Key stages in ensuring the sealing performance of transformer tanks include optimized structural design, high-quality welding processes, selection of reliable sealing materials, and rigorous sealing testing.
These stages are interconnected and work together to ensure that the tank does not leak, infiltrate, or damage its insulation performance during long-term operation.
Structural Design: Reducing Leakage Risk from the Source
Avoid "+" joint welds: This type of structure is prone to stress concentration, increasing the risk of cracking. T-type or L-type joints should be preferred.
Use corrugated tanks or folded plate structures: Corrugated tanks compensate for oil volume changes through elastic deformation, reducing the impact of internal pressure fluctuations on the seal; folded plate tanks reduce the number of welds through overall bending, significantly reducing the probability of leakage.
Design a reasonable sealing groove structure: A rectangular groove sealing structure is recommended, combined with high-performance sealing strips, providing a large contact area and uniform stress distribution.
The compression of the sealing strip should be controlled at 25%–30% to balance sealing effect and service life.
Welding Process: Ensuring Weld Tightness and Integrity
Application of Gas Shielded Welding Technology: Such as CO₂/MAG welding, which effectively prevents oxidation in the weld zone and improves weld tightness, is widely used in corrugated sheet connections.
Controlling Welding Defects: Porosity is mainly caused by insufficient shielding gas coverage or inadequate purity, which can be prevented by increasing gas flow rate, eliminating nozzle spatter, and improving gas purity.
Using a laser weld tracking system enables millimeter-level precision welding, automatic deviation correction, and significantly improves weld consistency and sealing reliability.
Reducing Total Weld Length: Simplifying the structure as much as possible while meeting strength requirements reduces the possibility of leakage from the source.
