China's domestically developed 2.8-meter longitudinal welded pipe machine Photo: Courtesy of Taiyuan Heavy Machinery Group Co.

China's domestically developed 2.8-meter longitudinal welded pipe machine has been successfully commissioned at a customer's site, setting a new domestic record for the maximum specifications of such equipment and strengthening the competitiveness of Chinese-made machinery in the sector, the Science and Technology Daily reported on Thursday.

The equipment was independently developed by Taiyuan Heavy Machinery Group Co. and is expected to help ensure a reliable supply of machinery at controlled cost, while reducing reliance on foreign suppliers for critical equipment, according to the report.

Longitudinal welded steel pipes serve as vital arteries for transporting energy and other materials and are widely used in major infrastructure projects. During the 15th Five-Year Plan period (2026-30), China will accelerate the development of six major networks, including interconnected underground pipeline networks, driving continued demand for large-diameter longitudinal welded pipes.

A company official said that as a core component of the production line, the specifications of a longitudinal welded pipe machine and the quality of its welding directly affect the maximum diameter, pressure resistance and overall quality of the finished pipes.

The official told the Global Times on Thursday that many production lines for oil and gas transmission pipes using longitudinal submerged arc welding typically manufacture pipes with diameters of around 1.4 to 1.8 meters. The newly commissioned 2.8-meter machine could expand manufacturing capabilities for larger-diameter pipes, creating more possibilities for applications in major water diversion projects, oil and gas transmission networks, energy infrastructure, hydropower facilities and bridge construction.

The machine is the largest of its kind developed domestically and can manufacture longitudinal welded pipes with diameters ranging from 0.6 to 2.8 meters. It is expected to produce pipes that transport fluids more efficiently and enhance its competitiveness in the global market for ultra-large-diameter welded pipes.

According to the report, the company revamped the traditional annular-frame design during the development of the machine and optimized the frame structure, simplifying manufacturing and on-site installation while significantly shortening the production cycle and improving delivery efficiency.

The machine is also equipped with an intelligent automatic weld-seam alignment system that enables precise positioning throughout the welding process, reducing errors caused by manual operations and helping ensure consistent pipe quality.

Against the backdrop of China's carbon goals, high-end equipment must not only deliver quality products but also reduce energy consumption, a company official said. Equipped with high-efficiency energy-saving motors, the machine can cut electricity consumption by up to 25 percent compared with traditional models, the report said.

Metallurgical equipment is one of the company's signature businesses, the official said, adding that the company's continued advances in straightening equipment, independently developed equipment for complete sets of seamless steel pipe production lines and now ultra-large-diameter longitudinal welded pipe machinery demonstrate its efforts to turn breakthroughs in key technologies into greater industrial self-reliance.