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Material Compatibility with Insulating Oil

16 May 2025

Expert Oil Diagnostic Services

Insulating oil such as mineral oil, ester oil and silicone oil plays a critical role in the operation of transformer. Using this oil for insulation and cooling must be compatible with various materials within the transformer to ensure reliable operation. This article explores the importance of material compatibility and the effect of incompatibility.


Importance of Material Compatibility

Insulating oil interacts with several materials, including metals, gaskets, and insulation. Incompatibility between the oil and these materials can lead to degradation, leakage, and ultimately, transformer failure. Ensuring compatibility helps maintain the integrity of the transformer, reduces maintenance costs, and extends its operational life.


Testing for Compatibility There are two objectives of testing for compatibility:

  1. To evaluate the chemical and thermal stability including identify physical changes.

  2. To establish the correlation between oil and material related to the production of gases.


Effects of Incompatibility

Incompatibility between insulating oil and material can lead to several issues:

  1. Degradation of Gaskets and Seals: Incompatible oil can cause gaskets and seals to swell, harden, or crack, leading to oil leaks and reduced transformer efficiency.

  2. Corrosion of Metals: Reactive sulfur compounds in the oil can cause corrosion of copper and aluminum windings, leading to electrical failures.

  3. Insulation Breakdown: Chemical reactions between the oil and insulation materials can reduce the dielectric strength of the insulation, increasing the risk of electrical breakdown.

  4. Generation of gases: Can give wrong interpretation.


As conclusion, by conducting compatibility testing and selecting the correct materials, can mitigate the risks of degradation, leakage, and failure.


EtODS Experienced Performing Material Compatibility Study



Stray Gassing Study




For more info on our insulating oil analysis services, please don't hesitate to contact our team members:


Shaily Hatun Mohamed Saleh (shaily.hatun@tnb.com.my)

Muhammad Hadi Ahmad Fauzi (hadi.fauzi@tnb.com.my)

Roshaniza Ismail (roshaniza.ismail@tnb.com.my)

Nur Syahida Akryl Azam (nursyahida.azam@tnb.com.my)


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