Norwegian offshore and maritime services company Westcon Yard recently acquired the world’s largest, most powerful all-electric pipe-bending machine.
Capable of a colossal 660,000Nm of continuous, servo-controlled torque, the custom-designed machine will be used for precision bending of thick-walled carbon steel pipes up to 273mm in diameter. It is the second all-electric pipe bender that Unison has supplied to Westcon’s pipe production facilities in Ølensvåg, Norway. The first, a 90mm single-stack model from Unison’s Breeze range, was installed at the beginning of 2015 and enabled the company to bring much of its pipe fabrication in-house.
With the new machine, Westcon intends producing virtually all the pipe sizes it needs in-house, without having to use pre-fabricated bend sections. Although Unison’s bending machines are used by a number of leading ship and submarine builders to produce large pipe and tube assemblies, this is by far the most powerful that the company has ever designed and built. Unison’s range of all-electric bending machines now extends from 16mm to 273mm.
Westcon specialises in building and repairing ships for the offshore and fishing sectors, and in servicing, maintaining and repairing semi-submersible and jack-up rigs used by the offshore oil and gas industries. In recent years, Westcon has invested heavily in its pipe fabrication operations for ship and rig outfitting. Its Ølensvåg site now has a large 3,650sqm purpose-built engineering workshop, with more than 1,500sqm allocated to pipe production. The new facilities include a fully automated materials-handling system – based on 9m-high pipe storage racks and robotic feeders – together with an automatic pipe cutting machine and the two Unison CNC-controlled all-electric tube benders.
Most of the pipes that Westcon produces are one-off items, typically manufactured from carbon steel, with each pipe spool normally being up to 6m in length. The pipes often involve very tight radius bends, to as little as 1.5 times outside diameter, and need to be constructed to millimetre accuracy.
Until about six months ago, Westcon fabricated all pipes in sectional form, using multiple cut-to-length straight sections and bought-in preformed bend parts. The individual sections, bends and end connection flanges were then welded together to create the final assembly – with each weld requiring cleaning, inspection and non-destructive X-ray testing. This was an expensive and time-consuming process that was also heavily reliant on outside suppliers meeting tight delivery schedules. Rapid turnaround time is critical for repair organisations like Westcon, where the out-of-service costs of ships and rigs can be astronomical.
Following delivery of its first Unison bending machine, Westcon has produced all pipes up to 60.3mm in diameter in-house, from straight piping stock. This eliminated the need to buy-in preformed bend parts for these pipe sizes, and reduced the number of cutting, welding and testing operations needed for each assembly substantially. The pipes are currently cut slightly over-length before bending, to allow for any changes introduced by the process. After bending, they are remeasured, cut to final length and welded to the necessary flanges. As its expertise develops, the company intends to improve the process by cutting the pipes to length prior to bending.
“We have only been using our first Unison machine extensively for a few months and are still on a learning curve,” explains Tommy Nilsen, Head of Prefabrication at Westcon’s Ølensvåg facility. “Despite this, we are already achieving superb bend accuracy and repeatability with good throughput – and we are confident of increasing this even further when we change the process sequence.”
Unison all-electric pipe bending machines feature servomotor-driven motion axes and fully automated software-controlled setup. Simplicity of operation and the fact that Unison was prepared to develop custom pipe-bending solutions were two of the key reasons behind Westcon’s original order. Both the 90mm and the 273mm machines are fitted with an innovative laser springback system, which automatically measures and adjusts bend angles to compensate for the tendency of tubular parts to spring back slightly after being bent. The machines also both feature quick-change tooling, which is a major advantage for applications that involve bespoke, one-off manufacturing.
The Unison machines’ unique mechanical design, combined with the precision axis control capabilities of Unison’s Unibend software – especially with respect to carriage and pressure die boost – makes it easier to achieve very accurate and repeatable results, with minimal changes to the wall thickness or ovality of the pipe that is being bent. These attributes are ideal for manufacturers of marine, offshore and subsea equipment, who invariably need to work to tight tolerances and strict process guidelines.
The material storage/retrieval system, pipe cutting and bending machines at the Ølensvåg facility are fully networked. The engineering department creates the necessary machine control programs from customer-supplied drawings or CAD files, or from data derived directly from a physical pipe using a laser-based coordinate measuring machine (CMM). To help simplify the process, Unison has also supplied Westcon with Advanced Tubular Technologies’ powerful VTube software. This generates production-ready programs for tube and pipe benders direct from CAD data, and also translates CMM data for reverse engineering purposes.
“Based on our experience so far, now that the larger bending machine is in place, we expect to substantially reduce production times for all pipe sizes,” adds Nilsen. “It’s like going from 1930 to 2016 in one stride! We are now effectively a year ahead of the rest of the world in terms of our pipe fabrication capabilities.”