Why is it important for Engine 3 to maintain a pressure of 390 psi during fire pump failure?

Maintaining a pressure of 390 psi during fire pump failure is crucial to ensure that there is sufficient water pressure to effectively reach the fire scene. In firefighting operations, water supply is vital for successful fire suppression; any dip in water pressure can severely compromise the effectiveness and efficiency of the response.

When a fire pump fails, it is imperative that the crew can still deliver the necessary amount of water at a high enough pressure to combat the fire. This is where the 390 psi comes into play; it acts as a predetermined threshold to ensure that, even in the event of a pump failure, the system can still provide adequate pressure for firefighting efforts.

This focus on maintaining high pressure directly impacts the ability to deliver water through hoses to firefighters and to the fire location, enabling them to effectively extinguish the flames and protect lives and property. Thus, ensuring sufficient water pressure is fundamental to the fire suppression strategy.