What type of pump is classified as non-positive displacement?

A centrifugal pump is classified as a non-positive displacement pump because it moves fluid by converting rotational energy into hydraulic energy. This is achieved through the use of an impeller that spins within a casing, imparting velocity to the fluid, and then directing it out through a discharge pipe due to the centrifugal force generated. Unlike positive displacement pumps, which move a fixed volume of fluid with each cycle, centrifugal pumps are characterized by their ability to handle varying flow rates and pressures depending on the system's resistance. This dynamic operation allows centrifugal pumps to be used in applications requiring constant flow, such as in water supply and drainage systems, where the fluid is continuously drawn in and pushed out without any set volume per cycle.