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Changing dry to wet return

Klmdss
Klmdss Member Posts: 4
Is it possible or nonadvisable to lower a current dry return, which is about 3 to 6 inches aboves the waterline over of 20ft span into a wet return?  There are no real obstacles.  I can't get it all the way down to the floor, but can get it well below the water, probably close to the lwco trigger?  One pipe steam, no Hartford loop.

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 23,276
    It's not only possible -- it's a very good idea, unless it is part of the venting (unlikely on a one pipe system). It's likely that in the original installation it was below the water line, and a new boiler was put in without paying any attention to the water line.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    ethicalpaul
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,517
    @Kimdss

    The return needs to be either 28" above the center of the gauge glass (Or higher if a dry return)

    If you turn it into a wet return it needs to be 2" below the gauge glass lower (bottom) connection)

    Hap_Hazzard
  • Klmdss
    Klmdss Member Posts: 4
    Thanks, def can get below bottom of gauge, probably right around 2 inches. 

    And that can be done (mostly) in copper, right?
  • JUGHNE
    JUGHNE Member Posts: 11,060
    Where are the steam main air vents located at now?

    Once return is wet no air or steam will pass, obviously.
  • Klmdss
    Klmdss Member Posts: 4
    air vent is located at the end of the steam main, right before it drops down to the return.
  • Jamie Hall
    Jamie Hall Member Posts: 23,276
    Should be good to go assuming the vent is adequate.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • JUGHNE
    JUGHNE Member Posts: 11,060
    IIWM, I would go with type L copper wet return.
    You can go smaller than the "dry" return was.

    Also I would add an isolation ball valve on each end, placed above the water line.
    At each end then install a tee with ball valve with hose fitting/brass cap.
    Then you can close the isolation valves and flush out the wet return with house pressure....hose on the water heater tank drain....flushes out that tank also.

    Pictures?
    delcrossv
  • Klmdss
    Klmdss Member Posts: 4
    I had to sell a kidney to buy all the copper and fittings and nearly gave myself a hernia twisting off the100 year old fittings, but everything seemed to go well enough. I realize too late I probably could have gotten away with 3/4 pipe instead of 1 inch. I did swap a couple 45s with 90s near the boiler to get around a sewer pipe. Figure wouldnt be much of an issue since its under the water line now.

    I was going to add the shut off and the cleanout T as recommended but couldn't quite size it right with nipples and fittings available if I wanted to keep the copper all below the water line. It won't do any good until I replace the other return, and shouldn't be too much trouble to add them back in later if I can get a short piece of black iron pipe cut and threaded.