TRANSFORMER OIL MATERIAL COMPATIBILITY

Transformer Materials Compatibility

MIDEL 7131 Synthetic Ester and MIDEL eN 1204 Natural Ester

As a general rule, materials that are used in the manufacture of standard mineral oil-filled transformers are compatible with MIDEL 7131 (synthetic ester fluid) and MIDEL eN 1204 (natural ester fluid).

These lists of compatible and incompatible materials have been compiled through a combination of testing and external data review, which the technical department at M&I Materials Limited are continuously conducting. This include for commonly used transformer materials, as well as some ancillary materials such as hoses and adhesives.

In all cases the user should confirm the suitability of any material to be used in equipment with MIDEL ester-based liquids.

The below list also draws attention to materials which are considered incompatible or are recommended for use only in particular circumstances. For example neoprene rubber may be used as a binder in cork composites but should not be used on its own. The list is not exhaustive and is intended for guidance only.

Materials are listed by type but within a specific type there may be available several proprietary formulations. The response of different formulations to MIDEL ester-based liquids may vary according to the additives used. This applies particularly to elastomers and polymers.

It is strongly recommended that if a material not listed is critical to equipment performance, the manufacturer should be consulted and tests carried out. We would be pleased to liaise with the manufacturer and if necessary arrange for additional tests to be carried out.

Compatible Materials

Incompatible Materials

Tap Changers

MIDEL fluids are approved for use with a range of tap changers from industry leaders such as MR and ABB. For more information on tap changer compatibility, including other brands of tap changer, get in touch with Insulect’s technical team.