Why use multi-stage centrifugal pumps? State the principal reason for employing multi-stage centrifugal pumps (impellers in series). Choose the best answer.

Concept

• In series arrangement, each impeller contributes head; the total head is the sum of heads developed by all stages, at approximately the same discharge.

Result
Multi-stage pumps are therefore chosen primarily for high head duties (e.g., boiler feed pumps).

Common pitfall
High discharge is typically increased by parallel pumps or larger single-stage impellers, not by series staging.

Final Answer
To produce high heads.