What type of valve is commonly used for shutting off water supply in residential plumbing?

The ball valve is commonly used for shutting off water supply in residential plumbing due to its design that allows for quick and effective operation. Ball valves have a spherical disc inside that controls the flow of water. When the valve is open, the ball rotates to allow water to flow through; when the valve is closed, the ball turns to block the passageway completely, creating a reliable seal.

This mechanism makes ball valves highly effective for both shut-off and control applications since they require only a quarter turn to open or close. Additionally, they tend to be durable and less prone to leaking over time compared to some other valve types.

In contrast, while gates valves are also used for shut-off purposes, they are typically slower to operate and are not ideal for frequent on-off control as they can wear out more quickly. Check valves are designed to prevent backflow rather than to shut off supply, and pressure relief valves are used to manage excess pressure in a system rather than to control water supply. Therefore, the ball valve is the superior choice for effectively shutting off water in residential plumbing systems.