The world’s largest continuous ERW tube welding machine

Zekelman Industries and SMS group write record history at the Blytheville site in USA with the world’s largest continuous 28-inch ERW tube welding line with a wall thickness of up to 25.4 millimeters. The highly automated ERW tube welding line has been ordered in April 2019 and is in operation since mid-2021. With a capacity of more than 400,000 tons per year, the new 28-inch plant within Zekelman Industries will complement its Atlas Tube division. 

Production capacity over 400,000 tons p.a.
Operating speed of up to 35 m/min
Structural and piling tubes from 10 3/4 to 28’’
Hollow sections up to 22x22‘’ and 34x10‘’
Wall thicknesses up to 1”

What makes it so special?

Since the commissioning of the 28-inch ERW tube welding line at Zekelman’s Blytheville site in mid 2021, structural and piling tubes are manufactured with diameters ranging from 10 3/4 inches to 28 inches (273 to 710mm) and wall thicknesses of up to 1 inch (25.4mm). In addition, it is possible to produce square and rectangular hollow sections with dimensions of 8 inches x 8 inches (203.2mm x 203.2mm) up to 22 inches x 22 inches (558.2mm x 558.2mm) or 34 inches x 10 inches( 863.6mm x 254mm). 

For the North American market, this means a more diverse product range for HSS (Hollow Structural Sections) products that find various end uses in infrastructure and building construction. Moreover, with this line, Zekelman Industries is also able to produce products larger than 20 inches domestically for the first time on an ERW tube welding line. 

Increased productivity with PERFECT arc^® welding technology

This 28-inch ERW tube welding line uses the PERFECT arc^® welding technology for the cross joining of strip up 25.4 millimeters thick. The PERFECT arc^® welding system which was developed and patented by SMS group, is a GMA (Gas Metal Arc) tandem welding process: a set of tandem torches applying single-wire gas metal arc welding. Able to cross-weld the 25.4 millimeter thick coil ends in only one welding pass with reliable fusion, it significantly saves cycle time in the cross welding station and thus, increases the productivity of the entire plant. Welding is performed at up to 800A per wire.  

The PERFECT arc^® inverter welding power sources feature digital technology, which can deliver efficiency exceeding 90%. Depending on the operating point, energy savings of up to 30% can be achieved compared to welding power sources still using conventional thyristor technology. 
Simplified and shortened changeover process of equipment

Regarding the wide product and dimension diversity the line is offering, one of the major goals is to simplify and shorten the changeover process of equipment. A simplified process enables an effective production flexibility of product sizes. Therefore, the principle is to change roll assemblies instead of complete stands. All size-dependent equipment in the pipe mill is equipped with change assemblies, where rolls are changed as required for size change.

This development includes special solutions for the different equipment types and for the different changeover processes

Size change

Grade or gauge change

Off-line rebuilding.

Off-line rebuilding is performed using special devices to make roll change faster and to handle the equipment easier.
X-Pact^® Quicksetting for automatic roll adjustment enables production flexibility 

Design and configuration of the new welding line meet the strictest requirements regarding product quality and throughput. X-Pact^® Quicksetting, developed by SMS group, automates roll adjustments in the production process of ERW welded tubes. This smart system provides automatic roll adjustments to their new working position after a size change. Thanks to a data-based approach, changeover and setting times are minimized, boosting productivity and ensuring continuous improvement in product quality. The system meets the current demands for high flexibility in production with smaller batch sizes and wider production mixes.

X-Pact® Quicksetting stands at the forefront of computer-controlled automation, adjusting all critical dimensional settings automatically. Its roll management module allows for planning ideal configurations and necessary rolls for upcoming tube formats, even during production. This intelligent system significantly reduces changeover and setting times, enhancing efficiency and setting new industry standards.

An intuitive web-based interface allows operators to select the desired tube format and transfer these settings to the plant. The automated execution ensures consistency and repeatability, enabling later reproduction of tubes with identical quality. For plants larger than 16 inches, automated horizontal roll changing is implemented using change carriages, significantly shortening changeover times and maximizing production capacity.

For Zekelman Industries, X-Pact^® Quicksetting has been a game-changer. This system supports producing capacities of over 400,000 tons per year at operating speeds of up to 35 m/min. Furthermore, it is the first plant of its size with X-Pact® Quicksetting.

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