A 3 Port Water Valve - But How & Where ???

[Tonyi]

Hi i have a water saving project where i need a 3 port or T water valve for a toilet flush & wash hands system.

The valve is required to be siuated outside the toilet cistern where the mains water feed is into the toilet:
port1 is the mains water feed
port2 is the mains water out
port3 only opens & flows when the water pressure drops (that is less than the mains water pressure ie somebody has opened the tap and water is flowing through the main port pipe path).

This is for a hand wash basin tap that water flows on toilet flush.
I can't for the life of find a valve that stops when water is at mains pressure and flows at reduced pressure.
I know exactly what i want but can't seem to source it.

i tried to draw up what i need, can anybody help or advise?
http://www.plumbingforums.com/photo/3-port-water-valve-397.html

perhaps the item already exists but i don't know whats it's called.

or if somebody has a better suggestion i would love to hear it.

Thanks.

 

[frodo]

check out a paddle valve flow switch

when it since's flow, it opens a switch, that can turn on a valve, such as a honeywell 2 way zone valve

 

[Tonyi]

Hi Frodo thanks for the feedback.
i checked out the paddle valves.
i was hoping to keep it a passive (non powered active) system.
With electrics and solnoid valves anything is possable at a BIG $ price

 

[frodo]

Hi Frodo thanks for the feedback.
i checked out the paddle valves.
i was hoping to keep it a passive (non powered active) system.
With electrics and solnoid valves anything is possable at a BIG $ price

cooling tower fill valve and or a 3 way diverter valve

google them, and have fun playing