Pneumatic systems are used in a wide array of industrial applications which are dependent on the potential force of the compressed air to create and transmit kinetic energy. Flow control valves are self-explanatory, in that their function is to control the flow rate. This is usually in a specific section of a pneumatic circuit, which results in a slower overall actuator speed. Flow control valves either inhibit the air flow altogether, or they regulate the air flow in one direction only, which means that the air can flow freely in the other direction.
Pneumatic flow control valves are one of many components that control the amount, pressure and rate at which air moves through the system. Each application will have different flow rate requirements and will require a different size, shape or type of pneumatic flow control valve; the speed of the system's actuator depends upon how quickly the air flows into it and is sent out by the exhaust. Flow control valves are often classified by the number of entry and exit ports they have, and how many flow paths are created, such as two, three and four-way directional valves.
They come in a wide range of port sizes, configurations and styles, including meter-in (also called reverse flow) and meter-out versions, controlling the input and output flows respectively. Other types of flow control valve feature a tapered stem, with a graduated orifice which permits the controlled flow to be progressively adjusted as it passes through the valve.