Background of the Change in Compressed Air Cleanliness Grade
In industrial production, the quality of compressed air directly affects the quality of the final product and the service life of the equipment. According to internationally recognized standards, the cleanliness of compressed air is classified into multiple grades. The compressed air system fromClass 2Changed toClass 3, which typically signifies a reassessment and adjustment of the requirements for gas‑supply quality. This change is not merely a downgrade; rather, it stems from a comprehensive evaluation that takes into account actual process needs, energy‑efficiency management, and the operational status of the equipment.
Differences in Core Indicators Between Class 2 and Class 3
The cleanliness of compressed air is primarily assessed using three key parameters: solid particulates, moisture (pressure dew point), and oil content. Classes 2 and 3 exhibit distinct thresholds across these three metrics:
- Particulate matter:Class 2 imposes stricter limits on both the number of particles per unit volume and their particle size, whereas Class 3 permits a relatively higher concentration of fine particles.
- Moisture content:Class 2 requires a lower pressure dew point to ensure that no condensation forms at lower temperatures; the dew point requirement for Class 3 is relatively more lenient.
- Oil content:This includes liquid oils, oil mists, and oil vapors. The total oil content limit for Class 2 is significantly lower than that for Class 3, imposing stricter requirements for oil removal filtration.
Analysis of Common Causes of Level Changes
Companies often choose to downgrade their compressed air quality class from Class 2 to Class 3 to meet the following practical needs:
- Precise matching of process requirements:Following upgrades to certain end-use gas‑powered equipment or production processes, the actual demand for gas‑source cleanliness has decreased; supplying excessively high‑purity gas in such cases results in resource waste.
- Operating Costs and Energy-Saving Optimization:Maintaining Class 2 standards requires higher-precision filters and more efficient dryers, which result in significant system pressure drops and increased energy consumption. Relaxing the specification to Class 3 can effectively reduce pressure drop, lower energy consumption, and decrease the frequency of consumable replacements.
- Equipment Aging and Maintenance Strategies:When the performance of existing purification equipment has deteriorated and there is no budget for a comprehensive upgrade in the short term, adjusting the target compliance level can serve as an operational strategy during the transition period.
System Adjustments and Smooth Transition Measures
Following the implementation of the grade change, in order to ensure the safety and stability of the compressed air system, corresponding supporting measures must be taken:
- Optimize filter configuration:In accordance with Class 3 standards, re-evaluate and adjust the filtration accuracy of both the main and branch pipelines, and remove or bypass any unnecessary high-precision filter elements to reduce system pressure drop.
- Adjust the operation of the drying system:In response to the relaxed moisture content specifications, appropriately adjust the dryer’s operating parameters to prevent energy waste caused by over‑drying.
- Strengthening end-point monitoring:At critical gas‑use points, increase the frequency of routine quality inspections to ensure that the modified Class 3 gas supply continues to meet minimum production requirements and to prevent product defects caused by fluctuations in gas quality.