Anti-corrosion of steel pipe - 3PE

Literature states: "steel surface condition is called environment, that can achieve insulation with the soil around the pipe through the coating, and the tube surface condition is different from the surrounding soil and therefore anti-corrosion layer of the steel pipe is an important barrier to prevent soil erosion. " This is the basic starting point for evaluating outer coating performance. Joe Leighton British company discussion on the development pipeline coating systems comes from two different perspectives: the European view is to make it able to withstand moisture, prevent corrosion, which is "barrier" point of view. From this point of view to produce a "PE" protective layer. And the point of view of North America is to make it to be with oxidation resistance, chemical resistance and resistance to negative stripping to prevent corrosion performance, this is the "glue" point of view. From this point of view, a "FBE" law protective layer was born.

Another current trend abroad is that these two points of view, "barrier" and "bonding" combined, developed into a new point of view, namely the combination of European "PE" protective barrier layer and North America Act "FBE" protection layer method, developing into an integrated model of "3PE" protective layer. This new idea, new technique, new method in China has begun to be widely applied.

(1) The basic functions of the outer coating of ERW steel pipe

There are two aspects:

First, to protect the ERW steel pipe surface from electronic chemical corrosion, bacterial corrosion of soil medium as a basic physical protection;

Second, basic mechanical protection methods and structure against the soil medium creep moving stress,static stress and abrasion strength.

(2) basic principles of the city gas pipeline outside coating selection 

a, good insulation properties and mechanical properties;

b, good resistance to cathodic stripping performance;

c, good resistance to water, gas permeability;

d, good chemical medium soaked performance resistance and anti-aging properties ;

e, low temperature resistance and high temperature performance;

f, easy to filling and Mending;

g, reasonable prices.