What is the minimum flow rate at which automatic fill pumps must fill the tank?

The minimum flow rate at which automatic fill pumps must fill the tank is determined by ensuring that the system can maintain adequate water levels for optimal performance and reliable operation of the sprinkler systems. A flow rate of 65 gallons per minute (GPM) ensures that the tank can be replenished quickly enough to handle potential demands that could be placed upon it, while also factoring in any potential leaks or usage that may occur within the system.

This flow rate is often based on hydraulic calculations and regulations aimed at maintaining adequate water supply during emergencies, ensuring that the sprinkler system can be effective when needed. A higher flow rate provides a buffer for performance under various conditions, helping to ensure that tanks do not run dry when automatic sprinkler systems activate.

The other options presented are simply lower than this established standard, which could compromise the efficacy of the sprinkler system in responding to a fire emergency. This could result in inadequate water supply and potentially jeopardize safety measures intended to protect life and property.