An air-operated valve, also known as a pneumatic valve, is a type of power-operated pipe

valve A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fittings ...

that uses air pressure to perform a function similar to a

solenoid upright=1.20, An illustration of a solenoid upright=1.20, Magnetic field created by a seven-loop solenoid (cross-sectional view) described using field lines A solenoid () is a type of electromagnet formed by a helix, helical coil of wire whose ...

. As air pressure is increased, the compressed air starts to push against the piston or diaphragm walls which causes the valve to actuate. Whether the valve opens or closes depends on the application. These valves are used for many functions in pneumatic systems, but most often serve one of two functions. The first activates a part of the system when a specific pressure is reached. The second prevents damage by maintaining a constant pressure or flow rate inside a system or releasing pressure when it reaches excessive levels.

Types

Air-operated valves may be 2-way, 3-way and 4-way. 2-way valves can be either normally closed or normally opened. These valves have two ports that help the valves regulate the flow of air into a system. These valves often provide a simple on-off function. 3-way valves can be normally closed, normally open, and offer a universal function where gas can be diverted through a third opening to move the valve into the normally closed or normally open position. 3-way valves

pressurize A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor. Compressors are similar to pumps: both increase the pressure on a fluid and both can trans ...

and exhaust one outlet port to control a

single-acting cylinder In mechanical engineering, the cylinders of reciprocating engines are often classified by whether they are single- or double-acting, depending on how the working fluid acts on the piston. Single-acting A single-acting cylinder in a reciprocat ...

or pilot another valve. Three-way valves may be used in pairs to operate a double-acting cylinder, thus replacing a four-way valve. A primary function of the 3-way valve is to save/store air that's compressed in high cyclic applications. 4-way valves are used for systems that require higher air pressure. Four-way valves are the most commonly used components for directional control in a pneumatic system. The 4-way valve can have four or five ports, with different positions and uses. Their most common function is to regulate the motion of a cylinder, motor, or other powering components.

Applications

Pneumatic systems support production lines, mechanical clamps, train doors, and many other parts of industrial businesses.

References

{{Tech-stub Valves

Types

Applications

See also

References