On Wednesday, 1 August 2018 23:18:41 UTC+1, JimK wrote:
Tim Lamb Wrote in message:
In message , Jim K
writes
Tim Lamb Wrote in message:
OK so I finally got around to installing some toilets.

An earlier decision to use mains water is leading to noise where the
isolator valve is used to control cistern water flow to less than the
overflow will handle.

Any suggestions? An inline restrictor of some sort?

Are these valves the farty little screwdriver slot service valve
things? If so try a bigger bore type.

Yebbut... I think the issue is restricting the flow rate by creating a
vortex/slot.

A pressure regulator and restrictor would do a better job but there are
3 bogs and you are required to fit an isolating valve anyway.

Bar showers have restrictors fitted. I just wondered if there was an
easy fit, in line job. Perhaps those microbore tap connectors have their
uses after all.


Istr the noise is cavitation caused by the restriction of the
valves, larger surface area = less cavitation = less noise.
YMMV
--
Big valve, small valve, the size of the orifice when restricted will be the same to have the same effect.
A pressure reducing valve is the answer situated well away (whole house?)

Sometimes the noise is caused by the water falling in the cistern.
You can get a plastic "condom" that reduces this effect.
Goes on the float valve outlet.