TPT September 2019

T UBE M I L L S & R OL L FORM I NG L I NE S

Three-roll cross rolling mill in quick operation for Vallourec Deutschland (VAD)

chairman of the management board of Vallourec Deutschland GmbH, “With the investment in a new CRM here in Düsseldorf-Rath we want to specifically expand our product range in the direction of higher quality premium materials with higher resistance to deformation, in particular in regard to alloyed and high-alloy materials. At the same time we want to expand our dimension range, too: in particular in regard to thin-walled pipes and pipe lengths we want to take a further step towards the new market requirements.”

In terms of the finished product quality (ovality, eccentricity, straightness and reproducibility), the new mill’s performance targets were reached just after the equipment start up, and then followed in steps by the productivity and availability goals. The machine was built, assembled and pre-tested in the workshops at Danieli’s headquarters, and installed during an outage of approximately eight weeks for demolition, excavation, civil works and erection. Innovative prefabricated foundation modules and erection techniques were adopted to achieve the short shutdown targets. According to Dr Ulrich Menne,

DANIELI has reported that Vallourec Deutschland (VAD) has achieved excellent performance operating its new Danieli cross-rolling mill. After just two months of performance testing, VAD released the mill acceptance certification. The cross-rolling mill (CRM) supplied to VAD is a newly designed machine developed by Danieli Centro Tube to meet VAD’s demanding requirements, which include the flexibility to roll carbon, alloy and high-alloy carbon steel grades, starting from 400 to 850mm OD ingots. The finished products are tubes ranging from 244 to 711mm OD (9 5 / 8 " to 28").

Danieli SpA – Italy Website: www.danieli.com

Streamlining tube mill production A CUSTOMISED cold welding system developed by British company PWM (Pressure Welding Machines) in partnership with US manufacturer Virtus Precision Tube (formerly Luvata) has streamlined and improved the process of copper tube production. and laser welding. PWM successfully test welded VPT’s strip using a portable ST40 cold pressure welding machine, capable of joining copper strip as wide as 45mm and as thin as 0.2mm. Precision engineered to create reliable permanent welds stronger than the parent material, the ST40 enabled VPT to reduce scrap by about 1.5 per cent during production trials.

quickly resolved. For example, we went through four design improvements to arrive at our current tooling.” Steve Mepsted, managing director of PWM, said, “This has been a fascinating bespoke project to work on. VPT shares our commitment to quality and innovation and together we’ve created a customised welding solution that significantly improves business performance. We’re delighted with the outcome.” Pressure Welding Machines Ltd – UK Email: pwm@btinternet.com Website: www.coldpressurewelding.com

The system has improved uptime, reduced costs and created a better working environment for operators, according to Joe Napier, VPT’s engi- neering programme manager. “We produce over 40 million pounds of roll-and-weld copper tube each year, in sizes from ¼" to ½",” he said. “The cold welding system we have developed with PWM is part of our continuous improvement programme. It supports our ongoing drive to develop high- performance tubing solutions for the HVAC and refrigeration heat exchanger markets. “The new cold welding process is more straightforward than the cross- weld process we used for a decade, and works the first time, every time. It’s faster, easier to standardise, requires less operator input and training. Most advantageous of all, the new weld is stronger and capable of handling the tensions we place on the strip during tube production.” Before approaching PWM, VPT tried alternative methods of joining strip such as brazing, dovetail profiles, lap joints

PWM has now supplied VPT with three ST40 welders that run full-time in production. Adaptations such as automatic flash trimming and annealing of the weld (to soften it and make it less brittle), and automation of the weld cycle and die opening system have been developed to streamline the process. VPT will field

Virtus Precision Tube – USA Website: www.virtustube.com

the new system across all tube mill production lines, and currently has four more ST40 units on order with more to follow. “Technical assistance from PWM, particularly from its chief design engineer, Ivan Turner, has been incredible throughout,” said Mr Napier. “Any problems we had during the development and early fielding of the units were

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SEPTEMBER 2019