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Replacing steam boiler main vents

I have an old single pipe steam system in a two story colonial in New Hampshire. I have been trouble shooting some noisy pipes and have been able to replace most of the radiator valves. But I also found 3 old Hoffman No. 2 (1/8") valves on the mail lines in the basement. They are in really bad shape but of course you can no longer buy Hoffman No. 2 valves. They look like regular angled radiator valves but I assumed the main line requires a different valve than my radiators. Can anyone suggest what type valve I should replace these with?


  • gerry gill
    gerry gill Member Posts: 3,078
    Can you fit a Gorton #2 where those old vents are?
    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Steamhead
    Steamhead Member Posts: 16,904
    Those #2 valves were vacuum vents made for radiators.

    How long are your steam mains, and what pipe size? This will tell us how much air you need to vent.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
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