What is the unique characteristic of positive-displacement pumps compared to other types of pumps?

Positive-displacement pumps are defined by their method of operation, which involves moving fluid by trapping a fixed amount of it and forcing that volume into the discharge pipe. This characteristic of delivering a fixed volume per stroke is what differentiates them from other pump types, such as centrifugal pumps, which rely on the kinetic energy generated by a rotating impeller.

In a positive-displacement pump, the volume of fluid that is moved with each stroke is constant, regardless of the pressure in the system, which allows for very precise control over flow rates. This is particularly advantageous in applications where maintaining a specific flow is critical, such as in dosing processes or in certain industrial applications.

While factors like output pressure adjustment, efficiency rates, and maintenance requirements can vary across pump types, the unique mechanism of fixed volume delivery per action is a defining feature of positive-displacement pumps, ensuring they produce a consistent flow regardless of the circumstances.