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Repacking a steam valve

Kool Rod
Kool Rod Member Posts: 175
If it is leaking at the union, you could try tightening the nut. Use two wrenches and just turn it a tiny bit. If this fails to do the job, you can loosen the fitting and clean the flange faces with steel wool and then use Permatex on the faces when you retighten the fitting. All this of course has to be done with the boiler shut off. If you disconnect the radiator be prepared to catch any water and crud that may flow out of the radiator.

- Rod


  • movin2gas
    movin2gas Member Posts: 25
    What and how?

    I have a leaking steam supply valve on one of my radiators. Is repacking something I can do myself? I found this stuff on Amazon: http://www.amazon.com/gp/product/B000DZDQWG, is this appropriate for that kind of valve? And what's the general procedure for doing this (beyond shutting off the boiler!)

  • Supply House Rick
    Supply House Rick Member Posts: 1,404
    repacking valve

    yes you can repack the stem of the steam valve yourself. get some graphite string at any good hardware store, [make sure it is real string] made for that purpose. the valve stem is retained by a nut which can be unscrewed, so the string can be wound around the stem, and then the nut is replaced. at the same time leave the handle off, so no one will be tempted to close the valve, causing all sorts of problems for the system with trapped condensate,etc.

    you might also check your pressure at this time to make sure it is below 1.5 psi MAX. if not, then find out why, or you may have other things to fix/replace.-nbc
  • movin2gas
    movin2gas Member Posts: 25
    Maybe repacking is not the solution?

    Thanks for the tip. I just found this video, he repacks the valve at the end:


    After viewing this, I'm not sure it's going to fix my problem. The leak seems to be in the horizontal connection between the valve and the radiator, it's dripping condensate at a pretty good clip. Am I barking up the wrong tree?
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