An electromagnetic coil with improved insulation properties at high temperatures. A bobbin is insulated by a thin ceramic composite layer that is produced by winding a glass or ceramic fiber over the support structure and impregnating it with a pre-ceramic polymer. The pre-ceramic polymer is then modified to form a ceramic SiO.sub.2 matrix around the fibrous layer. The ceramic matrix secures the glass or ceramic fibers in place and produces a dense layer. A ceramic coated magnet wire is then wound around the insulated support structure. The magnet wire is a conductor that is spiral-wrapped with a glass fiber impregnated with a pre-ceramic polymer.

A method and apparatus for constructing a tubular assembly 40 comprising an inner portion (24) and a further portion (23) surrounding the inner portion. The inner portion (24) comprises reinforcement (37) and the further portion (23) being formed from a strip (50) of material comprising two opposed longitudinal marginal side portions (53). The apparatus comprises an assembly station (220) comprising a wall (253). The apparatus comprises means for advancing the inner portion (21) along a first path (231) extending passed the wall (253), and means for advancing the strip (50) along a second path (232) and causing the strip to encircle the wall (253) and thereby wrap about and surround the inner portion (21). The apparatus further comprises means (321) for introducing resinous binder into the reinforcement (37) as the strip (50) is being wrapped about the inner portion (21).

A method for producing a pre-insulated pipe, comprising inserting a length of jacket pipe (10) into a guide channel (110) having a front end (111) and a rear end (112); fixing said length of jacket pipe (10) in said guide channel (110); providing a first end (21) of a length of insulated inner piping (20), said length of insulated inner piping comprising a length of inner pipe surrounded by at least one layer of compressible insulation material (26); inserting, at said front end of said guide channel, into said length of jacket pipe, said first end of said length of insulated inner piping (20); applying an overpressure at least in an interior of said length of jacket pipe (10), around the inserted first end of the length of insulated inner piping (20); and moving said first end of said length of insulated inner piping (20) to said rear end of said guide channel (110); wherein said overpressure is such that said at least one layer of insulation material (26) is radially compressed; removing said overpressure to fix said length of insulated inner piping (20) in said length of jacket pipe (10) in order to form a pre-insulated pipe.

A thin ribbon spirally wound polymer conduit and method of forming, wherein a helical reinforcing bead is interposed adjacent overlapping layers of ribbon. Further, a method of continuously forming spirally wound conduit wherein a sacrificial layer, preferably having a different base polymer to that of the conduit, is first applied to the former before the conduit is formed overtop.

A thin ribbon spirally wound polymer conduit and method of forming, wherein a helical reinforcing bead is interposed adjacent overlapping layers of ribbon. Further, a method of continuously forming spirally wound conduit wherein a sacrificial layer, preferably having a different base polymer to that of the conduit, is first applied to the former before the conduit is formed overtop.

A method for producing a pre-insulated pipe, comprising inserting a length of jacket pipe (10) into a guide channel (110) having a front end (111) and a rear end (112); fixing said length of jacket pipe (10) in said guide channel (110); providing a first end (21) of a length of insulated inner piping (20), said length of insulated inner piping comprising a length of inner pipe surrounded by at least one layer of compressible insulation material (26); inserting, at said front end of said guide channel, into said length of jacket pipe, said first end of said length of insulated inner piping (20); applying an overpressure at least in an interior of said length of jacket pipe (10), around the inserted first end of the length of insulated inner piping (20); and moving said first end of said length of insulated inner piping (20) to said rear end of said guide channel (110); wherein said overpressure is such that said at least one layer of insulation material (26) is radially compressed; removing said overpressure to fix said length of insulated inner piping (20) in said length of jacket pipe (10) in order to form a pre-insulated pipe.

A device for winding a reinforcing strip onto a repair length on either side of a portion to be repaired of a pipe, including: a carriage bearing a reel holder and a reel, means for rotating the carriage around the pipe and for translating same along the longitudinal axis of the pipe so that the strip is wound around the pipe in the form of a helix, means for reversing the direction of translation movement of the carriage so that, at each change of direction, the carriage moves in a direction opposite to the previous one and a layer of reinforcing strip is wound around the pipe, overlapping the previous layer. The means for translating the carriage include a conveying chain and the reversing means are actuated automatically without the intervention of an operator.

A method for producing a pre-insulated pipe, comprising inserting a length of jacket pipe (10) into a guide channel (110) having a front end (111) and a rear end (112); fixing said length of jacket pipe (10) in said guide channel (110); providing a first end (21) of a length of insulated inner piping (20), said length of insulated inner piping comprising a length of inner pipe surrounded by at least one layer of compressible insulation material (26); inserting, at said front end of said guide channel, into said length of jacket pipe, said first end of said length of insulated inner piping (20); applying an overpressure at least in an interior of said length of jacket pipe (10), around the inserted first end of the length of insulated inner piping (20); and moving said first end of said length of insulated inner piping (20) to said rear end of said guide channel (110); wherein said overpressure is such that said at least one layer of insulation material (26) is radially compressed; removing said overpressure to fix said length of insulated inner piping (20) in said length of jacket pipe (10) in order to form a pre-insulated pipe.

A tube (10) and a method of constructing such a tube, the tube (10) being in the form of a composite film structure comprising a co-extrusion of a plurality of layers bonded together to provide an integrated structure. The layers comprise an inner layer (11), an intermediate layer (12) and outer layer (13). The intermediate layer (12) is of a material compatible with two adjacent layers (11, 13) between which it is interposed, wherein the intermediate layer (12) provides a bridge between the two layers (11, 13) to provide the tube (10) as an integrated structure. The exterior surface (15) of the tube (10) is optionally treated or modified or is provided with a coating, typically for bonding with another substance such as a resinous binder. A hollow structure in the form of a tubular element configured as a pipe and constructed using the tube (10) is also disclosed.

A tool for fixing a protective textile sleeve about an elongate member contained therein and method of use thereof is provided. The tool includes a clamp assembly having opposed clamp members attached to one another for pivotal movement relative to one another between an open state and a closed state. The clamp members have clamping surfaces, wherein at least one of the clamping surfaces has at least one outlet. A fluid source is arranged in fluid communication with the at least one outlet, and a heat source is configured to heat fluid from the fluid source to create steam. The steam is dispensed outwardly from the at least one outlet to cause an adhesive on the sleeve to become activated to bond with an adjacent abutting surface.