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How should I connect two sections of steam cast iron baseboard at a 90 degree corner?

brucebruce Member Posts: 222
I got some special fittings to go with the cast iron baseboard to connect two sections in a corner one for top tappings and on for bottom ones. They are flexy gizmos that look like they will reduce the size from 3/4 to maybe 1/2 inside. Will this cause a problem by making a dam and keeping condensate trapped in the first section of the baseboard unable to get to the return drain at the end of the second section?


  • heatpro02920heatpro02920 Member Posts: 991
    Do you have a picture...

    I have a way to do it with no fancy fittings, but I want to make sure I am thinking of the correct situation...
  • brucebruce Member Posts: 222
    Sorry no pics

    Sorry I have no pictures. It's a 90 degree inside corner, The cast iron baseboard is tapped 3/4 top and bottom. I have trim covers for the corner but there isn't much space.
  • Dan HolohanDan Holohan Moderator Posts: 11,877

    is this two-pipe steam?
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  • brucebruce Member Posts: 222
    It is one pipe

    This is a replacement situation. 16 feet of cast iron base board now fed by one pipe steam system. Supply is 1 and 1/2 inch steel almost flat run out from main line. This run out also supplies another small rad on the floor above. The existing base board has 3 cracks, 2 at the far end and another at a point just before the inside corner. Per Dan's book TLAOSH I plan to add a 3/4 or 1 inch (which is best?) return line from the far end of the baseboard back to the wet return. I'm wondering why this baseboard cracked in the first place. The two 8 foot pieces are joined together with 3/4 copper male adapters and 90's. How much will this baseboard expand? It is held by the exterior wall one one end and I can't see the pipe on the supply end because it comes horizontally out of a cabinet. Thanks for your help!
  • pipekingpipeking Member Posts: 252

     a 3/4 blk union fit inside the trim? what about copper? 
  • Dan HolohanDan Holohan Moderator Posts: 11,877
    If it's anchored and expanding

    it can break. I think 3/4" should be fine for the drain. Don't forget the air vent.
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