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Hoffman #7 Valve Rebuilding

Gordo
Gordo Member Posts: 829
Here is a video on my take on rebuilding the Hoffman #7 radiator valve.
I hope this is of use.
If so, please like and subscribe on my YouTube channel!
https://www.youtube.com/watch?v=9NbHvUsaIZc&t=43s
All Steamed Up, Inc.
"Reducing our country's energy consumption, one system at a time"
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Baltimore, MD (USA) and consulting anywhere.
https://heatinghelp.com/find-a-contractor/detail/all-steamed-up-inc
LionA29MilanDJim_Rsammyg

Comments

  • Gordo
    Gordo Member Posts: 829
    @Jim_R : Thank you for your comments!

    As near as my imperfect research indicates, there are so far known to me three versions of the #7 Hoffman valve.

    All of the ones I've seen have the 1918 patent date on the handle cap.

    The published info I have is from the 1925 Hoffman Data Book, as you see in the video. (there is a 1923 version I don't have, yet.)

    The next Data Book came out in 1934 as shown in the second video in this series, then again in 1935 ( which is possibly a simple reprint... not sure... don't have it yet)

    After that, it skips to 1951. The 1957 edition is a reprint of the 1951 edition. By 1951, the #7 is nowhere to be found.

    It can be speculated that since the main #7 valve patent ran out in the mid 1930s AND it could not handle vacuum as well as the "packless" valves of the same era, the valve was dropped sometime on the eve of WWII.

    If anyone can add to this, please do.
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
    https://heatinghelp.com/find-a-contractor/detail/all-steamed-up-inc
    Koan