Pressure above 53 PSIG or temperature above 400 F will close both pressure-regulator and shutoff valves, and open the emergency pressurization valve. Which values are these thresholds?

Pressure above 53 PSIG or temperature above 400 F will close both pressure-regulator and shutoff valves, and open the emergency pressurization valve. Which values are these thresholds?

• A. 40 PSIG / 350 F
• B. 53 PSIG / 400 F
• C. 60 PSIG / 450 F
• D. 70 PSIG / 500 F

Answer: (B)

The test is looking for the specific threshold values that trigger the emergency path. When either the pressure exceeds 53 PSIG or the temperature exceeds 400 F, the system shuts off the normal pressure-regulator and shutoff valves and opens the emergency pressurization valve. This threshold pair—53 PSIG and 400 F—is the point at which the emergency path must take over to protect the cabin and equipment. The use of “or” means the emergency path activates if either parameter crosses its limit, not only if both do.

The test is looking for the specific threshold values that trigger the emergency path. When either the pressure exceeds 53 PSIG or the temperature exceeds 400 F, the system shuts off the normal pressure-regulator and shutoff valves and opens the emergency pressurization valve. This threshold pair—53 PSIG and 400 F—is the point at which the emergency path must take over to protect the cabin and equipment. The use of “or” means the emergency path activates if either parameter crosses its limit, not only if both do.