What is a compressed air system

A compressed air system is a coordinated network that generates, prepares, and delivers compressed air to machines and processes within a facility. A correct design ensures the right air pressure, flow rate, and quality at the appropriate points in the system.

Because compressed air can be tailored precisely to the requirements of each application, it is used across many industries, including manufacturing, food and beverage, electronics, and automotive.

A well-dimensioned air preparation offers clear advantages throughout the system:

• Reliable operation: Clean, dry, and correctly regulated air reduces malfunctions and unplanned downtime.
• Longer equipment life: Reduced contamination and moisture protect seals, valves, and cylinders, extending maintenance intervals and service life.
• Energy efficiency: Correct pressure settings, low pressure drops, and suitable filtration and drying help to avoid unnecessary energy consumption. This supports efficient operation and reduces lifecycle costs.
• Safety: Stable air quality and pressure, combined with appropriate safety components, contribute to safe machine operation and protect both process as personnel.

Key steps in compressed air preparation

The following sections describe the typical process flow in an industrial compressed air system.

1. Ambient air intake

The process starts with ambient air drawn into the system through an intake filter. This filter removes coarse dust and larger particles before they reach the compressor. Clean intake air:

• Protects the compressor
• Reduces wear
• Improves the quality of the compressed air from the outset

This ambient air is the raw material that will be compressed and conditioned for use in the application.

2. Compression

At the heart of every compressed air system is the compressor. Its task is to increase the pressure of the ambient air to the level required by the application. Depending on the demand profile, different compressor technologies may be used, for example:

• Screw compressors
• Piston compressors
• Scroll compressors

Regardless of the type, the basic principle is the same: electrical energy is converted into compressed air energy. The selection and dimensioning of the compressor have a direct impact on energy consumption and system efficiency.

3. Air reservoir

After compression, the air is typically stored in an air reservoir (receiver). This component performs several important functions:

• Compensates for fluctuations in air consumption
• Ensures a stable supply during peak demand
• Provides short-term storage of compressed air
• Helps stabilize system pressure
• Allows the air to cool slightly, which promotes initial condensate separation

A correctly sized reservoir supports efficient compressor operation and contributes to a stable, reliable system.

4. Refrigeration dryer

Compressed air always contains moisture. If this moisture is not removed, it can lead to corrosion, contamination, and malfunctions in downstream components. A refrigeration dryer cools the compressed air so that water condenses and can be separated out. The result is dry air with a defined pressure dew point, suitable for standard industrial environments. For applications with higher requirements—for example, outdoor installations in cold climates or sensitive processes—adsorption dryers may be used in addition to or instead of refrigeration dryers to achieve lower dew points.

5. Decentralized air preparation

Regulator functions

• Switching and regulating: On/off valves and pressure regulators control the air supply and set the required pressure for each machine or sub-system. This enables precise adaptation to the process and avoids unnecessary overpressure.

• Measuring: Pressure sensors and flow sensors monitor key parameters in real time. This supports condition monitoring, helps detect leaks or pressure drops at an early stage, and provides valuable data for optimization.

• Safety: soft-start valves gradually pressurize the system during start-up, preventing sudden pressure surges and potential movement of the application. Safety valves and lockout/tagout (LOTO) solutions help protect personnel and equipment and support safe maintenance procedures.

Compressed air quality

• Condensate removal: Water separators, adsorption dryers, and membrane dryers remove residual moisture from the compressed air. This protects valves, cylinders, and other components from corrosion, sticking, and premature wear. Depending on the dew point requirements, these technologies can be used centrally or locally.

• Particle filtration: Surface and cartridge filters remove solid contaminants such as dust, rust, and scale. By combining different filter grades (e.g. pre-filters and fine filters), the air quality can be matched to the sensitivity of the downstream components.

• Oil removal: Coalescing filters remove oil aerosols from the compressed air, while activated carbon filters adsorb oil vapors and odors. This combination enables low-oil or oil-free compressed air quality, which is essential in sectors such as food, pharmaceuticals, and precision manufacturing.

6. Delivery to the machine

In the final step, the prepared compressed air is delivered to the machine or system. Here it is used to actuate pneumatic components such as:

• Cylinders and grippers
• Valves and valve terminals
• Pneumatic tools and handling systems