Abstract: An injection head for an apparatus for the production of twin-wall pipes has an external melt channel leading to an external nozzle and an internal melt channel leading to an internal nozzle. From the internal melt channel, a conically expanding internal nozzle channel leads to an internal nozzle outlet of the internal nozzle. In the region of the internal nozzle channel, an internal nozzle adjustment device is arranged by means of which the gap cross-section of the internal nozzle channel is displaceable and adjustable up to the internal nozzle outlet by radial displacement.

Abstract: An injection head for an apparatus for the production of twin-wall pipes has an external melt channel leading to an external nozzle and an internal melt channel leading to an internal nozzle. From the internal melt channel, a conically expanding internal nozzle channel leads to an internal nozzle outlet of the internal nozzle. In the region of the internal nozzle channel, an internal nozzle adjustment device is arranged by means of which the gap cross-section of the internal nozzle channel is displaceable and adjustable up to the internal nozzle outlet by radial displacement.

Abstract: An apparatus for the continuous production of a twin wall pipe has mold block halves supplied in pairs to form a mold, and a pipe head, which has an external nozzle for the extrusion of an external hose and an internal nozzle for the extrusion of an internal hose. A support air and venting channel which is annular-cylindrical and concentric with respect to the center longitudinal axis of the pipe head opens out between the external nozzle and internal nozzle.

Abstract: A twin-wall pipe comprises an internal pipe and an external pipe. The external pipe is corrugated, having elevations and troughs. The twin-wall pipe is further provided with a socket. In a transition portion towards the twin-wall pipe and the socket, provision is made for at least one overflow passage which interconnects the clearance between the external pipe and internal pipe in the vicinity of the transition portion and an adjacent elevation. a?b refers to the radial height b of the overflow passage relative to its width a in the circumferential direction.

Abstract: An apparatus for the continuous production of a twin wall pipe has mold block halves supplied in pairs to form a mould, and a pipe head, which has an external nozzle for the extrusion of an external hose and an internal nozzle for the extrusion of an internal hose. A support air and venting channel which is annular-cylindrical and concentric with respect to the centre longitudinal axis of the pipe head opens out between the external nozzle and internal nozzle.

Abstract: A device for producing pipes made of thermoplastic with annular transverse profilings with a cross section in the form of undulation peaks and undulation troughs has half-moulds, which complete one another pairwise along a straight mould section to form a closed mould, which can be moved in a movement direction. Projecting into the mould is an extrusion tool, which has a nozzle support body. To produce an adequate seal between the half-moulds and nozzle support body, the latter is covered with exchangeably attached hollow half-shells, which form a cylindrical external face.

Abstract: Into a molding path moving in a direction of conveyance is extruded an internal tube from a first extruder and an external tube from a second extruder, the external tube being concentric with the internal tube. During the production of a normal compound pipe, the smooth internal tube is welded together with the external tube which is provided with transverse grooves. At the transition from the normal compound pipe to the expanded pipe socket, the extruder speed of the first extruder is increased from a speed n1,1 to a speed n1,2. During the production of the pipe socket, the speed of the first extruder is reduced to a speed in1,3, wherein n1, 2>n1,3>n1,1 applies.

Abstract: During the manufacture of a compound pipe, which is composed of an internal tube and a corrugated external tube, a slight overpressure relative to atmospheric pressure pa is applied to the inside of the internal tube, which is guided across a calibrating mandrel during the manufacture. At the transition to the formation of a pipe socket, a partial vacuum p3 relative to atmospheric pressure pa is temporarily applied the internal tube.

Abstract: A twin-wall pipe comprises an internal pipe and an external pipe. The external pipe is corrugated, having elevations and troughs. The twin-wall pipe is further provided with a socket. In a transition portion towards the twin-wall pipe and the socket, provision is made for at least one overflow passage which interconnects the clearance between the external pipe and internal pipe in the vicinity of the transition portion and an adjacent elevation. a?b refers to the radial height b of the overflow passage relative to its width a in the circumferential direction.

Abstract: Into a molding path moving in a direction of conveyance is extruded an internal tube from a first extruder and an external tube from a second extruder, the external tube being concentric with the internal tube. During the production of a normal compound pipe, the smooth internal tube is welded together with the external tube which is provided with transverse grooves. At the transition from the normal compound pipe to the expanded pipe socket, the extruder speed of the first extruder is increased from a speed n1,1 to a speed n1,2. During the production of the pipe socket, the speed of the first extruder is reduced to a speed in1,3, wherein n1,2>n1,3>n1,1 applies.

