Why are vane pumps unsuitable for liquids containing solid particles?

Vane pumps are generally considered unsuitable for liquids containing solid particles because they rely on a precise, sliding seal between the rectangular vanes and the fixed casing to function effectively.1

In a vane pump, centrifugal force throws the vanes outward to maintain contact with the casing wall, creating the necessary seal to move fluid from the suction side to the discharge side. The presence of solid particles can interfere with this mechanism by causing abrasive wear, obstructing the movement of the vanes within their slots, or preventing the vanes from maintaining a proper seal against the casing. This leads to a loss of pumping efficiency and potential mechanical damage to the pump's internal components.1

If your application requires handling fluids with solid particles, other types of positive displacement pumps, such as diaphragm pumps or screw pumps, are typically better suited for the task.1