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General Process Guidelines for Weld Repair 1. Scope of Application 1.1 These General Process Guidelines for Weld Repair apply to the repair of defects in pressure welds on the shells of steel pressure vessels as well as in butt welds of pipes. 1.2 When this General Procedure Code for Weld Repair is insufficient to ensure the quality of defects in special situations, separate specialized procedure documents must be developed. 2. Welders: Welders who are responsible for repairing welds on pressure-bearing components must pass the examinations stipulated in the \"Rules for the Examination and Management of Welders for Boilers, Pressure Vessels, and Pressure Pipelines\" issued by the General Administration of Quality Supervision, Inspection and Quarantine. In cases where repairs are required more than twice, a welder with experience in such repairs must be assigned by the person in charge of welding. 3. Welding materials: The welding materials used for welding should, in principle, be the same as those used for the original weld. However, if the original weld was created using submerged arc automatic welding and that weld needs to be repaired locally by using shielded metal arc welding, then corresponding shielded metal arc welding electrodes can be used. 4. Removal of defects 4.1 Based on the markings made by the non-destructive testing personnel and the records on the X-ray films, the defects are removed thoroughly using carbon arc gas gouging or other methods. 4.2 For manual welding repairs of stainless steel welds, lime slurry solution should be applied within a certain range on both sides of the weld before the repair is carried out, to prevent splashes from damaging the surface of the stainless steel. 4.3 When the removal depth has reached 2/3 of the plate thickness and the defect has not yet been removed, further removal should cease; instead, one side should be repaired first, then the defect should be removed from the other side, followed by welding repairs. 4.4 To remove welding defects, processes such as high-speed grinding wheels, carbon arc gas gouging, and air chisels can be used. After the defects are removed, it is necessary to clean out all iron shavings, slag, and dust from within the groove before welding repairs can be carried out. 5. Welding 5.1 In principle, the welding method is the same as that in the original process; however, when the original weld was created using submerged arc automatic welding and the length to be repaired is less than 500 mm, shielded metal arc welding can be used. 5.2 The selection of welding materials and the main process parameters are determined in accordance with NBT 47015 and the welding process. 5.3 The geometric dimensions of the weld surface shall meet the requirements specified in the product drawings and process specifications. 5.4 The Rework Record Card shall detail: product name, work order number, rework area, welding materials used for rework, welding method, welder’s name, rework date, and signature for welding inspection. 6. Inspection 6.1 The welding inspector shall supervise the entire rework process. 6.2 Check whether the repaired welding materials, methods, equipment, groove cleaning, and main process parameters are the same as those used during product welding or comply with relevant regulations. 6.3 Check whether the welder’s stamp and relevant repair records are correct and complete. 6.4 The non-destructive testing of the rewelded welds shall meet the same criteria as those for the non-destructive testing of the products of this series.