Toilet fill valve

Is the 70mm important in order to meet existing pipework?

If not plenty of bottom fill valves on Screwfix, Toolstation, Ebay and from any plumbing merchant or shed, B&Q, Wickes etc.). Screwfix and Toolstation are open during lockdown. The standard is 1/2 inch british pipe thread.

Random Example

Fitting instruction can be found from a link on this page

For personal collection Screwfix and Toolstation have a click and collect policy during lockdown. Check the stock level in the local outlet, order and pay on-line, wait for the confirmation (text) go and collect.

B&Q Example - alternatives available

What is the problem with the existing valve?

I suspect the old one has this.

The next question is there sufficient pipe movement to fit the more usual offerings?

I looked at mine and it seems the tail is about 50mm.

If there is enough room, maybe a 15cm flexible connector pipe could help solve the problem.

Something like:

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.