What component is primarily responsible for liquid transfer in a fire pump?

The impeller is the primary component responsible for liquid transfer in a fire pump. It is a rotating part that imparts kinetic energy to the water being pumped. As the impeller spins, it creates a difference in pressure, drawing water into the pump from the source and pushing it out through the discharge pipe. The design of the impeller is critical because its shape and the number of blades determine the pump's efficiency and the volume of water it can move.

The other components mentioned do not serve this function. The compressor is typically involved in compressing gases and has no role in transferring liquids. The fan is designed to move air and is irrelevant when it comes to pumping water. The condenser, on the other hand, is used in cooling systems to change a gas to a liquid and does not participate in the transfer of liquid in fire pump operations. Understanding the unique role of the impeller helps clarify how fire pumps function effectively in firefighting scenarios.