Reasons for the wrong side of large-diameter spiral steel pipe

In the production process of spiral steel pipe, if the production process is unreasonable and the machine parameters are not properly set, there will be deviations, especially for large-diameter spiral steel pipes, which is often referred to as the wrong side phenomenon.

During the production of spiral steel pipe, the wrong side occurs from time to time, and there are many influencing factors. In production practice, the steel pipe is often degraded because of the wrong side and out of tolerance. Therefore, it is very necessary to analyze the cause of the wrong side and its preventive measures. The following are the common reasons for the wrong side.

1. The sickle bend of the steel strip is the main factor causing the misalignment of the steel pipe. In the forming of the spiral welded pipe, the camber of the steel strip will continuously change the forming angle, resulting in the change of the weld gap, resulting in seam opening, misalignment or even overlapping.
2. When the excess height of the butt welding seam of the head and tail of the steel strip is large, if it is not handled properly during overforming, it is easy to cause a large misalignment.
3. Due to the poor shape and dimensional accuracy of the head and tail of the uncut steel strip, it is easy to cause the steel strip to bend hard and cause misalignment during butt joint.
4. The poor edge condition of the steel strip is another important reason for the wrong side.

Therefore, observing the camber after uncoiling of the steel strip coil, controlling the vertical roller to enable the disc shear to cut off part of the camber and continuous control and correction of the forming angle are effective methods to reduce the misalignment of the steel strip camber in the production process.

The treatment plan for the spiral steel pipe that has been misaligned after production is as follows:

1. Grind the wrong side position, and then carry out repair welding.
2. If the wrong side often occurs, you can only replace the equipment.