California ICC UST Inspector Practice Exam

An automatic shut-off device must stop the flow into the tank when?

1. The tank is 90% full

2. The delivery truck is 95% empty

3. The tank is filled to no more than 95% capacity

4. The fuel level is 48 inches from the bottom of the tank

The correct answer is: The tank is filled to no more than 95% capacity

The requirement for an automatic shut-off device to stop the flow into a tank is primarily about preventing overfilling, which can lead to leaks, spills, and environmental hazards. The device is designed to activate before the tank reaches full capacity in order to provide a safe margin and ensure that the tank is not filled to more than 95% of its capacity. When the tank is filled to 95% of its capacity, the automatic shut-off device shuts off the flow of fuel, allowing for the necessary space needed for product expansion and to prevent spillage due to overfilling or temperature increases that can cause the liquid to expand. This requirement is a crucial safety measure and is often mandated by both state and federal regulations governing underground storage tanks. The significance of this standard is reflected in the design and operation protocols for fuel delivery systems to mitigate potential environmental impacts and ensure safety in the operations of underground storage tanks.