What is the minimum residual pressure that should be maintained during pumping operations, except when pulling a draft?

Maintaining a minimum residual pressure during pumping operations is crucial for ensuring adequate water supply and operational safety. The correct response identifies that a minimum residual pressure of 10 psi should be preserved. This pressure is significant because it helps ensure that there is sufficient pressure in the system to deliver water effectively, while also preventing the potentially damaging collapse of the water delivery system or hoses.

If the pressure drops too low, there may be the risk of inadequate water delivery, especially in critical firefighting operations where every second counts. Additionally, maintaining 10 psi serves as a safeguard against issues like backflow, which can compromise water quality and system integrity. Thus, the emphasis on a minimum residual pressure of 10 psi reflects both operational effectiveness and safety protocols in firefighting operations.