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A mix of pex fittings and pipe.

Intplm.
Intplm. Member Posts: 2,165
in A-C, Heat Pumps & Refrigeration

Expandable PEX -A- with the expansion collar. Has anyone used the [ fitting ] with the expansion method with a crimp connection? If so, did it fail?

And has anyone used fittings meant for the crimp method with the expansion method fittings?

Has anyone used the PEX -B- using the expansion method? If I'm not mistaken Sioux Chief has come out with a PEX -B- that can be expanded. Is this also being used?

Comments

  • hot_rod
    hot_rod Member Posts: 23,224

    I have crimped pex A without issues.

    I don’t see how a crimp fitting works after you expand the tube? The crimp fitting fits inside the tube already

    Yes several pex B manufacturers allow expansion

    The official answer lies in the listing numbers on the tube, and fittings, you can find all that and more at the PPI website

    Early on pex manufactures claimed to void the tube warranty if you used fittings other than their brand

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,212
    edited May 7

    Why don't you use the Viega fittings like @kcopp suggested and that you commented on?

    https://forum.heatinghelp.com/discussion/196981/merflex-pex

    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • GGross
    GGross Member Posts: 1,233

    Uponor pex can safely be crimped, expanded, sharkbite, you can't use an F1960 fitting with a crimp collar though, because the pipe needs to be expanded to accept the f1960 fitting, it won't just slide in there, and then once expanded the crimp ring won't be the right size.

    Sioux chief does make a Pex-B that is approved for F1960 (cold expansion) fittings. I know many people who use this without issue.

  • Intplm.
    Intplm. Member Posts: 2,165
    edited May 8
    https://forum.heatinghelp.com/discussion/comment/1801177#Comment_1801177

    I do use Viega and Uponor. I'm wondering if others have used mixed fittings etc. with different joining methods.

    Expansion uponor, that fitting. Has it been used to crimp pipe with success? I haven't and wouldn't try it blindly.

    @Alan (California Radiant) Forbes your post ( thank you for showing it again,) was part of what I was thinking about when I started this conversation.

    I have used both methods, expansion, and crimp. Has anyone interchanged the fittings?

    As to the tubing. PEX -B- was not recommended for expansion till recently. or am I misinformed?

    Alan (California Radiant) Forbes
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,269
    edited May 8

    This all sounds cut and dry for many folks, but you need to understand that not every application is new construction using all new tubing.  Some of us do repair work on existing equipment that has other than our standard product already existing in the home/building.  This is a good question that many would like to know the answer to.  Wouldn’t it be nice if there were only one standard for PEX tubing and there was no such thing as PEX-AL-PEX or PEX-a or PEX-b or QUEST or that rubber ONIX stuff.  Then there would be only one fitting design and this question would not need to be answered.  

    I like the fact that there is a place to look that stuff up

    “The official answer lies in the listing numbers on the tube, and fittings, you can find all that and more at the PPI website”  Thanks @hot_rod. 

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • dko
    dko Member Posts: 668
    edited May 8

    Instead of going solely by Pex-A, Pex-B, and Expandable Pex-B, go by the standard they meet.

    F1807, F1960, F2080, F2159, etc… It will be listed on the pex and fitting.

    Then match the fitting/joining method to the standard of the pex. Some pex tubing meet multiple standards like the sioux powerpex- meaning you can use multiple joining methods.

    Each fitting will only have one standard method of joining, meaning you can't use F1807 crimp method on F1960 expansion fittings. Nor can you use F1960 expansion fittings with F2080 expansion method (rehau).

    Just match the standards and you won't have an issue.

    GGross
  • hot_rod
    hot_rod Member Posts: 23,224

    the method of crosslinking determines the flexibility of the pex tube. It questionable in my mind if the B pex can tolerate expansion?

    Are Zurn and Sioux chief the only brands promoting expanding B pex?

    There are a number of online videos showing the tube splitting after expansion


    Time will tell how well the B pex expansion pans out.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Intplm.
  • dko
    dko Member Posts: 668
    edited May 8

    Definitely questionable as the explanation for it is "through meticulous enhancements" per Zurn.

    I'm sure there's some tech sheet out there explaining in detail why this new type B pex is now expandable.

    Sioux chief retroactively approved their powerpex b for expansion. Stating any pex-b dated 2018 onwards will be approved for expansion. Maybe they were waiting for testing and approval process? They put a 25 year warranty on it and must be expanded using a self-rotating head.

    Anyway, I'd agree and stay safe with using pex-a for expansion.

    Intplm.
  • GGross
    GGross Member Posts: 1,233
    https://forum.heatinghelp.com/discussion/comment/1801267#Comment_1801267

    Legend has a PE-RT that is approved for F1960 cold expansion. I share the same concerns you do, I haven't seen any failures locally on the Sioux Chief stuff and everyone we sell it to is expanding it.

    Intplm.

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