Leaky union with O-ring face seal

Old 04-12-07, 12:59 PM
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Leaky union with O-ring face seal

Hi all, a while back I had a pressure reducing valve installed, due to high water pressure. The 1" copper pipe comes up through the slab at a slight angle, and with not much length to work with. The installation has a slow leak at the coupling nut that connects to the inlet of the PRV. I tried tightening the hell out of it, no help there. I was assuming it was a metal to metal union, and was going to apply some pipe sealant to the metal faces, but then noticed the O-ring. Is there a lubricant or sealant that will help seal the o-ring? I have some Loctite 567 which is a great pipe thread sealant, but not sure it is any good for an o-ring. Thanks for the help.

Old 04-12-07, 02:52 PM
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Greg: The o ring needs to be pliable, and round. If it has flattened out, you may want to consider getting a new one. Sometimes they get caught in the union and are squashed on edge. A new o ring would be a cheap "try out" before we go further with it. Hopefully that will do it. Plumber's lube or pool pump lube would be a good lubrication for the o ring.
Old 04-13-07, 09:08 AM
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O-Ring leak

O-ring joints should not be run at a angle, any pinch or nick will cause a leak. If you can, straighten out the pipe and re-install with a new o-ring, if not try to replace the union with a metal to metal connection, lots of luck.

"If all else fails, read the directions"

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