TPT November 2021

AR T I C L E

Fives

For a laser welded tube line this could mean saving up to $1,800 per day in terms of blades, to which can be added one hour/day downtime abatement for avoid d blade replacement. It is straightforward to calculate the really short payback of the investment. Along with the blades, the risk of pinching goes away, leading to a 10 per cent extra blade saving and tube scrap production, as usually occurs at production startup. Compared to blades, the laser cut width also happens to be much thinner (0.5mm against 4mm), which results in a comparable scrap reduction that comes with each cut. In addition, no need for lubrication or cooling. The tube is preserved from stains without any blade extra-cost risk, when traditional cut-offs are used without lubrication. On the speed side, the orbital laser cut can reach much higher speeds than cutting with blades, reaching up to 20m/min on laser welded stainless tube lines, thanks both to the laser capability and to the possibility of cutting the tube regardless of the rotation direction, an important feature not achievable with blades. From the material point of view, laser cut-offs open the door to special alloys, such as Inconel, that cannot be treated with the common cold saw cut-offs. Looking to the mechanics, we can appreciate a rigid and lightweight structure allowing to adapt the pass-line simply by adjusting the height of the fifth wheel support structure, without having to move the whole basement; this leads to short deep foundations and also the very low basement pass-line. In addition, no extra foundations are required to support the cable run. Finally, the mechanical assemblies can be lifted from the top for an easy maintenance, while the light and low vibration concept requires less maintenance leading to a longer lifetime for the equipment. The overall cost savings compared to a classic orbital blade cut-off can be estimated at 15 per cent. A flexible design has been adopted to easily update the configuration, increasing the system performance, in terms of tube thickness and running speed, by adding more laser heads and/or increasing the source power, according to the production requirements. However, the power consumption is 60 per cent less than an equivalent blade cut-off. A look into the future The next step for Fives’ engineers is to extend the fibre laser technology to HF welded tubes. Given the possibility to reach speeds up to 80m/min the still open challenges are posed by the co-existence of inner scarfing and the anti-spatter device as well as by the

Shandong Province Sifang Technical Development Group

Fibre laser technology, developed by international engineering group Fives, applied to in-line laser welded stainless steel tube cutting, is a patented and safe technology. It is a solution for hollow sections as well as round tubes, with a dedicated system to prevent spatter spreading inside the tube

resistance of the laser heads to the emulsion water. This would open a completely new perspective for tube producers, giving them a powerful weapon on the plant cost effectiveness and safety side that gains supremacy over the established, but dangerous and costly, friction saw technology. Conclusion We have seen how the Fives patented fibre laser technology brings an important cost efficiency and flexibility to laser welded stainless steel tube producers, thanks to a breakthrough solution with a design that leaves no consideration behind. The main issues producers might be concerned with, such as safety and quality, have been addressed with engineered and tested solutions that reassure even the most hesitating mind.

Fives www.fivesgroup.com/steel/tube-mills

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NOVEMBER 2021