Xylem Flygt 2620.172 Service And Repair Instructions page 55

3. Grease the threads of the impeller screw and the washer.
The proper lubrication of the screw and washer is lubricating grease for assembly of
bolts etc., for example, Kluber ALTEMP Q NB 50 or equivalent.
4. Check that the impeller screw is clean and easy to screw into the shaft end.
This is to prevent the shaft from rotating with the impeller screw.
5. Assemble the conical sleeve in the impeller.
Make sure that the conical sleeve bottoms in the impeller.
6. Assemble the impeller with the conical sleeve onto the shaft.
7. Mount the diffuser part and tighten. Continuously check that the impeller can rotate
easily.
Tightening torque: 22 Nm (16.2 ft-lb)
If the impeller cannot rotate easily, the shaft may have been displaced relative to the
main bearing. Make sure that the gap between the adjustment screw and the conical
sleeve is correct.
8. Turn the adjustment screw clockwise until the impeller contacts the suction cover.
Tighten a further 1/8 turn, 45°.
The extra 1/8 turn will make sure that the clearance between the impeller and the
suction cover is correct in the next step.
2620.172/.281 Service and Repair Instructions
4 Maintenance
53