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Cost of Adding Main Air Vents

the vents were installed 15" before the <i>turndown point</i>, but if you never had any before, anything would be an improvement.<BR>I would put them on at the elbow down(but nipple-up) at that point. :-) <BR><BR>Dave


  • NShak
    NShak Member Posts: 38
    Cost of Adding Main Air Vents

    Homeowner Question

    I need to add at least one main air vent at the end of each (2) steam mains. There are no vents there now and there isn't a plug where an old vent may have once been placed.

    Got different quotes & different plans... Let me know what you think-

    1) Drill & tap -> qouted $300 for each one.
    2) Crack & remove the existing "elbow section" (where the main drops down to the wet return) and then replace that section with a vent attached -> quoted ~30 minutes ($50-75) per main.

    Thanks in advance for the responses.
  • Prices,

    are generally not discussed here,, but what you mention is not unreasonable if they are the proper size, and installed in the right place. :-)

  • NShak
    NShak Member Posts: 38

    Sorry about the pricing issue... not that terribly important anyway.

    But which option (drill & tap vs crack & replace) would you recommend? Does the main vent have to be 12 inches back from the drop off to the wet returns or can it be at the elbow? I think the vent needs to sit on a stalk 12 inches above the main to minimize water/steam damage?

    If the elbow is OK, then I suppose I could start with the drill & tap and if it cracks the elbow, then that would force me (my pro) to finishing cracking it off and replacing it.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,510
    main vents

    somewhere here, there is a picture of a vent, mounted on the vertical pipe [down from the elbow] in the upper wet return. this location may be more accessible for installing a vent for the first time.

    wherever located, it should not be in a straight shot of a slug of water firing directly into the vent, and destroying the innards. the velocity of the water-hammer slug is quite high.--nbc
  • MikeyB
    MikeyB Member Posts: 696
    Vent Tree

    I believe Brad White posted this some time last year, I have the attatchment but I am unable to attatch it to this post, might want to try to search for it or you can e-mail me and I will send it over

  • Here is Brad White's drawing. Note the thoughtful use of the pipe union. This allows you to do the makeup & repair on your work bench and then connect it all easily to the main with one fitting.

    - Rod
  • NShak
    NShak Member Posts: 38

    Great diagram! Thanks.

    I will probably have to go with the lower (antler) arrangement.

    Will check the "Find a Pro" section for someone near central NJ.

  • You might also want to take a look at Gerry Gill's website.

    He's one of the super steam pros and has some really good pictures on main venting on his website.
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