Air Compressor Oil Selection Guide for Different Specifications: Mineral Oil / Semi-Synthetic / Fully Synthetic – How to Choose

Air Compressor Oil Selection and Related Specifications

Small air compressors may use standard mechanical oil, avoiding excessively high viscosity. Compressors with an air delivery of 0.6 cubic meters or higher require specialized air compressor oil. For factory-grade high-pressure or high-output compressors operating continuously, strictly adhere to the oil grade specified in the manual; do not substitute arbitrarily. Common grades are 32 or 46. Air compressor oils are categorized into mineral oil, semi-synthetic oil, and fully synthetic oil. Selection should be based on the operating environment and compressor specifications.

Application Ranges for Different Types of Air Compressor Oil

Solvent-refined mineral oil compressor oil is recommended for approximately 1000-2000 hours of use.

Hydrotreated semi-synthetic mineral oils have a recommended oil change interval of 2000-4000 hours.

Synthetic compressor oils have a recommended oil change interval of approximately 8000 hours. With proper monitoring and maintenance of the lubricant during operation, the oil change interval can be significantly extended.

Synthetic products offer a broader operating temperature range, minimal sludge and gum formation, low volatility to reduce oil consumption, stable performance to lower maintenance costs, and extended bearing/equipment lifespan. They are now widely recommended by screw compressor manufacturers and specified in warranties, though they carry a relatively higher price point. When selecting synthetic compressor oil, consult the supplier regarding compatibility between the oil and sealing materials. Perform system flushing during oil changes.

Specification Standards for Screw Air Compressor Oil

China has adopted the international standard ISO 6743/3A-1987, establishing the compressor oil classification standard GB/T 7631.9-1997. This standard classifies oil-injected rotary compressor oils (including vane and screw types) into three categories based on load intensity: light load L-DAG, medium load L-DAH, and heavy load L-DAJ. Among these, DAG and DAH are mineral oil-based, while DAJ is synthetic.