In message , Lobster
writes
Spike wrote:

And how do I disconnect the plastic from the mains? The connectors
are all push fit by the looks of things... do they come apart easily?
If so, how?!

On the stuff I've used, there's a collar around the mouth of the
fitting which you push inwards slightly, which makes it lose its grip
on the plastic pipe, which may be withdrawn. Happens very easily; no
need to force it, and if you do, something will break!

That sound like Speedfit - white stuff. They grey colour the OP mentions
makes me think it is more likely to be Hepworths Hep20. These fitting
are (usually - though they do make fixed fittings as well IIRC) also
dismountable, but in different way.

There is a website with useful info on it:

http://www.hep20.co.uk/

To separate the Hep2O fittings you unscrew the knurled 'ring' and pull
apart. Take care as inside there is a rubber O ring, and maybe a bit of
plastic that may fall out, or stick on the pipe. There is a 'Grab ring'
made of plastic with little stainless steel teeth (green IIRC) that will
stay attached to the pipe. To put back together, push the pipe etc back
in and screw back up.

to make the 'T' I would use a matching plastic fitting, though you can
use standard compression fittings. note that even with the plastic
fittings the pipe should have a support sleeve inserted in the end that
goes into the fitting (Speedfits is plastic I think, Hep2O is Stainless
steel.) I have made joints by mistake without them and all has been
fine, but sods law........

To cut the pipe the best/easiest thing to use is a pair of proper pipe
cutting 'secateurs'. but I have used a ~Stanley knife on occasion as
well, just requires a bit more fiddling about. Main things are to have
the cut square and not to have any rough bits hanging off.

Speedfit is available in the sheds, but I've only ever found Hep2O in
Plumbers Merchants

--
Chris French