Water – Replace Water Shutoff Valve Stem with Repair Kit

leakvalvewater

I have a leaking water shutoff valve (pictured below). It appears to be a sweat shutoff valve that is soldered on to the pipe. It does not leak if I tightly shut off the valve, but any attempt to open the value causes leaking (admittedly I have to close it pretty tight to stop the leak).

Obviously I'd like to fix this through the easiest method possible. I could replace the entire valve, which would require either cutting the pipe or removing the soldering and pulling the valve off. However, there are valve stem repair kits that would involve just replacing the valve itself.

My main question is, is this a viable way to repair the leak? Given the fact that it doesn't leak when fully closed, does that imply a failure of a o-ring that such a repair kit would replace? Almost all advice I can find about replacing water shutoff vales involves replacing the entire valve, not just the stem.

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Best Answer

Easiest fix - You have leaking packing (the seal around the valve stem) since it leaks only when open.

  1. Tighten the packing nut - hold the valve body still with one wrench so it does not try to twist the pipes while using another wrench to tighten the nut between the valve body and the valve handle (the "packing nut")
  2. If that does not fix it, shut off the water further back in your system and remove the packing nut (same process but loosen) - remove any old packing, apply new packing (hardware store plumbing section should stock it - teflon string, more or less, these days) then reassemble and tighten as in 1.
  3. You may need to take the valve stem out to repack. You can replace the sealing washer if needed which might make it easier to get shut off, depending on the condition of the sealing washer at present. This is rather less drastic than "a valve stem kit" that might or might not actually fit your particular valve.

If you do replace, get a 1/4 turn shutoff valve. They are far less prone to leaking or failing to operate after years of sitting open, as shutoff valves do.