A joint ring system for lined pipes includes a first pipe and a second pipe joined end-to-end, each pipe having an interior lining covering substantially all of an interior wall of the respective pipe. A first ring is disposed within and substantially flush with the joined end of the first pipe, and a second ring is disposed within and substantially flush with the joined end of the second pipe. The first ring is configured to create a first circumferential pressure seal against the interior wall of the first pipe, and the second ring is configured to create a second circumferential pressure seal against the interior wall of the second pipe. At least one of the first ring and the second ring is configured to create a pipe joint pressure seal against the other ring.

Electric welding coupler for the welding of pipes made of thermoplastic material or other weldable plastics comprising a cylindrical body made of thermoplastic material or other weldable plastics, containing at least one welding element, wherein the welding element is arranged close to the inner diameter of the cylindrical body, wherein the welding element forms at least two welding zones, a contact for feeding the electric current and at least one cavity, wherein the cavity is arranged in the cylindrical body, wherein a reinforcing ring is arranged around the outer circumference respectively outer diameter of the cylindrical body.

A joint ring, system for lined pipes includes a first pipe and a second pipe joined end-to-end, each pipe having an interior lining covering substantially all of an interior wall of the respective pipe. A first ring is disposed within and substantially flush with the joined end of the first pipe, and a second ring is disposed within and substantially flush with the joined end of the second pipe. The first ring is configured to create a first circumferential pressure seal against the interior wall of the first pipe, and the second ring is configured to create a second circumferential pressure seal against the interior wall of the second pipe. At least one of the first ring and the second ring is configured to create a pipe joint pressure seal against the other ring.

A raised pipeline sleeve for a pipeline includes a tubular sleeve body insertable into pipeline pipes. Recessed sleeve shoulders are radially positioned about each end of the tubular sleeve body with a central portion therebetween. An outer surface of the tubular sleeve body along the central portion is shaped to conform to an inner surface of the pipeline pipes. The recessed sleeve shoulders are recessed a distance radially below the central portion to support a pipeline seal between the recessed sleeve shoulders and the pipeline pipes. A raised hump extends radially from the central portion along the outer surface of the tubular sleeve body. As the tubular sleeve body is inserted in the pipeline pipes, the pipeline pipes engage the raised hump and conform the raised hump to the inner surface of the pipeline pipes whereby installation of the tubular sleeve body into and alignment of the tubular sleeve body about the pipeline pipes is facilitated.

A joint ring system for lined pipes includes a first pipe and a second pipe joined end-to-end, each pipe having an interior lining covering substantially all of an interior wall of the respective pipe. A first ring is disposed within and substantially flush with the joined end of the first pipe, and a second ring is disposed within and substantially flush with the joined end of the second pipe. The first ring is configured to create a first circumferential pressure seal against the interior wall of the first pipe, and the second ring is configured to create a second circumferential pressure seal against the interior wall of the second pipe. At least one of the first ring and the second ring is configured to create a pipe joint pressure seal against the other ring.