Solenoid water valves are electrically-operated devices that control the flow of water. Solenoid water valves are electro-mechanical devices that use a wire coil and a movable plunger, called a solenoid, to control a particular valve. The solenoid controls the valve during either the open or closed positions and do not regulate flow. They are used for the remote control of valves for directional control of liquids.

Solenoid water valves have two main parts: the solenoid and the valve. After the coil receives a current, the actuating magnetic field is created. The magnetic field acts upon the plunger, resulting in the actuation of the valve, either opening or closing it.

There are two general types of solenoid water valves: direct-acting and pilot-operated. Direct-acting solenoid water valves have a plunger that is in direct contact with the primary opening in the body. This plunger is used to open and close the orifice. The pilot-operated solenoid water valve instead works with a diaphragm rather than a plunger. This valve uses differential pressure to control the flow of water. The air-venting valve is opened to allow the pressure to equalize and permit the water to flow through.