There is a vast difference between the likelihood of a given tank actually being hit
by lightning and the likelihood that the tank will sustain damage if it is hit [8].
Therefore, all those measures relating to the minimization of potential differences
between different parts of a tank and between the parts of the tank and the surrounding
elements should be taken as mandatory actions, irrespective of whether a decision is
made to install air terminals or not for the interception of lightning currents to protect
the tank from a strike.
Lightning-related damage can be caused by one or more of the following actions in
the oil industry [8]:
† heat and possibly vaporization of materials from the extreme current flow;
† side-flashing or arcing to adjacent structures as a result of the high voltages;
† damage to equipment from induced current/voltage/frequency fluctuations;
† ignition of flammable/explosive vapours by the strike or side-flashing;
† ignition of flammable/explosive vapours by corona discharges;
† possible hydrolysis and subsequent ignition of water in storage vessels.