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2 pipe with traps on rads. Where to set metering valve?

delcrossv
delcrossv Member Posts: 1,919
in Strictly Steam

Conventional 2 pipe system with traps on each radiator. I'm putting in Mepco metering valves to replace broken inlet valves on the rads so I have adjustability. The Mepco valves have an adjustable orifice for use with Vapor(?) systems (replaces the orifice on the inlet).

Question is: do I set the orifice so the rad gets 80-90% filled like a vapor system, or leave it wide open?

Valve specs below

Mepco 2.jpg
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 25,624

    That's one of those questions… how big is a box? The metering orifice should generally be set so that the radiator is about 80 to 90 percent hot at the end of a long run. Then you can control the heat in the space by reducing the throttling valve (the accessible handle) to what you want.

    Be aware that the above is pressure sensitive, and any adjustments should be made when the system is operating at its normal pressure — usually no more than a few ounces. Not that the valves can't be used on higher pressure systems — they can — but the orifice will be set smaller.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    delcrossv
  • delcrossv
    delcrossv Member Posts: 1,919
    edited December 2024
    https://forum.heatinghelp.com/discussion/comment/1827638#Comment_1827638

    @Jamie Hall even for conventional 2 pipe? It's not a Vapor system and runs at under 1 psi (but I could adjust it lower).

    This is looking like a multivariate tweak between pressure and setting the stop.

    Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.
  • Jamie Hall
    Jamie Hall Member Posts: 25,624

    The work fine on a conventional two pipe system. Just adjust the metering section to suit the system working pressure, that's all.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    delcrossvmattmia2
  • delcrossv
    delcrossv Member Posts: 1,919
    https://forum.heatinghelp.com/discussion/comment/1827642#Comment_1827642

    Ok. I'll set it for 90% fill at the end of a long run and be done with it.

    Thanks!

    Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.
  • KarlW
    KarlW Member Posts: 182

    If you are putting in new valves, have you considered Thermostatic Radiator Valves (TRVs)?

    These can provide better comfort, but at a cost - your boiler gets (effectively) even more oversized as you may be heating 6 radiators instead of 10 at a time.

    delcrossv
  • delcrossv
    delcrossv Member Posts: 1,919
    https://forum.heatinghelp.com/discussion/comment/1827645#Comment_1827645

    Thought about it, but people will be monkeying with those as much as manual regulating valves.

    Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.
  • jessestaton
    jessestaton Member Posts: 6

    I am going to chime in here late regarding the TRVs. We have a 2 pipe vapor system and I have been thinking about the same thing as OP, installing Adjustable Orifice valves from Mepco (currently have Steam Radiator Inlet Orifice Plates only since all but one of the original adjustable valves have been replaced sometime over the last 100 years )
    I was considering TRVs as a more comfortable solution but started thinking about it.
    Using a TRV with a vapor system with our water "traps" could allow too much steam into the radiator.
    So fixed orifice plates set to 80% of the radiator capacity must be installed along with TRVs to avoid steam passing thru the radiator.

    delcrossv
  • mattmia2
    mattmia2 Member Posts: 11,780
    https://forum.heatinghelp.com/discussion/comment/1837294#Comment_1837294

    On a vapor system you still need the orifice plate or original vapor valve with a trv.

    As to the original question, as @Jamie Hall said, you can run a conventional 2 pipe system like a vapor system with a vaporstat and metering valves. If you do it correctly the steam traps should never close and last more or less forever.

    delcrossvjessestaton

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