GAST Air Motor 8AM-NRV-28A

Air Motors & Mixers

GAST Air Motor 8AM-NRV-28A

The 8AM-NRV-28A is GAST's 3.7 kW (5 HP) flange-mounted, reversible 8AM air motor with a 2,500 rpm free speed, 21 Nm peak torque, 1/2" NPT ports and a 22 mm keyed shaft.

  • Air
    Powered
  • ATEX
    Safe
  • Variable
    Speed
  • Reversible

Explosion-Proof Power
for Hazardous Areas

The 8AM is the second-largest frame in GAST's AM range, delivering 3.7 kW (5 HP) at 2,500 rpm and 20.9 Nm of maximum torque. The -NRV-28A is a four-vane reversible unit with a flange mount and a 22 mm keyed shaft, intended for direct coupling to pumps, gear reducers and heavy mixers. The lower free speed compared with the 4AM and 6AM gives more usable torque without gearing.

Air consumption is 83 L/s at full load and 7 bar, so the motor needs a 1/2" supply line (or larger for runs over 2 m), a 5 µm filter and a lubricator. It can be stalled or overloaded continuously, is spark-free and cool running, and carries CE and ATEX II 2 GD c T4 marking for Zone 1 and 2 hazardous areas. An AG816 20:1 worm gear reducer is catalogued for the 8AM.

  • Instant
    Stall-Safe Torque
  • Cool
    Running
  • Compact
    Footprint
  • Long
    Service Life

Technical Specifications

Max power3.73 kW (5 HP)
Max speed (free)2,500 rpm
Torque: max / starting @ 5.5 bar20.9 Nm (185 in-lb) / 13.2 Nm (117 in-lb)
Torque at max speed14.9 Nm (132 in-lb)
Air consumption (max)83 L/s (5.0 m³/min, 175 cfm)
Air inlet / exhaust port1/2" NPT
Output shaftKeyed, 22.35 mm (0.88 in)
MountingFlange (NEMA 56C type), operates in any plane
RotationReversible (RV)
LubricationLubricated
Max operating pressure7 bar (100 psi)
Weight12.7 kg

Materials

Body & End PlatesCast Iron or Aluminium
RotorSteel, dynamically balanced
VanesComposite, self-lubricating
ShaftStainless Steel
BearingsSealed ball bearings
MufflerAluminium / sintered bronze

Performance Curve

061218243005001,0001,5002,0002,500Speed (rpm)Torque (Nm)
  • 6.9 bar (100 psi)
  • 5.5 bar (80 psi)
  • 4.1 bar (60 psi)
  • 2.8 bar (40 psi)
Indicative torque versus speed at four air inlet pressures (starting torque at 5.5 bar as reference); power peaks at roughly half of free speed. Certified GAST curves are supplied with the datasheet.

Dimensions

FramePower (kW)Length (mm)Diameter (mm)Shaft Ø (mm)Weight (kg)
1AM / 1UP0.03–0.1925880.8
2AM0.3–0.712578122.3
4AM0.7–1.3180100164.5
6AM2.0–3.02501402213
8AMthis model3.5–5.53001802824

Typical dimensions for the model range; certified dimensional drawings are available on request.

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