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steam main vents

tom_11 Member Posts: 58
I have a one pipe oil fired steam system. what size main vents do i need . I have one pipe. that is 12 ftlong,six ft of 2inch the other is one and one half inch for six ft. The other is fifteen long 9 ft of two inch,the other is six ft of one and half.thank you


  • Ken_40
    Ken_40 Member Posts: 1,320
    The brand we prefer is

    Gorton. They make a few vents that would probably all fill the bill.

    Two things: The way most main vents are located are WRONG! The main vents are NOT supposed to be at the end of the main, on a tee (from whence the return piping "drop" begins) The main vent is supposed to be 15" or more upstream from the return piping ell. The reason being, water and condensate will "crash" into the bull-headed tee, allowing condensate and remaining steam to slam into the dead end, before being forced to the gravity route - and the slamming action will daramatically shorten the life of any main vent.

    By lowering the pressure to a 2 lb. MAX setting, the life of the main vent can be prolonged some, but no where near as properly as the correct piping. No one bothers to make it right, so if you don't have a 2" x 3/4" tee 15 or more inches befor the condensate "drop," don't lose too much sleep.

    Finally, each separate main pipe or "branch" (with more than two rads attached), even if only 5' long, should be vented as well.

    Check this out: www.gorton-valves.com/

    Let us know how you make out.

  • That's a pretty small system

    use a Gorton #1 or Hoffman #75 on each main.

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