What is the minimum acceptable residual pressure at the intake gauge in relay pumping operations?

In relay pumping operations, maintaining a minimum acceptable residual pressure at the intake gauge is crucial for ensuring effective water supply and operational safety. The correct answer indicates that the minimum acceptable residual pressure is 20 psi. This value is significant because it ensures that there is enough pressure in the system to supply adequate flow to the fire scene, prevent cavitation in the pump, and maintain efficient operation throughout the relay.

If the intake pressure drops below this threshold, it could lead to pump failure or a reduction in flow, compromising firefighting efforts. Understanding the importance of this pressure helps operators manage relay operations effectively by making sure that the system is functioning correctly and that all equipment is receiving sufficient water supply while avoiding harm to the pump and apparatus.