When operating centrifugal pumps in series, what happens to the total pressure?

When centrifugal pumps are operated in series, the total pressure generated by the system increases. This occurs because each pump contributes to the overall pressure head acting on the fluid as it passes through them sequentially. Essentially, the outlet of the first pump feeds into the inlet of the second pump, allowing the second pump to impart an additional pressure boost to the fluid.

As the pumps are aligned in such a manner that the discharge pressure of the first pump becomes the suction pressure for the second pump, this cascading effect allows the total pressure experienced by the fluid to be cumulative. Therefore, if each pump adds a specific pressure head, the total pressure is effectively the sum of the individual pressures provided by each pump in the series.

While it is common to think of doubling when two identical pumps are used, the actual increase will depend on the characteristics and efficiency of the pumps, as well as the specific application. Nevertheless, the fundamental concept that operating pumps in series increases total pressure is accurately captured in this choice. This principle is essential for various applications where higher pressures are needed to move fluids through systems such as pipelines or to overcome resistance in elevated systems.