Which type of pump operates by compressing fluid and displacing it?

The type of pump that operates by compressing fluid and displacing it is the piston pump. Piston pumps utilize a reciprocating action where a piston moves within a cylinder, creating a space that fills with fluid on the suction stroke and then compresses and displaces that fluid on the discharge stroke. This mechanism is effective for delivering precise volumes of fluid under high pressure, which is crucial in many applications, including those found in aquatic pest management.

In contrast, diaphragm pumps also use a similar principle of creating a seal and a displacement chamber but rely on a flexible diaphragm instead of a piston. Centrifugal pumps operate by using a rotating impeller to impart velocity to the fluid, which does not involve the compression of fluid in the same manner as a piston. Gear pumps work by trapping fluid between gears and moving it through the system, which is not a compression-based mechanism. Understanding the specific operational principles of each pump type clarifies why the piston pump is distinctly characterized by its compression and displacement of fluid.