What type of pump can move large volumes of water while adding little head?

Axial flow pumps are specifically designed to move large volumes of fluid at relatively low pressure. They achieve this by utilizing a propeller or an impeller, which pushes the water along the axis of the pump. This design allows them to effectively handle high flow rates, making them ideal for applications where substantial quantities of water need to be transferred without requiring significant force to overcome resistance (head).

In contrast, centrifugal pumps are more suited for higher head applications as they utilize centrifugal force to impart velocity to the water, which can then be converted into pressure. While rotary and diaphragm pumps are efficient for particular low-flow or high-pressure situations, they do not excel in moving large volumes at low head. Therefore, the characteristics of the axial flow pump make it the appropriate choice for applications requiring high volume transfer with minimal elevation change.