High performance silicone transformer oil

LK-STO 50

Next-Generation Cooling & Insulating Solution for High-Voltage Equipment

LK-STO 50 is a crystal-clear, non-toxic, non-halogenated silicone-based transformer fluid / Silicone Transformer Oil engineered for high-performance electrical insulation and efficient thermal management. Based on 50 cSt PDMS, it delivers unmatched dielectric strength, oxidation resistance, and environmental safety ideal for transformers and electrical systems that demand reliability across extreme conditions.

Key features

  • High Dielectric Strength: Excellent electrical insulation; meets IEC 836 and ASTM D 4652-92 standards.
  • Superior Thermal Stability: Withstands extreme temperatures and resists oxidation ideal for long-term transformer performance.
  • Enhanced Heat Dissipation: As a liquid system, it efficiently removes heat from the core and coil, offering greater overload capacity, lower maintenance, and extended insulation life a distinct advantage of silicone fluids.
  • Optimal Viscosity (50 cSt): Ensures efficient flow and reliable cooling under various operating conditions.
  • Safe & Environmentally Friendly: Non-toxic, non-halogenated, and additive-free; classified as non-hazardous and safe for long-term use.
  • Moisture & Chemical Resistance: Inert and stable even in harsh environments, protecting internal components.
  • High Fire Safety Margin: Flash point above 285°C and fire point of 370°C, with lower heat release than other Class K liquids.
  • Broad Material Compatibility: Compatible with a wide range of solid insulation materials, enhancing design flexibility.

Typical Properties

Parameter Unit Value
AppearanceCrystal Clear Liquid
Density at 25°Cg/cm³0.96
Viscosity at 25°CcSt~ 50
Water Contentppm< 50
Specific HeatkJ/kg·K1.51
Thermal ConductivityW/m·K0.151
Refractive Index at 25°C1.404
Breakdown VoltagekV50
Relative Permittivity at 25°C2.5
Dissipation Factor at 25°C0.0001
Volume Resistivity at 25°COhm·cm1.0 × 1014
Flash Point (Open Cup)°C~ 300
Fire Point (Open Cup)°CAbove 340
DC ResistivityGΩ·mAbove 100
Pour Point°CBelow minus 50

Applications:

LK-STO 50 is specially designed for use in transformers as a cooling and insulating liquid. One of its key advantages is its ability to efficiently remove heat from the transformer’s core and coil assembly. This helps the transformer to:

  • Handle higher electrical loads
  • Require less maintenance
  • Achieve a longer operational life

Silicone liquids like LK-STO 50 offer the highest thermal stability among all insulating fluids, making them ideal for demanding and high-temperature applications.

FAQs

What is LK-STO 50?

LK-STO 50 is a high-performance, silicone-based transformer liquid designed for efficient cooling and superior electrical insulation in high-voltage equipments. It is based on 50 cSt polymer and is known for its thermal stability, dielectric strength, and environmental safety.

  • Excellent dielectric strength (50 kV)
  • High thermal stability across wide temperature ranges
  • Efficient heat dissipation
  • Non-toxic and non-halogenated
  • Fire-safe with a high flash point (~300°C)
  • Chemical and moisture resistant
  • Compatible with solid insulation materials

Unlike mineral oils and esters:

  • It is non-toxic and non-halogenated
  • Offers higher thermal stability
  • Provides a wider operating temperature range
  • Has a lower heat release rate, improving fire safety
  • Is chemically inert, minimizing degradation over time
  • Transformer fluid LK-STO 50 is recyclable.
  • Power transformers
  • Distribution transformers
  • High-voltage switchgear and reactors
  • Insulated electrical systems operating under severe thermal and environmental conditions
  • Non-hazardous
  • High flash point (~300°C) and fire point (>340°C)
  • Exhibits low smoke generation and low heat release rate
  • Free from halogens and additives that can produce toxic by-products

The dielectric breakdown voltage is ~50 kV, meeting the requirements of IEC 836 and ASTM D4652-92 standards.

The transformer fluid LK-STO 50 has a viscosity of ~50 cSt at 25°C, offering an optimal balance between flowability and thermal transfer, ensuring efficient circulation and cooling under various operational conditions.

Yes, product transformer fluid LK-STO 50 is environmentally friendly because it is –

  • Recyclable
  • Non-toxic and non-hazardous
  • Additive-free and halogen-free
  • Has excellent oxidative stability and long service life, reducing fluid replacement frequency and waste generation

No, LK-STO 50 is not manufactured in China. It is produced by Elkay Chemicals in India, adhering to high-quality manufacturing standards and strict regulatory compliance. We ensure consistent product quality and reliable supply from our state-of-the-art facility in India.

Yes, LK-STO 50 transformer oil  manufactured by Elkay Chemicals in India is available for international shipping. We supply to customers across various global regions, including North America, South America, Europe, Asia, the Middle East, Africa, and Australia.
Our logistics and export team ensures smooth and compliant delivery to all major international markets. For detailed shipping information and support, please contact our sales team.

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