What characterizes a flat characteristic curve in a pump?

A flat characteristic curve in a pump is characterized by a slight variation in head from shutoff to design capacity. This means that as the flow rate (capacity) increases or decreases, the change in the head produced by the pump remains relatively small. This characteristic can indicate that the pump operates efficiently across a range of flow rates without significant loss of pressure.

This flatness suggests that the pump is stable in performance and can handle varying system demands without drastic changes in head, making it preferable for applications where flow rates might fluctuate. It is particularly useful in systems requiring consistent pressure despite varying demands.

In contrast, the characteristics represented by the other options are associated with different pump behaviors. A large increase in head at shutoff typically suggests a steep curve, indicating that the pump will provide significantly high pressure when flow is not occurring, but this isn't indicative of the flatter curve that would provide better operational stability. A continuous rise in head as capacity decreases describes a different performance profile, often found in pumps designed for specific applications where lower flows are expected, leading to higher heads. An ideal curve for parallel pump operation would generally include pumps that can share load effectively and is not specifically linked to flat characteristics, as they often have more defined curves to allow for optimal integration.