What characteristic is unique to a positive displacement pump?

A positive displacement pump is characterized by its ability to deliver a consistent flow regardless of the pressure in the system. This is a fundamental property of such pumps, meaning that they move a fixed volume of fluid for each cycle of operation. As the pressure increases in the discharge line, the pump continues to deliver the same amount of fluid, which is particularly advantageous in applications where a constant flow rate is critical.

This characteristic is in contrast to other types of pumps, such as centrifugal pumps, where the flow rate can vary significantly with changes in pressure. The design of positive displacement pumps typically allows them to operate effectively against varying resistance in the discharge line, making them ideal for applications where precise control over the flow rate is needed.

In summary, the ability to maintain a steady flow rate irrespective of pressure variations sets positive displacement pumps apart from other types of pumps, reinforcing their importance in many industrial applications.