Shell Products

Shell Diala S2 ZU-I


Shell Diala S2 ZU-I is a fluid designed to protect your valuable equipment. Widely recognised and approved by leading equipment manufacturers, it is non-corrosive to copper and does not require a copper passivator, as proved in the latest copper corrosion tests. Manufactured from highly refined mineral oils, it has resistance to oil degradation by oxidation and good low-temperature properties, which are vital for efficient heat transfer inside the transformer, even at low temperatures.


Designed to protect

Protecting components from damage can help to increase service life and maximise your return on investment in equipment. Shell Diala S2 ZU-I provides continuing transformer protection in service. In the industry-standard test, it produced

  • less than 50% of the maximum specified limit for sludge.

Designed for long oil life

Shell Diala S2 ZU-I is an uninhibited electrical insulating oil that offers reliable and predictable long-term performance. It meets the oil life and oxidation requirements (164 hours at 120ºC) specified in the industry-standard test (IEC 60296).

Designed for HIGH efficiency

Shell Diala S2 ZU-I is designed to help maximise effectiveness by helping equipment to meet or exceed its design capabilities. Compared with the industry minimum requirements, it offers

  • good low-temperature viscosity, which provides optimised heat transfer at low temperatures.

Specifications and approvals

Shell Diala S2 ZU-I meets the requirements of the key industry tests and the specifications of most equipment manufacturers and utility companies.

Real-world val ue delivery

Shell Diala S2 ZU-I is one of the latest uninhibited electrical insulating oils from Shell. It has been designed to offer reliable performance and effective protection for transformers throughout their operating lives.


Whatever your needs or application, we can provide a full range of oils and greases, including synthetic, high-performance products and additional services.