Damage treatment: The staff should present the single-line diagram according to the technology before construction, mark the code of the pipeline, prepare the relevant welding process card, and prepare the groove according to the welding bottom. Before cutting the pipe, the original trademark should be transplanted, and the acetylene flame of the carbon steel pipe should be used for cutting. When cutting, the correct size and smooth surface should be ensured. Using mechanical or ion to cut stainless steel pipes and non-ferrous metal pipes, it will be found that the surface of the pipe is relatively flat, without cracks, heavy skins and burrs, and the inclination of the end face will not exceed 3mm. Inspectors should reconfirm the grooves, dimensions, and assembly requirements before handing over the process, so that the quality of the groove can be confirmed and the welding process performed correctly.
The prefabrication of the pipeline: the quality and the ease of installation, the specific segment marks should be marked on the pipeline, and the free pipe section and the closed pipe section should be reasonably selected. The adjustment length of the on-site connection pipeline should maintain a margin of 50mm, and the corresponding number and welding seam should be marked on the preform. Ensure that the prefabrication direction of the pipeline is consistent with the installation direction on site, so as to prevent the inconsistency between the installation and the icon. The welding group of the pipe fittings shall be flush with the inner wall, and the misalignment of the inner wall shall not exceed 10% of the wall thickness and shall not exceed 2mm. Pipe Installation: Pipe plugs and plastic seals should be removed prior to installation. If it is lifted, the angle should be kept inclined at 45°, and the steel pipe should be tapped by hand to further remove the debris in the pipe. After cleaning, it needs to be reconfirmed by the relevant quality personnel. At the same time, it is forbidden to place any items in the test tube during installation. Regarding the safe transportation of the pipeline to the construction site, the unloading and specific placement should be carried out according to the specific direction of the icon. The setup of the pipe is the key to ensuring the quality of the weld and good formation of the back of the pipe. If the gap and blunt edge of the groove are not suitable, it is easy to cause defects such as undercuts, weld flashes and incomplete penetration. It should be ensured that the gap is uniform and the inner wall is kept flush. If the wall thickness is inconsistent, it should be repaired according to specific regulations.
