FEATURE NEWS:
Sheathing for high voltage cable
Uniwema® is a new range of universal welding machinery developed by Nexans in Germany for the sheathing of core cable in high voltage cables. The metal sheath, with helical corrugation, is water and gas tight. It helps to ensure flexibility and also gives protection against high impacts and other external pressures.
For sheathing high voltage cables Nexans recommends the Uniwema 200 model because core diameters in this application range from around 45mm to 200mm. Nexans continues: “The sheath can be applied continuously with, for instance, aluminium with a wall thickness of approximately 0.5mm to 2.5mm (depending on the cable core diameter) in a very economic process compared to conventional extrusion or press technology.”
With Uniwema, a metal strip is fed in to
the machine and, in a single operation, the strip edges are trimmed and formed around a cable core. The opposing strip edges are welded using the TIG (Tungsten Inert Gas) welding method. Standard Uniwema machinery is equipped with a single electrode, but in applications where the maximum allowable welding current with one electrode is insufficient (for the welding of thicker strips or if a higher speed is desired) the Uniwema can also be operated with a 3-electrode welding torch system.
For fully continuous TIG welding, Nexans has developed a new system called TwinTorch®. The TwinTorch system consists of two torches, a control program and two welding rectifiers. If the worn out electrode has to be changed, the
PLC-controlled process will ignite the second torch. The worn out electrode can then be exchanged easily. TwinTorch technology, says Nexans: “ensures an uninterrupted, high quality welding seam without any welding defects”.
A split clamp caterpillar capstan, located downstream from the welding station, pulls the sheathed cable through the machine and, if added flexibility is desired, pushes it to the corrugation unit. Nexans concludes: “The perfect coordination of the forming and welding operations with the split clamp caterpillar capstan is a pre-condition for obtaining a uniform welded seam, thus ensuring optimum product quality.”
Company: |
Nexans Deutschland Industries GmbH & Co. KG |
Country: |
Germany |
Fax: |
+49 511 676-3777 |
Email: |
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Website: |