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A Hartford Loop Q & A

HeatingHelp Posts: 465
edited April 2018 in THE MAIN WALL
A Hartford Loop Q & A

The Hartford Loop is an arrangement of piping between a steam boiler’s header and its gravity-return piping.

Read the full story here


  • dgn
    dgn Member Posts: 29
    What about a Gifford Loop where the return connects to the equalizer above the water line? Described here:
    I have this setup and never a peep of hammer. Water line in glass bobs about an inch or so when boiler is firing. Aside from this article on HH, curious why I rarely read about it.
    Danny Scully
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,516
    Good question! Was your Gifford loop installed by design, or by accident? How high is it in relation to the waterline?—NBC
  • dgn
    dgn Member Posts: 29
    I can't say for sure, but I'd guess it was installed by accident. Why? The waterline in the glass, after condensate returns after shutoff, is just about even with the middle of the close nipple going into the equalizer. So the waterline is probably a bit below the return when firing. Given the lack of hammer and amount of bounce seen in the glass, I guess it's working out fine for my situation.

    Still, I'm curious why far more discussion about Hartford Loops than Gifford if the referenced article states the Gifford is a superior solution.
  • Dan_NJ
    Dan_NJ Member Posts: 174
    "A Gifford Loop is like a Hartford Loop, except that the bottom of the inside of the close nipple is located above the boiler waterline rather than below it. (The waterline is defined by the level at which an automatic feeder would start feeding water.)"

    So from the article they are not talking about the "normal water line" of the boiler, but rather the auto-feed water line? I don't have an auto feeder. How far below the boiler normal water line would an auto feeder normally be set up to start feeding? If that point is more than 2" below boiler normal water line and my Hartford loop connects at 2" below boiler normal water, isn't it already a Gifford loop?
  • dgn
    dgn Member Posts: 29
    Dan - As shown in the diagram at the top of this article, the loop connecting below the water line is a Hartford. I believe this is what you're describing your setup is. In a Gifford Loop, the return is above the waterline of the equalizer (and normal water line).
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 15,447
    Yes, the drawing shows a Hartford Loop.
    Retired and loving it.
  • AMservices
    AMservices Member Posts: 597
    I use the Gifford loop on every steamer I install.
    No problems with banging. Only it's even more important that the connection be made with a st 90, close nipple and 90, or "y" fitting.
    Compared to boilers I see during service, water line is stays much more stable.
    Make perfect sense.
    If any pressure builds in the boiler, the force of that pressure will push down on the surface of the water. If there's a port lower then the water line, water will be pushed through it, lowering the water level.
    That can't happen if the return connects above the water line.

    The Hartford loop was a evaluation to steam heating that saved countless lives.
    The Gifford loop does the same thing and adds better performance.

    Try teaching that to someone who's been installing steam systems for more then ten years, is like teaching a 10 year old dog to jump through a ring of fire.

  • GBart
    GBart Member Posts: 746
    I used to tell my classes that the Hartford Loop was where 91 and 84 wait that's a disaster.
  • dgn
    dgn Member Posts: 29
    @GBart - Ha! Been there, drove that many, many times.
  • GBart
    GBart Member Posts: 746
    yeah, we've spent billions on that making it better, now they want to build a tunnel, Ct had this extremely poor concept of directing it's highway's to the cities thinking it would bring increased commerce and spending, it doesn't it brings gridlock and accidents, another classic is Rt 9 in Middletown, a highway with several sharp turns and two stop lights..........brilliant.