To realize the transmission of natural gas at high throughout, the demand for large-diameter, high-pressure, and high-grade steel pipelines is growing. Through analysis, the X80 gas pipeline with diameter of 1 422 mm/12 MPa is recommended for the transmission capacity of 300×108 m3/yr to 500×108 m3/yr. More than 30 enterprises, including steel plants, pipe plants, valve plants and construction companies, were investigated to demonstrate the feasibility of 1 422 mm/12 MPa/X80 pipeline in respect to rolled co...