Pneumatic Systems - Glossary

This glossary serves as a reference for terms related to pneumatic systems, providing clear and succinct definitions for a wide array of components, measurements, and concepts integral to these systems. Pneumatic systems, which use compressed air to perform work, are employed across various industries, from manufacturing to robotics.

Term	Definition
Actuator	A pneumatic actuator (e.g., rack and pinion) is a device that converts energy from compressed air into mechanical motion.
After cooler	A heat exchanger that cools air leaving the compressor to condense moisture.
Air motor	A motor powered by compressed air rather than electricity, e.g., a vane motor.

Air, free	Air at atmospheric conditions at any specific location.
Air, standard	Dry air at 20°C (68°F), 101.3 kPa (14.7 psi) and 0% relative humidity.
Automatic drain	An automatic drain is a device that automatically removes condensate from the air system.

Bar	A unit of pressure, equal to 100,000 pascals or approximately atmospheric pressure at sea level.
Bore size	The internal diameter of a cylinder.
Check valve	A check valve in a pneumatic system allows flow in one direction and prevents backflow.

Compressor	A machine that increases the pressure of air by reducing its volume.
Compressed air	Air that is at a higher pressure than atmospheric pressure.
Cracking pressure	The pressure at which a valve begins to open.
Cushioning	Cushioning is a technique used in pneumatic cylinders to slow down the piston at the end of its stroke to prevent impact.
Cylinder	A pneumatic cylinder is a device that converts compressed air into mechanical energy through linear motion.

Cylinder cap	The closed end of a cylinder where the piston rod does not emerge.
Cv	Cv is a measure of the flow capacity of a valve.
Dew point	The temperature at which air is saturated with moisture and condensation begins.
Double acting cylinder	A double acting cylinder uses air pressure to move the piston in both directions.
FRL (Filter, Regulator, Lubricator)	An FRL is a combination unit that prepares compressed air for use in pneumatic systems.

Filter	A device that removes particulates and contaminants from air.
Kv	Similar to Cv but in metric units, Kv indicates the flow rate of water in cubic meters per hour at a pressure drop of one bar.
Manifold	A pneumatic manifold has multiple ports for distributing or collecting air to/from different lines.

Muffler	Also called a silencer, a muffler is a device that reduces the noise created by the exhaust of pressurized air.
Non-return valve	Another term for a check valve; it allows flow in one direction only.
Packing	Sealing material used to prevent leaks in pneumatic systems.
Pascal	A unit of pressure in the International System of Units (SI), equivalent to one newton per square meter.
Pneumatic gripper	A pneumatic gripper is a pick-and-place device that uses compressed air to operate gripper jaws, also called fingers. These fingers, similar to human fingers, help in grasping, holding and releasing the work pieces.
Poppet valve	A valve consisting of a hole and a tapered plug, usually operated by a solenoid.
Port	An opening in a cylinder or valve where air enters or exits.
Pressure, absolute	The total pressure within a system, including atmospheric pressure.
Pressure, atmospheric	The pressure exerted by the weight of the atmosphere, approximately 101.3 kPa at sea level.
Pressure, gauge	The pressure of a system above atmospheric pressure.
Pressure, relative	The difference between the absolute pressure and the atmospheric pressure.
Relative humidity	The amount of moisture in the air compared to the maximum amount of moisture the air can hold at that temperature.
Rodless cylinder	A cylinder where the piston moves within the cylinder without an external rod.

Silencer

Also called a muffler, a silencer is a device that reduces the noise created by the exhaust of pressurized air.

Single acting cylinder	A cylinder where air pressure is applied to only one side of the piston, causing movement in one direction only.
Slide unit	A device that allows for linear movement in a pneumatic system.
Solenoid valve	A solenoid valve is an electromechanically operated valve controlled by an electric current.
Vacuum	A condition where the pressure is below atmospheric pressure.