Abstract:
The paper describes in detail the four factors resulting in the corrosion of buried steel pipeline.that is environment, corrosion control effectiveness, material of pipe steel, and stress of pipeline, presents a total statistics on petroleum asphalt, coal-tar enemal, extruded polyethylene coating, PE tape, FBE, and multiple coating system and the individual percentage of theirs per years during 1990-1995, and points out that the selection of all kinds of coatings, being different behaviors, should be defermined according to the geological conditions and corrosive environments along pipeline route. Meanwhile, to solve the problems on coating design, the comprehensive evaluation method, like factor weighted mean method, should be established. The surface preparation and field coating for welded joint should be put stress on and the wall thickness requirements should be considered where the high-strength thin-wall pipe is used.