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Main Vent Location

denick
denick Member Posts: 10
I have no main vents on the 3 mains of my 1 pipe system. the 2 are 1 1/2" mains. They are only 20 and 30 feet long. The 2" main is 70' long. The mains all end and drop in very tight places. The last radiator takeoff is within 8" or less of the end on all.

Question, can the vents be installed before the last takeoff? About 12" before will give enough room for a 6" rise and the vent.

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 24,479
    Yes they can. It's not ideal, but it will work very well.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    EBEBRATT-Ed
  • JUGHNE
    JUGHNE Member Posts: 11,248
    You can also put vents on the vertical drop.
    Install a tee perhaps 6-8" below the drop 90.
    Just so the vent stays above the water line.

    Some will drill and tap the existing vertical drop.
    1/4" tap will handle 1 Gorton G2.
    ranzerox
  • jhewings
    jhewings Member Posts: 139
    JUGHNE said:


    1/4" tap will handle 1 Gorton G2.

    I think you mean 1/2" tap for Gorton G2?

    I did this, not on the pipe after it turns down, but 18" before the elbow. It went OK but the drill size for a 1/2" tap is 11/16 which was not available locally. I used a 5/8 hole saw and went slowly. Clockwise, counter clockwise, clockwise etc. Plenty of cutting oil. This was part of a new boiler install so I skimmed the boiler anyway (several times). The cutting oil probably requires skimming.

  • JUGHNE
    JUGHNE Member Posts: 11,248
    Yes, the G2 has 1/2" threads. However it only needs an opening of a 1/4" to reach full venting capacity.

    For instance if you want to vent with 4 G2's then you need a 3/4" tap.
  • jhewings
    jhewings Member Posts: 139
    JUGHNE said:

    Yes, the G2 has 1/2" threads. However it only needs an opening of a 1/4" to reach full venting capacity.

    Ah OK Thanks