I. Common Cause Analysis
Slow air delivery in screw air compressors is usually not caused by a single fault, but rather reflects systemic issues. Common causes include clogged intake filters, excessive differential pressure across the oil‑air separator, a stuck or improperly set minimum pressure valve, poor oil‑air separation leading to inadequate oil return, reduced cooling system efficiency (such as dust buildup on coolers or fan malfunctions), and wear of the compressor rotor or decreased volumetric efficiency.
II. Step-by-Step Troubleshooting and Recommendations
- Inspect the Intake System: Clean or replace the air filter, and verify that the intake hose is free from collapse or leaks;
- Examine the Oil Circuit and Separation System: Check that the oil level is normal, and measure whether the differential pressure across the oil‑air separator exceeds the limit (typically >0.8 bar—replace if so);
- Verify the Function of the Minimum Pressure Valve: After shutdown, disassemble the valve body, remove carbon deposits, and ensure spring elasticity and smooth movement of the valve spool;
- Assess Cooling Performance: Clean the cooler fins and measure exhaust temperature; if it remains persistently high (>105°C, be cautious);
- Monitor Operating Parameters: Compare rated discharge volume with actual flow rate; if consistently low and no obvious leaks are present, consider professional inspection of the clearance between the male and female rotors.
III. Preventive Maintenance Tips
Regularly replace the “three filters and one oil” (air filter, oil filter, oil separator element, and dedicated screw compressor oil) according to the manufacturer’s recommended service intervals; ensure adequate ventilation for the equipment; record exhaust pressure, current, and temperature before and after each maintenance session to facilitate trend analysis. Never operate the equipment while it is malfunctioning, as this can accelerate wear on the compressor unit.