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Fixing a Small Leak on a Big Manifold

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lkstdl
lkstdl Member Posts: 41
Supply manifold on a hot water hydronic system, 30 psi max, 8 x 199K boilers in cascade
4" black pipe, malleable iron tees, brass shutoff valves
All joints taped (Blue Monster) and doped (Megaloc).

After several months of operation we noticed tiny drips at two of the joints, a malleable tee and a brass ball valve. (The thousand or so other joints throughout the system are holding up fine.)

What to do?
  • Drain water, disconnect boilers, cut pipe, disassemble, thread cut ends, add a union, reassemble?
  • Drain water, solder joints? Will solder work on a threaded fitting that is already taped and doped?
  • Hydronic Leak Sealant such as PurePro or Hercules Base Hit II?
  • Epoxy putty applied to outside of pipe? Pro Poxy20 or JB Weld?
Thanks for your collective wisdom!

Luke
Luke Stodola

Comments

  • mattmia2
    mattmia2 Member Posts: 9,944
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    1
    Mad Dog_2
  • EzzyT
    EzzyT Member Posts: 1,297
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    Option 1 would be my approach 
    E-Travis Mechanical LLC
    Etravismechanical@gmail.com
    201-887-8856
    BenDplumberMad Dog_2
  • hot_rod
    hot_rod Member Posts: 22,472
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    The right way to do it? Or a bandaid? :s
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    mattmia2BenDplumber
  • MikeAmann
    MikeAmann Member Posts: 998
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    Epoxy putty applied to outside of pipe? Pro Poxy20 or JB Weld

    Then wait and see. If more leaks develop, then take the thing apart and redo.
  • hot_rod
    hot_rod Member Posts: 22,472
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    If this is a system that you piped together, well...
    Nothing screams hack louder the putty around a pipe. Regardless of the brand.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    BenDplumbermattmia2Mad Dog_2
  • ScottSecor
    ScottSecor Member Posts: 864
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    Take apart and redo.  Consider pre-made connectors with male ends that often come with unions.  Something like these https://www.supplyhouse.com/Chamflex-CH125012FM1000-1-1-4-x-12-ChamFlex-Hose-Swivel-MNPT-X-Fixed-MNPT

    My biggest concern is why are (only) these joints leaking? 
    Mad Dog_2
  • JimP
    JimP Member Posts: 87
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    Are these tiny leaks? If so, I’d tear long strips of cotton cloth and wrap those joints. Watch them and see if they stop leaking over time. If it’s low pressure and tiny leaks they might scale and seal up. If they don’t I’d take everything apart and redo it. That’ll be a tough job with 4” pipe so I’d try the cotton wrap first.
    Mad Dog_2
  • joechris9136
    joechris9136 Member Posts: 2
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    pack it with lead wool or ball wick
    Mad Dog_2
  • JimP
    JimP Member Posts: 87
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    👍ball wick if you can go round and round where the threads meet the fitting and valve.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,833
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    Take it apart and fix it right. Use a little dope (sparingly) on the inside threads of the fitting. Tape and dope on the male portion some of which gets "pushed out" of the joint so doping the inside helps.

    In fact, read the instructions on a can of Rectorseal True Blue. The recommend doping the inside threads on anything over 1 1/4"
    hot_rodmattmia2Mad Dog_2
  • lkstdl
    lkstdl Member Posts: 41
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    Take apart and redo.  Consider pre-made connectors with male ends that often come with unions.  Something like these https://www.supplyhouse.com/Chamflex-CH125012FM1000-1-1-4-x-12-ChamFlex-Hose-Swivel-MNPT-X-Fixed-MNPT

    My biggest concern is why are (only) these joints leaking? 

    I'm confused about what you are proposing Scott. Are you saying use a 4" diameter flex hose instead of a union? I've used a similar product from HoldRite for connections to the individual boilers, to the buffer tank, to the indirect, etc. but HoldRite only makes them up to 2" diameter.
    Luke Stodola
  • lkstdl
    lkstdl Member Posts: 41
    edited March 2023
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    Take it apart and fix it right. Use a little dope (sparingly) on the inside threads of the fitting. Tape and dope on the male portion some of which gets "pushed out" of the joint so doping the inside helps.

    In fact, read the instructions on a can of Rectorseal True Blue. The recommend doping the inside threads on anything over 1 1/4"

    Yup, we doped the female threads on initial assembly. Its possible I was just a little too gentle on the tightening. I didn't want to damage the brass valve by going too tight.

    We used a 4' pipe wrench, with some EMT over the handle as cheater bar, so I thought it was tight enough. But we can always get one more person on the cheater bar to make it another turn.

    Between the two drips its probably less than 1 oz of water per day. Didn't even notice it till we were putting the insulation on.
    Luke Stodola
  • hot_rod
    hot_rod Member Posts: 22,472
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    The issue with hydronic leaks is the expansion and contraction as it heats up and cools down, so it would be a reach to think it will seal itself off. Often the leak gets worse as the hot, cold swing continues.
    It’s a gamble, but if you are installing insulation it should be leak free, or you will be replacing expensive insulation also.
    Bummer, but I suspect you know the right way to fix it😏
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    mattmia2lkstdlMad Dog_2
  • ScottSecor
    ScottSecor Member Posts: 864
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    @lkstdl I assumed your leaks were on the individual boiler pipe, not the actual 4" common header.  They also make four inch "pump connectors" that might help you out.  We often have welded headers made up when we're using 4" and larger pipe.

