Copper pipe water line is out of round....can I still use a compression fitting valve and just add some teflon tape at the compression nut to ring seat fit. it is slightly oval. I noticed a slight wetness just behind compression fitting. I think I can reset it with a little Teflon placed over the ring setting where the nut stresses down on it.


I do not think that teflon tape will help with an out of round tube in a compression fitting. My first thought would be to try to restore the tube to roundness by proper use of Vise-Grips with a rag to prevent scoring of the sealing ring. There is a die clamp device designed for gripping tubing to make a flare in the end. This die might be used to restore the tubing to roundness. You might have to remove the ring seal and put on a new one after truing the end of the tubing.

But be prepared to cut off the out of round end and join a fresh piece of good tubing.

  • 3
    I might try to round the pipe like Jim says but if already tightened. I would tighten it further and that should pinch the ferrul on the tubing and seal, using Teflon on a compression fitting is not a good idea. – Ed Beal Jul 29 '18 at 19:27
  • 2
    I agree with @Ed beal on this, attempt to further tighten and it might seal up. What have you got to lose, it already leaks and is out-of-round. IMO people often do not tighten compression fittings enough. – Jimmy Fix-it Jul 29 '18 at 20:05
  • @JimmyFix-it - Guilty. Mine always leak the first time. – Mazura Jan 11 '19 at 9:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.