Why are SSAW steel pipes on the wrong side?

Why are SSAW steel pipes on the wrong side?

The misalignment of spiral submerged arc welded steel pipes refers to the parallel deviation of the strip along the thickness direction due to the misalignment of the edges on both sides of the strip when the steel pipe is formed and butted. The wrong side will cause the effective wall thickness of the steel pipe to be reduced, thereby affecting the mechanical properties of the steel pipe to a certain extent. Due to the irreparability of misaligned edges, misaligned edges are one of the main factors causing the deterioration of steel pipes.

Common reasons for misalignment of spiral steel pipe (SSAW):
1. When the head and tail butt weld reinforcement of the strip is large, if it is not handled properly during over-forming, it is easy to cause large misalignment.
2. The bending of the steel strip sickle is the most important factor causing the misalignment of the steel pipe. When the spiral welded pipe is formed, the camber of the strip will continuously change the forming angle, causing the weld gap to change, causing the weld to open, dislocate or even overlap.
3. The edge of the steel strip is in poor condition.
4. The shape and size accuracy of the head and tail of the untrimmed steel strip are poor, which can easily cause the steel strip to bend hard and cause misalignment during docking.

To address the main causes of misalignment of spiral welded pipes, take the following preventive measures.
1. Efforts to reduce strip bending
(1) Improve the ordering standards of raw strip steel for bending to meet the needs of producing qualified products.
(2) Before butt welding forming, the operator is required to operate carefully and use the control vertical roller correctly to reduce manual bending.

2. Correct operation of equipment and targeted routine inspections
(1) Regularly check the position of the strip conveyor line to prevent the strip from wandering.
(2) Correctly use the strip steel to control the vertical roller to prevent the plate edge from thickening.
(3) Frequently check whether the relevant positions and parameters of the forming machine, guide plate, pre-bending machine, and bridge output roller are appropriate, and make timely adjustments if any problems are found.

3. Control the solder joint position of internal welding. Control the welding of the welding seam within the bite point of the steel pipe without radial displacement of the plate edge (that is, no misalignment) to avoid misalignment defects.

4. Set up a steel pipe misalignment adjustment device

Article source: https://article-realm.com/article/Business/52106-Why-are-SSAW-steel-pipes-on-the-wrong-side.html