Compressed air quality class 2 as specified in ISO 8573-1:2010

ISO Overview of Standard 8573-1:2010

ISO ISO 8573‑1:2010 is the core standard developed by the International Organization for Standardization for classifying compressed air quality. The standard categorizes the principal contaminants in compressed air into three classes—solid particles, moisture, and oil content—and assigns air quality to distinct grades based on the concentration levels of these contaminants. Among these, “Grade 2” denotes a high level of compressed air purity and is widely used in industrial sectors with stringent requirements for air cleanliness.

Core technical specifications for Class 2 compressed air quality

In ISO In the 8573-1:2010 standard, compressed air meeting Class 2 quality must simultaneously comply with the limit requirements for the following three major contaminants:

• Solid particlesAccording to the particle size distribution, the number of particles per cubic meter of air shall not exceed 400,000 for particles in the range of 0.1 to 0.5 micrometers; 6,000 for particles in the range of 0.5 to 1.0 micrometers; and 100 for particles in the range of 1.0 to 5.0 micrometers.
• Moisture (humidity): The pressure dew point must be controlled at -40°C or lower (under standard reference conditions), and liquid water must be completely excluded from the system.
• Oil content: The total oil content (including liquid oil, oil mist aerosol, and oil vapor) shall not exceed 0.1 mg/ m³.

Typical application scenarios for Class 2 compressed air

Class 2 compressed air strikes a favorable balance between cleanliness and operating costs, and is typically suitable for the following production processes that are sensitive to air quality:

• Precision Manufacturing and the Electronics Industry: Used for purging pneumatic control components and precision instruments, as well as for the encapsulation and testing of electronic components, to prevent particulates and moisture from causing product defects.
• Food and Beverage Industry: Used in pneumatic drives for food packaging machinery, aeration in fermentation processes, and container blow-molding, ensuring that air contact does not contaminate food.
• Pharmaceuticals and Chemicals: Used for auxiliary operations in the production of non-sterile pharmaceuticals, pneumatic conveying of powdered materials, and instrument air supply to chemical reaction vessels.

Recommendations for Achieving and Maintaining Level 2 Air Quality

To ensure a stable supply of compressed air that meets Class 2 standards, both a well‑designed system and rigorous daily maintenance are essential.

• Configure high-efficiency purification equipment: At the compressor’s downstream end, appropriately match a refrigerant‑type or desiccant‑type dryer with multi‑stage precision filters, including oil‑removal filters and activated carbon filters.
• Pipeline Network Design and Material Selection: Use pipe materials such as stainless steel or aluminum alloy, which are resistant to rust and have smooth inner walls, to minimize secondary contamination and pressure loss in the piping network.
• Regular Inspection and Maintenance: Conduct regular sampling inspections using calibrated dew-point meters, particle counters, and oil‑content analyzers, and replace filter elements and desiccants strictly according to the prescribed schedule.