What defines an overhung pump?

• A. A pump whose impeller is supported by a cantilever shaft from its bearing assembly
• B. A pump with multiple impellers mounted in a row
• C. A pump that uses a submersible mechanism
• D. A pump designed solely for vertical installations

Answer: (A)

An overhung pump is characterized by its design in which the impeller is mounted on a shaft that extends out beyond the bearings supporting it. This design allows the impeller to be "overhung" or cantilevered from the bearing assembly, creating a more compact design that can be beneficial in certain applications. The cantilevered nature of the shaft means that the impeller is not directly supported by a casing, which can lead to simpler maintenance and fewer alignment issues.

This configuration is particularly advantageous for pumping applications involving low to moderate flow rates and pressures, making it a popular choice in many industrial settings. The other options describe different types of pumps or configurations that don't align with the characteristics of an overhung pump. For instance, a pump with multiple impellers would refer to a multi-stage pump, while submersible mechanisms and vertical installations pertain to entirely different pump designs and functionalities.