Which of the following statements about rotary pumps is false?

Rotary pumps are indeed capable of handling high-viscosity liquids, which is one of their primary advantages. They create a continuous flow and can efficiently move thicker fluids that would be challenging for other pump types, such as centrifugal pumps. This ability makes them suitable for various applications, including the transfer of oils, syrups, and other viscous materials.

In terms of speed range, rotary pumps typically have a broad operational velocity, allowing them to be applied in diverse situations and meet varying process requirements. Their design permits adjustments in speed, making them versatile in industrial settings.

Moreover, while some rotary pumps may handle self-priming mechanisms, generally, they do require some form of priming, especially when installed in a suction application. This is due to the necessity of creating a fluid column to avoid cavitation which can damage the pump.

Given these characteristics, it's straightforward to recognize that the statement claiming rotary pumps cannot handle high-viscosity liquids is false, affirming their capability in this area and clarifying why it's misleading.