On 10/11/2020 21:50, alan_m wrote:
On 10/11/2020 13:55, Pancho wrote:

One other point, my old one suffered terribly from water hammer. I
replaced it with a Fluid master PRO45B (brass shank) and the water
hammer disappeared.

Often they come with two water pressure restrictors - perhaps if the
wrong one was fitted to the original valve you get the problem that you
had.

Yeah I read all that, and even considered fitting a kind of air
reservoir as a shock absorber, then someone suggested just fitting this
valve would fix it. I didn't believe them, but tried anyway, they were
right.