Analysis and solutions for misalignment of spiral welded pipes

During the production process of spiral welded pipes, if the production process is unreasonable and the machine parameters are not set appropriately, deviation will occur, especially for large-diameter spiral welded pipes. This is what people often call the misalignment phenomenon.

The treatment plan for spiral steel pipes that have been offset after production is as follows:

1.Method

1. Grind the wrong edge and then perform repair welding.
2. If the wrong side occurs frequently, the only option is to replace the equipment.

2.Cause

1. The sickle bend of the steel strip is the main factor causing the misalignment of the steel pipe. In the forming of spiral welded pipes, the sickle bend of the steel strip will continuously change the forming angle, causing the weld gap to change, resulting in seams, misaligned edges and even overlapping edges.
2. When the weld reinforcement of the head-to-tail butt welding of the steel strip is large, if it is not handled properly during over-forming, it is easy to cause large misalignment.
3. Due to the poor shape and size accuracy of the head and tail of the untrimmed steel strip, it is easy to cause the steel strip to bend hard and cause misalignment during docking.
4. The poor edge condition of the steel strip is another important reason for the wrong edge.

Therefore, observing the sickle bending situation of the steel strip coil after uncoiling, controlling the vertical roller so that the disc shear can cut off part of the sickle bend, and continuously controlling and correcting the forming angle are effective ways to reduce the misalignment of the steel strip sickle bending during the production process.