What must be equipped on the fill line of a storage container to prevent gas discharge?

The requirement for a backflow check valve on the fill line of a storage container plays a crucial role in safety and operational efficiency. This type of valve is specifically designed to prevent the reverse flow of gas, ensuring that once the compressed natural gas (CNG) is transferred into the storage container, it cannot flow back out. This is particularly important during filling operations, as it helps maintain system integrity and pressure while also reducing the risk of leaks or accidental gas discharge.

By securing gas within the intended storage area and preventing backflow, the backflow check valve contributes to overall safety by minimizing the potential for hazardous situations that could arise from unintended gas release. The valve operates automatically, providing a critical line of defense against any potential system failures or mishaps.

In contrast, while safety relief valves, excess-flow check valves, and pressure gauges have their specific functions, they do not directly address the need to stop gas from discharging back into the system. Safety relief valves are designed to open at predetermined pressure levels to release excess pressure; excess-flow check valves are typically used to stop the flow in the event of a line rupture, and pressure gauges monitor system pressure but do not prevent backflow. This distinction highlights the essential role of a backflow check valve in