Abstract: A parallel, zoned heating cable wherein parallel electrical conductors are spaced outwardly from a central heating element preferably formed of a fibrous material containing carbon or graphite or coated with a conductive polymer. Heat conducting dielectric members are preferably located between the heating element and the electrical conductors for improved thermal distribution of the cable. The conductors are alternately connected by splices to the electrical conductors to produce heat of a constant wattage.

Abstract: A skin effect heat generating pipe for use with a low frequency alternating current source includes a ferromagnetic pipe (e.g., steel) having thickness substantially greater than the penetration depth of the current of the frequency of the power source. A shunt conductor in the form of an electrically conductive metal layer (e.g., copper) is applied as a discrete layer to the inner surface of the pipe and in electrical contact therewith throughout the length of the shunt conductor, thereby forming a parallel resistance circuit wherein both the shunt conductor and pipe each are capable of conducting substantial current. One end of the pipe is electrically connectable to a first terminal of the power source. A return conductor installed in the pipe and electrically insulated therefrom has one end electrically connected to the second end of the pipe and its other end electrically connectable to the other terminal of the power source.

Abstract: A self-monitoring heat tracing system including a heating conductor, a monitor conductor, and a control circuit which monitors the integrity of the heat tracing conductor and provides alarm signals to indicate abnormal temperature conditions in the heating system or discontinuities in the monitor circuit.

Abstract: A new and improved heat transfer apparatus and method, wherein a heat tracing conduit assembly provides a self-contained closed conduit loop formed of two concentric tubular conduit members which may be laid as a single unit on the fluid pipe, thereby eliminating the need for a separately mounted return conduit.

Abstract: A method and apparatus for parallel-type heating cables. In accordance with the present invention a heating core element is formed by connecting two essentially parallel bus wires with a plurality of electrically conductive splices to a centrally disposed resistive element and around which heating core element a protective sheath is formed. The present invention permits this heating core element to be formed by splicing the spaced apart, essentially parallel wire elements followed by a single extrusion application of a protective sheath.

Abstract: A heating assembly adapted to be releasably mounted externally of an instrument for the transfer of heat to the instrument by conduction to maintain the instrument at a desired temperature.

Abstract: A heating assembly adapted to be releasably mounted externally of an instrument for the transfer of heat to the instrument by conduction to maintain the instrument at a desired temperature.

Abstract: An electrical heating cable which limits power output once an established temperature limit is reached. The cable includes a high-resistance element and a temperature-sensitive variable resistance element electrically connected in series between two electrical conductors otherwise insulated from each other by insulating material. The temperature-sensitive resistance undergoes a substantial positive increase in resistivity when the temperature of the cable nears the established temperature limit. The increase in resistivity substantially reduces the heat-generating current flowing in the cable to limit the power output.

Abstract: An electrical heating cable which limits power output once an established temperature limit is reached. The cable includes heating elements in the form of temperature-sensitive variable resistance elements electrically connected in parallel between two supply bases at spaced positions along the length of the buses. The heating elements not only serve to generate heat for heating but also undergo a substantial positive increase in resistivity when the temperature of the cable nears the established temperature limit. The increase in resistivity substantially reduces the heat-generating current in the cable to limit the power output to within established heat limits.

Abstract: A mounting apparatus for releasably securing an external member to a tubular member having a resilient, curved clamp member with open ends. The curved clamp member extends for more than 180.degree. but less than 360.degree., having a diameter less than the diameter of the tubular member prior to mounting the curved clamp member to the tubular member. The curved clamp member further includes a mounting portion opposite the open ends for engaging an external member for holding the same securely to the tubular member.

Abstract: A preinsulated pipe assembly and pipeline formed from a plurality of such assemblies. Each pipe assembly includes a pipe with a heater housing mounted thereon to form a cavity along the exterior of the pipe and a preformed insulation layer for insulating the pipe and the heater housing. A connecting assembly is used to join the pipe assemblies and form a pipeline. Pull means detachably connected to a heating element facilitates placement of the heating element in the heater housing cavities, and a pulling assembly attached to the heater element permits removal of the heater element after installation of the pipeline.

Abstract: A preinsulated pipe assembly and pipeline formed from a plurality of such assemblies. Each pipe assembly includes a pipe with a heater housing mounted thereon to form a cavity along the exterior of the pipe and a preformed insulation layer for insulating the pipe and the heater housing. A connecting assembly is used to join the pipe assemblies and form a pipeline. Pull means detachably connected to a heating element facilitates placement of the heating element in the heater housing cavities, and a pulling assembly attached to the heater element permits removal of the heater element after installation of the pipeline.

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.

Abstract: Pipe heat transfer assembly and method of making same, wherein a strip of heat transfer material is pre-shaped to a solid flexible form for closely .[.comforming.]. .Iadd.conforming .Iaddend.with a heat transfer element for either heating or cooling and which is also pre-shaped to fit closely within an external channel member, whereby the entire assembly may be more easily and rapidly installed with unskilled labor in the field on a pipe to be heated or cooled, using retaining band means as the holding means for the assembly, with the assurance of complete coverage of the heat transfer element by said heat transfer material so as to eliminate air gaps. The heat transfer material may be pre-shaped by molding or extruding, with the heat transfer element embedded therein during such pre-shaping, or with a preformed space for the heat transfer element.