Hidrostal A2Q - Check;readjust impeller clearance; Check impeller clearance “B”

8 | Maintenance
32 / 49 Hidrostal AG
• Qualified electricians
1. Check electric motor, motor cover, cable inlet and cable for visual
damage.
8.4.3 Check/readjust impeller clearance
Personnel:
• Trained personnel
Personal protective equipment:
• Protective clothing
• Safety shoes
Required tool:
• Feeler gauge, thickness gauge
8.4.3.1 Check impeller clearance “B”
1
3
B
5
4
2
Impeller clearance “B” is the gap between impeller (1) and rear cone (2).
The impeller clearance “B” must be kept as small as possible to hinder fibres
or solids from entering the seal space. Due to abrasive media, the clearance
can increase over time.
1. Make sure that the pump is positioned in a vertical position on a surface
and attach lifting gear on the drive unit to prevent it from tipping.
2. Remove the three hexagon socket cheese-head screws (3).
3. Remove the base (4).
4. Pull off the suction cover (5) and the spacer rings.
5. Using a feeler gauge, measure the impeller clearance “B” between
impeller (1) and rear cone (2) at several points on the circumference.
6. Compare the smallest measured value with the value listed in the
following table:
Hydraulic size Permissible impeller
clearance “B”
A2Q, BN2, BE2, BN3,
BK3
0.2…0.5mm