Where is the issue venturi tube located on the Type 3 system?

The issue venturi tube in a Type 3 system is located downstream of the emergency shutoff valve. This positioning is essential because the venturi tube functions by creating a low-pressure area that allows for the proper mixing of fuel and air, as well as enabling the correct operation of the system's fuel delivery.

By placing the venturi tube downstream of the emergency shutoff valve, it ensures that in the event the valve is closed to stop the flow of fuel, the venturi tube will not operate. This is important for safety and control, as it prevents any fuel from being mixed or delivered when the emergency system is activated.

Locating the venturi tube downstream also ensures that it operates within a stabilized pressure range, leading to more consistent performance in terms of fuel atomization and combustion efficiency. Therefore, this arrangement is critical for maintaining the proper operation and safety of the fuel system as a whole.