Essential Components and Maintenance of Pneumatic Circuits

Essential Elements of Pneumatic Circuits

Pneumatic circuits rely on several key components to generate, transport, and control pressurized air:

• Energy Generator: This element provides pressurized energy to the circuit. In a pneumatic system, this is primarily the compressor.
• Transport Elements: These are the pipes or hoses through which the air circulates, joining the various circuit elements.
• Actuators: These are the receivers that convert the received energy into other types of energy to perform a specific action (e.g., linear or rotary motion). In pneumatic circuits, the main component is the cylinder.
• Control Elements: These elements open or close the circuit, regulating the flow. In pneumatic circuits, these are primarily valves, which allow or prevent the movement of the fluid.

Air Compressors and Their Types

The compressor is the element that provides pressurized air to the circuit. Compressors are generally categorized by their mechanism:

Reciprocating Compressors

Based on a rod-crank mechanism, their operation is similar to an internal combustion engine. Cooling fins are positioned around the piston to reduce the air temperature reached as a result of compression. This type is the most widely used and most economical.

Rotary Compressors

This type consists of a compression chamber and a rotor that, when rotated by the motor, absorbs and compresses air in the chamber. There are several subtypes, such as vane and screw compressors.

Pneumatic Control Elements: Valves

Valves are the primary control elements that regulate or prevent the flow of air. Valves are typically classified based on their function:

• Distribution Valves
• Lock (Shut-off) Valves
• Flow Control Valves

Distribution Valves (Routes and Positions)

Distribution valves are characterized by the number of ports (routes) and positions they possess:

• The 2/2 valve has two ports and two positions and is often used in circuits with single-acting cylinders.
• 4/2 valves have four ports and two positions and are used when the cylinders are double-acting.

Check Valves (Non-Return Valves)

This type of valve allows air flow in one direction (1-2), while in the opposite direction (2-1) the air circulates freely, preventing backflow.

Protection and Maintenance Elements (FRL)

Proper maintenance is crucial for pneumatic system longevity. Some essential protection and maintenance elements include:

• The Dryer: Reduces the amount of water vapor in the air. It often consists of porous material that absorbs moisture and allows air to pass.
• Filter: Removes impurities from the air. Its operation is often based on a spinning action, separating solid impurities from the air stream.
• Lubricator: Adds oil mist to the fluid to facilitate transport and reduce friction within moving components.
• Release Valve (Safety Valve): Vents air when the pressure reaches the allowed limit, preventing system damage.
• Silencer: Situated just off the circuit exhaust, it reduces noise pollution generated when air is released.