Which type of pump uses a positive displacement mechanism?

A rotary pump is indeed a type of positive displacement pump. This type of pump operates by trapping a fixed amount of fluid and then forcing it into the discharge pipe. This mechanism allows for a consistent flow rate, regardless of the system pressure. Positive displacement pumps, including rotary pumps, are particularly useful for applications requiring high viscosity fluids or specific flow rates.

Furthermore, while diaphragm pumps also operate based on positive displacement principles, they specifically utilize a diaphragm to create the pumping action. However, the option that focuses specifically on the broader category of rotary pumps clearly outlines the mechanism in question for positive displacement.

Centrifugal pumps, on the other hand, operate on a different principle, using rotational kinetic energy to move fluid and do not fit the definition of positive displacement pumps. Therefore, understanding the operational mechanism of rotary pumps clarifies why this choice aligns with the characteristics of positive displacement mechanisms.