In our latest blog, we will delve into a crucial aspect of compressor system maintenance: preventing contamination. Contaminants in a compressor system can cause significant issues, from equipment failures to compromised product quality. Understanding the sources of contamination and how to mitigate them is essential for maintaining a reliable and efficient system.

Sources of Compressor System Contamination

The Compressed Air and Gas Institute identifies four primary sources of contamination in compressed air systems:

1.   Intake Air Quality

2.   The Compressor Itself

3.   Piping

4.   Storage Receivers

Let’s explore each of these sources in detail.

Intake Air Quality

The air that feeds the compressor inlet can carry various contaminants, including viable and non-viable particles, water vapour, oil vapour, and other gases. These contaminants enter the system primarily through the intake air.

Key Considerations:

·     Location: The placement of the compressor intake is critical. It should be positioned to minimise exposure to pollutants.

·     Intake Filter: The first line of defence against airborne contaminants. It must be inspected and replaced regularly according to the manufacturer’s guidelines.

Despite the best efforts to filter intake air, certain small particles can still pass through. Atmospheric air in industrial environments typically contains numerous dirt particles and microorganisms that are too tiny to be captured by standard intake filters.

The Compressor Itself

The compressor can introduce additional contaminants through wear and tear. During normal operation, particles from worn components can enter the compressed air system. Additionally, the compressor itself can contribute to water and oil contamination.

Preventative Measures:

·     Regular Maintenance: Following the manufacturer’s maintenance schedule is vital. This includes checking and replacing worn parts and ensuring that ventilation openings and condensate drains are functioning correctly.

·     Coalescing Filters: These are crucial for removing oil aerosols and capturing particulates that the intake filter misses.

Piping and Storage Receivers

Piping and storage receivers can store significant amounts of contaminants, including particles, water, and oil. As compressed air cools, it causes condensation, leading to liquid water within the system. This environment is conducive to corrosion and the growth of microorganisms.

Preventative Measures:

·     Use of Non-Corrosive Materials: Selecting non-corrosive piping materials can prevent rust formation.

·     Proper Filtration: Installing appropriate filters can help remove contaminants before they reach sensitive equipment.

·     Routine Inspections: Regular checks and maintenance of the piping system and storage receivers are necessary to ensure cleanliness and functionality.

Understanding the Types of Contaminants

Particles: Dirt, dust, and other particulates can enter the system through the intake air and can cause blockages and wear on components.

Water: Atmospheric air can contain substantial amounts of water vapour. If not properly managed, this water can cause rust, damage equipment, and lead to bacterial growth.

Oil: Oil vapours from the environment or introduced through oil-lubricated compressors can contaminate the system. Even oil-free compressors need filtration to remove these vapours.

Gases: Harmful gases such as carbon monoxide, carbon dioxide, and other hydrocarbons can enter through the intake air or be produced by the compressor itself.

Mitigation Strategies

To effectively manage these contaminants, consider the following strategies:

1.   Regular Filter Replacement: Ensure all filters, including intake and coalescing filters, are replaced as per the manufacturer’s recommendations.

2.   Proper System Design: A well-designed system that considers the placement of intakes and the use of non-corrosive materials can significantly reduce contamination risks.

3.   Routine Maintenance: Regular maintenance by trained personnel is crucial to identify and address potential issues before they become major problems.

4.   Air Quality Monitoring: Implementing online monitoring and periodic air testing can help maintain high air quality standards.


At CMC, we understand the importance of maintaining a clean and efficient compressor system. By taking proactive measures to prevent contamination, you can ensure the longevity of your equipment and the quality of your output. If you have any questions or need further assistance, please do not hesitate to contact us. Our team of experts is always ready to help you maintain the highest standards of compressed air quality.