World’s Largest Retained Mandrel Seamless Pipe Plant to Feature Danieli FQM® Technology

Chinese seamless pipe manufacturer Hengyang Valin Steel Pipe has selected Danieli’s advanced FQM® (Fine Quality Mill) technology for its new hot-rolling production line in Hengyang, Hunan province. With an annual production capacity of 800,000 tons, the facility will be the world’s largest retained mandrel seamless pipe plant.

This investment will enable Hengyang Valin to manufacture seamless pipes with diameters ranging from 323.8 to 610 mm and wall thicknesses between 7.2 and 65 mm. These high-quality pipes will serve the energy and infrastructure sectors in both domestic and international markets.

The state-of-the-art production line will feature a cone-type piercing mill, along with an FQM-based retained mandrel mill, seamlessly integrated with Danieli’s newly patent-pending extracting and sizing mills. These mills, designed with a 3-roll configuration and a single-drive system, will incorporate fixed and adjustable stands with an alternating bilateral changeover mechanism, offering enhanced technological and operational benefits.

Scheduled for commissioning in the summer of 2026, the new production line will be fully managed by Danieli Automation’s advanced process control and system solutions, ensuring optimal efficiency and precision.