Transferring Class I flammable liquids involves strict safety conditions to prevent fire or explosion risks. According to NFPA 30, Flammable and Combustible Liquids Code:

Inert gas (I): Pressurizing the tank with inert gas (e.g., nitrogen) is required to prevent the creation of a flammable atmosphere. Air (II) is not acceptable because it introduces oxygen, which can result in combustion.

Pressure relief device (III): A pressure relief device is mandatory to prevent over-pressurization, which could cause a tank failure or explosion.

Interlock (IV): While useful for operational safety, it is not specifically required for pressurizing tanks.

NFPA 30, Chapter 18: Requirements for transferring flammable liquids under pressure.