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Main Vent locations

I have noticed that main vents are always located at the end of the main loops. Wouldn't it make more sense to instal the vents right after the last riser on the run? That way you get steam to the radiators faster.

Or am I missing something?


  • Jamie Hall
    Jamie Hall Member Posts: 15,334

    sometimes the main vents are elsewhere -- most vapour systems and some two pipe.  However, in most cases (not all) they are at, or very near, the end of the steam mains.  So long as they are beyond the last riser, though, the placement won't make any significant difference in how fast the steam gets to the last riser and, therefore, how fast it gets to those radiators.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
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