Method for preventing oil leakage of oil immersed transformer
Writer： Hengfeng you electric Time：2023-04-13 views：times
Oil immersed transformer occupies a large market share in China, but the oil leakage of oil immersed transformer is also a disadvantage of this type of transformer. Over the years, manufacturers and users have been looking for solutions and effective treatments. Through communication with manufacturers, power plants, power maintenance and other institutions, and combined with their own analysis in the maintenance process, the following reasons are summarized and the treatment scheme is put forward.
1. Select seals with good materials
When inspecting and repairing oil immersed transformers and dealing with leakage, seals with good high temperature and oil resistance shall be selected. The most commonly used sealing material in domestic transformer industry is nitrile rubber. Its oil resistance mainly depends on the content of acrylonitrile in nitrile rubber. The higher the acrylonitrile content, the better the oil resistance, the higher the hardness, and the less the possibility of deformation. Generally, nitrile rubber with shore hardness between 70 and 80 shall be selected. When evaluating the oil resistance of gaskets, gasket aging test and compatibility test with transformer oil shall be carried out. The gasket shall be soaked in hot oil at 120 ° C for 168h, and then the change rate of weight, volume and hardness shall be measured. This is a standard seal with small deformation.
2. Select high-quality butterfly valve
Zf80 vacuum eccentric butterfly valve is selected as the butterfly valve. Compared with ordinary butterfly valve, the mechanical strength and surface finish of vacuum eccentric butterfly valve have been greatly improved, and one of the biggest advantages of this product is to adopt double-layer seal at the interface of transformer flange, so as to eliminate this phenomenon. Oil leakage at transformer interface.
3. Plug the leakage with electric welding
For oil immersed transformers caused by casting pores, sand holes, welds, welded joints, welds, desoldering and cracks, electric welding can be used to plug the leakage. Before plugging and welding, the leakage point shall be found first. If the leakage point is small, the leakage point can be directly welded by electric welding point; If the leakage point is large, asbestos rope or metal filler shall be filled first, then surfacing shall be carried out around it, and then small welding rod shall be used. High current fast arc repair welding.
4. Standardize the replacement process of seals
For transformers of different models and capacities, whether flanged or threaded, the dust and rust on the connection surface must be removed before replacing the seal. After cleaning the seal, apply sealant on both sides of the seal (usually 609 polymer liquid sealant). After the sealant has dried for a period of time, the solvent evaporates, and then tighten the flanges and screws.
5. Improve the installation technology level to prevent leakage caused by improper installation methods
If the flange interface is uneven or deformed and misaligned, correct the interface first. If the flange is seriously misaligned and cannot be corrected, the flange can be cut and re welded. Ensure that the interfaces are parallel. During installation, the compression of gasket shall be about 1 / 3 of its thickness.
6. Quickly seal and block the leaking rubber rod to block the leakage
This method is applicable to the leakage points of transformer with small liquid leakage and thin radiator wall, which are not suitable for electric welding plugging. When plugging with plugging adhesive tape, the oil, paint and oxide at the plugging part must be completely removed to make the metal show a real color. Then adjust the glue plugging in proportion to block the leakage until there is no leakage.
The above is how to prevent oil leakage of oil immersed transformer. If you still don't understand, you can call our transformer manufacturer's staff: + 86 15853252696, or if you need to visit the specification and model of oil immersed transformer for more information, you can click the link above.
