Two intermeshing helical rotors compress air continuously. Oil-flooded or oil-free.
Typical range
5–500+ HP, 100–175 PSI standard
Best for
Continuous duty, industrial plants, high CFM demand.
Components
- Male & female rotors (airend)
- Oil separator (flooded)
- Oil cooler & aftercooler
- Minimum pressure valve
- Inlet (modulating) valve
- Thermostatic valve
- Controller (PLC)
- VSD (optional)
Common issues
- High discharge temp → low oil, blocked cooler, fan failure, faulty thermostatic valve
- Oil carryover → failed separator element, overfilled sump, scavenge line blockage
- Won't load → inlet valve stuck, solenoid failure, low system demand
- Short cycling → undersized receiver, leak in control line
Maintenance
- Daily: check oil, separator differential, temps
- 2,000 hrs: change oil filter, air filter, oil
- 4,000–8,000 hrs: separator element, coolant analysis
- Annual: airend vibration check, valve inspection