A pneumatic system can range from simple pistons powered by air to systems consisting of multiple actuators typically used in mining operations. Pneumatic systems use compressed air as a source of power. Compressed atmospheric air is the most abundant and least expensive power source for most pneumatic systems and compared to hydraulics, pneumatics are relatively quiet, easy to use and economical.
To better understand how pneumatic Instrumentation works, here is a list of the essential components found in a pneumatic system.
Regulator and gauge
A regulator and gauge are both attached either to the compressor tank or compressor. A regulator functions mechanically or electronically to release compressed air to the system and a gauge, on the other hand, is a measuring instrument. Both of these components are responsible for helping the operator monitor and regulate the correct PSI of the compressor.
It is a pump powered by gas or electricity. The pump compresses air to increase PSI and depending on the design, some compressors have a separate tank used for storing compressed air before it is pumped into the system.
A check valve is a one-way valve connected to a hose which is then attached to the compressor tank and then the buffer tank. The purpose of a check valve is to allow compressed air to travel and accumulate inside the buffer tank and at the same time, prevent the air from flowing back into the compressor.
Accumulator or buffer tank
A buffer tank works as a second holding unit for compressed air originating from the compressor. A buffer tank stores high-pressure air and keeps it on standby ready for use by the actuator, and it also helps prevent airflow surges within the actuator. It regulates the compressor’s cycle and allows the instrument to maximize shut-offs. Lastly, the buffer tank also puts distance between the actuator and the compressor when the application requires it.
Feed lines are a series of tubes or hoses that transfer compressed air into and out of the actuators. The larger the tubing, the better it is capable of allowing highly-pressurised air to travel fast while also eliminating airflow back-up.
A directional valve is usually situated before the actuator. If the system has multiple actuators, multiple directional valves are also necessary. The function of a directional valve is to receive mechanical or electrical input from the control. These valves are responsible for releasing, stopping, or redirecting airflow.
The actuator is the main component of a pneumatic system which is where all the work happens. There are different types of actuators depending on what is required for the assembly and the most common type of actuator is the plunge and cylinder. In this type of actuator, compressed air is pumped into the cylinder as it subsequently moves a piston forward as the air gets pushed into the pneumatic chamber. To visualize how an actuator works, some day-to-day examples include construction tools using air for power, and dentistry equipment that also uses the same working principle.