What issue should be monitored when paralleling two centrifugal pumps?

When paralleling two centrifugal pumps, ensuring that the pump capacities are the same is crucial because it helps maintain a balanced load distribution between the pumps. When pumps have similar capacities, they can share the flow demand effectively without one pump being overloaded while the other is underutilized. This can lead to more efficient operation, reduced wear and tear on the pumps, and a lower risk of cavitation or surge conditions, which can occur if one pump is attempting to pump more fluid than it can handle compared to the other.

In systems where pumps operate in parallel, it’s essential that when one pump starts to operate, it can supplement the flow without causing a significant change in the system’s total head. If one pump has a significantly different capacity from the other, it can lead to operational issues, including instability in the system and potential damage to the pumps. Hence, uniform capacities of the pumps promote better reliability and efficiency in the overall system.