On Thursday, 27 December 2018 18:56:16 UTC, DerbyBorn wrote:
Reducing flow rate can.

Rsducing the flow to a degree that the rate is reduced as the valve is
almost closed will cause you problems in filling the cistern fast enough at
times of high demand.

sometimes you don't need much flow reduction, sometimes you do.
FWIW an inline valve has the least effect on flow when the cistern valve is closing, the most when it's full open.


NT