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boiler drain vavle

HenryT Member Posts: 128
Hi all, i discovered a very slow leak on my steam boiler drain valve and looking to replace thefaucet type to ball valve.

My questioms are:

What type of ball vavle would i need? Copper or black or steel?

Do i need pipe dope?

Is there ball valves that are threaded for this fitting and lastly why is the old one leaking?

Pics attached.

thanks in advance!


  • Jamie Hall
    Jamie Hall Member Posts: 22,926
    Where is the drip?

    if it's from the bonnet of the valve and the stem, you may be able to get away with just tightening it up a bit; the packing has a way of aging.  If it's from the outlet, the odds are that again age has taken it's toll, but it would be the seat or the washer on the valve, which is likely to be replacable.  Not, however, that refacing the seat and replacing the washer is all that easy -- even getting the thing apart can be a wrestling match and, of course, you have to drain the boiler to do it.

    I would be inclined to use a brass or bronze valve as a replacement; I doubt that electrolytic corrosion would be that much of a problem.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • HenryT
    HenryT Member Posts: 128

    Jamie, thanks for the quick response. I am unfamiliar with the terminology of the valve so i would just say it is dripping from the farthest part away from the boiler, the part where it looks like you can connect another hose to it.

    So per your suggestions, I can use bronze or brass as replacements, but may i use a ball valve? and do i need pipe dope or some type of water seal? because it looks like the installer have some type of seal on the fitting.

    sorry if i completely missed your point.

    thanks again.
  • bob young
    bob young Member Posts: 2,177

    Do yourself a favor & call a plumber. your questions indicate you might jam yourself up. stick to what you know. if the valve snaps inside the fitting , you have no heat.   a plumber
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,849
    edited March 2012
    You'd want a full-port ball valve.

    Make sure its temperature rating is high enough. Brass is generally fine with steel. You're also going to need a pipe nipple to screw into the reducing tee after you get the draincock out. Assuming you can get it out. You can use either thread sealer or PTFE tape on a 3/4" fitting. With PTFE you'll have a better chance of getting it apart later. Your existing valve is in there with thread sealer, so it's not coming out of there without a fight, and the problem is, brass it pretty soft, so you may end up having to drill it out and chase the threads. At least its not screwed right into the boiler.

    If I were doing this I'd take the equalizer out of the reducing tee and see if I could get it loose from the boiler return. If that came off I'd replace it with a 2" x 2" x 2" tee and put a 2" full-port ball valve on there so I could blow down the boiler once a year or so. A 2" ball valve is going to set you back $40-$50, but it'd be worth it for the life you'll get out of the boiler if you can blow it down.

    If you feel like you'd like to learn a little more about this first--or at least put off doing anything until the end of heating season, you can get a shut-off valve or a threaded cap made for hose fittings at a garden supply store. Screw that on and your leak will still be there when you get around to fixing it.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • HenryT
    HenryT Member Posts: 128
    edited March 2012
    Thanks ALL>

    Thank you all for your comments. 

    I tried closing the valve tighter but still have a slow leak. Assuming Ill wait to do this in the summer, do you think the leak will worsen in a matter of months where it will cause flooding due to the leak and the water feeder kicking in?

    Of course I can cap it as Hap mentioned, but just trying to manage the worst case scenario.
  • crash2009
    crash2009 Member Posts: 1,484
    edited March 2012

    I would just cap the fitting for now, and shop around for a new valve to install in the summer.  If something bad happens, and you get stuck, it will be less of a hassle in the summer.  I have 2 leaks, just like yours.  I capped them 2 years ago, still haven't replaced them.  If you have your mind set on replacing, look into the NIBCO 585-70-66-HC  I have had them on for a few seasons, they show no signs of wear, as of yet.  http://www.nibco.com/cms.do?id=2&pId=113&d-1342853-p=4
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