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Air Vent Requirement

Hello,

I would like to know if I need vent at the end of the steam line shown in the pic. Just to give some information, the steam line in the picture is coming off a main steam line. The main steam line has its own vent at the end.

The steam line shown has only one steam riser (in the pic) and is around 8-10 feet in length before it drops down as a condensate line.

Thank you

Comments

  • Steamhead
    Steamhead Member Posts: 17,927

    Maybe. How well does the radiator on that line heat?

    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Suchitapage
    Suchitapage Member Posts: 12

    I don't know yet. The client just purchased this building and I can't do steam travel test until the heating season begins to know the actual performance of the steam system. So, wanted to know if it's required in theory.

  • Jamie Hall
    Jamie Hall Member Posts: 26,249

    The theory is complicated. Best to just see how it works…

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • 109A_5
    109A_5 Member Posts: 2,564

    Is there a vent at the other end of this pipe (Red Arrow) before it drops down to the wet return ?

    image.png
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • mattmia2
    mattmia2 Member Posts: 13,779

    is this one pipe or 2 pipe?

  • 109A_5
    109A_5 Member Posts: 2,564

    @mattmia2 makes a good point. If it is a two pipe system is there a vent at the other end of this pipe (Yellow arrow) before it drops down to the wet return. If this pipe is for something else disregard. More pictures of the system may have helped.

    image.png
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • Suchitapage
    Suchitapage Member Posts: 12

    That pipe is a steam pipe but it's a separate line. It does have an air vent though at the end. I have attached the picture of the other side of the wall from where it's coming. The pipe is highlighted in the rectangle box.

    image.png
  • Suchitapage
    Suchitapage Member Posts: 12

    No. I have attached a pic of the other side of the wall

    image.png
  • Jamie Hall
    Jamie Hall Member Posts: 26,249

    On a one pipe steam system, vets on the main or the risers will determine how fast steam reaches a given radiator. The vent on the radiator will determine how long after steam gets there before the radiator is filled. Two different functions — but on most one pipe systems the runouts and risers do not have vents, and the radiator vent handles both functions, and that is perfectly fine if the radiator heats adequately along with the rest of the system. If a specific radiator gets steam much more slowly than desired, then a vent on the runout or riser can help

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Dave in QCA
  • 109A_5
    109A_5 Member Posts: 2,564

    If the main in question does not have a main vent, a main vent may be beneficial. However if there is multiple steam mains you may have to vent all of them (not just one main) and balance that part of the system (the mains) for even building heating.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System