How does Engine 3's DP change when both discharges are utilized?

When both discharges of Engine 3 are utilized, the discharge pressure (DP) typically experiences a slight increase. This outcome can be attributed to the increased demand for water flow through the engine as both discharges are activated. The engine has to work harder to maintain the required pressure when supplying water to two outlets simultaneously, leading to a marginal rise in discharge pressure.

Furthermore, this situation also reflects the relationship between flow, pressure, and the engine's pump performance. When a hydraulic load or demand increases—such as opening additional discharges—there is often a corresponding need for the pump to adjust its operation to maintain system pressures. As a result, while there may be a rise in DP due to the increased flow demands, this increment is usually moderate rather than dramatic or overly significant, characterizing it as a slight increase in this context.