What is the purpose of the fresh air inlet on a tank?

• A. Gas freeing
• B. Cooling
• C. Pressure control
• D. Venting

Answer: (A)

When a cargo tank needs to be made safe for entry or for further operations, the atmosphere inside must be diluted and vapors removed. The fresh air inlet provides a supply of outside air to the tank so that sweeping air can flow through from top to bottom and carry hydrocarbon vapors toward the deck vent system. This dilution and removal of vapors is what makes the environment gas free, allowing safe work inside the tank. It’s not primarily for cooling or simply for venting, though it works in tandem with the venting system to control the atmosphere. The fresh air inlet isn’t used to pressurize or vent the tank by itself; its role is to bring in fresh air to enable effective gas freeing.