Cutting and welding spiral steel pipes are crucial processes in pipeline installation and construction. Standardized operation ensures joint quality and improves construction efficiency and safety.
Cutting Processes: Common cutting methods include plasma cutting, flame cutting, and mechanical cutting. Flame cutting is often used for large-diameter, thick-walled spiral steel pipes due to its low equipment cost and ability to cut large thicknesses, making it suitable for on-site operations. Plasma cutting is often used for thin-walled or stainless steel spiral steel pipes, resulting in smooth cuts, a small heat-affected zone, and minimal deformation. For pipe ends requiring high precision, sawing or lathe cutting can be used to ensure perpendicularity and dimensional accuracy. Before cutting, proper marking and positioning are necessary. After cutting, burrs and iron oxide should be removed, and debris on the end face should be cleaned to ensure a clean and neat welding contact surface.
Welding Processes: Electromagnetic arc welding is the primary method for welding spiral steel pipes, including manual arc welding, gas shielded welding, and submerged arc welding. Manual arc welding and CO2 gas shielded welding are commonly used in on-site construction due to their flexibility and adaptability. Before welding, the bevel and both sides must be cleaned of oil, rust, and moisture. A suitable bevel should be cut according to the pipe wall thickness. During welding, the principle of tack welding first, followed by layer welding, should be followed by multi-layer, multi-pass welding for thick-walled pipes. Interpass temperature should be controlled to avoid defects such as incomplete penetration, slag inclusions, and porosity.
During welding, ensure the weld is full, free of cracks and undercut. After welding, clean the slag. For critical pipelines, non-destructive testing is also required. Strict adherence to specifications for cutting and welding effectively ensures the pipeline's sealing performance, pressure resistance, and structural strength, meeting the requirements of water supply and drainage, oil and gas transportation, and municipal engineering applications.
GB/T 7714
Zhao Haikun,Li Xiao,Li Jianping.On-site Welding Technology and Common Defect Prevention for Long-Distance Pipeline Spiral Steel Pipes[J].Welding Technology,2018,47(05):62-65
MLA
Zhao,Haihong,et al.“Field Welding Process and Common Defect Prevention of Spiral Steel Pipe in Long-Distance Pipeline.”Welding Technology,vol.47,no.5,2018,pp.62-65.
APA
Zhao,H.,Li,X.,&Li,J.(2018).Field welding process and common defect prevention of spiral steel pipe in long-distance pipeline.Welding Technology,47(5),62-65.
