What component of a pump connects the motor to the impeller?

The coupling flange is the correct answer because it is the specific component that serves to connect the motor and the impeller within a pump system. This connection is crucial as it transmits the rotational motion from the motor directly to the impeller, enabling the conversion of mechanical energy into hydraulic energy, thereby facilitating the movement of the fluid.

The coupling flange ensures that the motor remains securely attached to the impeller, allowing for efficient operation of the pump. In a pump assembly, the motor generates the necessary power, and without a proper connection—such as the one provided by the coupling flange—the pump would not function effectively.

The stuffing box, on the other hand, is involved in preventing leakage around the shaft that connects to the impeller but does not directly connect the motor and impeller. The casing is the outer shell of the pump that houses its internal components and directs the flow of water but does not facilitate the connection between the motor and impeller. The impeller itself is a rotating component that actually moves the fluid and is connected to the shaft of the motor via the coupling flange, rather than serving as a connector itself.