Alfa Laval ALP 100, Operating Instructions Manual

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6 Function description
6.1 Structure
Figure 3: Structure of ALP pump
Figure 4: Structure of ALP pump with magnetic coupling and motor
1 . Overflow valve 5. Balancing cylinder 9. Pump 13. Coupling hub
2. Screw plug 6. Ball bearing 10. Pump bracket 14. Outer rotor
3. Idle screw 7. Main screw 11. Motor 15. Inner rotor
4. End cover 8. Pump housing 12. Pump bracket foot 16. Containment can
Screw pumps are rotating displacement pumps whose displacement effect
results from the meshing of three rotating screws and the enclosing housing.
The radial support of the screws is effected by the sliding contact in the
housing which requires lubrication by the pumped liquid. Screw pumps are
therefore not suitable for dry running and can only be used up to specific
pressure and viscosity limits. Due to the narrow tolerances, pumping of
suspended solids is not possible.
Axial support of the main screw is carried out by a deep-groove ball bearing.
An internal overflow valve protects against excessive pressure that could
cause housing parts to burst.
200007725-1-EN-GB 25
EN