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Copper Joint that leaks in main pipe Solution please

acl10acl10 Posts: 344Member
Can anyone give me a good solution besides changing the pipe. On the main pipe around 20 feet away from the boiler the joint leaks. At that juncture there is alto of water hammer and it keeps cracking the solder. I used 50/50 solder and it still cracked. I asked someone about brazing but he told me you cant mix the two solders. Is there any other way to join the copper pipes or any other ideas.

I really appreciate any comments.


  • JUGHNEJUGHNE Posts: 5,578Member
    edited April 2014
    More pictures please,

    I don't type very fast but I'm trying to be the first to ask; could you post pictures of your boiler showing all the piping around it? Also how old is this copper piping installation and is this the only leak you have observed?  Others beside me are probably curious.

    And more questions; which came first: the water hammer or the leak?  Does the pipe sag at this coupling?  If so that may explain the water hammer and the problem to trying to re-solder a wet joint with water inside it.  If this is the only problem I would cut out the coupling, add a length of pipe with repair couplings or a union.  After cutting though, pushing the piping up and down to drain the water out will help the solder take.  If it is always flowing then the union has worked as you can raise the pipes up as you solder to keep the water back from your joint.  Assuming this is a steam main it should in theory drain all water out when cold.  But is all your steam pipe copper? That is the reason of the request for more pictures.  All pipes that carry steam are supposed to be black threaded pipe.  If they carry only condensate return water then copper would work.
  • acl10acl10 Posts: 344Member
    edited April 2014
    Follow up

    The water hammer was there first. This is part of the main. Its in middle of the basement not near the boiler. The most of the main is iron pipe. This section was changed because there was a leak in the iron pipe. I did drain the water when I soldered it because I put a valve in the main to drain the water. Is there some union you can use on copper? It doesn't sag so that's not the problem. I cant do anything about the water hammer. Is there a way to thread the copper?
  • nicholas bonham-carternicholas bonham-carter Posts: 7,817Member
    Copper problems

    It would be best to replace the copper with iron pipe., which can withstand the water-hammer which apparently you can do nothing about.

    The expansion and contraction with temperature changes of copper pipe is so great as to weaken the joints.

    Post some pictures of your boiler and it's piping, and let's devise a plan to cure the water-hammer.--NBC
  • acl10acl10 Posts: 344Member
    More pictures

    Here are the pictures of the valve to get drain the water and other pictures of the pipe. So far this is the only joint that leaks.
  • JUGHNEJUGHNE Posts: 5,578Member
    edited April 2014

    There are copper sweat unions which would put this together, just check one out of any size and it will be self explanatory.(if that is 2" check the price first)   And the newer "no lead" solder is susposed to be stronger than 50/50.  But with a section of copper between 2 sections of iron this might happen again.  With the rate of expansion and contraction of copper being much greater than iron this will push/pull on the joints again; perhaps this is what caused the first failure.  I believe that most here would recommend going back to an iron pipe repair with a union.  IMHO.--------Looking at the last of 9 pictures you posted you can see the hanger rub marks where the copper is moving as it heat/cools;  the iron will not move that much and puts the copper between "the rock and a hard spot".
  • Charlie from wmassCharlie from wmass Posts: 4,053Member
    your torch is too small to fully heat the pipe

    and the solder needs to be silver bearing, 50/50 is too soft and the only stuff around now seems to be full of impurities. Copper should not be used for steam piping, but you know that. If you need to fix this I strongly suggest replacing it with iron and finding out the cause of the water hanging in the pipe or you will never be done with this.
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  • acl10acl10 Posts: 344Member
    Here are pictures of Boiler piping

    Here are pictures of the piping around the boiler although I don't know what I can do at this point.
  • Jamie HallJamie Hall Posts: 10,277Member
    Water hammer

    can generate overpressures quite sufficient to actually break pipe -- never mind joints.  I quite agree that the best way to handle this one is to change that copper out and put in iron.

    But you say you can't do anything about the water hammer.  Why not?  Water hammer isn't an inevitable part of any plumbing system -- whether it's residential or 60 inch municipal mains.  Don't give up on that -- you control the system, you should spend some time to figure out where the water hammer is coming from and fix it.

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    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • PumpguyPumpguy Posts: 346Member
    As others have said...

    your best bet is to change out the copper steam lines for screwed iron pipe. 

    That said, for repairs to this failed copper joint, first get a slip coupling for this tube size.  These have the inside diameter sized to slip over the outside of the existing tubing. 

    To install, cut out the failed joint, slide the slip coupling in place and solder or braze the joint. 

    For a stronger joint, I would look into PHOS COPPER brazing rod.  A Google search will tell you all you need to know.  You will need to heat the joint to red heat, but the nice thing about Phos copper is it is much stronger, and is self fluxing on copper to copper joints, so you don't need to worry about getting the joints super clean.
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  • acl10acl10 Posts: 344Member
    What do you suggest

    What do you suggest I do to correct the water hammer. I posted the pictures.
  • Double DDouble D Posts: 296Member
    One source of your hammering

    may be in your improperly piped boiler. Do you have the make & model number of that boiler?
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