All-electric tube bender extends shape-forming capabilities of aerospace maker

As an example of the exacting specifications that SLE faces, one current part for a military fighter program calls for a shape with multiple 2D bends but minimal straight sections between bends, using thin wall titanium tubing. Tube ovality also has to be less than 5% after bending - as compared with an industry norm of 10% - and the part shape has a positional and length tolerance of just +/- 0.005 inches after bending and welding. As the part is made from titanium, bending must be right first time as adjustments after shape forming are almost impossible. The consistency and repeatability of the Unison machine is a critical enabler for fabricating this part, as well as other titanium tube parts that SLE currently makes.

Another aspect of the advantages of the Unison machine for a contractor such as SLE is the ease of programming. Tubes are often the last parts to be defined and designed - whether they are for an engine or airframe. Using its own bespoke macro-driven CATIA V5 closed-loop CAD/CAM facility, and Unison's three-dimensional simulator, SLE can create new CNC bending programs for the Unison machine very rapidly - providing ideal support for clients that are unable to supply tube/pipe details until the very late stages of projects.

"All-electric tube bending technology has given this client both a rapid return on investment, and a means of tackling emerging challenges such as bending exotic materials," adds Steve Haddrell of Unison.

SL Engineering Ltd has the fullrange of in-house resources required to offer complete solutions for the manufacture of specialised rigid tube assemblies and precision machined components used in some of the most demanding applications in the aerospace, industrial gas turbine, marine, oil and gas, and medical industries. Founded in 1959, SL Engineering has always specialised in high-precision tubular assemblies - from a starting point of products for motorsports applications. Today, the company employs around 50 staff. Its core capabilities include CNC tube manipulation, CMM tube inspection, multi-axis CNC machining for manufacturing complex end fittings, plus all required support processes including welding, brazing, assembly, pressure testing, and NDT (dye penetrant and x-ray inspection). To support its work in aerospace, SL Engineering has attained qualification to many key industry standards including AS9100 (Rev C) aerospace quality management systems, BS EN ISO9001, and NADCAP special process approvals for welding, brazing and NDT. To reinforce its position as a leading tube assembly specialist, SLE has also achieved SC21 award status for the last three consecutive years - making it one of the top performing aerospace organizations in the UK in terms of business performance and continual improvement. This performance has been all the more impressive as SLE also achieved 22% growth in business during 2013.

Safety upgrade for stainless steel rolling mill

ABB's new safety PLC has provided the platform for Sandvik Materials Technology to add zoned safety guarding to a large cold rolling mill at its Sandviken plant in Sweden. The mill is a key part of the production line for precision strip steel at the plant.

Sandvik's cold rolling mill has been upgraded a number of times throughout its life - including recent changes that added servomotors, and new machine control using ABB's standard AC500 PLC and touchscreen operator interface panels.

The latest upgrade adds safety PLC modules from ABB's AC500-S PLC to the machine control system to enhance the safety of the 20m-long mill with a networked architecture using the PROFIsafe protocol over PROFINET to provide independent control of six separate safety zones. The zoned arrangement means that parts of the machine can remain operational while an operator gains safe access to some other zone - where safety is assured by disabling power.

Some 50 safety PLC I/O channels are employed to link to gate switch and light curtain guarding, and emergency stop buttons. The I/O also monitors pressure switches to sense that hydraulic power is disabled so that maintenance can take place, and controls power supplies to the motor drives. Safe speed control is another aspect of the safety control provided by the new PLC - to ensure that hands or fingers cannot be trapped between the mill's belt and rollers.

Sandvik chose ABB's AC500-S safety PLC for this application because of good experience of the standard non-safety AC500 PLC architecture on both this machine and other machinery control projects. The AC500-S safety PLC also offered Sandvik the possibility of using floating point numbers, which simplified the safety programming required for this project for tasks such as calculating speed.

