Tim Lamb wrote:
In message ,
harry writes
On Wednesday, 7 September 2016 16:50:35 UTC+1, Brian Gaff wrote:
Yes indeed, one that goes underwater is the way to go. I need one for my
toilet cistern as well as it has the wrong valve size, ie its for a mains
feed not a gravity feed and so it constantly sounds like a babbling brook.

Snip
The only difference is the jet is a bigger hole for gravity fed ones.
They won't close against mains pressure.

Oh yes they will:-)

I have just connected an old gravity fed cistern to a 5 bar mains
supply. Shuts off OK but *howls* as it reaches the close off point.

On dipping tubes... I thought these are not permitted on mains feeds due
to suck back contamination risks. The way round was a collapsible
plastic tube.


Or a small hole near the top of the tube to allow air back in.

Tim

--
Trolls AND TROLL FEEDERS all go in my kill file