During a relay operation, when should the upstream pump operator adjust to maintain nozzle pressure?

During a relay operation, when should the upstream pump operator adjust to maintain nozzle pressure?

• A. Only when the nozzle team signals via hand gestures.
• B. Adjust based on engine tach and not nozzle.
• C. Make dynamic adjustments based on upstream gauge readings alone.
• D. Adjust whenever nozzle pressure deviates from the target discharge pressure as observed on the nozzle and upstream gauges.

Answer: (D)

Keeping nozzle pressure steady in a relay means continuously watching real-time pressure and adjusting as needed to stay at the target discharge pressure. The upstream operator should adjust whenever the nozzle discharge pressure deviates from the target, using readings from both the nozzle gauge and the upstream gauge to guide the change. This approach accounts for friction losses, elevation changes, and shifts in flow, ensuring the nozzle team always has the required pressure. Relying only on engine RPM or on a single gauge isn’t sufficient. RPM doesn’t directly reflect the pressure at the nozzle, and using only the upstream gauge can miss pressure drops that occur between the upstream point and the nozzle. Signals from the nozzle team can be delayed or misinterpreted, so the best practice is to continuously compare observed nozzle pressure to the target and make proportional adjustments whenever a deviation is detected, guided by both gauges.

Keeping nozzle pressure steady in a relay means continuously watching real-time pressure and adjusting as needed to stay at the target discharge pressure. The upstream operator should adjust whenever the nozzle discharge pressure deviates from the target, using readings from both the nozzle gauge and the upstream gauge to guide the change. This approach accounts for friction losses, elevation changes, and shifts in flow, ensuring the nozzle team always has the required pressure.

Relying only on engine RPM or on a single gauge isn’t sufficient. RPM doesn’t directly reflect the pressure at the nozzle, and using only the upstream gauge can miss pressure drops that occur between the upstream point and the nozzle. Signals from the nozzle team can be delayed or misinterpreted, so the best practice is to continuously compare observed nozzle pressure to the target and make proportional adjustments whenever a deviation is detected, guided by both gauges.