California ICC UST Inspector Practice Exam

When must an automatic shut-off device stop the flow into the tank?

1. When the tank is 90% full.

2. When the delivery truck is nearly empty.

3. When the tank is filled to no more than 95% of its capacity.

4. When the fuel level is 48 inches from the bottom.

The correct answer is: When the tank is filled to no more than 95% of its capacity.

The requirement for an automatic shut-off device to stop the flow into a tank is based on the principles of safety and spill prevention. The correct response indicates that the shut-off device must activate when the tank is filled to no more than 95% of its capacity. This threshold is established to ensure there is adequate space for fuel expansion and to prevent overfilling, which could lead to spills. When a tank reaches this critical fill level, the automatic shut-off device is designed to engage, effectively halting the delivery process before the tank is completely full. This proactive measure helps to protect the surrounding environment and adhere to regulatory requirements by avoiding potential environmental hazards associated with overfills and spills. In contrast, filling the tank to only 90% or allowing operation when the delivery truck is nearly empty does not provide the necessary safety buffer and could lead to overfilling events. The option pertaining to a fuel level of 48 inches from the bottom may not take into account the varying sizes of tanks, making it an inadequate standard for automatic shut-off activation.