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Fill valve fitting on American Tube & Controls/Weil Mclain

michaelj1michaelj1 Member Posts: 5
Would like to increase the pressure for purging purposes. wondering if it is adjustable. On a 1968 residential boiler.


  • JUGHNEJUGHNE Member Posts: 7,220
    Is the supply from the boiler connected to the back side of that device? Then do the 2 zone valves on either side feed your emitters?

    Is there anything connected to the top of this?
    Where is the cold water connected to the boiler and does it have a pressure regulating fill valve?

    And you came here for answers, I only have more questions ;) .
  • michaelj1michaelj1 Member Posts: 5
    First paragraph yes yes
    gauge and air vent
    Supply valve on left, going into fitting I'm trying to figure out.
    That fitting shuts the water off at 9 pounds.
  • JUGHNEJUGHNE Member Posts: 7,220
    Could you remove the fitting and replace it with a tee?
    Then add a pressure red valve with the fast fill feature in your supply line.
  • newagedawnnewagedawn Member Posts: 566
    that fitting between the air scoop and the expansion tank was used by plumbers and are notorious for vapor locking, you might have to change that to get any water pressure in the boiler at all
    "The bitter taste of a poor install lasts far longer than the JOY of the lowest price"
  • michaelj1michaelj1 Member Posts: 5
    Thank you. I thought about removing it, but then I'd have to go back out to the truck, try and remember what it was I was going for, go back and look, repeat.
    What is the fitting called?
  • newagedawnnewagedawn Member Posts: 566
    edited April 2017
    sorry, dont know what that fitting is called, i call it a plumbing piece of junk , , i know its vapor locked tho!!!! at least in my experience when no water will fill boiler
    "The bitter taste of a poor install lasts far longer than the JOY of the lowest price"
  • CTOilHeatCTOilHeat Member Posts: 54
    Is that just a Fill-trol? They ship with the Xtrol tank pre-set at 12 psi and it regulates the fill water pressure to whatever the tank pressure is.

    If the tank has lost pressure and now has a charge of 9psi, that's what the system pressure will fill to. If this is the case you can change the pressure of the tank back up to 12...or whatever you want, really. These tanks suck for purging purposes

    If you are talking about something else, sorry.
  • ericmmffericmmff Member Posts: 13
    The fill valve has a screen in it at the incoming compression fitting. It likes to clog up .Fill the Tank to 25 psi then purge.
    Drop tank pressure to 12 psi when done.
    A watts fill valve can easily be piped in instead.

    You will need a different tank also. That tank and fill valve are only compatible to each other. Good time to replace any vents or gauges that are suspect. Also relief valve.
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