Xylem Flygt 2620.172 Service And Repair Instructions page 56

4 Maintenance
Use an 8 mm hexagon bit adapter (Allen socket) with a 100 mm (4 in) extension.
9. Fasten the impeller:
a) Place the washer on the impeller screw.
b) Lock the impeller to prevent rotation.
c) Tighten the impeller screw.
d) Tighten a further 1/8 turn, 45°.
e) Check that the impeller can rotate freely.
10.Mount the strainer and the nuts.
Tightening torque: 22 Nm (16.2 ft-lb)
54
Use pliers, a screwdriver, or similar.
Tightening torque: 22 Nm (16.2 ft-lb)
2620.172/.281 Service and Repair Instructions