We’ve mentioned that roll adjustment had a great influence on ensuring the quality of high frequency welded pipe in the process of production, so now we can talk about techniques of roll adjustment when changing roll.
1) Replace the steel pipe specifications, we generally replace a complete set of roll. Roll adjustment method is: use a wire to pull a centerline from the unit inlet to the outlet, and make the molding line to meet the technical requirements. After changing the roll specifications, we need to make a comprehensive adjustment for forming roller, guide roller, squeeze roller, sizing roller firstly, and then focus on the adjusting the closed hole of forming roll, guide roller, squeeze roller.
2) The role of the guide roller is to control the direction of the pipe seam and tube’s bottom line height, ease the edge of the extension, control the rebound of the edge of the tube, ensure that the pipe straight without turning into the squeeze roller. Such as the guide roller adjustment is not good, it is easy to cause steel pipe seam torsion, lap welding, waving deformation around edges and other welding defects in the steel pipe welding process.
3) The squeeze roller is the key equipment of the welded pipe unit, its role is to make the pipe body which the edge of had been heated to the welding temperature to complete the pressure welding under the pressure of extrusion roller. In the production process, wo should control the size of the extrusion roll opening angle. When the extrusion pressure is too small, the weld metal strength will decrease, and it will crack when it is forced; When the extrusion pressure is too large, the welding strength will be reduced and the outer-burr amount will be increased, it will be easy to result in lap welding and other welding defects.
4) In the slow turning starting sequence of the welded pipe unit, we should pay close attention to the bearing rotation of the various parts of the roll, and adjust the roll at any time to ensure that the welding pipe welding quality and process size in line with the requirements.