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Leak near valve, what's the fix?

bipbap Member Posts: 191
I noticed a slight drip near one of our steam radiator valves. It's not at the valve but close. It's at the dark line in photo.
What's the fix for it?
I've also noticed this radiator sounds like it's a pot of boiling water when the heat kicks on and the vent spits and sputters water.
Is there maybe water sitting in it and it caused this pipe to rust or leak?
Any ideas?
Thank you!


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    That is from the bonnet of the valve, which can be unscrewed, and thoroughly cleaned before bing put back on with just a smidgon of some hightemperature automotive caulk, (others here may have specific brand names).
    I do notice some string dropping out of the packing nut which should not be there, but if it isn’t leaking, you can leave it in place.—NBC
  • Fred
    Fred Member Posts: 8,542
    It looks like the packing nut, around the valve stem is also cracked. It may be time to replace the whole valve.
  • New England SteamWorks
    New England SteamWorks Member Posts: 1,505
    Time to replace the valve.
    New England SteamWorks
    Service, Installation, & Restoration of Steam Heating Systems
    EBEBRATT-Ed Member Posts: 15,525
    Good eye @Fred , I thought that was a cobweb at first but I suspect you are correct.
  • jgach11886
    jgach11886 Member Posts: 13
    I think the packing nut is not cracked but has a piece of hair or something on it. But overall probably better off replacing the valve.
  • nicholas bonham-carter
    Replacing the valve is a real chore, since the old spud must be removed and replaced with the new spud which comes with the new valve. Some of the new valves are not as good as the old on steam, so if possible always repair, repack the old valve. The height may be different as well.—NBC
  • NYCDave
    NYCDave Member Posts: 78
    Hey guys, I also have a leak from the same place on one of our valves… I took off the bonnet and there seems to be some sort of crumbly old gasket there... I thought the bonnet was supposed to be a metal on metal seal? Any advice on whether I should use some sort of gasket or sealant or just put it back after a thorough cleaning? Would appreciate your insights.
    JUGHNE Member Posts: 11,061
    edited September 2018
    I have used Teflon rope packing, very small diameter.
    Roll a little around the shaft and tighten the bonnet. Add more and retighten. It will conform to the shape needed.
    Just don't try too much at a time as the bonnet may crack or strip.

    Also there is some high temp plumber grease for the shaft threads if you need it.

    If you were at a dead man's auction 30 years ago you might have picked up a roll of "Lucky Strike" asbestos packing, probably has some lead in it for lubricity. But those ships have sailed.
  • nicholas bonham-carter
    If you are talking about the bonnet, as opposed to the packing nut, then some valves had a hard gasket, and some had a metal to metal seal.
    Clean the surfaces thoroughly, examine them for dents, gouges, etc, and try it metal to metal. If that doesn’t work, some silicone gasket goo would probably fix it, as it should only have to hold a couple of ounces of pressure.—NBC
  • luketheplumber
    luketheplumber Member Posts: 149
    I would first try to fix the valve and the floor
    I just earned my GED and am looking for a apprenticeship with one of these steam gurus on this site!