Abstract: A twin-wall pipe comprises an internal pipe and an external pipe. The external pipe is corrugated, having elevations and troughs. The twin-wall pipe is further provided with a socket. In a transition portion towards the twin-wall pipe and the socket, provision is made for at least one overflow passage which interconnects the clearance between the external pipe and internal pipe in the vicinity of the transition portion and an adjacent elevation.

Abstract: During the manufacture of a compound pipe, which is composed of an internal tube and a corrugated external tube, a slight overpressure relative to atmospheric pressure pa is applied to the inside of the internal tube, which is guided across a calibrating mandrel during the manufacture. At the transition to the formation of a pipe socket, a partial vacuum p3 relative to atmospheric pressure pa is temporarily applied the internal tube.

Abstract: An apparatus for continuous production of a composite pipe comprises half shells which combine in pairs to form a molding path, wherein at least in one pair of half shells is formed a socket recess which has an extension b when seen in the conveying direction. Furthermore, an extrusion head is provided, with an outer die and an inner die leading out thereof, the outer die and the inner die having a distance a from each other when seen in the conveying direction. The distance a of the inner die from the outer die with respect to the extension b of the socket recess in the conveying direction is such that a?b applies.

Abstract: An apparatus for the manufacture of compound pipes with an oval cross-section is equipped with mould halves which advance in a direction of production and of which two at a time combine as a pair on a moulding path to form one mould. An injection head of at least one extruder is arranged upstream of the moulding path. An external nozzle used for the creation of an external tube is substantially circular in shape and is located at a distance upstream of the moulding path. An internal nozzle with a cross-section similar to the oval cross-section of the pipe to be created is located inside the moulding path. When entering the moulding path, the external tube extruded through the external nozzle is expanded in one direction and pressed together in a direction which is perpendicular to the former.

Abstract: An apparatus for the manufacture of compound pipes with an oval cross-section is equipped with mold halves which advance in a direction of production and of which two at a time combine as a pair on a molding path to form one mold. An injection head of at least one extruder is arranged upstream of the molding path. An external nozzle used for the creation of an external tube is substantially circular in shape and is located at a distance upstream of the molding path. An internal nozzle with a cross-section similar to the oval cross-section of the pipe to be created is located inside the molding path. When entering the molding path, the external tube extruded through the external nozzle is expanded in one direction and pressed together in a direction which is perpendicular to the former.

Abstract: In a method and an apparatus for producing pipes having a transverse profile from thermoplastic material, mold segment halves are used on a molding path and are circulated in pairs. A main conveying device is provided for returning the mold segment halves, the main conveying device being designed like a gantry crane. A conveying bridge encompassing the molding path is provided with two conveying carriages which are displaceable at right angles to a direction of production and in opposite directions relative to each other and to which is in each case attached a downwards facing conveying arm comprising a holding device for in each case one mold segment half. Downstream of the downstream end of the molding path are provided parking positions for additional mold segment halves. Disposed downstream of the molding path is an auxiliary conveying device which is provided for removing the additional mold segment halves from the molding path in order to subsequently return them to the parking positions.

Abstract: A pipe construction kit for a sewer pipeline comprises several pipes made of plastic, which exhibit a circular cross-section. Between in each case two pipes there is to be arranged a shaft base body made of plastic, exhibiting a central connection section. The connection section exhibits a foot having a supporting surface and, diametrically thereto, a connection element for a shaft. On both sides of the connection section there are formed pipe sections for connection with the pipes. The diameter d of the shaft is significantly smaller than the diameter D of the shaft base body.

Abstract: A twin-wall pipe comprises an internal pipe and an external pipe. The external pipe is corrugated, having elevations and troughs. The twin-wall pipe is further provided with a socket. In a transition portion towards the twin-wall pipe and the socket, provision is made for at least one overflow passage which interconnects the clearance between the external pipe and internal pipe in the vicinity of the transition portion and an adjacent elevation.

Abstract: A method and an apparatus for the manufacture of pipes of thermoplastics with transverse profile features comprises mold segment halves which are circulated by twos on a molding path. A conveying device of the type of a gantry crane is provided for recirculation of the mold segment halves. On a conveying bridge that bridges the molding path, provision is made for two conveying carriages, which are movable in opposite directions and cross-wise of the direction of production and which have mounted on them a downward conveying arm with a holding device for a respective mold segment half. Provided downstream of the downstream end of the molding path are parking positions for additional mold segment halves, those of which that are closest to the molding path being carriages which are movable out of the path of displacement of the conveying arms.

Abstract: A pipe assembly comprises a first pipe section and a second pipe section of which at least one pipe section is provided with a spigot which is provided with outwardly annularly extending projections with flanks. A seal is arranged between two adjacent projections against their flanks. At least those projections between which the seal is arranged are formed as projections of increased wall thickness forming a portion of increased wall thickness and comprising a higher filling ratio than more distantly arranged projections.