Currently refitting the bathroom down at Mum's 70's bungalow.

Main water supply comes in to a stop tap in the bathroom, below the LHS
of the toilet cistern. New cistern has the inlet on the RHS so I was
thinking of moving the stop tap to the right for a neater job. Anyway,
this afternoon, I had to quickly rip out the old bog and lift the floor
boards as I thought I had a leak under the floor*.
Anyway, I now know the incoming supply is a black plastic pipe, 22mmm
OD, presumably the old alkathene stuff.

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?)

*Leak turned out to be inside the body (i.e. cold to hot) of the new
bath mixer. Grrrr.

--
steve