What type of pump is a diaphragm pump classified as?

A diaphragm pump is classified as a positive displacement pump because it operates by trapping a fixed amount of fluid and forcing that fluid into the discharge pipe. This mechanism relies on a flexible diaphragm that moves back and forth, creating a vacuum on the intake stroke that draws fluid into the chamber. During the discharge stroke, the diaphragm pushes the fluid out, maintaining a constant flow rate regardless of the system pressure, which is a key characteristic of positive displacement pumps.

By ensuring a specific volume of fluid is moved per cycle, diaphragm pumps are particularly effective in handling viscous fluids and those containing solids, making them valuable in wastewater treatment applications. This positive displacement action contrasts sharply with centrifugal pumps, which rely on rotational energy to move fluid and do not offer the same level of accuracy in flow rates under varying pressures.