What is a fundamental characteristic of rotary pumps?

Rotary pumps are designed to move fluid by trapping a fixed amount of it and then forcing that trapped volume into the discharge pipe. A fundamental characteristic of these pumps is that they often do not require valves for their operation. This is primarily because the pumping action is achieved through the rotary mechanism, which can effectively control the flow of fluid without the need for additional components like valves to manage direction or flow rates.

For many rotary pump designs, the continuous motion of the rotating elements creates an inherent pressure difference that allows fluid to move through the pump without the need for valves to open and close. This can also result in fewer potential points of failure, making rotary pumps generally simpler and more reliable compared to positive displacement pumps that do traditionally rely on valve mechanisms for flow control.

The focus on operating without valves showcases the efficiency of rotary designs, allowing them to be particularly useful in applications where consistent flow and low maintenance are desired.