Under proper design, excellent manufacturing, and a favorable operating environment, the sealing life of a transformer tank can typically reach 20 to 30 years, roughly consistent with the overall design life of the transformer. A fully sealed structure (such as a corrugated tank) achieves complete isolation between the transformer oil and air through welded seals and elastic compensation mechanisms, significantly slowing down the aging of the insulating oil and material corrosion, thus ensuring long-term sealing performance.
Key Factors Affecting Sealing Life
Structural Design: Fully sealed transformers use a design where the tank cover and edges are welded together, eliminating the need for an oil conservator. They rely on the corrugated tank or expansion radiator to automatically adjust for changes in oil volume, avoiding the leakage risks associated with traditional "breathing" structures. The corrugated plate walls have an expansion and contraction capacity exceeding 10,000 cycles, sufficient to withstand long-term temperature cycling.
Manufacturing Process: Welding quality is the core factor determining the sealing life. The application of gas shielded welding reduces defects such as porosity and cracks; simultaneously, reducing the number of welds (such as in a folded plate tank) effectively reduces the probability of leakage.
Operating Environment: Harsh environments such as high temperature, high humidity, salt spray, and dust can accelerate the aging of sealant components and metal corrosion, shortening the actual seal life. For example, in coastal areas, without special anti-corrosion measures, sealing performance may deteriorate prematurely.
Maintenance and Inspection: Although designed as "maintenance-free," the pressure relief valve, seal condition, and oil level still need to be checked regularly. Some models lack an external oil level gauge, requiring the use of a probe for detection, increasing the difficulty of maintenance.
