正常操作时，确保释压活门关闭。释压活门打开表示燃油通气系统出现问题。

A For normal operations, make sure the pressure relief valve is closed. An open pressure relief valve is a symptom of a problem in the fuel vent system.

B For normal operations, make sure the shut off relief valve works; If you open pressure relief valve, that indicates a problem in the fuel vent system.

C For normal operations, make sure you close the pressure relief valve. If you leave it open a problem will be shown in the fuel vent system.