On the schematic, you will see valves labeled "Demand Pump" and "Primary Pump." The logic built into the hydraulic architecture dictates that:
If you were to highlight just one system on the schematic, you would see that it powers specific panels scattered across the wing, ensuring that no single hydraulic failure results in asymmetric drag or loss of control. Boeing 747 Hydraulic System Schematic
: Each system has its own reservoir to store fluid, which is pressurized by the pneumatic system to ensure a constant supply to the pumps. Distribution of Services On the schematic, you will see valves labeled