TPT May 2011

T echnology U pdate

Laser guidance system for automated welding in longitudinal pipe mills

META Vision, a supplier of optical seam tracking systems for tube and pipe mills, has announced a new version of its VistaWeld system aimed specifically at increasing the speed and accuracy of submerged arc welding (SAW) in longitudinal pipe mills. Based on a review of typical longitudinal SAW mill operations involving tack and outside diameter (OD) welding, the new system addresses some well-known issues. In particular, the latest VistaWeld includes accurate, non-contact tracking of the true root position and built-in look- ahead compensation as standard features. The system harnesses the power of Meta’s recently introduced smart laser sensor (SLS) technology. It integrates a high resolution, high performance SLS sensor head within an updated VistaWeld architecture based on an Ethernet backbone and Meta’s new, flexible Ethernet IO board. The combination has made it feasible to include the desired features while reducing system complexity and improving ease of use. TruRoot tracking finds the actual root of the joint for OD SAW, even though the root may be covered by the tack weld. The software uses the higher resolution and quality of the SLS sensor, together with image analysis algorithms from Meta’s well-known multipass welding system, to detect the edges of the tack weld in the bottom of the joint. From this and the overall joint profile, the true root position can be computed. Tracking the actual root derived in this way improves penetration for the OD weld itself while also improving ID/OD weld interpenetration. OD SAW on longitudinal pipe mills typically uses a multi-torch configuration with as many as five or six individual wires welding in one pool. The New linear cage forming THE linear cage forming by Olimpia80 is the technical answer to the main requirements of today’s welded tube market and allows rapid production, minimised stock of finished product and cost reduction. This is mainly achieved by maximising flexibility,

The screen of Meta’s new SLS-based VistaWeld system for longitudinal SAW pipe mills

weld head is therefore large, taking into account the number of torches and need for flux delivery and recovery. As a result, the laser sensor has to be positioned a relatively large distance in front of the weld area. This so-called look-ahead distance can be 250mm or more. Depending on the shape of the pipe, tracking inaccuracies can result if simple algorithms are used. The standard tracking feature within the new VistaWeld uses the look-ahead distance, welding speed and other information to determine the correct position for the welding head at all points along the pipe. It is particularly beneficial if the pipe forming method has given rise to geometric distortion, as is often the case. Tests on one series of longitudinal reduction of set up time and the reduction of roller costs. The innovation consists in the possibility of producing any tube size, included in the mill range, without any roll change and in few minutes with an extreme reduction of set up time. Advanced linear cage forming (LCF) is the result of many years of experience and development work and can be applied to the production of rounds and sections. For production of round pipes the new LCF has

pipes showed that, in some cases, look-ahead tracking was four times more accurate than conventional tracking, significantly enhancing production by improving weld quality and minimising defects. For example, the superior vertical tracking accuracy maintains the correct stickout (distance from contact tip to work) over the complete length of the pipe, improving weld quality and eliminating weld defects. The improvement in horizontal axis tracking precision combines well with the TruRoot feature to give a double accuracy benefit. Meta Vision Systems Ltd – UK Fax: +44 1865 887901

Email: sales@meta-mvs.com Website: www.meta-mvs.com

been applied to complete forming section of mill, including fin pass stands. It is a unique compact system consisting of 11 stations: six stations operating as breakdowns, two stations operating as pre-fin passes, and three stations operating as final fin passes. An almost complete closure of the tube (360

degrees) is achieved. Olimpia80 Srl – Italy

Email: olimpia@olimpia80.com Website: www.olimpia80.com

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M ay 2011

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