Which of the following components typically requires a 2-inch minimum discharge pipe?

The sewage pump requires a 2-inch minimum discharge pipe because it is designed to move wastewater and solids efficiently from below the grade level to a higher elevation, typically into a sewer line or septic system. The larger diameter pipe allows for the proper flow rates necessary to accommodate the volume and velocity of sewage being pumped, minimizing the risk of clogs and ensuring that the wastewater is removed quickly and effectively.

In comparison, kitchen sinks, washing machines, and bathtubs typically have smaller discharge or drain pipe sizes, often ranging from 1.5 inches to 2 inches depending on the design and local plumbing codes. These appliances don’t deal with the same volume or types of solids that a sewage pump does, thus they do not require the larger pipe size to function properly. The specific requirements for plumbing components are based on their intended use, flow characteristics, and local code regulations, making the sewage pump's 2-inch minimum discharge pipe a distinctive requirement in plumbing systems.