Each inert gas system gas main must have an automatic shutdown valve at the outlet of the gas production plant. When must this valve close automatically?

The correct response indicates that the automatic shutdown valve at the outlet of the gas production plant must close automatically upon blower failure. This is crucial for safety reasons, as a blower failure could lead to an inability to adequately purify the inert gas. Inert gas systems are essential for maintaining a safe atmosphere in cargo tanks by preventing the risk of fire or explosion, particularly in oil and chemical tankers.

When the blower fails, the gas supply can become inadequate or contaminated, jeopardizing the inerting process. Thus, the valve’s automatic closure serves as a safety mechanism to prevent unregulated release of inert gas into the system, reducing the risk of inadvertent increases in tank pressure or introducing combustible gases.

The other circumstances, such as pressure loss, rising tank pressure, or during routine maintenance, are managed by other safety protocols within the inert gas system, but the immediate and critical response to a blower failure is designed to quickly mitigate potential hazards and maintain operational safety.