Hertz Kompressoren Eagle Series (oil-free)

Eagle 37 – 90 kW, two-stage, fixed and variable speed

Hertz Kompressoren Eagle Series (oil-free)

Two-stage, direct-coupled oil-free rotary screw range for processes that cannot tolerate any oil in the air stream.

Type
Oil-free rotary screw
Power
50–125 hp (37–90 kW)
Flow
134–547 cfm (3.8–15.5 m³/min)
Pressure
101–145 psig (7–10 bar)
Cooling
air-or-water
Drive
direct
Lubrication
oil-free
Models
Eagle 37 – 90 kW, two-stage, fixed and variable speed
Typical applications
  • Food and beverage
  • Pharmaceutical
  • Electronics
  • Textile processes intolerant of oil carryover

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: Gearbox / bearing lubricant only — the compression chambers are oil-free
Change interval: Per OEM gearbox interval (typically 4,000–8,000 hr)

Class 0 oil-free positioning: no lubricant in the air path. Do not substitute a standard screw fluid for the gear oil.

Wear parts
CategoryIntervalSource
Inlet air filter2,000 hr or on ΔP
Gearbox oil + filterPer OEM interval
Airend shaft sealsInspect at major service
Intercooler / aftercooler cleaningAnnual
Check valve and blowdownAnnual inspection

Consumable part numbers change by revision and region — pull the current number from the OEM portal.

Preventive maintenance
Daily
  • Check fluid level in sight glass at running temp
  • Listen for unusual noise / vibration
  • Check discharge pressure & temperature vs baseline
  • Verify condensate drain function
  • Log package amps if metered
Weekly
  • Blow down receiver and drain traps
  • Check for oil carryover at first drop leg
  • Inspect for fluid or air leaks around airend and separator tank
  • Verify safety valve is not weeping
Every 2,000 hr / 6 mo
  • Change fluid filter
  • Change air filter (or sooner per ΔP)
  • Sample fluid for TAN / metals / water
  • Clean cooler exterior with low-pressure air (never > 30 psi against fins)
Every 4,000 hr / 12 mo
  • Change separator element
  • Change fluid
  • Inspect scavenge line & orifice for coking
  • Check coupling / belt alignment & wear
  • Torque electrical lugs to spec (typ. 45–75 in-lb #4–2/0 AWG)
Every 8,000 hr
  • Rebuild inlet valve
  • Rebuild minimum-pressure check valve
  • Regrease or replace motor bearings per OEM interval
  • Verify safety valve setpoint against gauge
Common faults & first checks
  • Interstage pressure drift indicating airend or check-valve wear
  • High discharge temperature from a fouled intercooler
  • Condensate carryover if the aftercooler drain is neglected
Controller(s)
Strengths
  • Oil-free air path for sensitive processes
  • Two-stage compression for better specific power
  • Fixed and variable-speed builds
Weaknesses
  • Higher capital cost
  • Airend overhaul is a specialist job, not a field rebuild
  • Requires trained oil-free service support
Field notes

Capacity range from the public Eagle brochure. Oil-free class claims should be confirmed against the certification supplied with your specific unit.