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Specialist Materials for Industry and Science

Cast Resin Transformers

Cast Resin Transformers

In the past, cast resin transformers have been widely used in a range of applications. However, there are some aspects in which they compare unfavourably against the benefits MIDEL 7131.

To illustrate this point, some of the key features of synthetic transformer fluid MIDEL 7131 have been outlined below.

Properties of MIDEL 7131

Fire Resistance

Protection against fire is a primary concern when installing transformers, as they can often be located in high risk areas such as inside buildings or on trains.

MIDEL 7131 offers a 100% fire safety record that makes it ideal for use in high risk environments such as underground power transformers.

Environmental Impact

MIDEL 7131 is also notable as an environmentally friendly transformer fluid. It is readily biodegradable and non-water hazardous, giving it an advantage over competing products. Additionally, Midel-filled transformers are much cheaper to recycle than cast resin transformers, as the fluid can often be retrieved and re-used.


Potential faults can be caught early on in Midel-filled transformers with DGA testing, allowing you to fix any damage before the problem becomes costly and time consuming. If a fault is detected, coils can be repaired with relative ease in liquid-filled transformers, whereas with cast resin they will often need to be replaced if a fault develops.

Midel ester has actually developed a reputation as the 'fill and forget' fluid, due to its robust nature, leading to very low maintenance requirements. In particular, cleaning is a much easier task; cast resin transformers must be tended to regularly especially in dusty environments.

Ask Us About MIDEL 7131

The information above is by no means an exhaustive list of the advantages MIDEL 7131 offers. It is the improved all-round performance and increased safety that have helped establish Midel ester fluid as a market leading product in transformer insulation.

If you wish to find out more about MIDEL 7131 or natural ester MIDEL eN, you can contact us by email, phone or post and we will be happy to answer any questions.



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Products of M&I Materials Ltd.