I've had mixed luck with re-using the fittings (ring and nut). Easiest way
is to use a tubing cutter
and cut it off.
Cheers,
cc

"Walter R." wrote in message
...
I am replacing the shut-off valve under my sink. A compression fitting
connects the valve to the 1/2 inch copper line.

How do I get the old compression ring and old compression nut off the
copper line? Is there a special tool for it? Or, can I just re-use the old
compression ring?

Thanks

Walter
The Happy Iconoclast www.rationality.net