In article ,
Dave Plowman (News) wrote:

With a properly made compression joint it isn't possible to remove the
olive without splitting it - it should be sort of cold welded on, without
noticeably distorting the pipe diameter.

If you can pull off the olive or turn it it wasn't tight enough.

Olives are always well compressed on to the pipe when
I've dis-assmbled joints in the past. Never seen a
loose one.

Serves me right for not soldering them all I guess!

G.