Which part of the rotary vane pump moves as it operates?

The rotary vane pump operates using vanes that slide in and out of slots in the rotor. As the rotor turns, the centrifugal force causes the vanes to extend outwards against the pump casing, creating a sealed chamber that captures and transports fluid. This movement of the vanes is critical as it helps in drawing the fluid into the pump and then pushing it out, propelling it through the system.

The correct choice emphasizes the vanes' role in the operation of the pump. Unlike an impeller, which is used in centrifugal pumps and relies on rotation to create flow, the operation of a rotary vane pump is directly dependent on the sliding motion of the vanes. Additionally, while pistons and gears have their applications in different types of pumps and mechanical systems, they do not apply to the rotary vane pump's mechanism, reinforcing why the vanes are the central moving component in this context.