How can the Hydraulic SOV be closed to interrupt fluid to the EDP?

How can the Hydraulic SOV be closed to interrupt fluid to the EDP?

• A. Press the white hydraulic shutoff switchlight
• B. Press the ENG FIRE switchlight
• C. Press the white hydraulic shutoff switchlight and the ENG FIRE switchlight
• D. Pull the hydraulic circuit breaker

Answer: (C)

To interrupt fluid to the engine-driven hydraulic pump, you need to secure the hydraulic supply from two angles: close the hydraulic path and secure the engine itself. The white hydraulic shutoff switchlight closes the hydraulic shutoff valve, stopping the flow toward the EDP. The ENG FIRE switchlight, when pressed, activates engine-fire protection and closes engine-related valves as part of fire suppression, which includes isolating the hydraulic lines feeding the EDP. Using both actions guarantees there is no hydraulic pressure path to the EDP, even if one valve would otherwise remain open or the engine would still be running. Relying on only one action could leave a route for fluid to reach the EDP, so the combined operation is required.

To interrupt fluid to the engine-driven hydraulic pump, you need to secure the hydraulic supply from two angles: close the hydraulic path and secure the engine itself. The white hydraulic shutoff switchlight closes the hydraulic shutoff valve, stopping the flow toward the EDP. The ENG FIRE switchlight, when pressed, activates engine-fire protection and closes engine-related valves as part of fire suppression, which includes isolating the hydraulic lines feeding the EDP. Using both actions guarantees there is no hydraulic pressure path to the EDP, even if one valve would otherwise remain open or the engine would still be running. Relying on only one action could leave a route for fluid to reach the EDP, so the combined operation is required.