∮325*4 What aspects should be paid attention to when repairing large-caliber sanitary elbows
∮325*4 What should you pay attention to when repairing large-caliber sanitary elbows. Generally speaking, the outer diameter of the sanitary elbow zero-cut specification is generally more than 159, or the meter weight is more than 40 kg, especially the large-diameter, high-wall thickness stainless steel Tubes are used to cut and sell more. The zero-cut length of stainless steel pipe is more than 200mm, and the longest is no more than 2m. When repairing large-diameter sanitary elbows, the construction unit shall perform welding procedure qualification in accordance with the JB4708 'Steel Pressure Vessel Welding Procedure Qualification' standard, and prepare the welding procedure accordingly. When repairing large-diameter stainless steel pipes with anti-intergranular corrosion requirements, the welding process specifications should be strictly followed during welding, and the temperature between the weld bead layers should be strictly controlled. When the weld bead is rooted, the carburized layer should be polished clean. The repaired parts still need to ensure the original requirements. Before repairing large-diameter stainless steel pipes, use acetone or alcohol to clean the oily and ineffective debris at the joints. Plasma cutting breaks should be polished to a metallic luster. Direct welding of large-diameter sanitary elbows is not allowed on the non-welded surface. For arc ignition, when manual arc welding is used, there should be an anti-spatter layer in the range of 100mm on both sides of the joint to remove spatter. The large-diameter sanitary elbow after repair should be pickled and passivated. Generally, the pickling passivation is mainly done by the dipping method, and it can also be done by the wet mopping method or the paste coating method. The surface of the large diameter sanitary elbow after pickling shall not have obvious corrosion marks, shall not have uneven color markings, and shall not have oxidation color on the surface of welding and hot processing. After pickling, it must be rinsed with water, and no pickling liquid is allowed to remain. The surface of the passivated stainless steel should be rinsed with water and wipe off the water after it is neutral. After the surface treatment of large-diameter stainless steel pipes with anti-intergranular corrosion requirements, passivation film inspection must be carried out. Generally, the inspection shall be carried out according to the drawing regulations. If there is no requirement on the design drawing, the blue dot method shall be used for the passivation film inspection. Our company operates all year round: sanitary manhole, stainless steel joint, stainless steel chuck, stainless steel elbow, stainless steel tee, stainless steel clamp, sanitary elbow sanitary tee, sanitary clamp, sanitary ball valve, sanitary butterfly valve , Stainless steel head, stainless steel union, sanitary check valve, sanitary diaphragm valve, sanitary quick-install elbow, sanitary quick-install tee, sanitary quick-install ball valve, sanitary quick-install butterfly valve, sanitary quick-install Union, sanitary quick fitting, sanitary mirror tube, sanitary stainless steel pipe, sanitary seamless pipe, stainless steel sanitary pipe, sanitary leather pipe joint, stainless steel leather pipe joint, sanitary sampling valve, sanitary quick install Wire, sanitary quick-installed outer wire, sanitary quick-installed leather joint, sanitary level gauge. Various materials, conventional stock, non-standard can be customized.