Flow through a 4.5mm bore

[frank999]

On a similar thread ti this question:
http://www.diynot.com/diy/threads/bore-of-a-standard-isolator.459308/

Can anyone help work out flow rates for the below, and am I making any wrong assumptions?:

I have a valve who's technical spec states KV** as 0.54 m3/h, they tell me this is calculated on average mains water pressure.

So with 1000 litres/m3, this valve gives 540 litres per hour, which equates to 9 litres a minute, which doesn't sound great if I have a 114 litre water tank to fill.

Any help appreciated.

 

[muggles]

Sounds about right but it does of course depend on what the manufacturer thinks "average" mains pressure is