To limit the probability that vibrations due to inadequate support will lead to the breakage or failure of the fill pipe, which could lead to the 150 mm maximum clearance of the fill pipe from the bottom of the tank being exceeded, which could lead to free-fall or splashing of the liquid as it enters the tank, which could lead to the buildup of static charges, which could lead to the ignition of vapour, which could lead to harm to persons.