An automatic shut-off valve is a type of valve that automatically shuts off the flow of water when it detects a leak. There are two main types of automatic shut-off valves: mechanical and electronic.
Mechanical shut-off valves use a float to detect leaks. The float is connected to a lever that opens and closes the valve. When the float rises, it opens the valve and allows water to flow. When the float falls, it closes the valve and stops the flow of water.
Electronic shut-off valves use sensors to detect leaks. The sensors are usually located near the base of the unit where they can detect leaks in the pipes or fittings. When a leak is detected, the sensor sends a signal to the control unit which then shuts off the flow of water.
Both types of automatic shut-off valves have their advantages and disadvantages. Mechanical shut-off valves are less expensive than electronic shut-off valves but they can be more difficult to install because they require access to both sides of the pipe. Electronic shut-off valves are more expensive but they are easier to install because they only require access to one side of the pipe.