What is a water shut off valve?

A water shutoff valve refers to a small local valve that is used to control the water flow to a plumbing fixture. This type of valve is commonly found under the sink or under the toilet tank.

The shutoff valve is composed of a handle that controls the valve's flow of water, a water pipe inlet connection located at the rear part of the valve and a small water outlet connection located at the top or side of the shutoff valve. There are two types of shutoff valves: a compression valve and ball valve. The ball valve is considered to be the shutoff valve with the highest quality.