Precautions for repairing stainless steel containers

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Precautions for repair: There are the following precautions for repairing stainless steel containers, for your reference. 01 When repairing stainless steel pressure vessels, it is necessary to avoid scratches on the stainless steel surface caused by sharp or hard objects; if work needs to be done inside the vessel, protective measures such as using padding should be taken. 02 Stainless steel sheets should be cut using plasma cutting or mechanical processing; when mechanical processing is used, the machine tool must be cleaned thoroughly. Use of carbon arc gouging for cutting is not allowed. When rolling stainless steel into coils, the coiling machine should use iron-ion-free materials to cover the surface of the rollers. 03 During the repair process of replacing or patching the housing, tools such as wedges and shims that come into contact with the housing surface and are needed temporarily should be made of stainless steel suitable for the housing. 04 When repairing stainless steel pressure vessels that require resistance to intergranular corrosion, it is necessary to strictly follow the welding procedure specifications during welding, carefully control the temperature between weld layers, and polish away any carburized layers when cleaning the weld roots. The repaired area still needs to meet the original requirements. 05 Before repairing stainless steel pressure vessels, oil and other contaminants at the joints should be cleaned using acetone or alcohol. The cut area should be created by plasma cutting, and the surface should be polished until it has a metallic shine. When welding, it is not allowed to initiate the arc directly on the surfaces of the stainless steel that are not to be welded. When using manual arc welding, a splash guard layer with a width of 100 mm should be installed on both sides of the joint to help remove any splashes. 06 Stainless steel pressure vessels after repair must undergo acid washing and passivation; generally, immersion is the primary method for this process, but wet wiping or the use of paste applications can also be employed. 07 The surface of stainless steel after pickling shall show no obvious signs of corrosion, nor any patches with uneven coloring; the surfaces that have been welded or heat-treated shall not exhibit any oxidized colors. After pickling, it must be rinsed thoroughly with water; no residual pickling solution is allowed. The passivated stainless steel surface should be rinsed with water, and once it is neutral, the water droplets should be dried off. 08 For stainless steel pressure vessels that require resistance to intergranular corrosion, a check of the passivation film must be carried out after surface treatment. This check is generally performed in accordance with the specifications given in the drawings; if no such specifications are provided in the design drawings, the blue-dot method is used to examine the passivation film.