A system for coupling pipes includes a first pipe having a tapered, spigot end; a second pipe having a tapered, spigot end; a coupler having two tapered socket ends adapted to internally receive the respective tapered, spigot ends of the first pipe and the second pipe; and a resistive element. The first pipe, the second pipe, and the coupler are made from a reinforced thermosetting resin (RTR). The resistive element includes a first layer and a second layer of thermoplastic material; and an electrically conducting resistive heating element with positive and negative terminals for connecting electrical power. The electrically conducting resistive heating element is sandwiched by the first layer and the second layer of thermoplastic material. The resistive element is disposed between an interior of the coupler and at least one of: an exterior of the first pipe and an exterior of the second pipe. Upon application of electrical power to the positive and negative terminals of the resistive element, the electrically conducting resistive heating element generates heat sufficient to melt the thermoplastic material such that, when the heat is removed, the hardened thermoplastic material seals the first pipe and/or the second pipe to the coupler.

A system for coupling pipes includes a first pipe having a tapered, spigot end; a second pipe having a tapered, spigot end; a coupler having two tapered socket ends adapted to internally receive the respective tapered, spigot ends of the first pipe and the second pipe; and a resistive element. The first pipe, the second pipe, and the coupler are made from a reinforced thermosetting resin (RTR). The resistive element includes a first layer and a second layer of thermoplastic material; and an electrically conducting resistive heating element with positive and negative terminals for connecting electrical power. The electrically conducting resistive heating element is sandwiched by the first layer and the second layer of thermoplastic material. The resistive element is disposed between an interior of the coupler and at least one of: an exterior of the first pipe and an exterior of the second pipe. Upon application of electrical power to the positive and negative terminals of the resistive element, the electrically conducting resistive heating element generates heat sufficient to melt the thermoplastic material such that, when the heat is removed, the hardened thermoplastic material seals the first pipe and/or the second pipe to the coupler.

A pipe coupling construction which can be used for coupling of a high-pressure pipe includes an inner bush of a non-metallic material and an outer bush, which bushes in axial section have parts which mesh with each other in order to transmit axial forces. The inner bush can be fused or adhered to an outer cover layer of the pipe. The coupling has a metal sleeve construction. The outer bush has an outer bush protruding end which protrudes with respect to the inner bush and the metal sleeve construction is at least partially located within the outer bush protruding end. The metal sleeve construction and outer bush in axial section have parts which mesh with each other.

A pipe coupling construction which can be used for coupling of a high-pressure pipe includes an inner bush of a non-metallic material and an outer bush, which bushes in axial section have parts which mesh with each other in order to transmit axial forces. The inner bush can be fused or adhered to an outer cover layer of the pipe. The coupling has a metal sleeve construction. The outer bush has an outer bush protruding end which protrudes with respect to the inner bush and the metal sleeve construction is at least partially located within the outer bush protruding end. The metal sleeve construction and outer bush in axial section have parts which mesh with each other.

Double pipe system with a primary pipeline conducting a medium and a secondary pipeline which is arranged around the primary pipeline for protection, containing pipes and fittings of the primary pipeline, wherein the pipes and fittings of the primary pipeline are connected together, and pipes and fittings of the surrounding secondary pipeline, wherein the pipes are configured as one-piece plastics pipes and the fittings are configured as half-shells, wherein the half-shells of the fittings and the adjoining pipes of the secondary pipeline are connected together by means of electric welding sleeves, or in that the half-shells of the fittings and the adjoining fittings consisting of half-shells are connected together by means of electric welding sleeves.

Double pipe system with a primary pipeline conducting a medium and a secondary pipeline which is arranged around the primary pipeline for protection, containing pipes and fittings of the primary pipeline, wherein the pipes and fittings of the primary pipeline are connected together, and pipes and fittings of the surrounding secondary pipeline, wherein the pipes are configured as one-piece plastics pipes and the fittings are configured as half-shells, wherein the half-shells of the fittings and the adjoining pipes of the secondary pipeline are connected together by means of electric welding sleeves, or in that the half-shells of the fittings and the adjoining fittings consisting of half-shells are connected together by means of electric welding sleeves.

The invention relates to a method for connecting a thermoplastic line element (3) to a connecting element (2). The method comprises the steps of: providing the at least one thermoplastic line element (3); providing the connecting element (2) having a thermoplastic body (4 wherein a heating element (6 is embedded in the body (4 for generating heat in a welding region (5 for welding the body (4 to the at least one line element; joining the connecting element (2) to the at least one thermoplastic line element (3; providing a welding device (10) for welding the connecting element (2 to the at least one thermoplastic line element (3); welding the connecting element (2 at least one thermoplastic line element (3 by generating heat in the welding region (5 by means of the welding device (10).

The welding of the connecting element (2) to the at least one thermoplastic line element (3) is stopped by the welding device (10) before the end of the planned welding duration if an error criterion is met.

An electroweldable saddle-type fitting having a saddle-type wall that defines on opposite sides a convex surface and a concave surface is provided. The wall has a predetermined curvature radius able to be coupled with the curvature radius of the heat-sealable pipe section, and is associated with a first electric wire winding, associated with the convex side and bearing a first pair of electric terminals arranged on the concave side for the application of an electric current for heat fusion of the saddle-type wall. The fitting also has a cylindrical sleeve made of heat-fusible material, provided with a further electric wire winding bearing a further pair of electric terminals for the application of an electric current, and are arranged on the concave side of the wall. The further electric wire winding is arranged on the inner surface of the cylindrical sleeve to apply an electric current for heat fusion of the cylindrical sleeve on a heat-sealable by-pass pipe.

An electroweldable saddle-type fitting having a saddle-type wall that defines on opposite sides a convex surface and a concave surface is provided. The wall has a predetermined curvature radius able to be coupled with the curvature radius of the heat-sealable pipe section, and is associated with a first electric wire winding, associated with the convex side and bearing a first pair of electric terminals arranged on the concave side for the application of an electric current for heat fusion of the saddle-type wall. The fitting also has a cylindrical sleeve made of heat-fusible material, provided with a further electric wire winding bearing a further pair of electric terminals for the application of an electric current, and are arranged on the concave side of the wall. The further electric wire winding is arranged on the inner surface of the cylindrical sleeve to apply an electric current for heat fusion of the cylindrical sleeve on a heat-sealable by-pass pipe.

Described is a heating means for thermally connecting two objects each having a plastic material, wherein, during the connecting, a first inner object is surrounded at least partially by a second outer object, and the heating means surrounds the first inner object at least partially along a complete circumferential course around the first inner object, and is located between the first inner object and the second outer object. The heating means has a ribbon-type structure. The ribbon-type structure has an auxiliary heating material, which is inductively heatable, wherein the auxiliary heating material is spatially distributed or arranged along the circumferential course such that an electrical conductivity is interrupted at at least one position along the complete circumferential course around the first inner object. Further described are an arrangement and a system each having such a heating means as well as a method for thermally connecting two plastic objects.