Piston pumps and rotary pumps are classifications of which type of pump?

Piston pumps and rotary pumps are both classified as positive-displacement pumps. This classification is defined by the way these pumps operate—specifically, they move a set volume of fluid with each cycle or rotation regardless of the pressure in the system.

In piston pumps, the movement of a piston creates pressure to push the fluid into and out of a cylinder, which forces a specific volume of fluid through the discharge port. Rotary pumps achieve a similar effect through mechanical rotation, using various mechanisms to trap and move fluid, effectively displacing it with each rotation.

Understanding this classification is essential for applications like firefighting, where consistent and reliable water flow under various pressure conditions is crucial. Positive-displacement pumps are often favored in such scenarios because they can maintain pressure and flow rates that are more predictable than other types of pumps, particularly when dealing with varying operational conditions. This reliability is key in emergency situations where performance cannot be compromised.

Other types of pumps mentioned, such as centrifugal pumps and rotary pumps, do not encompass the same operational principles as positive-displacement pumps, which is why they do not fit into this classification.