From the analysis data of ERW steel pipe scrapping, it can be seen that the roll adjustment process plays a very important role in the production of welded pipes. That is, in the production process, if the rolls are damaged or worn seriously, some rolls should be replaced in time in the unit, or a certain type of ERW welded steel pipe should be continuously produced in sufficient quantity, and the entire set of rolls should be replaced.
When replacing the welded steel pipe, the roll needs to be adjusted accordingly to ensure the quality of the welded pipe. On the contrary, if the roll is not adjusted properly, it is likely to cause defects such as torsion, lap welding, edge fluctuation, indentation, scratches and even large ovality on the surface of the welded pipe on the protrusion and the pipe body.
The following is an introduction to the operation method of roll adjustment that should be mastered when changing rolls.
First of all, if the specification of ERW steel pipe should be changed, generally speaking, the whole set of rolls should be replaced. The steps of adjusting the roll type are: firstly, pull the steel wire at the inlet and outlet of the unit out of the center line, and adjust so that the pass pattern of each frame is on the center line, so that the forming line meets the technical requirements.
In order to ensure the welding quality of ERW steel pipes, the forming rolls, guide rolls, extrusion rolls and sizing rolls need to be adjusted once after replacing the rolls as required, and then focus on adjusting the closed-cell type, guide rolls and extrusion rolls. The role of the guide roller is to control the direction of the weld seam and the height of the bottom line of the welded pipe, reduce the edge extension, control the springback of the edge of the tube billet, and ensure that the weld seam entering the extrusion roller is straight and without distortion.
In short, during the welding process of welded steel pipe, when the welding machine is running at a slow speed, the welder must pay close attention to the rotation of the rollers of each part of the welded pipe, and adjust the rollers at any time to ensure that the welding quality and process size of the welded pipe meet the specification requirements.