Abstract: A flexible electric heater element in the form of a band, comprising heating wires disposed in an electrically insulating base enveloped in a sealed sheathing, the current-carrying wires extending outside the sealed sheathing and disposed along at least one of the narrower sides of the heater element.

Abstract: A pipe heat transfer assembly adapted to be easily and rapidly installed with unskilled in the field on a pipe to be heated or cooled includes an elongated rigid channel cover member and a separate elongated, preshaped, solid, flexible strip of thermoplastic resin heat transfer material having a first surface preshaped to conform closely to the inner cavity surface of the channel member and a second surface preshaped to conform closely to the shape of the pipe surface on which it is to be mounted. The strip of heat transfer material may be pre-shaped by molding or extruding. An elongated heat transfer element, which may be an electric heating wire or an elongated tube for a heat transfer liquid to flow therethrough, is embedded in the strip during such pre-shaping. Alternatively, a space for reception of the heat transfer element can be formed in the strip during the pre-shaping of the strip and the element subsequently installed in the space.