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F&T trap on return drop

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ACS
ACS Member Posts: 4
in Strictly Steam

Hi! I have a 2 pipe steam system (see first pic) and 2 return pipes coming back (see second pic ZOOM UP). On the ZOOM UP pic, you can see that the plumber removed an F&T trap (you see tape marking on two pipes) and replaced it with a copper air vent - this was done 3 years ago. I'm recently noticing two problems w the heating - the return pipe on the right is getting hot and the boiler is constantly cycling to hit thermostat temp (it does turn off but turns on again within 1 minute, til we hit thermostat temp). Could the removal of the F&T (replaced by air vent) be contributing to the problems i am having? I've also added a pic of the F&T from when it was removed. THANKS ALL!

IMG_2588.jpeg IMG_2590.jpeg IMG_9539.jpeg

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 27,060

    Oh my. That was, once upon a time, a vapour system — operating silently and evenly on no pressure at all to speak of.

    I wonder what else has been kludged over the years…

    Ii also wonder what the venting is now. And the condensate return.

    And how much oversize the boiler is…

    Where are you located? This really needs a steam person to take a look and see what is happening.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • ACS
    ACS Member Posts: 4

    long island

  • guzzinerd
    guzzinerd Member Posts: 419
    edited January 27

    Exact same thing was done to my 2 pipe system but with a MoM vent. I replaced it (was leaky) with a gorton #4, fixed the crossovers traps and increased the venting on the mains. Runs at less then 5inch pounds now. Not really a vapor system anymore but seems happy since the vaportrol never needs to cycle it down.

    20260105_135338.jpg

    Found the original 220, in the crawlspace, I've thought about restoring

    1000028724.jpg

    Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf

  • Steamhead
    Steamhead Member Posts: 18,330

    @ACS , that wasn't an F&T trap. It was a "vent trap" or "float trap/air eliminator" designed to keep water from escaping from the system, to vent the air and possibly to hold vacuum.

    The vent they used is a Hoffman #74, which has a very small vent port. I'd replace it with a Gorton #2, which vents much, much faster.

    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    mattmia2
  • ACS
    ACS Member Posts: 4

    @Steamhead, thanks… but could the old f&t trap have been serving a purpose other than removing air? should i revert back to f&t? also, if i still go with gorton #2, does the location matter? note: old f&t had inlet at top of returns, and outlet at bottom of returns (you can see tapemarks for old f&t placement in the first pic)… tx

  • mattmia2
    mattmia2 Member Posts: 16,117

    it wasn't an f&t trap, it was a special vent trap for a vapor system.

    do all the emitters heat? if the emitters are all mostly hot it is cycling on pressure because the boiler is too big. you can add a time delay to delay the cutin a bit when the vaporstat shuts the boiler off if everything else is ok other than the short cycling.

  • ACS
    ACS Member Posts: 4

    ah, got it. i have 9 emitters. of these, 3 of them ONLY heat on one side (always supply side). all others heat ok. thanks mattmia2.

  • Steamhead
    Steamhead Member Posts: 18,330
    https://forum.heatinghelp.com/discussion/comment/1884509#Comment_1884509

    Replace the Hoffman vent with the Gorton #2 and everything should heat faster.

    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting

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