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Jacobus - Maid O Mist #1

My new Jacobus - Maid O Mist #1 has what seems like an adjustment on the top. On the pic it is the knurled brass wheel that screws a cylinder into the aperture at the top. Since this vent is described as Non-Adjustable, what is this thingy for (sorry for the technical word) :-)


  • BobC
    BobC Member Posts: 5,182

    Most of their vents use this design so you can clean or change the orifice, one of the lines great strengths is you can buy the 5L radiator vents that come with 5 different screw in orifices so you can set the vent rate where you need it - that can save a lot of money when balancing a steam system.

    In the case of a main vent you want it as fast as it can be, I suspect it's built like this because they could use the same machinery on radiator and system air valves. That design should also make it easier to clean the valve if it ever becomes necessary.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Steamhead
    Steamhead Member Posts: 14,338
    The interchangeable orifice

    would also allow this same basic vent to be used on convectors, which require slower venting rates. 
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
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