When a screw air compressor no longer delivers its rated volume, production tools slow down and pressure drops. Airflow loss is rarely caused by a single sudden failure; it usually develops gradually from one of seven common issues.
The seven common causes
- Clogged air intake filter restricting inlet flow
- Blocked oil separator increasing internal resistance
- Dirty coolers raising temperature and reducing density
- Worn or sticking inlet valve limiting intake
- System leaks wasting output before the point of use
- Undersized or kinked pipework causing pressure drop
- Aged airend with worn clearances losing compression efficiency
Diagnosis order
Start with the cheapest checks: inspect and replace the air filter, drain and inspect the separator, and clean the coolers. Then measure pressure drop across filters and pipes, and run a leak audit on the distribution network. If the machine still falls short, measure the airend output directly and compare it with the nameplate rating.
When to call a technician
Persistent high discharge temperature or metal particles in the oil indicate internal wear. Do not ignore these signs; continuing to run a worn airend can turn a rebuild into a full replacement.