Steven Briggs wrote in message
...
In message .uk, Ed
Sirett writes
Question is, do I need special fittings for this or will just fit a
normal 22mm compression stop-tap?
Can 1/4 turn ball valves be used in this position (more reliable?)

The pipe is more likely 20mm OD. UNless you measured it accurately
in
which case I apologize.

Whatever you do any form of compression fitting on plastic pipe needs
a
support insert in the end.



Dead on 22mm, measured with verniers. As the pipe was painted above
floor level, I had assumed it was copper until I pulled up the floor
boards and saw it was actually black plastic. A google revealed a
couple
of threads suggesting this stuff is very thick walled, so I not sure
it
does need an insert, or if a standard 22m olive will do the job.

These pipes come in different thicknesses, one more heavy duty than the
other. Well, in Ireland and France they do, I assume also in the UK.
The fittings for them are easily available in plumbers merchants and
agricultural suppliers, and you would also get a fitting where one end
goes onto the alkathene and into which you can screw a fitting for
copper into the other end if necessary. I bought a 1/4 turn one
recently, but I'm sure you would get a tap type aswell. Probably just as
easy and no more/not much more expensive than an ordinary fitting.

Holly