Pneumatic Systems Explained: Components & Principles

Understanding Pneumatic Systems: Components & Principles

Prior to use, atmospheric air must be subjected to a series of treatments: filtering, compression, refrigeration, storage, and maintenance. These steps ensure the air is clean, pressurized, and ready for efficient operation in pneumatic applications.

The Compressor: Heart of Pneumatic Power

A compressor is a machine capable of producing compressed air, drawing power from a particular type of pneumatic energy. Its mission is three-fold:

1. To produce compressed air.
2. To store it for use in pneumatic systems to generate useful mechanical work.
3. To supply it to the connected pneumatic circuit.

Operating Principles of a Compressor

1. Takes outside air through a filtered duct.
2. The air is compressed in the compression chamber.
3. Provides adjustable output of compressed air, connecting the compressor to the pneumatic circuit installation.

Air Preparation Unit: Ensuring Quality Air

The proper preparation of compressed air is crucial for the longevity and efficiency of pneumatic devices. Key components include:

• Filter: Cleans the air of impurities and light water vapor, protecting downstream components.
• Regulator: A valve that maintains a constant, desired pressure of the air used, ensuring stable operation.
• Lubricator: Mixes a thin layer of oil, suspended as a mist, that travels to the moving parts of pneumatic devices, reducing friction and wear.

Pneumatic Circuits: Harnessing Compressed Air

Pneumatic circuits are systems that utilize pneumatic energy stored in compressed air to perform useful mechanical work. The essential devices within these circuits include:

• The compressor
• The air preparation unit (often called a FRL unit: Filter, Regulator, Lubricator)
• Tubes, pipes, and ducts for air transmission
• Control devices (valves)
• Output devices, also known as pneumatic actuators (e.g., cylinders, motors)

Pneumatic Components: Connectors, Cylinders, and Valves

Pneumatic Connectors

Connectors are essential elements for joining conduits and components within a pneumatic installation. Their characteristics include:

• Ease and speed of assembly
• Security of connection
• Effective leak prevention

Teflon tape is commonly used in pneumatic devices to prevent leakage through the joint of male threads, ensuring a tight seal.

Pneumatic Cylinders: Linear Actuators

Pneumatic cylinders are linear actuators that perform useful mechanical work by converting the energy of compressed air into straight-line motion.

• Single-acting cylinders: Perform useful mechanical work during the advancement stroke of the cycle, typically returning by spring force or external load.
• Double-acting cylinders: Are capable of performing useful mechanical work in both the advancement and retraction strokes of the cycle, powered by compressed air in both directions.

Pneumatic Valves: Control and Regulation

A pneumatic valve is used to control and regulate the flow of compressed air to pneumatic actuators.

• Directional Control Valves: Often referred to as 'way valves', these are used to direct and distribute the flow of compressed air to different actuators, controlling their movement.
• Check Valves: Also known as 'block valves', these are used to block the passage of compressed air when it moves in one direction, preventing backflow and ensuring unidirectional flow.
• Flow Control Valves: These valves regulate the flow rate of compressed air, serving to reduce or adjust the linear displacement speed of pneumatic cylinders or other actuators.