Transformer oil leak plugging without shutdown.

Keywords: Transformer oil leak sealing, transformer leak sealing, transformer flange oil leakage, transformer weld oil leakage treatment, transformer live leak sealing, oil leak sealing methods, transformer oil seepage The main causes of transformer oil seepage can be attributed to two aspects: on the one hand, issues left over from the transformer design and manufacturing process; on the other hand, oil leakage caused by improper installation and maintenance of the transformer. The main leakage points of transformers often occur at radiator interfaces, flat butterfly valve caps, bushings, porcelain insulators, welds, sand holes, flanges, and other locations. Qingdao Yuke New Material Co., Ltd. has developed a new water-oil compatible polymer alloy based on silicon steel alloy mixed with macromolecular reactive polymers. It provides strong adhesion on surfaces that can be simply treated by hand for both water and oil surfaces, effectively sealing high-frequency transformer oil. It is mainly used for transformer leakage, steam turbine leakage, generator oil seepage, reducer oil leakage treatment, etc., and can be quickly and effectively resolved without shutdown, pressure release, or oil drainage. Due to the material's excellent anti-aging properties, it ensures long-term effectiveness in leakage control. Transformer oil leakage is mainly concentrated in the following areas: over 50% of leakage points occur at radiator interfaces, flat butterfly valve caps, radiator plugs, and connecting flange seals; 16% are at bushings and porcelain insulators; 12% are at gas relay interfaces, etc. Additionally, there are some defects present during the transformer manufacturing process, such as welds, sand holes, etc. 1. Treatment of oil leakage at welding points: Cause of the problem: Mainly due to poor welding quality, including false welding, desoldering, and defects such as sand holes in the weld. During transformer manufacturing, these issues are covered by flux and paint, but they emerge during operation. Furthermore, electromagnetic vibrations can cause welding cracks, leading to leakage. Solution: For existing leaks, first identify all leakage points without omission. Continuously clean and trace the oil marks to find the source of the leakage. Use water-oil compatible sealant to seal the leakage points. After curing, long-term leakage control can be achieved. 2. Oil leakage in cast iron parts Cause of the problem: Oil leakage is mainly caused by sand holes and cracks in cast iron parts. Solution: For crack leakage, drilling stop holes is a method to eliminate stress and prevent extension. Depending on the crack condition, lead wire can be driven into the leakage point or sealed with a hand hammer. Then, clean the leakage point thoroughly and seal it with water-oil compatible sealant and titanium steel adhesive. 3. Oil leakage in radiators Cause of the problem: Radiator tubes are typically made from seamed steel pipes that are flattened and stamped. Leakage often occurs at the bent and welded parts of the radiator tubes. This is due to residual stress caused during the stamping process, where the outer wall of the tube is under tension and the inner wall is under pressure. Technical solution: After identifying the leakage location, perform appropriate surface treatment. First, use titanium steel adhesive for rapid sealing. After curing, reinforce with water-oil compatible repair agent. 4. Oil leakage at flange connections Cause of the problem: Uneven flange surfaces, loose fastening bolts, incorrect installation techniques leading to poor bolt tightening, and aging or cracking of seals can cause oil leakage. Technical solution: First, tighten the loose bolts and seal them with water-oil compatible repair agent. Then, treat the leaking flange surface to achieve complete leakage control. Tighten the loose bolts. 5. Oil leakage in seals Cause of the problem: Poor sealing is often due to the use of oil-resistant rubber rods or rubber pads for sealing between the tank edge and cover. If the joints are not properly handled, oil leakage can occur. Due to installation issues, the interface may not be tightly pressed, failing to provide effective sealing and resulting in leakage. Technical solution: Use water-oil compatible repair agent EG10 for bonding to integrate the joints, significantly controlling oil leakage. If convenient, simultaneously bond the metal casing, including the bolt areas, to achieve leakage control. 6. Oil leakage in bolts or pipe threads Cause of the problem: Rough processing during manufacturing and poor sealing can lead to oil leakage after the transformer has been sealed for some time. Technical solution: Seal the bolts with water-oil compatible repair agent to achieve leakage control. 7. Oil leakage in porcelain insulators and glass oil gauges Cause of the problem: Usually caused by improper installation or seal failure. Leakage points are often located at the junction between the porcelain insulator and the base. Technical solution: Use water-oil compatible repair agent and reinforcement tape to wrap and seal the leakage points entirely. Case 1: Oil leakage at the oil conservator lower oil pipe. Leakage occurred at the screw connection of the oil conservator lower oil pipe. After surface treatment, the leakage point was wrapped with water-oil compatible repair material as shown. Case 2: Oil leakage from pipe sand holes. A thermal power plant in Jiangsu experienced oil leakage at the main transformer oil pipe weld due to unbalanced tension caused by broken fan blades. The leakage point was wrapped with reinforcement tape. Case 3: Oil leakage from transformer weld. Due to welding process issues, thermal stress could not be eliminated, resulting in uneven thickness and multiple sand hole leakages. For severe leakage points, lead wire was used for temporary sealing, followed by sealing with water-oil compatible repair material. Case 4: Oil leakage from transformer flange due to aging seals and loose bolts. The bolts were tightened and sealed, and the flange surface was sealed with oil present. Case 5: Oil leakage from transformer bushings. Porcelain bushings, made of ceramic material, developed sand holes due to casting issues and were prone to cracking under temperature changes. Case 6: Oil leakage from transformer radiator fins.