XIAOPAI S9-S22 series sealed oil-immersed power transformers deliver reliable performance for outdoor substations, industrial yards and distribution networks from 6-10 kV to 35 kV. The sealed tank design eliminates the need for a conservator, reducing maintenance and the risk of oil leakage. Compared with dry-type units of the same rating, oil-immersed transformers offer 20-30 percent lower unit cost, higher overload tolerance and a longer field-proven service life. The product line is widely used in utility grids, factory step-down, wind and solar farm step-up, and railway power supply. Every unit is CE certified, with full factory testing per IEC 60076, custom packaging for sea freight, and complete export documentation for FOB Ningbo dispatch.