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Honeywell mercury steam valves

Brutus
Brutus Member Posts: 2
I am looking for help troubleshooting valves that are staying open

Comments

  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    Staying open

    Is your system 2-pipe, or 1-pipe?

    I suspect a 2-pipe system, with some Honeywell traps which will not close when the steam arrives.

    Any trap from that period has been designed for low pressure, such as below 1 psi, so is your system operating in that range?

    Check the pressure, and make sure it is below 16 ounces. A good gauge will be needed , from gaugestore.com.

    Replacement capsules are available for traps from tunstall inc.--NBC
  • Steamhead
    Steamhead Member Posts: 16,714
    Take some pictures

    of these units and post them here. Let's have a look at them. 
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Brutus
    Brutus Member Posts: 2
    Honeywell mercury steam valves

    Pics of traps
  • Steamhead
    Steamhead Member Posts: 16,714
    That's a Zone Valve

    the mercury switch probably functions as an "end switch" which can do things like start the burner when the valve opens.



    You may be able to get a new head unit for this thing. If not, you'll have to replace the entire unit. We've had good luck with Belimo zone valves on steam- these are ball valves rather than globe valves and don't restrict the steam flow as much.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting