Which statement about rotary pumps is incorrect?

Rotary pumps are designed to move fluids by trapping a fixed amount of liquid and forcing it through the discharge. One key feature of many rotary pumps, especially those that are positive displacement types, is their ability to self-prime to some extent. This means they can effectively draw fluid into the pump without the need for external priming, as long as they are completely filled with the fluid before the first use.

Since rotary pumps can often handle variations in fluid density and viscosity effectively, they can operate on a variety of fluids. Their ability to provide a smooth and consistent flow makes them ideal for numerous applications, including those found in HVAC systems, where maintaining a steady flow is crucial for efficient operation. Regular maintenance is indeed necessary for rotary pumps to ensure optimal performance and longevity due to moving parts and potential wear over time. Therefore, the requirement for priming before startup is typically not applicable for many rotary pumps, making this statement incorrect.