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7272 |
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Wednesday, May 04, 2022, Hall G2 10:50 AM Arc Spraying |
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Improved environmental safety of pipelines using high efficient wire arc spraying |
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Thomas Hohnen* / SMS group GmbH, Germany Michael Stark / SMS group GmbH, Germany Frank Lichtenthäler/ SMS group GmbH, Germany |
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Whenever large amounts of liquids or gases have to be transported over long distances, steel pipelines are chosen. They supply industry with raw materials, guarantee drinking water supply to large cities and guide energy carriers around the globe. Thereby, they have to contend with their biggest enemy: Corrosion. That is why corrosion protection is needed. A common standard for helical (HSAW), spiral (SSAW) or longitudinal submerged arc welded (LSAW) line pipes is the API 5L. For these kind of pipes, the typical outside protection consists of a polyethylene coating combined with a central cathodic protection system. However, studies are indicating that corrosion of pipelines is still the greatest “influenceable” challenge for pipeline users. Mainly failures occur in the field of the weld reinforcement: The polyethylene coating loses contact to the pipe at the weld seam due to movements or deformations of the steel pipe during transportation, lifting, laying down, etc. The risk of corrosion on the exposed areas can be minimize by means of a wire arc sprayed coating of Zn or ZnAl. Coating the whole pipe will even make a central cathodic protection and the coating with polyethylene unnecessary. A reduced risk of pipeline failures due to corrosion combined with the reduced use of plastic and its plasticizers will improve the environmental safety of the whole pipeline. To make this approach even more attractive to pipeline users, the coated line pipes need to be purchase at favorable conditions. Therefore, spraying equipment is needed, that combines a high deposition rate and a high deposition efficiency (DE). The wire arc system PERFECT spray 2000 meets both demands. Validation tests has proven a melting rate of more than 200 kg/h combined with a DE clearly above 75%. |