Should there be traps on this old radiator?

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Onepipe
Onepipe Posts: 87
in Strictly Steam

hey all. I have an old Moët vapor system that I’m working on that mainly has original column radiators throughout the house but in two rooms there are radiators with traps. I’ll include photos. The kitchen was re done in the 70’s and they put in cast iron base board with traps. I’m guessing the traps should not be there since it’s vapor. Also in an office there is a unique radiator type that I have not seen before that also has what looks to be old traps. I plan on using Orphase plates as some of the hand valves have need replaced and would also like to remove the traps at the same time to keep my “A” dimention down. If you could help me identify the radiator type and let me know if they should have traps that would be a huge help.

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Comments

  • mattmia2
    mattmia2 Posts: 18,226

    having traps on a vapor system won't hurt anything as long as they are good or failed open. they should never do anything if the pressure is kept under control and the vapor valves are set up correctly or they have orifice plates. I would encourage you to rebuild the original valves if at all possible.

    that "radiator" is a pretty standard convector cabinet with a cast iron element, although I don't know the brand. The cabinet acts as a chimney and is vital to getting the rated output of the convector.

  • Onepipe
    Onepipe Posts: 87

    ok thanks for the info and that makes since. As for the base board unit would the theory be the same?

  • mattmia2
    mattmia2 Posts: 18,226

    it is the same but you maybe have to be a little bit more carful about not getting condensate trapped in the baseboard. still not the first thing I would think of if a CI baseboard isn't heating on 2 pipe, but it is a lot more likely to be a problem than on a standard CI radiator because the passages are so much smaller.

    none of the returns should be steam hot, if you are having trouble with things not heating or banging looking for that and fixing it is the first step.

  • Jamie Hall
    Jamie Hall Posts: 27,904

    Don't bother to remove the traps unless they are failed — and then you just have to replace the element, not the whole thing. As @mattmia2 said, having them wont hurt anything — and as I said just now in another thread, the key to a vapour system is keeping the pressure differential where it belongs; a vapourstat set at 7 ounce cutout or less, and a 3 ounce differential usually works.

    If you have original vapour valves, don't replace them. In fact, don't touch them until you find out that someone else has messed them up. They were probably set correctly in the beginning, so leave them alone.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Onepipe
    Onepipe Posts: 87

    ok thanks for the help. The system was air locked when I showed up. There is only one large air vent on the dry return before it drops to the wet. There are not vents on the steam main. The vent is failed closed so once i got the air out things started to heat. So far things seems to be working fine but that was this afternoon. I still need to replace the vent as I did not have one large enough on the truck. Dry return seems steam free but there is also not a huge load on the system. The vapor stat is set at 12oz so I’ll get that turned down too. I know a few of the valves have been touched for sure or have been changed so those ones are on high alert. Thanks for the help.

  • mattmia2
    mattmia2 Posts: 18,226

    Most vapor systems only have a vent in the return near the boiler, usually near some sort of boiler return trap. The mains should vent in to the returns through crossover traps in most systems(although a few didn't have them and vented the mains through the emitters). The crossover traps need to be good for it to heat quickly.

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