【Major Equipment in the Chemical Engineering Sector】First full-scale tensile testing of X70-grade oil and gas pipelines in China from 376 to 2020

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This post was last edited by Desert Fish on 2022-6-22 at 10:53. Comply with the Work Safety Law! Take on the role of the primary responsible person! ---------------------------------------------- The past decade has seen significant development in China’s chemical industry, with the emergence of many new processes, products, and equipment. China’s chemical processing equipment has also experienced substantial progress, which has contributed to the rapid growth of the petrochemical sector. Here, we have compiled a list of the achievements and breakthroughs made by Chinese equipment manufacturers in terms of larger-scale production and greater use of domestic equipment. Everyone is welcome to share their thoughts and insights; let’s cheer for Made in China and support the development of chemical processing equipment! ------------------------------------------------------ In November 2020, a full-scale tensile test on land natural gas pipelines with pre-existing cracks was conducted in Qingdao Blue Valley. The pipeline used in this test is of X70 steel grade, with an outer diameter of 40 in (1016 mm); its high specifications make the testing process challenging. This represents the first time in China’s oil and gas industry that full-scale tensile testing of such pipelines has been carried out. Qingdao Marine Engineering Underwater Equipment Testing Co., Ltd. successfully completed the tests through processes such as standard research, scheme design, analysis and simulation, and on-site testing, thereby fully verifying the various performance indicators of the welds used for extending oil and gas pipelines. This experiment was successfully completed, significantly enhancing China’s technical capabilities in understanding the full-scale fracture mechanisms and failure modes of high-grade, large-diameter, high-pressure pipelines. It also led to the establishment of a full-scale testing and evaluation system for oil and gas pipelines. With the continuous development of the socio-economy, the demand for oil and gas is increasing day by day. Pipeline transportation is the most economical and reasonable method for transporting oil and gas. Currently, the use of large-diameter, high-strength, high-pressure pipelines for long-distance transport has become the mainstream trend in global natural gas transportation technology, and the safety issues associated with such transportation are receiving increasing attention. Previously, small-scale testing methods were generally used; the size effect was ignored during the testing and analysis process, and welding residual stresses and stress concentrations were released during sample processing, which often led to overly high test results. In practical applications, it is necessary to adjust and correct these results. The full-scale loading method of bending/tensioning plus internal pressure is the most advanced and rational new technical approach for simulating the loading conditions under which oil and gas pipelines operate, thereby obtaining pipeline performance data. However, full-scale testing of pipelines is technically challenging and requires high-performance equipment. For a long time, due to various constraints, China has had to entrust full-scale testing of its oil and gas pipelines to foreign laboratories. This results in high testing costs, long testing periods, and the inability to obtain key data from the tests, which greatly hinders research on high-grade pipeline steel technology in China. Qingdao Marine Engineering Underwater Equipment Testing Co., Ltd. has established full-scale testing capabilities for marine pipelines as well as onshore oil and gas pipelines, covering scenarios ranging from dynamic fatigue to static conditions, and enabling combined loading of external loads and internal pressure. The successful completion of this experiment also filled the technical gap in China regarding full-scale performance testing of oil and gas pipelines, providing a solid foundation for research on such pipelines in our country.