Tankerman · Operations — Gas Freeing
Gas-freeing a cargo tank that was under inert gas is done by:
- AImmediately blowing fresh air into the inerted tank
- BFirst purging with inert gas to bring hydrocarbons below the critical dilution line, then ventilating with fresh air✓ Correct
- CSealing the tank for 24 hours
- DAdding more cargo
Explanation
To avoid passing through the flammable range, the tank is first purged with inert gas to drive hydrocarbon content low enough that, when air is then introduced, the mixture goes from inert to safe without becoming flammable.
Authority: Tank Vessel Operations — Gas Freeing
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