The proposed heating element can be operated on a 6-220 V supply. It contains a 2-100mmthick conductive layer contg. 30-90% by volume of graphite in a synthetic resin. The electrical connection is made to this layer. The outside surface of this conducting layer is provided with a 0.5-3mm thick synthetic resin insulating layer contg. glass or polymer fibre, or other, mineral reinforcement. In some cases a 1-5mm thick outer metallic cover is also provided.
