Installing Primary Extractor Fan Blades

• Always install blades and doubler plates from a factory set.
• Doubler plates do not need to be changed every time blades are changed. Change doubler plates only when necessary.
• Change mounting bolts every second blade change. NOTE: Use a warning, Lock-Out Tag, not to start machine before carrying out work on machine! Never remove the complete fan assembly from the motor shaft. Always remove the blades and doubler plates before removing the fan hub.
  

1. Start with two bolts (9) just to penetrate hub (1).

2. Insert one fan blade (3) and a doubler reinforcement (4) between hub and base plate (7). Do this between the two earlier temporary bolts. (Backing plate should be on bottom of blade with curvature up). Place two bolts through baseplate, blade and doubler plate to penetrate hub by 19 mm (3/4 inch).

3. Repeat step 2 at 180° from the first blade.

4. Remove the first two temporary bolts in step 1.

5. Repeat step 2 for the two remaining blades.

6. Install the remaining eight bolts (9) with Loctite 271 (red) and a hardened flat washer (8). Mount bolts to penetrate hub by 19 mm (3/4 inch).

7. Remove the bolts without Loctite from steps 2 through 5 and reinstall with Loctite 271 (red) and a hardened flat washer (8). Mount bolts to penetrate hub by 19 mm (3/4 inch).

8. Mount four bolts (2) on doubler plates and blades. Use flat washers (6) and vibration resistant nuts (5) with Loctite 271 (red).

9. Torque sixteen hub bolts in an even fashion to 169 N˙m (125 ft-lbs).

10. Tighten bolts to 135.6 N˙m (100 lb-ft).