Off Sized Half inch copper pipe????

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Kramsee, Oct 10, 2021.

  1. Kramsee

    Kramsee New Member

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    Replacing a bathroom sink shut off valve, I sweated off the old, leaky ( what I believed to be a 1/2 inch ) valve and wanted to sweat on an adopter for a threaded valve. Believing the supply pipe to be 1/2 inch, I bought the appropriate fitting and valve. Long story short, the fitting is exactly the same diameters, inside and out, as the supply pipe. Standard half inch pipe fits as it should into the fitting but also slides into the supply pipe. It's the only way I can make it work! Pretty much making a sleeve. What's coming out of my wall to supply the water?????? Thank You!

    Yes, both are copper!
     
    Last edited: Oct 10, 2021
  2. fitter30

    fitter30 Well-Known Member

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    Refrigeration 1/2" tubing measures 1 /2" od. Refrigeration copper except 1/4" measured by od. They make 1/2" od compression x 1/2" male. pipe thread fittings. Try plumbing / refrigeration supply houses or supply house.com
     
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  4. John Gayewski

    John Gayewski In the Trades

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    What is the outside diameter of the pipe coming from the wall?
     
  5. LLigetfa

    LLigetfa DIYer, not in the trades

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    Standard rigid copper 1/2" pipe is nominal 1/2" ID and 5/8" OD. The actual ID depends on whether it is Type M, L, or K.
     
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  6. Kramsee

    Kramsee New Member

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    O.D. is 3/4 inch ..... I.D. is 5/8 .... Using a 2 1/2 inch length of standard 1/2 inch copper pipe, I sweated a 1/2 inch threaded coupler to one end ( to install the new valve ) then slid the other end of the 1/2 inch pipe into the odd sized supply pipe, than sweated that in. It fit in exactly as if it was made to do that. Odd thing is that the old shut off valve is sized to the odd size pipe, ( 1/8 inch of slop when fitting normal 1/2 pipe into it ) although it's identical in every other way as new valves. I took the old valve to Home Depot and between the HD employees and the couple Pros? that got involved, nobody could figure out what I had or what it was used for.
     
  7. fitter30

    fitter30 Well-Known Member

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    3/4" od is refrigeration tubing. Plumbers measure by id refrigeration and pipefitters od
    3/4" tubing is plumbing 7 /8" is refrigeration same pipe
    ACR and L same wall thickness only difference in pipe ACR is dried, cleaned and capped
    since wall thickness varies by type m,l,k still called by the same nominal size
     
    Last edited: Oct 11, 2021
  8. wwhitney

    wwhitney Well-Known Member

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    So the obvious question is whether the ID of the 3/4" OD copper tubing the OP has is sufficiently close to the ID of a 1/2" copper pipe (5/8" OD) solder cup to use it as such, or if the OP needs to find a 3/4" OD copper tubing by 1/2" copper pipe (5/8" OD) coupling.

    Cheers, Wayne
     
  9. Kramsee

    Kramsee New Member

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    Yeah, I'm figuring the guy that did this previous plumbing had free access to these off sized shut off valves and also had access to the refrigeration pipes. Peeking into the wall, it looks like he sweated a short length of the refrigeration pipe right onto standard half inch pipe, than sweated on the valve to the refrigeration pipe. I just did the opposite and sweated a half inch nub into the refrigeration pipe and finished off with normal 1/2 inch copper. Too lazy to open the wall and make it all half inch. :) Thanks for the info. Home depot had no clue to what I had going on.
     
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  10. wwhitney

    wwhitney Well-Known Member

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  11. Tuttles Revenge

    Tuttles Revenge In the Trades

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    We used to braze pipe into pipe to do that. But if the diameters are the same tolerance that a fitting and tube would be then a solder joint would work in that case too. So long as you really cleaned the inside of that old pipe to get any scale build up off.
     
  12. Reach4

    Reach4 Well-Known Member

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  13. Kramsee

    Kramsee New Member

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    So far, leak free but keeping an eye on it. I'm really just considering it as ( hopefully ) a long lasting temporary job. I could easily cut out some drywall and redo new from inside the wall but that requires dismantling and removing the 60 inch vanity and sink for access. Being that it's the " wifes " bathroom, urgency and speed for finishing it would be a priority with her supervising. Just not in the mood for dealing with that now! :)
     
    Tuttles Revenge likes this.
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