At what pressure should the relay pumper start pumping on a bumper to bumper relay?

The correct pressure for a relay pumper to start pumping in a bumper-to-bumper relay is set at 175 psi. This pressure is established to ensure that the water supply can maintain adequate flow and pressure to effectively deliver water to the firefighting operations at the scene.

By initiating at 175 psi, the relay pumper can provide sufficient pressure to overcome any potential friction loss in the hose lines and still maintain an effective flow rate for firefighting efforts. This pressure is a balance that allows firefighters to receive the necessary water while minimizing the risk of pressure drops that could occur if the pressure were set too low.

Understanding the rationale behind this pressure setting helps ensure effective and reliable water supply management during critical firefighting scenarios. It also emphasizes the importance of coordination between the supply and attack pumper to achieve optimal operational efficiency.