Table of Contents
Advertisement
8.5.1 Adjusting the impeller clearance
Tighten the fastening screws carefully to avoid damage to
the bearings.
The movement is 1 to 3 mm (0.039 to 0.118 in).
2
1
Impeller adjusting screws
1
Set screw
2
Fastening screw
The following method is suitable for pumps in vertical position.
Proceed as follows:
1. Loosen the fastening- and set screws so the impeller is sitting
on the suction cover or stationary wear ring. In this position, the
impeller clearance is zero.
2. Tighten the three set screws down by hand until they touch the
top surface of the volute.
3. The impeller clearance is created by turning the set screws to a
specific angle. Closed S-tube
well as the different head classes, have different impeller
clearances. See the table in the chapter above to determine the
correct impeller clearance and turning angle.
4. Once the correct angle is identified, turn the set screw clockwise
by the specified angle. Use a turning gauge to ensure the set
screw is tightened to the correct amount.
5. Tighten the fastening screws in two steps, according to the
sequence below:
• Tighten the screws one by one, from 1 to 6. Required torque:
40 ± 4 Nm (29.5 ± 3 lb-ft).
• Repeat the previous sequence to the final torque of 70 ± 4
Nm (51.6 ± 3 lb-ft).
2
2
1
2
®
®
and open S-tube
impellers, as
6
3
5
2
Tightening sequence
1
4
19
Advertisement
Table of Contents
