Topic of the month February 2010


Figure 1: The novel polyamide 12 moulding compound VESTAMID® LX9020 is specifically developed for offshore applications. Source: Evonik Industries.

Pipes and tubes fulfil a central function in modern energy technologies. These technical veins deliver and transport all kinds of solid, liquid and gaseous substances which activate, support and protect technical systems. Fuel lines, lubrications systems and devices for cooling and heating are some examples, which demonstrate that these components are of significant importance for the functionality of complex applications in various industries.
For a long time simple tubes have been very important for mankind – just think about blow pipes used for hunting or bamboo rods as a construction material for housing or the principles of early systems for water supply. Nowadays, tubes are superior components made of premium materials. Every year the exhibitors of the fairs Wire and tube demonstrate, how tubes with customized properties perform their required demands in an optimal way. Especially in the field of energy technologies the market persuades with innovative and intelligent product developments, which are also available to be transferred beneficially into other industrial branches.

Efficient Offshore Lines

Since decades Evonik Industries from Essen in Germany is experienced in the development of high-grade polyamide compounds for line systems in automotive applications. Scientist and engineers now realized the transfer of the accumulated know how onto material systems suitable for the production of thick-walled piping systems. Due to their application relevant benefits like creep resistance, mechanical ductility, thermal expansion behaviour as well as chemical stability, these pipes are increasingly being used in the oil and gas industry. In collaboration with Wellstream International Limited, Evonik has conducted intensive tests to prove compliance with international standards, like for example API 17J “flexible risers” and ISO 13628-2. Because of the positive results, Wellstream got the approval of Llyod´s Register to utilize the polyamide 12 moulding compound VESTAMID® LX9020 in the production of flexible pipes for conveying production and injection fluids in offshore crude oil production. Meanwhile this material system is successfully being employed in over 300 offshore pipes.

Leakage Free: Repair Bandages for Pipes


Figure 2: The Stopaq® Wrapping Band keeps tubes impervious and protects against corrosion and hairline cracks. Source: BASF.

The Dutch company Stopaq Europe B.V. has developed a highly efficient adhesive tape, which enables the protection of conventional tubes and pipelines from corrosion and hairline cracks. Due to its material composition, the Stopaq® Wrapping Band seals different surface defects and makes surfaces completely impermeable to water and gases. This development was made possible by employing the plastic material Oppanol® produced by BASF – a flexible polyisobutene (PIB) polymer. This material offers an ideal property profile for this application, because PIB remains flexible under any climatic condition – regardless of being applied in the desert or in arctic regions. This is a tremendous advantage compared to conventionally applied techniques for sealing pipelines, because those epoxy resin based systems are not always harmless to health. Additionally, they require the set up of air-conditioned tents on construction sites in hot regions, otherwise the solvents in the lacquers systems will evaporate due to the extended temperatures. Moreover, Oppanol® is nontoxic, adheres to extremely rough surfaces and provides a self-healing effect which closes up small cracks completely self-acting due to its flow properties.

Innovative: Tubes as Joining Elements

Professor Armin Lohrengel and his team members of the Institute of Mechanical Engineering at TU Clausthal are working on the development of a novel technology, which enables the joining of prefabricated parts without using other joining elements like screws or rivets. The realisation of novel light weight constructions and the development of path breaking strategies for saving materials are central aims of the project, which is financially supported by the Deutsche Forschungsgemeinschaft. Actually the life-span, the compatibility of different material combinations and the wear behaviour of so called “internal high pressure assembled crimp connections” are under investigation. The intelligent joining system is based on a comparatively simple method. First a metal ring is stuck onto a tube. Then the tube is being blown up from the inside using immense pressures up to 4000 bar. Due to the high internal pressure the tube deforms plastically and it stays stuck permanently to the ring, when the pressure impact is stopped. Mercedes is already using this new joining technique for the fabrication of camshafts, but there is no extended data material and there are no defined measurement categories for other industrial branches at this point. Due to the significant mass savings opportunities, this project offers great potential for novel concepts in lightweight design and engineering. Furthermore other innovations in the automotive sector are thinkable – future steering columns for example could be produced using crimp connections instead of screws. This idea provides significant advantages concerning the passenger protection, because these steering columns will slump down at a certain impact pressure.

Dr.-Ing. Christoph Konetschny
Material and Nano Expert
www.materialsgate.de


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- Perfectly Connected: Innovative Joining Techniques