The refueling connector on an automatic dispenser must include which safety feature?

The correct answer is that the refueling connector on an automatic dispenser must include an automatic shut-off mechanism. This safety feature is crucial as it ensures that the flow of compressed natural gas (CNG) is automatically stopped once the tank is full or if any abnormalities occur during the refueling process. This mechanism helps prevent overfilling, reduces the risk of gas leaks, and protects both the vehicle and dispenser from potential accidents or hazards.

In a situation where a manual shut-off valve is used, while it can allow for control over the flow of gas, it does not provide the automatic functionality that enhances safety during the refueling process. A pressure gauge, although informative, does not directly prevent unsafe conditions from arising during filling. Similarly, a fuel flow indicator can provide visibility into the dispensing process but does not actively control the refueling operation or protect against overfilling and related hazards. Therefore, the automatic shut-off mechanism is the essential feature for ensuring safety during CNG refueling.