Plants for tube-producing electric resistance welded (ERW) tubes have not been playing in the same category, until now. The new RD 710 brings a new dimension of ERW mill to the market. This largest ERW mill can produce tubes up to a maximum diameter of 28”, i.e. 710 mm.
Now why this new dimension of ERW tubes? For the OCTG (oil country tubular goods) market there are tube-making processes for this kind of diameter with a submerged arc welding process (SAW) and the markets for automotive and boiler tubes doesn´t use such sizes
But the construction market does!
Flexible production of Hollow Structural Sections
This ERW mill is capable to produce hollow structural sections (HSS) with dimensions of 22“ square (559 mm x 559 mm) or 34“x10“ (863 mm x 254 mm). These HSS are used as structural elements in buildings and other structures, for example stadiums or skyscrapers.
HSS bring significant benefits versus a comparable open section. The main benefits are:
- High strength-to-weight ratio
- Closed section
- Aesthetic appeal
- Cost-efficient production
The high gyration radius brings a high strength-to-weight ratio resulting in less weight and higher stability. Then, HSS are closed sections, which are advantageous for resisting torsional loads and, since HSS have approximately two-thirds the surface area of an open section of comparable capacity, the efforts in finishing (e.g. coating or painting) is less.
The shapes with smooth sides, rounded corners and closed sections have a natural aesthetic appeal so there is no need for cladding or facing.
On top of that, the production process is more cost-efficient than the alternative rolling processes due to lower Capex investments and lower conversion costs.
High wall thickness achieved with the RD 710
The RD 710 has been designed to allow customers utilizing these benefits and produce high-quality HSS. Not only the size range is pushing the limit, but also the wall thickness. With up to 1” (25.4 mm) wall, the line is capable to produce thick walled ERW tubes. These dimensional capabilities, combined with production speeds up to 35 m/min allow the RD 710 to run a nominal capacity of 400.000 tons per year.
The world’s largest continuous ERW tube welding machine
SMS group has successfully commissioned the RD 710 in 2022 at Zekelman Industries in Blytheville, AR (USA). Zekelman Industries and SMS group have enjoyed a long-term and trusting partnership for many years. The latest order – the world's largest continuous ERW line – is the next step in this successful cooperation. As a result, Zekelman further expands its leading position in the manufacture of structural tubes in North America.