To limit the probability of delays in shutting off the flow of liquid in an emergency situation [a fire involving the liquid], which could lead to the escape of liquid not being minimized, which could lead to the spread of fire, which could lead to damage to the building or facility.
To limit the probability of delays in shutting off the flow of liquid in an emergency situation [a liquid spill incident], which could lead to the spread of liquid, which could lead to the ignition of vapour from a nearby ignition source, which could lead to damage to the building or facility.
To limit the probability that inadequate inspection and maintenance will lead to the unwanted escape of liquid, which could lead to the spread of liquid, which could lead to the ignition of vapour from a nearby ignition source, which could lead to damage to the building or facility.