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Radiator fittings

josephcjosephc Member Posts: 35
I was able to find a radiator locally for our addition. Are to connections between radiator and supply and radiator and trap standard black pipe reducing bushings? Or are they a special adaptor?

The radiator was in one pipe steam service so our next challenge is to P-oil the threads and remove existing pipe connected to bottom and plug in top. Then get the fittings I need for supply and trap sizes.



  • FredFred Member Posts: 7,362
    The bushings are standard black pipe bushings.
  • delta Tdelta T Member Posts: 703
    If this was for a one pipe system originally, and you are adding it to a two pipe system or a hydronic system make sure that the top of the radiator sections are actually connected. There are a lot of one pipe radiators that can ONLY be used for one pipe steam. If you look closely you will see the tops of the sections are not connected. Other than that, yes, as Fred says all the connections should be standard NPT threads.
  • josephcjosephc Member Posts: 35
    I'm having a heck of a time trying to break fittings free on the old radiator. is it ok to use some heat from propane torch on the cast radiator? Ive put some penetrating oil on fittings but not budging.
  • FredFred Member Posts: 7,362
    You may have to cut the pipe and plug out. Fairly typical for fittings that are 50 to 100 years old. Cut the pipe off so that maybe an inch or so remains to grab onto. With a Sawzall (I prefer a close cut hand hack saw (it takes a little longer but it gives you a lot more control) cut into the pipe that is threaded into the radiator until you get to the threads of the radiator but do not cut into the radiator threads, Once you do that, the binding pressure will be relieved between the pipe and the radiator and you can turn the remnants of the pipe out.

    For the plug, you probably will have to cut the square or hex head off. That will give you an opening to repeat the process above. If it doesn't, just drill out the area where you cut the head off (it will be thin after cutting the head off) then repeat the process above. Take your time and don't cut into the radiator threads. You have more time than you have radiators.
  • josephcjosephc Member Posts: 35
    Fred - your method worked; I spent most of the day working on it and was able to remove what I needed to. I then pressure checked it and all ok. But when finishing up I put a 1/8 inch plug in where there had been a vent and where I had installed my pressure gauge and proceeded to wreck it by making it crack at the socket. I am at a loss now. Cant believe I got this far and then this. Is there any way to repair this or is it even worth the risk. I checked and it now doesn't hold pressure; can hear it coming out.
  • FredFred Member Posts: 7,362
    Oh My Gosh! Don't you just hate it when that happens? I am afraid that radiator is done for. You'll need to figure out where to find another one and start over. At least you know how to do it now.
  • nicholas bonham-carternicholas bonham-carter Member Posts: 7,641
    Maybe on round two of this, you could get an appropriate size of tap, and clean up the threads in the radiator, before screwing in the nipple, or spud.—NBC
  • AshleighChamberlainAshleighChamberlain Member Posts: 1
    Could you remove the last section of the radiator (i.e. shorten the radiator by one section)? It would be a lot of work, but you seem to have the patience.
  • FredFred Member Posts: 7,362

    Could you remove the last section of the radiator (i.e. shorten the radiator by one section)? It would be a lot of work, but you seem to have the patience.

    In theory, he could remove any one of the sections between the end sections but only the end sections are threaded to accept pipe. Even getting one of the middle sections out and the radiator put back together is far more effort than finding another radiator and even if he could do it, there is still the risk of leaks or even cracking another section.
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