The fact that the standard version of the ABB PLC was already used on the mill measurably simplified the safety upgrade. This is because the safety PLC hardware shares the same look and feel as standard AC500 PLCs allowing safety and non-safety functions to be mixed in the same system. This compatibility includes identical dimensions to CPU and I/O modules, and the same mounting and wiring scheme.

The new dual-processor safety CPU module and the safety I/O channels have been integrated alongside the machine's existing AC500 PLC - which controls a total of six DC and AC drives and motors. The DC motors drive the main steel belt and rollers. The AC motors adjust roller position to achieve the desired pressure during strip steel processing. The standard PLC also links with four operator interface panels from ABB's CP600 series.

Programming the safety solution was made simple by the fact that ABB's integrated PLC development tool, Automation Builder, included support for safety PLC programming in its CODESYS-based integrated development environment - and support for the PLCopen Safety Library. ABB also provided its own safety code analyzer tool, SCA, which verifies the safety programming rules.

The familiarity of the programming environment and the sophistication of these tools helped Sandvik's developers to quickly understand safety PLC programming concepts. This allowed them to develop the enhanced machine safety architecture in a very short time - meeting the company's tight timescales set for this upgrade project - and quickly bring the enhanced mill into operation.

This project also took place before ABB had actually launched the AC500-S safety PLC. Prior to commercial release, the new PLC was extensively field tested in a large number of pilot applications. Sandvik was one of ABB's pilot customers and developed this safety control system before the product and tools were formally launched. This was made possible by good support from ABB's product development team. Since this application, Sandvik has gone on to use the safety PLC on three other machine refurbishment projects.

"We were very pleased to find such an easy-to-apply solution for adding state-of-the-art protection, in the form of the ABB's safety PLC - which integrated directly with the machine's existing PLC," says Torbjörn Pettersson, an engineering development specialist with Sandvik Materials Technology.

"The fact that ABB could supply the spectrum of machine control components required for this project, from the non-safety and safety variants of the PLC, to the operator panels, motor drives, contactors and safety hardware, both simplified and speeded this upgrade," says Jonas Rehnberg of ABB Sweden. "The modularity of the new safety solution also means that it is now very easy to upgrade or modify safety functionality in the future, to enhance the safety of the mill even further, or to integrate additional aspects of the production process."

The safety PLC - the AC500-S - is a recent addition to ABB's well-known AC500 PLC range and features a dual processor architecture that complies with SIL3 (IEC 61508:2010 and IEC 62061)/PL e (ISO 13849-1) functional safety levels. The integrated AC500-S safety PLC can run even if the non-safety PLC is stopped for maintenance. This means that personnel can still easily move within the machine during the maintenance phase, because the safety PLC will continue monitoring the state of the machine's safety sensors and executing its safety function.

Current Challenges and Way Ahead for Shale Gas in Australia

Author: Izwan Rasul

Currently, US is the only country with commercially available shale resource. Taking cue from the US, countries with shale resources are beginning to realize its potential, in particular Australia that has begun exploring its shale resources to supply it to the market once production begins.

Australia also has a large coal seam gas (CSG) reserves identified in the eastern region and is committed to meet CSG-LNG export requirements over the next twenty years. However, there has been a decline in conventional gas production which would impact the rising gas prices with significant flow-on effects to domestic retail electricity. Such scenario provides ample opportunities for the cost competitive shale gas to contribute to domestic and export requirements in Australia.

Ongoing Shale Gas Development
Currently, there are three shale wells in production in the Cooper Basins.

• Moomba-191 - producing 65 mcm/d (million cubic metres per day)
• Encounter- 1 - producing 59.4 mcm/d
• Moonta- 1 - producing 45.3 mcm/d

Shale gas industry has been gaining traction in Australia with an estimate of $500 million investment on shale exploration and completion works in the Cooper- Eromanga Basin over the next 1-2 years. But as in any other nascent market, challenges faced by Australia in realizing its shale gas potential is abound. They include infrastructure issues, geological understanding, water availability and operating cost. This is mainly because most of the prospective shale gas areas are in remote locations namely the Canning, Cooper and Georgina Basins. Compared to the US, pipeline and road networks are undeveloped impacting the rate of shale gas development.

