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Copper lines for radiators

RJ_4 Member Posts: 484
I am replacing old cast iron radiators with new steamview steel tube radiators in a 90 yr. old 11 story bldg. Have 2 problems. (1) New radiators are relocated approx. 16 ft. from there respective risers, the old cast radiators were about 18 inches away at 1 inch pipe. Not sure if pipe should stay at 1 inch.

(2) Do to little room to run piping, thinking of running small amounts of horiz. pipe to rads. using type L copper with brass nipples. I have used this in the past on industrial steam tables with success. Any suggestions?


  • I was always taught

    never to run copper for steam; the only allowable place would be below the water line at the boiler.

    As far as size, keep it 1" since there has to be enough room for steam at the top and condensate at the bottom unless you like to hear the hammering sound of water flashing to steam.

  • Copper, for steam heating, is generally regarded as a "No-No" due to work hardening at the joints from the constant expansion / contraction.

    Since you mentioned that this is a 1 pipe steam system I would also be concerned about getting enough pitch so that the condensate would return properly on the new longer runs to the new radiators.

    If you don't have a copy already, I highly suggest that you get a copy of Dan's book "The Lost Art of Steam Heating" (See "A Steamy Deal" at the bottom of this page) It contains all the "rules" and tips you need to get a steam system running properly. My copy has paid for itself many times over.

    - Rod
  • RJ_4
    RJ_4 Member Posts: 484

    Thanks for your inputs. I am on my 2nd Lost art book , wore out the 1rst one. Steamin since 1974. Just thought I would get some 2nd opinions ,I have learned after 35 yrs. in the trade, never be to proud to ask a question.
  • bob young
    bob young Member Posts: 2,177

    with a run that long you might consider a return. 3/4 " should do the trick.
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