Rogers Machinery KNW Oil-Free Rotary Screw
Water-cooled two-stage oil-free rotary screw, 40–1,500 hp. Process industry duty.
Type
Oil-free rotary screw
Power
40–1,500 hp
Flow
200–7,000 cfm
Pressure
45–232 psig
Cooling
water
Drive
gear
Lubrication
oil-free
Models
KNW Series (custom configurations 40–1,500 hp)
Years produced
Rogers has licensed Kobelco KNW for NA since 1990s.
Sound level
Package-dependent — usually installed in a compressor room, not enclosed.
Ambient range
Water-cooled; process-plant install typical.
Motor efficiency
IE3 / NEMA Premium; VSD variants inverter-driven.
Warranty
Long-term airend contracts; factory-scope overhauls.
Control modes
- Load/Unload
- VSD
Typical applications
- Process industry
- PET / textile
- Chemical
- Utility
Specs & intervals below are from publicly published OEM literature and long-standing field practice. Torque values, exact revision-dated part numbers, and safety-critical settings vary by serial number — always cross-check the unit’s OEM manual and nameplate before ordering parts or performing service.
Fluid
Spec: Gear oil per manual (not in air stream)
Change interval: 8,000 hr
Wear parts
| Category | Interval | Source |
|---|---|---|
| Air filter | 4,000 hr | |
| Gearbox filter | 4,000 hr | |
| Intercooler cleaning | Annual | |
| Blowoff valve seat | 16,000 hr |
Consumable part numbers change by revision and region — pull the current number from the OEM portal.
Preventive maintenance
Daily
- Log stage temps & pressures, verify condensate drains
4,000 hr
- Change gearbox filter & air filter, clean coolers
8,000 hr
- Change gearbox oil, inspect valves
40,000 hr
- Factory airend overhaul
Common faults & first checks
- Stage 2 temp high — intercooler cleaning due
Strengths
- Custom-engineered for the application
- Long service life
- Kobelco airend heritage
Weaknesses
- Long lead times
- Factory-level airend service
Field notes
Rogers licenses Kobelco KNW airend technology and packages for NA industrial process installations.