BSOs are rubber bags manufactured by SAT and installed inside the power transformer tank. They allow for variations in oil volume, thus protecting the oil from any type of contamination (external corrosive agents such as air, ozone, nitrogen, humidity, etc.). Their high-resistance fabric and technology coated with nitrile rubber, vulcanized at high temperatures under vacuum, guarantee the following advantages :

• Its excellent impermeability;

• Manufacturing without the use of glue;

• Vulcanized flange, ensuring greater reliability;

• Quick and easy assembly;

• High mechanical resistance;

• Manufacturing on request;

• Lightweight and easy to move product;

• Internal barrier film with high impermeability and adhered to the rubber during the vulcanization process.