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Specialist Materials for Industry and Science

MIDEL 7131 Synthetic Ester

MIDEL 7131 Synthetic Ester

MIDEL 7131 is a fire safe, synthetic ester-based transformer fluid that has been successfully serving the global market since the 1970s. Our customers choose MIDEL 7131 for a wide range of applications because of its flexibility, reliability, high performance and asset life extension.

MIDEL 7131 has been specifically developed to provide a safe alternative to traditional fluid and dry-type transformers. It offers high temperature performance, increased fire safety, greater environmental protection and superior moisture tolerance. MIDEL 7131 has an enviable track record boasting thousands of projects, many of which are located in demanding or critical areas such as offshore and underground.

Recently the transformer industry has reported the failure of multiple large units due to the presence of corrosive sulphur. MIDEL 7131 has been tested by independent laboratories to ASTM D1275 B, Standard Test Method for Corrosive Sulphur in Electrical Insulating Oils and IEC 62535, Insulating liquids - Test method for detection of potentially corrosive sulphur in used and unused insulating oil. It was found to be Non-Corrosive.

In addition MIDEL 7131 is RoHS compliant; it does not contain the flame retardants PBB and PBDE, nor is it formulated using lead, cadmium, mercury or hexavalent chromium. The concentrations of these heavy metal contents are all below 1ppm.

MIDEL 7131 filled transformers are available from all major transformer manufacturers. MIDEL 7131 is compatible with standard transformer insulating materials, components and with fluid processing equipment and procedures. Midel is suitable for a wide range of transformer applications, including sealed and free-breathing transformers located indoors or outside.

M&I Materials provide free Midel names plates for your transformers. To find out more or order your plates please contact us today. 

Benefits of Using MIDEL 7131

Areas of Application

For further information please visit our Documents or Contact Us today.


  • Apiezon
  • Metrosil
  • Midel
  • Wolfmet

Products of M&I Materials Ltd.