It seems to be something of an FAQ here as to how to remove radiators
for decorating without draining down and/or making a mess, and I just
came across the following valves at Screwfix which I thought I'd pass on
to the group as I've never heard of them before - are they new?

These replace standard radiator tails to allow the rad to be isolated
and removed from the wall still full of water. Fantastic! I'm buying a
boxful.

http://www.screwfix.com/app/sfd/cat/...33123&ts=16594

David