Figure 1: Existing Oil and Gas infrastructure in Australia

Source: DMITRE, SA,2012; US Energy Information Administration (EIA,2011b)

Infrastructure Challenges
The Cooper basin has a well equipped infrastructure with existing gas and liquid lines to the relevant east coast market. It is the only place which is ready for further development as it can rely on current connection to gas consumers. Besides, the Perth and Otway basins are well positioned for rapid development due to existing demand and transportation infrastructure can be expanded easily. Pipeline infrastructure in the Canning basin does not currently exist. A plan on the Great Northern Pipeline infrastructure will be able to connect gas supply to the Western Australia (WA) domestic market. However, before any pipeline is constructed, WA should have a demand of at least 50 PJ per annum which will make a pipeline economically feasible. Sufficient reserves are required to be constructed over a period of time before a financially risky exploration and appraisal process takes place. Local market needs to be established as a first step and gas have to be delivered via road until there is a bigger demand justifying the construction of a pipeline.

Skilled Workforce Shortages
One of the major obstacles is workforce shortage in Australia. An estimate of 450 staff is required for a 50 PJ project with an additional of 75 operational staff. Furthermore, labor is required for road construction, accommodation and transmission pipelines. Such workforce with a required skill set is limited locally and there could be a possibility in transfer of workers from CSG projects but only when CSG development slows down.

Figure 2: Shale production labor requirements for a 50 PJ development

Source: Sinclair Knight Merz, 2013

Environmental Impact
Shale gas production contaminates landscape and environment where some of the possible impacts include:

• Aquatic ecosystem gets affected due to contamination of land and surface water as a result of spillage of hydraulic fracturing additives and overflow. Tank rupture from its liquid waste storage also affects the ecosystem.
• Wellbore failure and subsurface migration will raise an impact on subsurface fauna, vegetation and landscape function indirectly.
• Noise, light pollution and local traffic may be impacted during ongoing construction and pre-production activities.
• Increased air emissions of methane and volatile compounds coming from drilling, hydraulic fracturing and high pressure compressors.

However, in Queensland and New South Wales, much work is being done on raising awareness on the difference between CSG and Shale fracking and working with local communities in order minimize any potential environmental impacts. Especially in NSW, drilling companies has to adhere with strict rules and regulation as cited in the South Australia Petroleum and Geothermal Energy Act 2000. Furthermore, the case in Western Australia is different as shale resources are very deep in the rural areas where no occupants exist.
Effective and timely addressal of the challenges above can propel shale gas revolution in Australia. In addition, issues pertaining fracking regulations, property rights, licensing restrictions and lack of investment need to be considered.

Australia's Shale Future Shows Positive Growth Signs
The main market for shale gas exports from the US is Asia. This is one of the primary reasons behind Australia's intention to develop its shale resources and begin production to cater to Asia's future gas demand. Although production has begun in the Cooper Basins due to the commercially ready infrastructure, other basins with low to zero population density are yet to be developed by the government. Currently, Australia ranks six in global shale resources with an estimated of 417 trillion cubic feet of recoverable shale.
High cost for extracting shale gas are making it difficult for existing companies but export market opportunities are huge if Australia pursues in realizing its potential with the backing of  government incentives. In addition, carbon pricing implementation in 2012 has made consumers to divert its focus to natural gas.

Currently, companies operating in the booming US shale market have ventured into the nascent Australian market. This is likely to increase the momentum in exploration and production of shale gas. Tapping the shale gas will not only propel Australia's economy but will also help to maintain its competitiveness in the global energy market. Nevertheless, the country needs to build a robust infrastructure, acquire skill sets, and assess ecosystem management and investment requirements thoroughly.