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Replacing Radiator Inlet Valve

FJL Member Posts: 354
How often should you need to replace the valve?  I just noticed that the inlet valve on one radiator is leaking from where the valve connects to the steam pipe coming out of the floor.  This valve is only a few years old.  I have a single pipe steam system.  Just  curious to know what could cause a valve to malfunction aside from it being a bad valve.  


  • Leaky Radiator Valve

    Some of the valves on my radiators are probably close to 100 years old so age is not normally a problem. Where exactly is the leak? Is there a crack in the valve casting or does it look like the metal on the pipe has rotted through?  It maybe that it just wasn't tightened enough when it was replaced. Unless it is causing a big problem I'd be inclined to wait until spring after the system has been shut down before repairing it. - Rod
  • FJL
    FJL Member Posts: 354
    Cite of Leak

    I'm not an expert on terms, but the leak is coming from the point where the valve attaches to the nipple of the steam pipe that sticks up out of the floor and feeds the radiator.  The leak is not coming from the nut that attaches the valve to the radiator.  At some point earlier this year, I did get some rattling and slushing sounds from that radiator but it was for a day or two.  
  • leaking valve

    if you can avoid changing that valve, you will save a lot of trouble. when you change the valve, the "spud", screwed into the radiator must also be changed.

    make sure the leak is not coming from the packing nut just under the handle, which is easy to tighten, or repack.

    if it is leaking from the bottom threads, then remove the valve from the spud, and the pipe. clean up the male and female threads, and rethread, using teflon tape. while you are twirling the wrench, maybe it is time to install a good lowpressure gauge [gaugestore.com-0-3 psi], because at the low pressures you should have, leaks are not very agressive. the only way you will be certain of the pressure is with an accurate gauge.--nbc
  • FJL
    FJL Member Posts: 354
    edited December 2009
    Thanks . . .

    for the advice.  The leak is not from the packing nut in the handle.  I already got a gauge installed on that rad.  What I really need to do is install a gauge on the boiler so I can get an accurate read at the source.  
  • and what is the pressure at that rad?

    i am sure that redoing the threads will cure this leak, unless your pressure has gone up too high-clogged pitail?--nbc
  • FJL
    FJL Member Posts: 354
    Metal Sliver

    I was looking again at the inlet valve at the site of the leak, using a flashlight, and noticed that the leak seems to be caused by a small sliver of metal stuck between the connect of the valve to the steam pipe.  I've never noticed it before.  Two summers ago, I had my apt repainted and the painter removed each of the radiators to do painting.  That sliver must have got caught somehow when he reattached the rads after painting.  Funny thing is that there was no leak last heating season.  I guess I'll have to remove the valve and clear away that sliver and clean the threads.  How odd. 

    BTW, how does one remove an inlet valve?  Where do you start?  With the nut connecting the union?  How do you loosen the valve from the feeder pipe?  You loosen the nuts just below the handle?  I'll see what I can find online.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,573
    valve removal

    first i would remove the union nut on the spud, which is screwed into the radiator, and then move the radiator slightly over to get turning clearance.

    next i would try to immobilize the nipple coming up through the floor, with a pipe wrench, while unscrewing the valve with another. be careful not to damage the union nut or any other threads!

    clean the threads of the nipple sticking out of the floor with a small brush so they are clean-likewise the female threads of the valve. when reassembling, wrap teflon tape around the male threads, and a light coat of pipe dope on top, or in the female valve threads. don't over dope it--this not mayonnaise on your sandwich here!!!. if you can see dope squeezing out of the joint, it is probably too much.--nbc 
  • FJL
    FJL Member Posts: 354
    edited January 2010
    Leaking from where?

    I am a bit confused about how water is leaking from this valve.  It looks as if the water is leaking from a place that is not a joint.  I can't get a full view of the precise area of the leak because the rad is right up against the wall.  But here is a picture of a valve and an arrow to the area from where water seems to be leaking.  Above that nut, not under it where it connects to the pipe: 
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,573
    i had this problem

    one wing of our building has settled since 1885, and that put pressure on one run of pipe, which of course was immobilised by the radiator. this pressure finally ruptured the valve body. if you can find the exact same make and model of valve, then you can avoid changing the spud-unless, when off you are not impressed with the quality of the valve!--nbc
  • FJL
    FJL Member Posts: 354

    Maybe I can feel around the valve after it cools off and see if I can feel a crack. 

    BTW, what is the spud?  I thought the valve was all one piece.

    My valve looks like the one in the picture.  Maybe it is the same.
  • Brian_74
    Brian_74 Member Posts: 237
    edited January 2010
    The spud is

    the shiny brass part in the picture. If I'm not mistaken (I'm just a homeowner) that part gets screwed into the radiator using a spud wrench (naturally). The slip nut then gets connected to the valve. So there are actually 3 pieces: the spud, the nut, and the valve.
    1929 Ideal Heating vapor system.
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