TPT March 2010

T echnology U pdate

Brushes used in tube construction

enable the welding procedure when the tubes are put together. Usually several rings of knotted wire brushes are mounted together to get one massive block of wheel brushes. The diameter of the brush, wire thickness and the overall shape of the brush are defined by the sizes of the tube, the material of the layers and the cut back machine in use. Lessmann offers brushes up to 500mm in diameter, filled with hard drawn high tensile wire. All production steps are controlled by CNC machines of the latest generation to get highest quality for maximum life time. Using Lessmann brushes is very effective and time saving. The brushes have a high durability due to the high quality of the wire producing an exellent brushing result. Lessmann GmbH – Germany Fax: +49 9082 70778

a clean surface to maintain a constant high capacity of the tube. Those inner surfaces of the pipeline are cleaned with so called dewaxing-pigs, a special construction which is mounted together from many single knots. In contrast to chemical solutions, which can also be used for removing the paraffin wax of the interior of the tubes, working with brushes is very environmentally friendly. No chemical waste accrues, which has to be disposed afterwards, so ecological problems can be avoided. Furthermore Lessmann offers brushes for removing the coating of tubes and pipelines. The external surface of steel pipelines is usually coated with epoxy resin and PE or PP layers. These layers protect the tube from corrosion, but they must be removed completely at the tube ends to

LESSMANN, Germany produces technical brushes that are used for cleaning or treating working pieces and surfaces. A major application area is the use of brushes in pipeline construction. Lessmann brushes are used for de-burring cutting edges. By using the brushes the burrs on the tube ends can be removed completely or a defined roundness can be obtained. Cutting edges of tubes are deburred very economically: brushes are the only tool that can reach the inner and outer edges of the tubes and can treat them in only one process step. As well as the manual treatment of cutting edges like de-burring with brushes on a table grinder it is common to use roller brushes in an automatic de-burring unit to be able to deal with high quantities. Steel tubes are usually treated with steel wire, for working with stainless materials, non-ferrous metal or brass, stainless materials or abrasive nylon as filling material are used preferentially. Another typical application is the cleaning of welded seams on pipelines. The welded seams must be removed of cinder and residue in order that the following welded seams of the multi-layered weld seam can be produced in a good condition. With a clean weld seam inaccuracies or faults in the previous welding process are evident at once and can be corrected immediately. For this application usually knotted wheel brushes with high tensile wires are used, because they work very effectively and save time. For transporting crude oil in pipelines, the oil is heated. This heating means that paraffin wax is diverged from the crude oil and tips in the interior sites of the tubes. The tubes must be checked for cracks regularly and, therefore, the paraffin wax and other deposits must be removed. It is also important to have

Email: info@lessmann.com Website: www.lessmann.com

Lessmann’s brushes are used for the economical de-burring of cutting edges

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M arch 2010

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