TPT January 2010

T echnology U pdate

Stainless steel tube-welding line gets CTA technology revamp

speed steel saw blades with a diameter of only 600mm to be used for all tubes produced on the line up to the maximum tube diameter. Following the start-up of the stainless steel tube-welding line, the average line production speed could be increased three times and the set-up times for tool changes could be reduced to less than three hours. Overall line flexibility could be increased to produce a wider product range and set-up times for dimensional changes were reduced, as it was no longer necessary to replace the saw blade with one with a larger diameter. VAI Seuthe GmbH (Siemens VAI) – Germany Email: info@siemens-seuthe.com Website: www.siemens-seuthe.com ArcelorMittal Stainless Tubes Europe – France Email: stainless.tubes-europe@arcelormittal.com Website: www.arcelormittal.com/stainlesstubeseurope

VAI SEUTHE GmbH has carried out the upgrading of a stainless steel tube-welding line with CTA ® technology, for the French tube producer ArcelorMittal Stainless Tubes Europe SA. CTA (central tool adjustment) allows the flexible manufacturing of a wide range of tube and pipe diameters with the same automatically controlled tooling set. This solution, combined with the installation of a laser welder and a unique flying-saw unit, resulted in a number of decisive operational and cost benefits for the producer. ArcelorMittal Stainless Tubes Europe, a customer of VAI Seuthe, had been operating a stainless steel tube-welding line for many years. It was outfitted with a 6" TIG welding aggregate, aconventional formingsectionand a flying band saw. With the given equipment, a maximum line speed of only about 5m/ min was possible, depending on the wall thickness of the end product. Set-up times for tool changes typically required between 12 and 24 hours. It was mainly because of these uneconomic operational parameters that the decision was made to modernise the line. VAI Seuthe was selected as the partner to jointly develop a modernisation concept and put the solution into practice. The upgrade of the existing 6" welding line comprised three main activity areas: Installation of an advanced CO 2 laser- welding aggregate by the customer in addition to the existing TIG welding unit: This allowed the line and production speed to be increased from 5m/min to 15m/min, depending on the wall thickness of the tube. By keeping the old TIG welding unit in the line, greater production flexibility was provided, since the TIG tube welding method is vital for specific applications.

Replacement of the first five forming stands of the conventional forming section with the patented CTA forming solution: This step enabled necessary changing times of the tube-welding line to be kept to less than three hours, as requested by the customer. This was possible because the same set of universal forming rolls mounted in a roller cage can be used for the production of a multitude of tube dimensions in the forming section up to the fin-pass stands. Replacement of the existing band saw with a newly designed flying cut-off unit: this was developed and built by VAI Seuthe in accordance with the customer request that it be capable of cutting the entire product mix of the line at low costs. The use of nearly backlash-free planetary gearings combined with a fine adjustment control provided by Siemens Simotion software allows high-

VAI Seuthe has upgraded a stainless steel tube-welding line with CTA technology

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J anuary 2010

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