On fire pump gauges, the dial must indicate pressure to at least twice the rated working pressure but not less than how many psi?

The requirement for fire pump gauges to indicate pressure to at least double the rated working pressure, but not less than a specific psi level, is rooted in safety and functionality standards for firefighting equipment. The correct answer of 200 psi is established by ensuring that fire pump systems can reliably display pressures under various operating conditions.

Providing a minimum indication pressure of 200 psi ensures that gauges are capable of accurately reflecting the operational status of the system, maintaining enough margin for safety and performance. This consideration is critical in high-demand scenarios where understanding the system's pressure is imperative for effective firefighting efforts.

In contrast, choices that specify lower psi levels, such as 150 psi, 175 psi, and even 250 psi, do not fulfill these safety and operational requirements as effectively as 200 psi. While a gauge can be calibrated to display pressures beyond the minimum threshold, calibrating it above 200 psi could contribute to overly conservative readings, potentially leading to confusion or misinterpretation of the system's condition during critical moments.