What pressure is necessary for Sniffle Valves to open and dump fuel overboard?

The correct answer pertains to the specific operational mechanics of Sniffle Valves in fuel systems. Sniffle Valves are designed to serve as pressure relief devices that manage the venting of fuel vapors and ensure safe operation of the fuel system under varying conditions.

To open and dump fuel overboard effectively, a pressure of 5 PSI is necessary. This pressure threshold is critical because it ensures that the valves function reliably without opening too early, which could lead to undesired fuel loss or vapor release during standard operation. By requiring a minimum pressure of 5 PSI, the Sniffle Valves help maintain the integrity of the fuel system while also allowing for necessary venting when pressure builds beyond safe operating limits.

The other pressure values (0.1 PSI, 2 PSI, and 10 PSI) either do not meet the required operational threshold or exceed it without any practical advantage in the context of Sniffle Valves. Thus, maintaining a specific pressure of 5 PSI represents a balance between operational safety and functional effectiveness within the system.