4.3.1.9.(1)

Intent 1:

To limit the probability of the escape of liquid from the tank, which could lead to the ignition of vapour from a nearby ignition source, which could lead to a fire or explosion, which could lead to harm to persons.

Intent 2:

To limit the probability of the release and subsequent ignition of vapour from the tank, which could lead to a fire or explosion, which could lead to harm to persons.

Intent 3:

To limit the probability of the buildup of excessive pressure inside the tank, which could lead to the failure of the tank, which could lead to the escape of liquid, which could lead to the ignition of vapour from a nearby ignition source, which could lead to a fire or explosion, which could lead to harm to persons.