Pneumatic actuation refers to a valve being tripped through the use of compressed air (gas). At a particular point in an industrial or manufacturing process, compressed air is released, causing a valve to open or close. The combination of solenoids and pneumatics is twofold. Solenoid valves are used in pneumatic processes and solenoid valves and pneumatic valves are used in combination. The combined valve is called a piloted valve. The larger solenoid valve is triggered by the smaller pneumatic valve. The pneumatic valve can act as an air cylinder contained in a main valve. A pneumatic solenoid valve is also referred to as a compressed air pilot valve.

  Pneumatic avalves can be designated as internally piloted or externally piloted. The valves can further be categorized by the number of connections or paths for flow they contain. Externally piloted valves use an external source of air pressure. Internally piloted use an internal source of air pressure. Two-way piloted valves can be used in dust collector systems. An internally driven pilot valve with four-way connections are generally found in pneumatic operations and are used to move double action cylinders. Pneumatic solenoid valves can be designed as stackable.