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L or M copper pipe

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  • L or M copper pipe

    What is recommended for boilers-tanks in high-rise piping .... L or M

  • #2
    type K if you can afford it. but typically type L is what's used.

    not because that type M can't handle the pressure or the heat, it's the constant circulating that's the wear and tear factor.

    phoebe it is


    • #3
      Thanks Rick! Professional answers as always


      • #4
        M is used for heating here. L is typically only used on Domestic water lines.

        I bet there is a supply house near you that rents the machine and sells the fittings. Typically about $25/day for the machine


        • ArizonaPlumber
          ArizonaPlumber commented
          Editing a comment
          Depending on how many fittings you are buying, especially for boilers and tanks, they would probably "Loan" it, at no charge.

      • #5
        I would think L grade copper is the minimum in a commercial hi rise building.



        • #6
          My boss always wanted me to use M pipe for my boiler work. I always used L and he would get mad at me. I said in 20 years have we ever had a problem with the pipes we put in. He said mo, I said thats why I use L pipe. The only time I used M pipe is for base board heat.
          Then wen we went with pro press I used L pipe for every thing.

          My seek the peek fundraiser page

          new work pictures 12/09


          • NHMaster3015
            NHMaster3015 commented
            Editing a comment
            You have seen how thin copper fin tube copper is and it holds up just fine. We have been using M copper for heat for decades now and I can't recall ever seeing pipe failure in a hydronic system using M copper. For a few years NH amended the code to require L copper for domestic water supply but have since backed off that and gone to either M, L or K copper. I see a lot of the problem being bad water conditions but rather than fix the water problem, too many plumbers would rather tear it all out and put plastic crap in instead. I do not understand why so many plumbers shy away from water treatment and filtration. It is a natural extension of the trade and properly installed it will eliminate copper erosion problems as well as greatly extend the life of faucets and fixtures.

            I didn't know you were in Bridgton. You are only about 45 minutes away from me. Do you fish the Songo river?

        • #7
          Closing in on 30 years plumbing never put in a piece of M copper took out and fixed a lot though, dam bid copper and go cheep plumbers


          • #8
            The one thing you all have in common is that you are PLUMBING contractors. Plumbers tend to use L (myself included). The heating guys use M and only M in this area. However, M copper is allowed on domestic water in the City of Chicago and you better believe that it gets used in a LOT of commercial settings. The difference between L and M copper when bidding a job with 1000's of feet of pipe is the difference between getting the job and NOT getting the job. Cost is King...... That said, I use L for all domestic and M for most heating. I propress just about everying. Too much flux is usually what leads to leaks on M in my experience


            • sewermonster85
              sewermonster85 commented
              Editing a comment
              M is ok to use on domestic water lines in chicago? Just curious because a costumer of mine recently bought a house on the north side and he has to rip out the whole domestic water due to it being in m pipe.

            • sewermonster85
              sewermonster85 commented
              Editing a comment
              But i must note that the plumbing inspector was a (Richard) can't say what I want to say...gotta keep the forum clean here. Lol.but he had a couple code violations very minor at vacuum breakers on the silcocks.Gate valves on the main shut off and at the water heater.It was a foreclosure owned by the bank ..There was no permit on file and in order to get his occupancy he has to put l copper in ..The main is k with a flare
              Last edited by sewermonster85; 06-17-2014, 08:47 AM.

            • Swade Plumbing
              Swade Plumbing commented
              Editing a comment
              M copper has always been ok for domestic water in Chicago. Table 18-29-605.5. type K, L or M allowed with proper ASTM rating. Granted this is from my 2003 book (page 187) unless they changed that recently. New IL state code onlineL
              Does not indicate any exclusions on type M, nor does it state type L or K required above ground. Only states K or L required UNDERGROUND.

              That all said, I only use L copper on domestic. But I see M copper in domestic all the time.

          • #9
            We don't have many boilers down here


            • #10
              Type M is universal down here on residential. And no residential boilers either.


              • #11
                Underground = K
                Domestic water = L or K
                Heat = M, L, or K if you've got money to burn.
                Drains and vents = DWV (do they still make that stuff?)

                That's how I was brought up. ;-)

                "It's a table saw, do you know where your fingers are?" Bob D. 2006



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