Synethetic Ester – MIDEL® 7131

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

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

Recently, the transformer industry has reported the failure of multiple large units because of the presence of corrosive sulfur. MIDEL 7131 has been tested by independent laboratories to ASTM D1275 B, standard test method for corrosive sulfur in electrical insulating oils and IEC 62535, insulating liquids - test method for detection of potentially corrosive sulfur in unused and used insulating oil. It was found to be non-corrosive.

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

The MIDEL 7131 filled transformers are provided by all key transformer manufacturers. The MIDEL 7131 is considered to be compatible with typical transformer insulating materials, components and also with fluid processing procedures and equipment. Midel is ideal for an extensive range of transformer applications, including free-breathing and sealed transformers located outside or indoors.

M&I Materials offer free Midel names plates for transformers.

Benefits of Using MIDEL 7131

  • Increased fire safety
  • High performance
  • Asset life extension
  • UL® Classified
  • ATEX Certification
  • REACH Registered
  • RoHS compliance
  • Low maintenance
  • Exceptional customer service
  • Expert technical support
  • Superior moisture tolerance
  • Greater environmental protection
  • FM® Global Approved Less Flammable Transformer Fluid

Areas of Application

  • Tapchangers
  • Retrofilling
  • Traction transformers
  • Rectifier transformers
  • Pole-type transformers
  • Power transformers up to 433 kV
  • Thyristor cooling in power electronics
  • Distribution transformers in urban areas and buildings

Other Equipment