The demand for power shows no signs of letting up. Steed Webzell reports on a positively vibrant energy sector, for manufacturers prepared to invest, that is
Whatever the situation – whether it's a complex part, a precise part, a tight margin part – latest manufacturing technology provides an economical solution. For instance, when Malmesbury-based Armadillo Engineering wanted to improve its cutting times on complex oil and gas components, the company elected to adopt laser technology from Yamazaki Mazak Optonics (01905 455780).
Already using Mazak machining centres for machining complex valves for oil pipelines, the decision to move into laser cutting was driven by a need to increase productivity.
"We've used waterjet cutting for many years for materials less than 12 mm thick, but we needed to speed up the process," explains managing directo, Paul Edwards. "We use the new Mazak laser on specific one-off jobs, such as bracketry for the US oil and gas sector, which demands very high tolerances and repeatability, but also comes at a premium price. Additionally, we are laser profiling materials to produce components for GPS sub-sea 'pigs' and indication valves for surface pipelines, and the laser will also help us develop the Scottish market."
Armadillo took the decision to invest in a Mazak Super Turbo X-510 Champion laser cutting machine equipped with 1.3 kW laser source. Crucially, the STX Champ has a rapid traverse rate of 24 m/min on the X and Y axes, and 25 m/min on the Z-axis.
Large and/or complex parts typically define machined components required for oil and gas contracts, as demonstrated by Dunfirmline-based FMC Technologies, a company that specialises in parts such as annulus wing blocks (AWBs). Made from carbide steel with Inconel welded features, these wing blocks are characterised by their complex multi-valve configurations, and are mounted on to sub-sea equipment to regulate the flow of hydrocarbons into and out of a well.
In a move to upgrade its AWB cell, FMC installed a large capacity Doosan HM1000 twin-pallet horizontal machining centre and a Doosan DBC110 horizontal boring machine, both supplied by Mills CNC (01926 736736).
Image: Large and complex parts are FMC's requirements - satisfied by Mills CNC
"As well as the two machines, we also proposed a 'zero-point' clamping system, because it would enable four faces of the carbide steel blocks to be machined in one set-up," says Andrew Jack, Mills CNC's technical director. "The zero-point clamping system ensures repeatable part positioning and, unlike traditional vice-like workholding equipment, which must grip at least two sides of a part, the zero-point system only requires one side to be clamped, thereby giving improved access."
It will come as no surprise that part complexity in the energy sector is also benefiting suppliers of multi-tasking turn-mill centres. A case in point can be seen at the Southend facility of Waverley Brownall, a manufacturer of high integrity oil/gas fittings that has cut cycle times, which has increased production efficiency and added more flexibility, by investing in a Nakamura Tome WT 100 twin-spindle, twin-turret turning centre from Turning Technologies, a member of The Engineering Technology Group (01926 818418).
"A typical part is a hexagon with a thread on both ends and a hole through the middle. So, on a single-spindle machine, we have to machine one end, take it out, reload it and make the other end," says director Dick Sheridan. "With the Nakamura, that comes off finished. By moving to a twin-spindle machine, you gain tremendously in efficiency.
Image: Parts come off finished now for Waverley Brownall, following investment in a Nakamura Tome machine
Image: Parts like this are produced by Waverley Brownall
"The milling capacity of the machine also comes into play when machining parts in exotic alloys," he adds. "We generally machine components in 316 stainless from hexagon bar, but you can't easily get hexagon bar in these materials, so it's a big plus to have the Y-axis, as we can use round bar and mill a hexagon on the part, while we are machining it. Anything we can do in 316, we can now do straight away in exotics."
Among the most complex of all energy components are turbines and until the middle of 2010, Market Bosworth-based subcontract machinist JJ Churchill could produce turbine blades only if the parts had their fir-tree root-forms pre-ground elsewhere, or if they were subsequently added by another subcontractor. No longer is this the case.
Following installation of a VIPER grinder, fir-trees can now be machined in-house. Purpose-built by Makino for grinding tough materials such as nickel alloys with licensed Rolls-Royce know-how, the machine was supplied by Makino-NCMT Grinding Division (020 8398 4277). A second, perhaps larger machine, is being considered for 2012.
"We view the VIPER process, based on a 5-axis machining centre platform, as the most cost-effective way of creep feed grinding nickel alloys for hot-end gas turbine components used in land-based power generation equipment," says managing director Andrew Churchill. "It has the extra advantage that milling operations can be performed in the same cycle. As a result, components normally come off the machine finished, unlike with conventional, multiple-machine methods for grinding fir-trees, which have a much larger footprint on the shopfloor and create a lot of work-in-progress."
Image: Creep-feed grinding the VIPER way is paying dividends for JJ Churchill
Renewables continue to grow in market prominence and, as such, increasing numbers of manufacturing technology suppliers are reporting sales success in this area. Tooling specialist Mapal (01788 574700), for instance, has just been awarded its largest contract to date for a wind power project.
