In terms of their operation, hydraulic pumps are classed as?

Hydraulic pumps are classified as positive displacement pumps due to their operational mechanism of moving a fixed volume of fluid with each stroke or rotation of the pump. In a positive displacement pump, fluid is confined in a chamber and displaced from that chamber by a mechanical action. This design allows for consistent flow regardless of the pressure in the system, making it highly effective in hydraulic applications where a specific volume of fluid must be moved.

In contrast, non-positive displacement pumps, such as centrifugal pumps, do not displace a fixed volume of fluid. Instead, they rely on the kinetic energy of a rotating impeller to create flow, which can vary based on system resistance. Turbine pumps, while a type of positive displacement pump, are more specifically categorized based on their design and application. The distinction lies in how they operate, with hydraulic pumps universally regarded as positive displacement due to their ability to maintain flow rates under varying pressure conditions.