Development and Property Analysis of Hi-performance Gas Transmission Linepipes under High Pressure and Axial Strain（Part Ⅲ）

Natural gas consumption has been remarkably increased over the last 50 years,and is expected to keep going up for the purpose to reduce CO₂ emission from primary energies. Along with the increase of natural gas supply,economic and safe transmission thereof needs to be ensured. Accordingly,high strength and large diameter welded pipes have been developed,and applied successfully,in various places throughout the world,including the arctic region,the seismic areas and the deep sea areas. Further increase of gas demand is expected,and additional requirements are put forward to long distance pipelines. Therefore,high performance pipes under high pressure and axial strain are studied for more stringent environment. The properties of the high quality pipes as developed for high-pressure gas pipelines are summarized. And finally,the possibility of further improvement of steel pipes for axial strain is discussed.