What percentage of its rated capability must a fire pump produce at 250 psi to satisfy Underwriters Laboratory (UL) standards?

To meet Underwriters Laboratories (UL) standards for fire pumps, a fire pump must produce at least 100% of its rated capability at certain pressures, such as 250 psi. This requirement ensures that the pump can deliver the necessary flow and pressure to effectively combat fires under various conditions. In firefighting applications, especially at these specified pressure levels, having the full rated output is critical for maintaining effectiveness and safety during operations.

Considering the context of the other options, aiming for only 25%, 50%, or 75% of the rated capability would not provide sufficient flow and pressure to operate effectively. Insufficient performance can hinder a responding crew’s ability to suppress a fire, making it vital for the pump to consistently perform at 100% capacity when needed.