FEP is the abbreviation for Fluorinated Ethylene Propylene. It is a type of fluoropolymer/fluoroplastic that can be used as both a cable sheathing and insulation material. FEP cables are often compared to PTFE and PFA cables as it shares similar properties such as an inert reactance to chemicals, high dielectric strength, and a broad temperature range (although it’s not as high as the others).
With these physical and electrical attributes, it’s often used on high temperature sensor wires as it allows the power transmittance with minimal losses during the transmittance of signals. As such, FEP insulation and/or sheathing is specified in industries including aviation, life sciences, oil, gas and petrochemical, and defence applications.