On Pipeline Coating Displacement of Oil and Gas Pipelines in China

Most of the oil pipelines and part of gas pipelines in China have been used more than 30 years so far, and the coating mainly consisted of petroleum asphalt is basically aged due to the long-term's service. The inspection to the coating to find and solve the problems on damage, cathodic disbanding and failure and so on in this kind of coating is very important to ensure the safety operation of the pipelines. In this paper, the inspection technologies and their application scopes are introduced, the displacement decision base of pipeline coating is given, the removal of old coating (aged coating), the preparation of pipe steel and the selection of new coating and quality control of coating displacement are described. The authors put forward some problems to urgently solved in coating displacement of oil and gas pipelines in China.