  • ScottSecor
    ScottSecor Member Posts: 864
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    We've also used Alberta Custom Tees with excellent results.   Not cheap, but something to consider when you need a 4" header with three or four 2" takeoffs. 
    Mad Dog_2
  • mattmia2
    mattmia2 Member Posts: 9,944
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    the threads on one or both pieces are probably out of spec if they didn't seal easily. that doesn't mean you can't make them seal, but it is ultimately poor manufacturing(or possibly your dies are worn or out of adjustment if you threaded the pipe).
    Mad Dog_2
  • Paul Pollets
    Paul Pollets Member Posts: 3,658
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    Mega press would also work. You could rent the tool and jaws if you don't own them
  • lkstdl
    lkstdl Member Posts: 41
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    Thanks, that's what I was assuming I'd have to do but I was hoping there was a less invasive solution :)

    A couple people suggesting ball wick. Is that something I'd use in addition to the tape & dope, or instead of?

    Luke Stodola
    Mad Dog_2
  • MikeL_2
    MikeL_2 Member Posts: 506
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    Yes, ball wicking, covered by tightly wound quality Teflon tape, and Megaloc or equivalent

    Mad Dog_2
  • mattmia2
    mattmia2 Member Posts: 9,944
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    Ball wicking in the threads. There are numerous thread on here where you can watch people argue about tape or dope or both on top of it but you should use one or the other or both. Just make sure you make it so you don't have to cut anything if you need to give it a 3rd try.

    lkstdlMad Dog_2
  • hot_rod
    hot_rod Member Posts: 22,472
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    This mproduct works well. I use it on straight threads instead of hemp. Much easier to apply and keep in the groove. Its a silicon resin, looks like dental floss

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    mattmia2lkstdlMad Dog_2
  • Mad Dog_2
    Mad Dog_2 Member Posts: 7,241
    edited March 2023
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    Y,This is a new job under warranty,, your name is on it.. as Hot Rod said,, epoxy is for something old you don't want to touch or open a can of worms...and...for amateurs...Bite the bullet and take apart.. if you used enough isolation valves,, its easy. Ok, In this application, larger screw pipe, I ALWAYS use LAMPWICK (Thinner cotton string AKA "Spool" wick) NOT BALLWICK (Same material but fatter and used on waste lines as a homemade washer). ALSO, Go around 6 - 8 times IN THE THREAD roots (grooves), apply Permatex, GRRRIP, or one of The Heavy, glue, Rectorseals...the ones with a heavy petroleum odor. Apply liberally To wicked threads and really work it in. Also, really work it in to the female threads too. (Shhhh...Most codes prohibit this), but wipe any excess dope to limit the dope in the system's media.

    Screw it together very tight but don't split the fittings! Wipe off all excess dope let it run a few days, and if there is any weepage, the Quick Wick should absorb it and swell. If it still weeps, Neck-crank it tighter. I LOVE Blue Monster tape on waste lines and some other applications, but my tried and true method for screw pipe of all sizes is Quick Wick and Megaloc or good teflon Paste like Real-Tuff or Rectorseal White. A questionable thread or something I have to take apart is getting the Permatex, et al. I was taught this 40 years ago from Deadman Who had 50 years in who were taught by their Deadman and so on and so in..back to the early days of Mr Whitworth and his invention. I for one REVERE these men before me...they were much 🤓 Smarter and erudite than some of you'll give them credit for. They INVENTED and DEVELOPED what you want to tinker with, CRITIQUE, and play Doubting Thomas with. Their hard work and ingenuity have stood the test of time, safely heating homes all over the world. Mr Watts, Gil Carson, And What Dan Holohan has brought us in education at the knee of these great men..is PRICELESS...Take it ti the Bank!! .. My Mount Rushmore Of Heating Heroes. Last, they did this all sans power tools, even electricity, computer, youtube, labor laws about much more than an 8 hour day. I'm all for cutting edge, new technology and I embrace the good, proven stuff, but what I have seen is that The Deadman WERE AND ARE right about most things we install every day. Sorry, I'm not dismissing their PROVEN track record... Mad Dog

  • Grallert
    Grallert Member Posts: 669
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    one or three depending on the size of the leak. But thats a lot of sodium silicate to use. I could seal up on its own again depending on the size of the leak.

    Miss Hall's School service mechanic, greenhouse manager,teacher and dog walker
    mattmia2
  • Mad Dog_2
    Mad Dog_2 Member Posts: 7,241
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    Sealants are gimmicks and at best stop gap. Would never put that in New boilers. As long as you as yiu have service valves, and don't have to bleed radiators in 100 apartments, just bite the bullet and fix the leak. We've all been there. Nad Dog

    mattmia2