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Specialist Materials for Industry and Science

Welcome to MIDEL 7131 Ester-Based Transformer Fluid

Midel is a fire safe and environmentally friendly transformer fluid that provides excellent service in thousands of sealed and free-breathing systems around the globe.

At M&I Materials Limited we have been developing and producing Midel for over 30 years and pride ourselves on delivering manufacturing excellence and high standards of technical support.

Midel has an enviable track record in transformer systems ranging from offshore wind turbines to underground rail networks and it is the primary choice for demanding applications and high risk locations.

Why MIDEL 7131 is the Right Transformer Fluid for You

Increased Fire Safety

Midel has a high fire point (>300°C), 100% fire safety record and FM Global approval.

High Performance

Midel is a robust fluid with enviable success in demanding applications that experience extreme temperature variations and high overloads.

Greater Environmental Protection

Midel is readily biodegradable and non-water hazardous making it safe for use in ecologically sensitive areas.

Superior Moisture Tolerance

Midel has significantly more moisture tolerance than mineral oil or silicone liquid and can enhance the life of cellulose insulation and transformer service life.

Low Maintenance

High temperature stability and resistance to ageing have earned Midel a reputation as the ‘fill and forget' fluid.


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Products of M&I Materials Ltd.