What must the pull-away device do in the event of a separation?

The pull-away device is an essential safety mechanism designed to address situations where a separation occurs between components during the transfer of Compressed Natural Gas (CNG). In the event of such a separation, the primary function of the pull-away device is to stop the flow of CNG instantly. This rapid response is crucial for preventing potential hazards, including leaks or explosions that might arise from uncontrolled gas release.

By immediately halting the flow, the device mitigates risks associated with the release of gas into the environment, ensuring that any residual pressures are managed safely. This functionality not only protects personnel and equipment at the site but also helps maintain compliance with safety regulations governing the handling and transfer of CNG.

In contrast, while some other options, such as releasing gas slowly or activating an alarm, may play significant roles in broader safety protocols, they do not directly address the urgent need to stop the flow of CNG following a separation. Closing the main valve is important for isolating the system but may not be as immediate as halting the flow through the specific actions mandated by the pull-away device under critical conditions.