Shell Diala S4 ZX-I
Shell Diala S4 ZX-I is a premium inhibited electrical insulating oil designed to meet the demanding performance requirements of modern power and distribution transformers. Developed using Shell’s advanced gas-to-liquid (GTL) technology, the oil provides outstanding oxidation stability, extended service life and excellent dielectric performance, making it suitable for high-reliability electrical equipment operating in challenging environments.
One of the key advantages of Shell Diala S4 ZX-I is its exceptional oxidation resistance, which helps deliver extended oil life and improved transformer reliability. The oil contains an advanced antioxidant system that slows the degradation process, helping maintain insulation performance and reduce the formation of sludge and acidic by-products. This allows transformers to operate efficiently for longer periods with reduced maintenance requirements and improved equipment longevity.
Shell Diala S4 ZX-I also provides superior transformer protection thanks to its ultra-low sulphur base oil formulation. Manufactured from zero-sulphur GTL base oils, the lubricant is intrinsically non-corrosive towards copper components and does not require metal passivators or other additives to prevent corrosion. The oil successfully meets stringent copper corrosion testing standards including DIN 51353, ASTM D1275 and IEC 62535, ensuring safe operation in transformers and associated electrical equipment.
Another key benefit of Shell Diala S4 ZX-I is its ability to support efficient thermal management within transformers. The oil’s low viscosity and excellent low-temperature flow properties enable effective heat transfer throughout the transformer system, helping maintain stable operating temperatures and improve electrical insulation reliability. The product is also carefully dried and handled during manufacturing to maintain very low water content and high dielectric breakdown voltage at delivery, enabling it to be used in many applications without additional treatment.
Environmental performance is another important feature of Shell Diala S4 ZX-I. The oil is readily biodegradable according to OECD 301B, making it particularly suitable for installations where environmental protection is a priority, such as transformers located near waterways, environmentally sensitive areas or urban infrastructure. The product is also free from PCBs, DBDS and metal passivator additives, supporting safer operation and regulatory compliance.
Shell Diala S4 ZX-I meets the requirements of IEC 60296 Type A inhibited transformer oils and is approved or recommended by major transformer manufacturers including Siemens Energy, Hitachi Energy, GE Grid Solutions and Maschinenfabrik Reinhausen. Physical characteristics include a density of approximately 805 kg/m³ at 20°C, viscosity of 9.8 mm²/s at 40°C, flash point of 191°C and a pour point of −45°C, ensuring reliable performance across a wide range of operating temperatures and environmental conditions.
