When two centrifugal pumps are connected in series the discharge changes by factor of?

Centrifugal pumps in series are used to overcome larger system head loss than one pump can handle alone.

• for two identical pumps in series the head will be twice the head of a single pump at the same flow rate - as indicated in point 2.

With a constant flowrate the combined head moves from 1 to 2.

Note! In practice the combined head and flow rate moves along the system curve to point 3.

• point 3 is where the system operates with both pumps running
• point 1 is where the system operates with one pump running

Series operation of single stage pumps is seldom encountered - more often multistage centrifugal pumps are used.

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