Analysis of Quality Status of Steel Plates as Used for Making Pipes for Oil-and-gas Pipeline Service

Statistical analysis is conducted for the quality status of steel tubes and pipes having been used for domestic large-scale long-distance oil-and-gas pipeline projects in recent years，mainly involving quality problems related to steel plates and coils，failure cause distribution of nonconforming tubes and pipes，and failure accident of the pipeline. It is pointed out that defective quality of the steel plate is mainly responsible for the pipeline failure accident. Compared with the imported X80 SAWL pipe，the home-made X80 SAWL pipe's standard deviation of tested yield strength is higher than that of the former by 50%，which shows that there is still a certain gap between the latter and relevant international advanced level. It is hoped to provide support to pipeline construction companies via such statistics and analysis of quality of steel pipes as used for pipeline service.