Abstract: An improved welding rod having a solid homogeneous core of thermoplastic material and a resistance element comprised of a plurality of wires is presented with a method and apparatus for forming the welding rod. The welding rod is positioned between members of the thermoplastic material to be welded and a current and pressure is applied to the resistance element causing the thermoplastic material of the solid core and the adjacent thermoplastic members to fuse and form a unitary weld. Simultaneously the electrical resistance element is embedded in the weld, mechanically reinforcing and strengthening the connection. There is also disclosed a method for electric fusion welding of thermoplastic members wherein the welding rod is pre-attached to one of the thermoplastic members.

Abstract: An improved welding rod having a solid homogeneous core of thermoplastic material and a resistance element comprised of a plurality of wires is presented with a method and apparatus for forming the welding rod. The welding rod is positioned between members of the thermoplastic material to be welded and a current and pressure is applied to the resistance element causing the thermoplastic material of the solid core and the adjacent thermoplastic members to fuse and form a unitary weld. Simultaneously the electrical resistance element is embedded in the weld, mechanically reinforcing and strengthening the connection. There is also disclosed a method for electric fusion welding of thermoplastic members wherein the welding rod is pre-attached to one of the thermoplastic members.

Abstract: A pipeline system with a localized environment for preventing, detecting, and containing leakage from a subterranean pipeline transporting hydrocarbon liquids and gases is disclosed. A steel pipe is enclosed in a sleeve of high density polyethylene and overlaid with a layer of geotextile material. Positioned in the interstitial space between the pipe and sleeve is a layer of geotextile material impregnated with hydrated lime which dissolves in the presence of water to create a highly alkaline solution to protect the pipe. Also positioned adjacent the inner layer are leak sensors/monitors for detection of leaks of hydrocarbon fluids and aqueous solutions.