

Cathodic
Protection is the controlled prevention of corrosion to
underground Pipes, such as water, sanitary, gas or steam
lines, storage tanks to hold propane, gasoline, or underground
metal structures.
Corrosion
is an electrochemical process which causes metals to deteriorate
in the presence of moisture. Electric current flows in
two ways. Primarily, it flows within a metal when the
electrons of the metal move in response to an electrical
pressure or voltage. Metal atoms exchange their electrons
readily and these move freely without affecting the atoms
themselves. This type of flow does not damage the metal
structure. This is how electricity works.
The other
type of current flow which causes the corrosion process
is where electric current leaves its metal path and flows
into a liquid. Instead of electron movement you have ion
movement. Corrosion occurs as these ions break free from
the metal surface.
To get
some idea of how widespread this problem of corrosion
is, it is estimated that 100 billion dollars is spent
each year in the United States for Corrosion Control.