"John Schmitt" wrote in message
news
On Mon, 10 Oct 2005 22:24:43 +0100, Doctor Drivel
wrote:

pushfit, pushfit, pushfit :-)

If you need to use plastic pipe use good
quality compression joints with
the olive wrapped in PTFE on the plastic
pipe. A far better and cheaper joint
than pushfit. Also easily demountable.

All the pushfits I have worked with
simply needed the collar to be
depressed to release.

Only Speedfit, or the cloned Speedfit does that.

No need for a spanner. How easy is that? No need for
even a spanner.

Most pushfit is difficult to demount. A compression joint on plastic pipe
is much superior to only relying on a very thin O ring - and cheaper. Even
with expensive plastic pipe cutters the odd nick can be left on the pipe end
and the O ring can be nipped. Then the grab rings can fail and the fitting
shoots out leaving a full open end. Some of the grab rings and corrode with
time if on the wet side of the O ring, again failing and catastrophic
failures. A compression joint is much more forgiving. No contest use
compression on plastic instead of pushfit fitting, which can take some force
to push on, especially in awkward locations.

Many in the trade have moved over to good quality compression joints when
using plastic pipes, completely disregarding and type of pushfit fitting..

Also PTFE tape is for use on taper threads, not on compression joints.

The plastic makers recommend the olive is wrapped with PTFE. I do not
recommend that an olive is wrapped with PTFE on a copper pipe, just a
"smear" of jointing paste.