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Main Vent selection

Thanks in advance for some really great insight.

My question is this:

If in fact there can never be too much venting of the main, what is the best option for replacing the Dole 1933 Air valve that is presently being used?

I'm looking at Gorton #1 and Hoffman #75 as my main options. There's quite a price different between the 2, and my instincts tell me to go with the more expensive Hoffman. Is there compelling reasons why I should choose 1 over the other?





Comments

  • BobC
    BobC Member Posts: 5,306
    The Hoffman will vent longer (it closes at a higher temperature) which is a good thing but it also vents at half the rate which can be a bad thing - how long is your steam main?

    In any case either will be a great improvement over old Dole vent.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • EzzyT
    EzzyT Member Posts: 1,201
    Like BobC said what's the length and size of your steam main? That all factors in on what size and how many steam main vents you'd need
  • JUGHNE
    JUGHNE Member Posts: 9,750
    He was comparing a G-1 to the 75. Isn't the 75 faster/larger than the G-1. But we consider the G-2 twice as fast as a Hoffman 75?
    (For about the same money).
  • EzzyT
    EzzyT Member Posts: 1,201
    JUGHNE yes you are correct
  • Steamhead
    Steamhead Member Posts: 15,329
    The Gorton #2 is 3-4 times as fast as a Gorton #1 or Hoffman #75. Sure it costs more, but it's less expensive than multiple smaller vents.

    But to make a proper recommendation, we need to know the length and diameter of the steam main. If there are other steam mains, include them too so we can get the whole picture.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • BobC
    BobC Member Posts: 5,306
    My bad, I thought he was comparing the G2 with the Hoffman. I've seen the Hoffman go for about twice the price of the Gorton #1, since it is the same as 1-1/2 G1's it can be a good choice if you want the higher vent closing temperature.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
    nicholas bonham-carter
  • gerry gill
    gerry gill Member Posts: 3,031
    im a big fan of the Gorton #2 vent personally.
    gwgillplumbingandheating.com
    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • EzzyT
    EzzyT Member Posts: 1,201
    Gerry your the vents and trap testing King
  • MattRuocco2
    MattRuocco2 Member Posts: 8
    Is it a big deal if I don't install a Gorton #2 on a 6" extension? The #2 is huge, over 6.5" tall and i can only fit it as-is between 2 joists on the ceiling. I could maybe do a 3" extension, but that's it. Thoughts before i order?
  • Fred
    Fred Member Posts: 8,518
    edited December 2015
    A 3" extension will be fine. many use no extensions.
  • JUGHNE
    JUGHNE Member Posts: 9,750
    Many use a 90 ell, then a piece of horizontal pipe that might get you to a place of more head room, then of course 90 ell up.
    I believe that the off set in piping like this might keep a "shot" of water hammer from killing the vent. (There was a reason that the WW1 trenches zigzagged back and forth, keep them from turning into a "shotgun" row house. ;) )

    I also add a wye strainer in the horizontal pipe with a blow down ball valve. A bit more obstruction for dirt and water bullets, and cheap insurance for about only 15% cost of one G2 vent, and one strainer could protect more vents at that point, so the insurance payments drop like a group or fleet rate.
  • Dave in QCA
    Dave in QCA Member Posts: 1,776
    I like to use a Gorton 2 if the mains are not insulated, Hoffman 75 if they are insulated.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • Abracadabra
    Abracadabra Member Posts: 1,948

    I like to use a Gorton 2 if the mains are not insulated, Hoffman 75 if they are insulated.

    @Dave in QCA just curious, why the different vent for uninsulated vs. insulated. I know the 75 will open up sooner vs. the Gorton staying closed longer. I just can't think of why to use one over the other if pipes are uninsulated vs. insulated.
  • Dave in QCA
    Dave in QCA Member Posts: 1,776
    What I have found is that when running one cycle per hour, even at 55 minutes off time, insulated pipes may not cool sufficiently to allow the G2 to open. In fact, I just checked some mains at my place today. A long distance from the boiler, in a cool room (65F), 55 minutes after the boiler shut off, the temp of the 2" main under the insulation was 132F, measured with a simple pocket probe analog thermometer. At this temperature, the air in the main will close the G2, even if the G2 itself does cool off more and open up. On the other hand, if the mains were not insulated, they would have cooled much more and the G2 would do a great job of venting the mains. For the insulated mains, the Hoffman may not vent as fast as a cold G2, but it sure vents faster than a warm one.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com