In article ,
"Allan" writes:
As part of the on going saga of fitting the new en-suite I have added
isolating valves to all the pipes. The only thing is that I notice that
even when fully open the flow rate of the taps isn't what it was before
there were any valves. This has led me to be concerned that my power shower
will also be "downgraded" due to the smaller bore through the isolating
valves. I am considering changing the valves on the shower supply pipes to
gate valves (the ones with the hand wheel). Is this a good move or am I
just talking bollox?

Gate valves are not good at isolating. What you want are full-bore
versions of the valves you are currently using, which normally have
a lever arm on them rather than a screwdriver slot.

--
Andrew Gabriel