What is Dielectric Strength and Industrial Isolation?
- Dielectric Strength and Industrial Isolation
Recall that corrosion is an electrical release of energy in the form of
and d.c. current from a metal surface when it is in contact with soil. If an
insulating barrier can be applied to block the flow of electrons along a
surface, then the corrosion process can be stopped. It acts as a resistor to
reduce the flow of electric current from a metal surface to the earth. This
property of a material being a barrier to the flow of electrons along a
surface or electric current from the surface into the earth is called its
All metals have a unique voltage stored within them that is related to the
amount of energy used to create them. When two different metals such as
and steel are connected together in the earth, the voltage difference
them will cause an electric current to flow through the earth from the metal
with the higher voltage to the metal with a lower voltage. At the same time
electrons flow on the metal from the steel to the copper. This is called a
"bimetallic or dissimilar metal corrosion cell."
In order to prevent copper piping from corroding steel pipe or tanks,
unions are inserted between them to separate and to electrically isolate the
copper pipe from the steel pipe or tank. Dielectric unions are the perfect
solution for breaking the connection between the two metals. Underground
propane tanks and steel piping must be electrically isolated from the buried
copper water piping to the water heater and the copper electric grounds at
and businesses. Unions are easily installed at the connection between a
pipe and a steel pipe and near a regulator or gas meter.