Definition:
A water shutoff valve is a small local valve used to control the flow of water to a plumbing fixture such as a faucet or toilet. These valves are usually found under the sink when controlling water flow to a faucet, and under the toilet tank when controlling water flow to a toilet tank.

The valve consists of a handle that controls the valve's water flow; a water pipe inlet connection in the rear of the valve and a smaller water outlet connection on the top / side of the valve.

The water inlet connection is usually sized at 5/8" OD (1/2" ID copper pipe) and the water outlet connection is usually 3/8" OD. The water inlet connection can be a soldered or compression type connection. The outlet connection is a compression connection.

The valve also comes in a straight and angle (90 degree) configuration.

Shut-off valves come in two valve types, compression valve type and ball valve type.

The ball valve type shutoff operates from the off to on position in 1/4 turn. It is the highest quality shutoff valve available.

The multi-turn compression shutoff valve type operates from the off to on position with multiple turns and uses a compression washer to control the flow of water through the valve.

Also Known As: shutoff valve, multi turn supply stop, quarter turn supply stop