Looking for electrically controlled valve for drinking water

It is called a solenoid and can be purchased from any commercial/industrial supply house. Like Grainger. You order the solenoid with the coil voltage you want and the NPT pipe size you want to use. Very simple. Google "solenoid" and you will see.

I am having difficulty wading through the numerous search results for "solenoid", even when I limit the search to water/liquids. The various sellers assume that folks already know about the various types of solenoids and their usage and compatible valving and application details. Solenoids are in vehicles, pneumatic and just about anything else that has a electronic control.

Is there anything that I can read to understand what is in the search results for solenoids where the search result is limited to drinking water systems ? Especially what valving is compatible with each type of solenoid?

Sorry, but I can't decipher the descriptions of the items provided by vendors of solenoids for drinking water systems.

Use a sprinkler valve. They are cheap and every home improvement store sells them. You'll need a 24VAC transformer to power it (also sold by the same stores for sprinkler systems).

and then wire in a passive infrared motion detector.

You might also try a floor pressure switch or switch mat vice a motion sensor to trigger the solenoid. When the dog steps on it it starts the flow of water.

buy a cheap motion detector flood light take the motion detector part and wire it up to a 120v solenoid and make sure you have GFCI protection.

The are a myriad of different solenoid controlled valves available. Plumbing supply shops will have them available.

eg. https://www.google.ca/search?q=sole...kGcefqwGr1YD4Dg&ved=0CFgQsAQ&biw=1440&bih=722

Go and visit an irrigation supply house.
There are many types of solinoid valves available,
Which one depends on pressure and what plumbing
fittings you want to use.
I am sure that if you explain it to them they will
advise you on what to use.

simplist is to use a motion sensor a suitable wall wart
and a suitable valve.

Go to a pet supply, buy a Lixit, and be done with it.
It is mechanical rather than electric, but it works well.