compression ring on copper pipe

[Mike Dodson]

How do i change the old ring that is now on the hot water line to my bathroom sink it will not come off. need to update the value and supply line to the sink faucet. just cut it off or can I heat it. thank you

[Rocket]

Compression rings use torque to apply “compression” between the line and fitting (this applies to PVC, copper, and brass). This means that the soft metal or plastic has to deform in order to seal off pressure.

This is why you can repetively disconnect a compression fitting and reconnect it, but, unwittingly each time you are applying a little more to torque to deform the line into compression to seal it.

So, it has to be cut off and replaced.

Hope that helps.

[BobF]

If I get lucky, the threads of the old nut will fit on the new valve. May not be the best solution, but it works and I have never had one fail.

If the threads don’t match, I can usually get the ring off with pliers. Grip the ring and twist it off. I prefer this method.

You can also cut off the end of the pipe (and the ring) with a hacksaw.

If the pipe is too short already, you can cut the ring diagonally with a hacksaw blade, almost all the way through, and it will then twist off. But you are risking fate with this method since a nick in the pipe will give you a leak.

[carl]

If it were me replacing the valve, i would elimanate the compression and us a solder on valve. i just think the only reason for the compression fitting is the original plumber is too lazy to solder the fittings. whe soldering a valve, i first remove the stem and seal to prevent possible heat damage to the rubber seal.

Just my opinion, and I am not SLAMMING plumbers, I just think compression fittings are a cheep fitting. (you will not fing them on aircraft :<)

[Paul]

I have a basic question. The city water pressure of about 100 psf delivers about 20 pounds of push in a 1/2 in pipe, trying to throw a compression fitting off the pipe. How much is the margin of safety preventing this from happening? Manufacturer instruction requires only half a turn beyond snug tight.

Also, is there any possibility of a “throw off” some years down the line after installation?

Thanks.

[Author]

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