Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

main vent selection

mikeca
mikeca Member Posts: 16
I have two 40 foot supply mains on my system. What do you reccomend for venting the mains? The current vents are on a T, I read that putting them on a nipple is a good idea?

Comments

  • yes, a nipple is a good idea.

    > I have two 40 foot supply mains on my system.

    > What do you reccomend for venting the mains? The

    > current vents are on a T, I read that putting

    > them on a nipple is a good idea?



  • yes, a nipple is a good idea.

    what size mains?
  • mikeca
    mikeca Member Posts: 16


    3" mains
  • 2.12 cubic feet of air, each.

    Number 2 Gorton's vent 5.5 cfm, all of the other vents are less than 2 cfm. You would need two of another type on each main for the same fast venting.

    Noel
  • mikeca
    mikeca Member Posts: 16


    thanks.
  • Tom_22
    Tom_22 Member Posts: 108
    How about main vent sizing for this two main setup?

    How about a 55' run of 2" main and a 20' run of 2" main coming off the same boiler. Each has only one tapping and adding fittings is not in the cards. Is a number one too much for the short run? Is a number 2 too much for the long run?

    Currently the long run has a "1" and the short run a plugged tapping. Also, the tap is on the end of the line in the elbow to the drip connection, and there is only enough room below the ceiling to put in about a 2" nipple. I suspect there was a vent there one time though. The end of run is an elbow, not a tee, so the flow might be smooth enough to prevent hammer.

    The short run radiators currently get hot about a minute ahead of the end radiators on the long run as it is. Would you put a vent on the short run anyway? I could put a longer nipple on it, let the vent stick up between the first floor joists. and make a little sheet rock box out for it.

    TomBk
  • #1 would be fine for both

    plenty of vent for those two.

    Noel
  • Steamhead
    Steamhead Member Posts: 16,736
    However

    since one main is almost three times longer than the other, you may want to add more venting capacity to the long one so the steam reaches the ends of both mains at about the same time.

    In that case, a Gorton #2 on the long one and a #1 on the short one will work great.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Tom_22
    Tom_22 Member Posts: 108


    Is it possible to overvent a main such as the 55' long 2" dia. by putting a #2 on it?
    Tom
  • Steamhead
    Steamhead Member Posts: 16,736
    Nope

    I've run into setups like yours frequently. The #2 on the long one and the #1 on the short one work great.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Eric L._2
    Eric L._2 Member Posts: 94
    Can I put a maint vent on big rad instead of

    main? I can't actually get a main vent on the main in house for a few reasons, could I take off one of the threaded plugs on the furthest, highest rad which never seems to get hot completely hot with a JACOBUS "D" valve? Gorton #2 maybe? Thanks
This discussion has been closed.