Abstract: Coupling piece (1) for an outer end of a multilayered conduit (26), comprising a coupling pipe (2) which is provided on the outer side with a radially upright wall (4), wherein the wall is widened in axial direction at a radial distance from the outer side of the body, wherein the outer side of the coupling pipe (2), the upright wall (4) and the widened portion enclose an annular insertion space into which the outer end of the conduit can be directly inserted, and wherein the radial distance between the widened portion of the wall and the outer side of the coupling pipe at the position of the entry to the insertion space is such that it is equal to or greater than the wall thickness of the conduit (26), wherein the inner wall of the coupling pipe is reinforced with an adjacent reinforcing layer of reinforced plastic or of metal which has a greater strength than the material of the coupling pipe (2), wherein the outer layer of the reinforcing layer which is adjacent to the inner wall, is provided with a relief

Abstract: A vibration-resistant reinforced concrete watertight pipe, at opposite ends of which coupling units formed of a separate material are formed, and a method of manufacturing the same are provided. The vibration-resistant reinforced concrete watertight pipe includes a reinforced concrete pipe having a reinforcement mat, which is assembled with longitudinal reinforcements and transverse reinforcements, disposed in a concrete layer, and a convexity coupling part and a concavity coupling part that are coupled to opposite ends of the reinforced concrete pipe and have coupling ridges and coupling furrows respectively. Here, the coupling part and the concavity coupling part are formed of a synthetic resin, which is different in physical properties from the reinforced concrete pipe, and have the same shape and thickness as the reinforced concrete pipe. Each of the convexity coupling part and the concavity coupling part has a metal core installed therein to increase a coupling strength.

Abstract: A hollow plastic product including a hollow main body, a reinforce member and a connector pipe is provided. Such a hollow plastic product is, for example, used advantageously as a component of an air-intake system or fuel supply system of an automobile. In one example, the hollow main body is a duct, hose or tube extending over a length, and the reinforce member is ring-shaped so that it extends around a circumference of an outer surface of the hollow main body. The reinforce member is manufactured by injection molding and is used as an insert when blow-molding the hollow main body, so that the reinforce member is integrally formed with the main body. The reinforce member has a defined welding surface formed with a first hole, to which one end surface of a connector pipe is thermally welded. Then the hollow main body is formed with a second hole in alignment with the first hole, thereby defining a fluidic communication between the hollow main body and the connector pipe.

Abstract: A welded pipe joint having reduced internal stresses comprises a pipe, a socket fitting, and an annular weld. The end surface of the fitting is chamfered, preferably in a concave profile, so that the weld profile subtends an angle of from about 100 degrees to about 120 degrees, rather than the customary 90 degrees. The pipe has no dam or other protuberance to confine the bead of added metal. Prior to welding, the fitting may have an annular lip immediately surrounding the surface of the pipe and may also have a ring spaced from the lip. The ring may be integral with the fitting and spaced from the lip by thin, radially spaced metal bars or may be separate from the fitting.

Abstract: A connection arrangement is provided for a mineral-insulated conduit with two ends to at least one tube-shaped structure, wherein at least one end is arranged partially overlapping with a tube-shaped structure and is affixed by welding or soldering, and wherein a sheath surface is arranged in the region of the overlap. The problem results of making available a connection arrangement for a mineral-insulated conduit to a tube-shaped structure, which is simple to produce and mechanically stable. The problem is solved in that the sheath surface has a structured surface, the end of the mineral-insulated conduit and the tube-shaped structure contact each other on all sides in the region of the overlap, and the contact surface is smaller than the sheath surface beyond the contact surface.