What is the primary reason that the maximum flow for a handline is 350 gpm (1,400 L/min)?

The maximum flow for a handline being set at 350 gallons per minute is primarily a safety measure related to nozzle reaction. As water is expelled from the nozzle, it generates a reaction force that can push backward against the firefighter operating the line. If the flow rate exceeds this limit, the nozzle reaction can become excessively high, making it challenging for firefighters to control the hose effectively. This can lead to dangerous situations where fire personnel may lose control of the handline, potentially leading to injury or inefficiency in firefighting efforts.

Establishing a maximum flow ensures that operating crews can manage the nozzle safely while still delivering an adequate volume of water for effective fire suppression. This balance between flow rate and manageable nozzle reaction is crucial for maintaining operational safety and effectiveness in emergency situations. The other options, while they may touch on related issues, do not directly address the core concern of nozzle reaction and the associated risks of uncontrolled high flows.