Repair of oil leakage and oil presence on the sealing surface

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Tags: Transformer leak sealing, Transformer oil leakage repair, Sulfur hexafluoride leak sealing, GIS gas leakage repair, Transformer with oil leak sealing, Reactor leak sealing, Flange oil leakage repair, Elevator base oil leakage repair, Bushing oil leakage repair, Bolt oil leakage repair, Gasket oil leakage repair, Weld seam oil leakage repair, Oil tank leakage repair, Oil storage tank leakage repair. http://player.youku.com/player.php/sid/XMjY2MTcwNDg2MA==/v.swf Oil leakage from oil-immersed transformers is a common phenomenon; the hazards associated with transformer oil leakage are well understood by those in the industry. Leaking oil is closely related to the manufacturing process of transformers, as well as the material of the components and the installation methods. Qingdao Yukew New Materials Co., Ltd., with its many years of experience in dealing with transformer oil leakage issues, has valuable insights on this matter. During the construction process, it was found that for the same imported components with the same installation requirements, imported original transformers can remain leak-free for 20 to 30 years, whereas domestic transformers start to leak within 3 to 5 years after installation – this is due to differences in the installation techniques. There are also issues such as the roughness of welds in the manufacturing process, and various pores and cracks in the forged base metal. The selection of sealing materials, bolt torque for tightening, and various other factors are all causes of transformer leakage. Common locations where leaks occur in oil-immersed transformers include: 1. Leaks at the sealing points, which mainly involve oil leakage from switches and valves, flanges, the bottom of the lifting base, bushings, as well as leaks from the top and bottom of the transformer box, as well as leaks from the terminal screen. 2. Leaks due to sand holes or weld defects, including oil leakage from the welds of the cooling fins and the transformer box itself, as well as leaks caused by defects in the casting process or weld-related sand holes. 3. Leaks caused by bolts, particularly those used for various connections, flanges, and butterfly valves. Analysis of conventional repair methods for transformer oil leaks: 1. For leaks at welds, repair welding is used; however, welding while there is still oil present requires extremely precise control over the welding process, and it may also contaminate the oil quality. Another method is draining the oil before welding, but this process is complicated and time-consuming, and the stresses resulting from welding make it easy for leaks to reoccur. 2. Oil leakage due to sand holes: Use a sharp tool in combination with a hammer to crush the sand hole, thereby forcing the metal to deform and sealing off the leak point. This method is very simple, but oil has strong permeability; as the metal expands and contracts with changes in oil temperature, the leak point can easily leak again. 3. Oil leakage caused by poor seals: Replace the sealing material. This approach yields excellent results as it eliminates the leakage at its source, but it usually takes longer to implement, is more costly, and repeated disassembly and assembly can affect the lifespan of the components. 4. Tightening the bolts is the best solution in cases of leakage caused by loose bolts; however, if the leakage is due to a problem with the seal rather than looseness, mechanical tightening will not resolve the issue, as highly penetrating oils can seep out from around the base of the bolts. After 2014, many companies specializing in fixing transformer leaks emerged on the market, offering various types of sealing adhesives. Imported ones can cost over 20,000 yuan per kilogram, while domestic ones cost a few hundred yuan per set; however, those that are truly effective at sealing leaks and can maintain that seal over time are extremely rare. These companies share one common feature: they mainly deal in the sale of materials and have very little experience in construction; they may undertake various types of repairs, but sealing leaks in transformers is just a simple form of repair. This is a misconception – sealing leaks in transformers is fundamentally different from ordinary repairs carried out under pressure. Qingdao Yuke Company has been specializing in transformer leak sealing for over a decade, boasting extensive experience in this field. The transformers we work on can last more than ten years on average. We have carried out leak sealing tasks on transformers at more than 20 hydropower stations, including those belonging to the Three Gorges Group, as well as at over 50 ultra-high voltage power supply stations belonging to entities such as the Southern Power Grid and **Power Grid. There are countless cases of work done on thermal power plant transformers as well. We rarely recommend specific materials to our clients; instead, we focus on providing them with more professional services. Even if clients choose to purchase materials on their own, we still offer them tailored construction advice. We insist that we may not be the cheapest option, but we are definitely the most reliable choice for you. The key material used by Yuke Company for sealing leaks in transformers is the oil and water-compatible repair material EG10. It provides strong adhesion both on oil surfaces and water surfaces; it does not shrink or deform during the curing process, can withstand temperature changes up to 140 degrees, and remains intact even under certain levels of deformation. It boasts an excellent resistance to oil penetration; the longer it is applied, the stronger the bond that is formed. Combined with YuKe’s unique application techniques, this sealing method provides a permanent solution. The material has no effect on the quality of the oil, and the application process is safe and pollution-free. Sealing can be carried out while the equipment is still in operation, as long as doing so poses no electrical hazard to people. It can provide a permanent fix for various types of oil leaks in transformers, as well as metal damage caused by oil leaks in steam engines. The extensive construction experience has earned it the affectionate nickname from clients as Yuke, the doctor of industry.