Figure 6-4.—U-tube analogy of the MOGAS system.
and no air pockets can form to hold explosive
mixtures of gasoline vapor and air. The constant
pressure applied by seawater is maintained by the
elevated loop design in the seawater system.
STORAGE TANKS
The saddle-type storage tanks (fig. 6-5) of the
MOGAS system are designed to provide the greatest
possible safety for the storage of gasoline.
A storage tank actually consists of two tanks—an
outer tank and a drawoff tank—and a cofferdam. The
outer tank encloses the drawoff tank, and a cofferdam
surrounds the outer tank. The cofferdam is part of
the protective system and is filled with nitrogen (N2)
or carbon dioxide (CO2) for protection against fire
and explosion.
Figure 6-5.—MOGAS saddle-type storage tank.
6-6
