The surface condition of steel pipe is known as the environment that this is through the steel pipe coating with the surrounding soil insulation, pipe surface condition is different from the four weeks the soil. Therefore pipe anti-corrosion layer is an important barrier to prevent soil erosion. A well-known foreign scholar put forward” 3PE France protective layer”, so far, anti-corrosion methods are widely used.

Basic functions of ERW welded steel pipe coating:

1, making the surface of ERW steel pipes free from electrochemical corrosion of the soil medium, the basic physics of bacterial corrosion protection.

2, resisting the move of the soil medium creep stress, static stress, and abrasion force method and structure of the basic machinery protection.

The basic principles of urban gas pipeline coating selection:

a, good insulating and mechanical properties;

b, good resistance to cathodic disbondment performance;

c, good resistance to water, gas permeability;

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

e, resistance to low temperature and high temperature performance;

f, easy mending, and mending;

g, at reasonable prices.