these 3/4 runs are the ones that run in the ceiling. This leaves the runs in the wall for later, since that would require substantially more work. I would like to use 3/4 Uponor PEX A. I'm wondering if there is a way to bridge a main run with Uponor PEX to Kitec?

Here is a picture of one of my fittings. The tubes all say Made by IPEX. Notice the fittings says B137.9/10 that apparently means it's Kitec.

Fitting Front


This pipe was very rigid. I cut it off with an angle grinder. The back of that fitting says Kitec

Fitting Back

It reads,

Kitec TN 2025 Taiwan

With the pipe's off they all read

PE-AL-PE 2025-3/4" 200 PSI @ 73.7°F/100 PSI @ 180°F

  • Your question, as asked, is a bit vague. It seems you are simply looking for a fitting to transition from PEX to Kitec plumbing. If so then you should specifically ask that. Unfortunately, that will probably be seen as a shopping question and get closed. If you're asking something else, please edit to be more explicit about what you're after. Also, the only thing I can read on the labeling on your plumbing is XPA, but that's got nothing to do with what you're asking about (AFAIK), so please consider a better pic to clarify that, too.
    – FreeMan
    Commented Jan 25, 2023 at 13:52
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    I'm not just asking for a fitting. I'm asking how to do something. Can you expand Kitec? Can you crimp onto an Uponor expansion valve? What what plumber do in these situations? Do you go to NPT and have them meet up there? I was thinking about that, but is it weird to bind two NPT fittings before you install them so you crimp on one side, and use expansion on the other? Commented Jan 25, 2023 at 15:26
  • Sorry, I'm not familiar, is Kitec a brand of PEX or a different type of pipe, or something else? Note: I'm not likely the one who is going to answer your question, I'm just trying to learn here...
    – FreeMan
    Commented Jan 25, 2023 at 15:28
  • 1
    @FreeMan Sure before PEX, there was Kitec. And apparently before Kitec there was PB tubes.. These are not PEX. In the case of Kitec I'm not exactly sure why they're not PEX but some estimates are 25% of house made or renovated before like 2007 have this tubing. The problem with it is it has a sudden failure mode and is known to always fail at some point. You're supposed to get rid of all of it. I put more information on the fitting in the question. The text reads B137.9/10 which apparently means Kitec. Commented Jan 25, 2023 at 15:32
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    In fact I think this is an excellent question. A common problem, how to gradually transition a house from bad old X to better new Y without nuking the whole joint, asked in the form of exactly one specific, solvable problem: Is it ok to transition by combining them and how do you do it?
    – jay613
    Commented Jan 30, 2023 at 15:16

2 Answers 2


Yes, you can slowly migrate.

You can find Kitec fittings as fittings for generic PEX-AL-PEX. My specific pipe was PE-AL-PE. But it doesn't seem to matter. SupplyHouse.com sells PEX-AL-PEX fittings by Mr. PEX, which seems to work. These fittings are only sold for radiant heating now, and they insanely expensive.

Kitec PEX-AL-PEX or PE-AL-PE to Male NPT

After you have it in MNPT (male NPT), it's easy to get it to PEX. You can just buy an FNPT (female NPT) to PEX fitting.

Female NPT to PEX


I don't think you are going to find Kitec to PEX stuff easily, if at all. You might be able to find Kitec to copper fittings, which you could then transition to PEX.

I have had some luck with Sharkbite fittings on some types of PB. But I would never use those long term. Only for a brief period of time while repiping. You might have the same luck with Kitec.

A better approach might be too run the PEX in parallel, which will let you convert one fixture at a time. The challenge you will run in to is capping off the Kitec. Do you have a supply of Kitec caps?

  • No, I have nothing Kitec. =( Commented Jan 30, 2023 at 14:47
  • If you don't have a way to cap off the Kitec stuff, then you're going to have a problem with your plan of only changing the immediately accessible stuff now, and the rest later.
    – longneck
    Commented Jan 30, 2023 at 16:11
  • Sharkbite caps for the Kitec might work, no? Sharkbit might not be a good "permanent" fix, but it ought to work for several months/years during transition.
    – gnicko
    Commented Jan 30, 2023 at 16:29
  • @longneck Well, I may be able to cap it off. If I find the right kitec to mnpt, and then get an fnpt cap. Commented Jan 30, 2023 at 16:58

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