Pipe prefabrication

Tube end forming with reduction in one operation by orbital pressing.

Pipe prefabrication (also: prefabrication of pipelines ) describes tasks in prefabrication (in particular cutting , welding and bending or forming and end forming ) that are carried out on pipes in order to create workpieces ready for installation. One also speaks of an assembly that is brought forward in the production plant , which is carried out according to isometrics , pipeline plans or models. Nowadays, the individual production steps are largely automated. Main applications of the pipe prefabrication are in the industrial pipeline and plant construction , the engineering , the shipbuilding , the aviation and aerospace as well as in the automotive industry .

background

The prefabrication of pipes and pipelines in the workshop is particularly important in industrial pipeline and plant construction , since this type of advanced assembly is significantly more cost-effective than construction site assembly. In order to be able to manufacture a pipe or entire pipe strings precisely or ready for installation, all isometrics of the pipes must first be known, which can be obtained from pipe plans or CAD data, from a drawing with dimensions or by measuring the interfaces with the help of special pipe measuring technology . The isometrics serve as the basis for the prefabrication work. Thanks to modern, integrating software systems, many work steps in pipe prefabrication can be automated and various production machines can be controlled directly.

Cutting / separating

Different processes are used for cutting work on pipes, depending on the material and geometry of the pipes. The most common are sawing , laser cutting and non-cutting cutting using a rolling knife.

welding

A large number of welding processes are also available for welding pipes and pipeline components. In the context of pipe prefabrication in the workshop, tungsten inert gas welding (TIG) and gas shielded metal welding (MSG) with inert or active gases are mainly used, depending on the requirements . Due to their high degree of automation , both processes can also be used for orbital welding.

Pipe bending

The pipes are often bent on inductive or cold pipe bending machines, depending on the material and outer diameter of the pipes and the quality requirements. Especially in the area of the cold bending (pipe outside diameter up to 300 mm) and with small bending radii (up to about three times the pipe outside diameter) has the rotary- established itself as a very precise bending process.

On modern CNC tube bending machines that work according to the rotary bending process, complex tube shapes can be produced with high accuracy in a very short time. By integrating the tube bending technology with tube measuring technology and tube bending software , the geometry data of the tubes to be manufactured can be converted very quickly into commands for the bending machine .

Pipe end forming

The forming of pipe ends takes place z. B. for the production of hydraulic armatures or fittings . Axial forming and orbital pressing (also spinning or rolling tube end forming ) are used for this. The procedures can be combined in sequence.

The axial forming enables the expansion , beading , tapering and calibration of pipe ends. Wall thicknesses can be upset in the forming area. Orbital pressing is used for the production of flanges (IUL) and multi-groove contours. In 2010, the Institute for Forming Technology and Lightweight Construction at the Technical University of Dortmund and Transfluid Maschinenbau GmbH developed incremental tube forming. This further development of orbital spinning enables, as a controlled roll forming technique (incremental) via a so-called bead rolling machine, the shaping of complex geometries with short clamping lengths at the pipe end, even if the pipe is already bent. The tube can be shaped from the inside out, outside in, and inside and outside at the same time.

literature

Christian Gerlach: A contribution to the production of defined free-form bending geometries for pipes and profiles. Shaker: Aachen 2010, ISBN 978-3-8322-9484-7
Hans-Jürgen Weger: CAD / CAM in bending technology. Integrated information processing in wire and tube bending technology. VDI: Düsseldorf 1990, ISBN 3-18-401111-9

Individual evidence

↑ Günter Spur, Reimund Neugebauer, Hartmut Hoffmann (Ed.): Handbook Forming . 2nd Edition. Hanser Verlag, 2012, ISBN 978-3-446-42778-5 , pp. 536 .
↑ Christoph Becker: Incremental tube forming of high-strength materials (Dortmunder Umformtechnik) . Ed .: Prof. Dr.-Ing. M. Smaller. tape 79 . Shaker Verlag GmbH, 2014, ISBN 978-3-8440-2947-5 .
↑ World market leader and top performance in the industry from South Westphalia. Chamber of Industry and Commerce Arnsberg, Hellweg-Sauerland, South Westphalian Chamber of Industry and Commerce in Hagen, Chamber of Industry and Commerce Siegen, August 2015, accessed on September 2, 2015 .

[1] Günter Spur, Reimund Neugebauer, Hartmut Hoffmann (Ed.): Handbook Forming . 2nd Edition. Hanser Verlag, 2012, ISBN 978-3-446-42778-5 , pp. 536 .

[2] Christoph Becker: Incremental tube forming of high-strength materials (Dortmunder Umformtechnik) . Ed .: Prof. Dr.-Ing. M. Smaller. tape 79 . Shaker Verlag GmbH, 2014, ISBN 978-3-8440-2947-5 .

[3] World market leader and top performance in the industry from South Westphalia. Chamber of Industry and Commerce Arnsberg, Hellweg-Sauerland, South Westphalian Chamber of Industry and Commerce in Hagen, Chamber of Industry and Commerce Siegen, August 2015, accessed on September 2, 2015 .