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Christmas Wishing for a Warm Classroom

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Forest
Forest Member Posts: 11
edited December 11 in Strictly Steam

Hello, all, I teach high school in a large 1930s brick school house. The building has a two-pipe steam system. The radiator for my classroom is a twenty-foot long 1.5"-2" pipe with metal fins hidden away in a sheet metal box, not unlike a baseboard heater. (Unfortunately we lost most of the beautiful cast iron radiators in the 1970s renovation.)

This radiator has not been heating more than a foot or two along its length. According to the teacher who had this room before me, this has been a problem that has persisted for many years, maybe a decade. Students have to wear their coats in class to be warm enough to study. Despite multiple requests to fix the lack of heat, the school district has done nothing to correct the problem, and for years this has notoriously been the room without heat.

Since I enjoy the steam system in my own home and reading HeatingHelp, I thought I would see if I couldn't do some simple repair myself. It seemed like the steam trap (a Hoffman 17C) might have failed closed; I thought maybe I could replace the cage unit myself. Before buying a new cage, I opened the trap. (There are shut-offs on both sides of the radiator.)

This is what I found inside ...

IMG_0884.jpeg

As you can see, it's full of debris. I cleaned out the trap out as best as I could, but now I'm wondering if the radiator (just a long pipe remember) is full solid of debris. Is it worth buying a cage? Any thoughts on how I should go about getting this radiator hot again?

Thanks,

Forest in Massachusetts

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 11,543

    Are they raisins?

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    ForestIronman
  • Forest
    Forest Member Posts: 11

    No, it seemed like metal or mineral flakes to me. There was also a fine sludge below. I didn't have any tools (except a pencil) to explore deep cleaning out at the time.

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 11,543
    edited December 11

    All seriousness aside:

    I would take an educated guess (because you are an educator) and say that it is rust from inside the pipe radiator. Steam should not make that much rust, so it has to be from the condensate.  It may have been happening since the radiator was installed. 

    How easy would it be to have that radiator removed by the maintenance department at the school and have it pressure cleaned?  High pressure steam or water with a gritty mix forced thru that pipe radiator might be needed. You may need to take it off site somewhere?

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • Waher
    Waher Member Posts: 359

    Try removing the debris with a nitrile glove and see if the radiator heats any better.

    You could try a stainless steel pull through cable with a bronze brush the same diameter as the pipe interior made for cleaning rifle bores. Otis Tec is what the Army uses.

    Forest
  • mattmia2
    mattmia2 Member Posts: 15,444

    does it heat if you dig that stuff out, put the lid on the trap and turn the valves on? don't leave it that way because it will put steam in the returns but it will tell you if it is working. how high above the boiler is that? that stuff might have been washed in there if the system flooded for some reason.

    Forest
  • Ironman
    Ironman Member Posts: 7,849
    https://forum.heatinghelp.com/discussion/comment/1876705#Comment_1876705

    My thoughts exactly.

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    EdTheHeaterMan
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 11,543
    https://forum.heatinghelp.com/discussion/comment/1876715#Comment_1876715

    I was thinking of making home made wine using raisins so I didn't need to age the grape's juices for so long!

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • neilc
    neilc Member Posts: 3,111
    https://forum.heatinghelp.com/discussion/comment/1876714#Comment_1876714

    can you borrow a shop vac and suck that out? doesn't look like there's any pressure under that trap body, make sure both ball valves operate in case you find some steam pressure, then if you're worried about sending steam thru to the returns, consider sacrificing the supply ball valve and setting it mostly closed to operate as a quasi orifice, throttle your heat if it flows at all,

    known to beat dead horses
    Forest
  • Forest
    Forest Member Posts: 11

    Thank you all for your helpful thoughts and suggestions.

    @mattmia2 My classroom is only one floor above the boiler. I'd like to think the debris was the result of a one-time flood, not a chronic problem.

    My initial cleaning out of the trap today didn't get the steam flowing, but I didn't have anything but pencils and wrenches at hand. I'll bring some better tools for cleaning the trap tomorrow and see if we can get some steam flowing through.

    I'm afraid the school wouldn't look kindly on what would be seen as "tinkering" with school property, so I'm reluctant to share this investigation with the principal or superintendent. But if I can fix the radiator with some knowhow from you all and little work on my part, I still feel I ought to try.

    dabrakeman
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 19,458

    @Forest.

    I understand the spot your in.

    Back in the day (78) I took a night class to get my electricians license. The instructor used to open the windows and lock the door and hang a newspaper over the door window. We would smoke butts all during class

  • Forest
    Forest Member Posts: 11
    edited December 13

    Unfortunately it seems that the radiator (a pipe) is also blocked up to an unknown degree by sludge and mineral flakes like fine crushed stone.

    Here's a picture of the existing cage unit. I was expecting a spring with it, but there was none. Is that normal?

    IMG_0890.jpeg
  • mattmia2
    mattmia2 Member Posts: 15,444

    the cage unit looks ok, the bellows expand out the bottom and close the seat. the spring is probably more a way of making a few cage units fit a bunch of different proprietary body designs by changing the spring.

    are you sure the boiler was firing and if there is a zone valve, that was open during your test? that seat is the smallest part of the return piping so debris that got past there probably didn't block it up.

    you can also try opening the supply with the cover off and see if steam gets in to the emitter and works its way to the trap.

    you could have the pitch of the piping trapping water in the supply blocking the steam or in the return keeping the air from getting out of the emitter.

    Forest

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