Abstract: A method is shown for installing a heat tube on a section of pre-insulated piping. A metal carrier pipe is covered with a first layer of foam insulation. Next, a routing device is used to cut a longitudinal slot along the length of the pipe so that the pipe exterior surface is exposed from the insulation. A heat tube is then installed within the longitudinal slot, whereby the heat tube contacts the exterior surface of the metal carrier pipe. A second layer of foam insulation is then sprayed onto the exterior of the metal carrier pipe, covering the previously formed longitudinal slot and installed heat tube. A polyolefin coating is then applied over the insulation to form a protective outer jacket for the insulated pipe.

Abstract: A method is shown for installing a heat tube on a section of pre-insulated piping. A metal carrier pipe is covered with a first layer of foam insulation. Next, a routing device is used to cut a longitudinal slot along the length of the pipe so that the pipe exterior surface is exposed from the insulation. A heat tube is then installed within the longitudinal slot, whereby the heat tube contacts the exterior surface of the metal carrier pipe. A second layer of foam insulation is then sprayed onto the exterior of the metal carrier pipe, covering the previously formed longitudinal slot and installed heat tube. A polyolefin coating is then applied over the insulation to form a protective outer jacket for the insulated pipe.

Abstract: A method is shown for installing a heat tube on a section of pre-insulated piping. A metal carrier pipe is covered with a first layer of foam insulation. Next, a wire brush is used to cut a longitudinal slot along the length of the pipe so that the pipe exterior surface is exposed from the insulation. A heat tube is then installed within the longitudinal slot, whereby the heat tube contacts the exterior surface of the metal carrier pipe. A second layer of foam insulation is then sprayed onto the exterior of the metal carrier pipe, covering the previously formed longitudinal slot and installed heat tube. A polyolefin coating is then applied over the insulation to form a protective outer jacket for the insulated pipe.

Abstract: A method is shown for installing a heat tube on a section of pre-insulated piping. A metal carrier pipe is covered with a first layer of foam insulation. Next, a routing device is used to cut a longitudinal slot along the length of the pipe so that the pipe exterior surface is exposed from the insulation. A heat tube is then installed within the longitudinal slot, whereby the heat tube contacts the exterior surface of the metal carrier pipe. A second layer of foam insulation is then sprayed onto the exterior of the metal carrier pipe, covering the previously formed longitudinal slot and installed heat tube. A polyolefin coating is then applied over the insulation to form a protective outer jacket for the insulated pipe.

Abstract: A method for the continuous production of pre-insulated piping having an inner metal carrier pipe having an interior surface and an exterior surface and an envelope of foamed insulation surrounding the inner metal carrier pipe exterior surface. A molding apparatus is provided for forming an annulus about a pipe to be insulated into which foam can be injected. The pipe is continuously moved through the apparatus with foaming material being injected into the annulus where it is molded and cured to form a foam insulated pipe. The molding apparatus is a roller-drum having a cylindrical length and a plurality of individual rollers arranged in a series of linearly staggered, circular arrays which define the annulus where the foaming material is cured.

Abstract: A method for the continuous production of pre-insulated piping having an inner metal carrier pipe having an interior surface and an exterior surface and an envelope of foamed insulation surrounding the inner metal carrier pipe exterior surface. A molding apparatus is provided for forming an annulus about a pipe to be insulated into which foam can be injected. The pipe is continuously moved through the apparatus with foaming material being injected into the annulus where it is molded and cured to form a foam insulated pipe. The molding apparatus is a roller-drum having a cylindrical length and a plurality of individual rollers arranged in a series of linearly staggered, circular arrays which define the annulus where the foaming material is cured.

Abstract: A method is shown for installing a heat tube on a section of pre-insulated piping. A metal carrier pipe is covered with a first layer of foam insulation. Next, a routing device is used to cut a longitudinal slot along the length of the pipe so that the pipe exterior surface is exposed from the insulation. A heat tube is then installed within the longitudinal slot, whereby the heat tube contacts the exterior surface of the metal carrier pipe. A second layer of foam insulation is then sprayed onto the exterior of the metal carrier pipe, covering the previously formed longitudinal slot and installed heat tube. A polyolefin coating is then applied over the insulation to form a protective outer jacket for the insulated pipe.

Abstract: A section of pipe is used in a pre-insulated piping system where the system is made up of lengths of insulated and jacketed pre-insulated piping. Each length of piping is made up of an inner carrier pipe having an interior surface and an exterior surface. An envelope of bonded foam insulation surrounds the inner pipe exterior surface and an outer protective jacket surrounds the envelope of foamed insulation. The length of piping has a joining end for joining to an adjacent length of piping, whereby the adjacent lengths of piping provide a continuous length of fluid conduit for conveying high temperature fluids. A series of metal thrust collars are located at spaced intervals along the length of the inner carrier pipe are enveloped within the layer of foamed insulation.

Abstract: An anchor system is shown for use with a pre-insulated piping system having an inner steel carrier pipe surrounded by a layer of insulation and then by an outer protective jacket. The anchor system includes an inner carrier pipe for insertion within the length of the piping system at a selected point. A steel anchor sleeve surrounds a portion of the length of carrier pipe and insulation. It terminates at one end at an outwardly flaring anchor plate which is subsequently embedded within a concrete anchor block. A steel end cap is welded to a second, opposite end of the sleeve and to the inner carrier pipe at a point along the length of piping which is outside the concrete anchor block and which is spaced apart from the location of the anchor plate, whereby heat from the high temperature fluids in the piping is transferred to the end cap at a location along the length of piping which is distant from the location of the anchor plate.

Abstract: A method is shown for manufacturing a polyethylene jacket of the type used in pre-insulated piping systems. A mandrel is first coated with a brittle polymeric coating. A melt profile of polyethylene is then extruded onto the mandrel and spirally wound to produce adjacent windings. The adjacent windings make contact to form a finished jacket which is in engagement with the brittle coating. After the jacket has set, an external compressive force is applied to the tubular member thus formed sufficient to crush the internal brittle coating, thereby freeing the polyethylene jacket from engagement with the mandrel. The jacket can then be removed from the mandrel.

Abstract: A joint is formed between two lengths of insulated pipes, which pipes have thermoplastic jackets. The jackets are joined together with a thermoplastic split sleeve. A welding rod arrangement is located along the edges on one side of the sleeve in a U-shaped configuration. The welding rod arrangement includes two side by side welding rods, each of which have a thermoplastic core with resistance wires embedded in the core. The split sleeve is wrapped around the joint with the sleeve overlapping the pipe jackets and also with the ends of the sleeve overlapping to form a longitudinal seam. The welding rod arrangement encircles each jacket in a partial spiral with a nonconductive core of thermoplastic located between the adjacent welding rod arrangements. In addition, the welding rod arrangement extends along the longitudinal seam. Electrical current is provided to the resistance wires, wherein the sleeve is welded to the pipe jackets and the split in the sleeve is welded closed.