I was replacing a ballcock valve on one of my toilets and found that the water supply was an older style connection. I decided to replace this while I was there. After removing the old water valve and cleaning off the threads, I noticed a few of the first threads deteriorated away. I believe this is an FIP 1/2" NPT connection on a brass pipe?



I applied nylon tape and installed the new water valve anyway and as I thought, it leaks. What is the best way to repair this? My next thought was to cut the pipe beyond the existing threads (as you can see I started) and rethread the pipe with a 1/2" NTP die by hand.

That is probably a steel nipple with a chrome sleeve over it, because a brass nipple would not have deteriorated. Remove it and install a new brass nipple.

also, use an angle stop not a straight stop for the toilet supply.

Unscrew the nipple from the fitting in the wall. Match the length with a new nipple and thread it in with a new angle valve.

Thanks for the help. I installed a new brass nipple. After installing the angle stop, I noticed it is still leaking very slowly.



What am I doing wrong here? I was careful to not tighten it too hard past hand tight, but I'm hesitant to over tighten it. Is it also possible that my angle valve was damaged by the old nipple's threads?

There's too many threads showing on that brass nipple. It needs to be tightened at least one more round.

That did it! A huge thanks!



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Throw away the tape and use a thread sealing compound/pipe dope, like I do.

use a shorter chrome plated (brass) nipple next time



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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



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