Longitudinally Welded Pipe Bevel Preparation
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Solution Overview
Problem
The existing methods for producing longitudinally welded metal pipes are inefficient and costly due to the need for multiple layers of run-up and run-out plates, which can lead to cavities and increased risk of welding defects, especially when preparing circumferential welds, requiring frequent changes of milling heads and increased production effort.
Innovation Solution
A method where the metal sheet is provided with a bevel on at least one transverse edge before bending, eliminating the need for chamfers under run-up and run-out plates, allowing for simpler and cost-effective preparation of circumferential welds using a milling head that can switch between a 90° angle and an inner V-profile, reducing production costs and effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If run-up and run-out plates are prepared with multiple layers to adapt to chamfers for circumferential welds, then the circumferential weld preparation is enabled, but cavities form between the plates and circumferential seam preparation, significantly increasing the risk of welding defects
Solution Approach 1:
The invention applies preliminary action by providing the bevel on the transverse edge of the metal sheet before bending it into a tube. This pre-prepared bevel eliminates the need for subsequent chamfering operations and multi-layer plate assemblies, allowing run-up and run-out plates to be directly attached without creating cavities. The bevel is created at a specific distance from the longitudinal edges to ensure proper positioning for circumferential welding while maintaining reliability.
Solution Approach 2:
The invention extracts the problematic chamfering operation and multi-layer plate structure from the manufacturing process. By providing the bevel directly on the transverse edge before bending, the patent removes the need for complex run-up and run-out plate preparations, eliminating the source of cavities and welding defects while simplifying the overall manufacturing process.
2Adaptability or versatility
If milling heads are changed frequently to produce different bevel angles for circumferential welds, then various bevel requirements are met, but production effort and production costs increase significantly
Solution Approach 1:
The invention applies universality by designing a single milling head configuration that can produce the required bevel on the transverse edge before bending. This universal approach eliminates the need to change milling heads for different bevel angles, as the bevel is provided in a standardized position and orientation that works for all circumferential weld preparations. The milling head operates in a fixed vertical position to mill the bevel, improving productivity while maintaining adaptability.
Solution Approach 2:
The bevel is prepared in advance on the transverse edge before the bending operation, allowing a single milling head configuration to serve all subsequent welding operations. This preliminary action eliminates the need for frequent milling head changes during production, significantly improving productivity while maintaining the versatility needed for different pipe configurations.
3Ease of manufacture
If chamfers are provided on transverse edges for circumferential welds, then weld preparation is enabled, but run-up and run-out plates require complex preforming and multiple layers, increasing production complexity
Solution Approach 1:
The invention applies preliminary action by providing the bevel on the transverse edge of the metal sheet before bending it into a tube. This pre-prepared bevel eliminates the need for subsequent chamfering operations and multi-layer plate assemblies, allowing run-up and run-out plates to be directly attached without complex preforming. The bevel is created at a specific distance from the longitudinal edges to ensure proper positioning for circumferential welding while simplifying the overall manufacturing process.
Solution Approach 2:
The invention extracts the problematic chamfering operation and multi-layer plate structure from the manufacturing process. By providing the bevel directly on the transverse edge before bending, the patent removes the need for complex run-up and run-out plate preparations, eliminating the source of cavities and welding defects while simplifying the overall manufacturing process.
Data Source
Figure 1~2
AI summary
The method involves bending the metal sheet (1) into a tube, so that two longitudinal edges form welded joints (6) for the longitudinal seam. A delivery plate (7) is provided on both sides of the welded joints. The execution of the longitudinal weld seam is started at the start plate, then along the weld joint and finally to the delivery plate. The metal sheet is provided with a chamfer (5) spaced from the longitudinal edges and ends, before bending during preparation of a circular weld seam on transverse edge (4). An independent claim is included for metallic pipe.