Pneumatic systems range from simple air-driven pistons to multiple-actuator mining operations. All pneumatic systems use a source of compressed air to power moving parts, or actuators. Pneumatic systems commonly use compressed atmospheric air, as it is abundant and inexpensive. Atomized oil is added to the air in some blends to ease its passage through mechanical systems. Pneumatic systems are generally preferred over similar, liquid-using hydraulic systems, due to their quietness, ease of use and cost efficiency.
A compressor is a pump powered by electricity or gas. This pump compresses the air to a higher PSI (pounds per square inch). Compressors may have a tank attached to store the air before it's released into the pneumatic track.
Regulators and Gauges
Regulators and gauges are instruments attached to the compressor or compressor tank. The regulator is either mechanically or electrically triggered to release air into the pneumatic track. Gauges are mechanic or electric measuring instruments. They allow the operator or computer system to check and regulate the PSI of the air inside the compressor.
Check valves are one-way valves that are installed to the hose connecting the compressor or compressor tank to the buffer tank. They allow the compressed air to accumulate in the buffer tanks, but do not allow backflow into the compressor or compressor tank.
Buffer Tank or Accumulator
Buffer tanks are secondary storage units for the compressed air originating from the compressor. They store the high-PSI compressed air for eventual use with the pneumatic actuators. These tanks help to prevent uneven airflow surges in the actuators; allow the compressor cycle to maximize its shutoff timing; and allow the compressor to be farther from the actuators in projects where this distance is useful or necessary.
Feed lines are hoses that transfer pressurized air through the pneumatic system. The largest diameter hoses that can handle the PSI the system is using are installed. Large diameter hoses allow the pressurized air to travel quickly, eliminating airflow backups.
Directional valves are placed before actuators. Multiple-valve systems are installed on projects with multiple actuators to power. Directional valves receive input from mechanical or electrical control sources. They re-direct, stop or release the pressurized air to its appropriate actuators at the times desired. Directional valves can be triggered by the action of a button, spring, lever, pedal, solenoid or other device.
An actuator is the component in a pneumatic system that does the work. There are numerous types of actuators, powered by pressurized air. Plunge and cylinder actuators are used frequently. The pressurized air is released into the cylinder to move a piston forward as the air is forced into the chamber. Examples of actuators at work are air-powered tools in construction and dentistry.