Gauge dials on fire pumps should indicate pressure up to at least twice the rated working pressure of the pump, but not less than what psi?

Gauge dials on fire pumps are critical for monitoring the pressure within the system, ensuring it operates effectively and safely. The requirement that the gauge must indicate pressure up to at least twice the rated working pressure of the pump is in place to allow for sufficient safety margins during operation.

The minimum psi threshold of 175 psi is established based on the need to adequately cover a range of scenarios that a fire pump might encounter, including pressure spikes or the need to function under high-demand conditions. If the gauge were set below this level, it might not provide accurate information or sufficient safety assurance at higher pressures that can occur when the pump is activated.

Choosing 175 psi as the minimum ensures that even for pumps with a working pressure that is significantly lower, the gauge can effectively monitor operations without being pushed beyond its design limits. Therefore, the requirement aligns well with safety standards and practices in the industry, ensuring that fire pumps provide reliable performance in emergency situations.