The contract covers the tooling needed for machining three different components used in wind power gearboxes. All of the parts are manufactured from GJS, a form of cast iron with spheroidal graphite. The contract extends from bridge tools, for finish boring and fine boring, to helix milling cutters and very large facing slide tools, used in conjunction with Mapal's Tooltronic system.
Tooling is also the focal point of improvements in cycle times at Costruzioni e Lavorazioni di Precisione (CLP) in Borgo San Dalmazzo, Italy, where a recent machining project with Sandvik Coromant (0121 504 5400) on 3.5 m diameter pump bodies for nuclear reactors is providing savings of €30,000 per batch.
By switching to Sandvik Coromant's CoroMill 300 multi-purpose toroid round insert cutter (with 20 mm diameter inserts) for roughing operations, Francesco Albanese, CLP's chief of works, says productivity has been boosted by 15%. Furthermore, a Coromant Capto C8 clamping device is used for the second stage, allowing the turning of some internal and external areas to be accomplished, using the milling centre's rotary table. Here, the application of a purpose-designed Sandvik Coromant N331 disk milling cutter (550 mm diameter) is improving the productivity of these operations by a further 15-20%.
Returning to the UK, down-hole equipment manufacturer Lion Engineering of Great Yarmouth says that changing to FeatureCAM feature-based CAM software from Delcam (0121 683 1000) has helped it boost the impact of a £1 million investment in Mazak machine tools over the past 18 months.
"Presently, we're as busy now as I have ever known it since joining the company in 1972," says director Martin Brown. "During the last downturn, stocks of parts were run down and these now need to be replaced."
Lion Engineering first moved into CAM four years ago and tried various CAM systems, but was never completely satisfied. The need for a change was highlighted even more after Lion Engineering invested in new Mazak machines, including an Integrex e-500 mill-turn, a VTC-800 5-axis mill, a VTC-300 4-axis mill and a Nexus 3-axis lathe with live tooling. The existing CAM system didn't have post-processors for the new equipment. In addition, it couldn't program the helical milling operations needed to produce critical features that keep the components stable in use. This all changed with the switch to FeatureCAM.
"Additionally, FeatureCAM gives us the high quality surface finish we need for our specialist surface treatments," says Mr Brown. "Our integrated machining and surface finishing service is one of the most important reasons why our customers prefer to use us."
With new developments in the nuclear and renewable energy sectors grabbing the headlines, and continued strong demand for oil and gas components, prosperity among UK machine shops is assured for those able to demonstrate committed investment strategies.
Box item 1
Massive KMT Lidköping VTG4000 grind-turn machines that enable high precision wind turbine bearing production on a very large scale are being fitted with Renishaw (01453 524524) encoders, deemed critical to accurate and rapid operation. The new KMT Lidköping (+46 510 88000) VTG4000 uses a combination of Renishaw SiGNUM optical linear and angle encoders to achieve the precision required, and Renishaw magnetic encoders on the exposed axes of the cutting heads.
Image: Renishaw technology has been used on this mill-grind machine for wind turbine bearing application
"Hard turning and grinding can be very demanding, and positioning accuracy is very important, with a direct effect on the quality of finished bearings," says Eive Johansson, Lidköping's VTG chief designer. "A standard size machine, using ballscrews on the axes, will maintain a 3 micron form deviation, yet, despite the considerable difference in relative size, the VTG4000 has been proven to achieve a form deviation of less than 1 micron, with feed resolution in 0.1 micron steps."
All Renishaw encoders feature an integral patented set-up LED, which speeds installation and removes the need for complex external/separate set-up equipment, or oscilloscopes.
Renishaw's LM10 magnetic encoder systems are fitted to the B-axes of the grinding heads, while the machine also uses a Renishaw RMP60 radio signal transmission touch probe to set the part in the machine's co-ordinate system.
Box item 2
Energy storage and clean fuel company ITM Power, which manufactures hydrogen energy systems at its factory in Sheffield, has chosen an aqueous, ultrasonic cleaning line from Turbex to wash and degrease many of the components and fittings involved in production. During the R&D phase, the company cleaned components by hand, using solvents, but for subsequent batch manufacturing it wanted to avoid the hazards of a large, solvent-based system. So an aqueous cleaning line, Versa 120, was ordered from Turbex (01420 544909) and installed in January 2011. The line comprises three 120-litre tanks placed side by side, served by an overhead gantry that automatically handles baskets of components weighing up to 35 kg between each stage.
"Oil or particulates on machined parts can cause valves and pumps to stick, while any grease on electrolyser components would pollute the catalyst and shorten its operational life," says project and test manager Alex Shields.
The first ultrasonic tank contains heated tap water and soap, which is rinsed off by deionised water in the second, non-ultrasonic tank. The third operation is ultrasonic rinsing in a tank of heated, deionised water. After using the system for six months, Mr Shields says that, in his opinion, the aqueous line achieves levels of component cleanliness equivalent to a solvent system.
Image: Aqueous ultrasonic cleaning is helping out at ITM Power
First published in Machinery, October 2011