Abstract: A pipe section provided with a socket end part for accommodating a spigot end part of a second pipe section, the spigot end part having a sealing ring and the socket end part configured with an obliquely tapered part having areas of varying dimension for deforming the sealing ring to differing extent along the circumference of the sealing ring when the socket end part engages the spigot end part.

Abstract: A plastics infiltration block for infiltration or attenuation purposes is disclosed. The infiltration block has an essentially rectangular parallelepipedal body having pairs of opposed first, second and third faces. At least one inspection channel extends through the infiltration block and inspection channel openings are positioned in opposed third faces of the infiltration block. The area of each inspection channel opening is at least 10% of the size of the area of the third face. The infiltration block can include a single infiltration block element or multiple coupled infiltration block elements. The infiltration block element has an essentially rectangular parallelepipedal body. A grid of duct walls forming substantially parallel ducts extend between each first face and the one or more inspection channels of the infiltration block, and between each second face and the inspection channels of the infiltration block.

Abstract: With a pipe section provided with a socket end part (1) which is intended for accommodating a spigot end part (2) of a second pipe section, the exterior of the spigot end part is provided with a sealing ring (5), the interior of the socket end part (1) has a part (13) obliquely tapering towards the centre axis (12) of the socket end part for deforming the sealing ring (5) when the spigot end part (2) and an adjoining cylindrical part (14) are inserted into the socket end part (1). The obliquely tapering part (13) has at least two areas (15) distributed regularly over the circumference in which the angle of the obliquely tapering part (13) varies relative to the centre axis (12) of the socket end part in the circumferential direction.

Abstract: Apparatus for manufacturing a socket end (12) which is provided with a sealing ring (9). The apparatus comprises an outer mould (1) for forming the outer contour of the sealing ring (9) and for forming the outer side of the socket end (12), and a core for forming the inner side of the socket end (12) and the sealing ring (9). The core comprises a first core part (7a), a sleeve-like core part (7) which can be displaced on the first core part (7a), for forming a front for the sealing ring (9), a core part (8) which adjoins the first core part (7a) and can be contracted in the radial direction, for forming the inner contour of the sealing ring (9), and a second core part (6), which adjoins the contractable core part (8), for forming the inner side of the pipe part. The contractable core part (8) has a radially innermost position with an external diameter which is smaller than the internal diameter of the sleeve -like core part (7).

Abstract: A method for producing a tube section from thermoplastic material, in which a tube section is extruded by means of an extruder which is provided with an extruder die having an inner core, which inner core defines an axial hollow space in the tube section, the tube section coming out of the extruder die downstream of the extruder die being internally cooled by means of an internal cooling member and externally cooled by means of an external cooling device. Immediately after the tube section leaves the extruder die, the internal cooling member brings about internal cooling of the tube. The external cooling device is positioned downstream of the internal cooling member, so that the external cooling of the tube section is brought about after the internal cooling.

Abstract: A method for forming an integral socket to a pipe made from biaxially oriented thermoplastic material is described. The pipe has a pipe body and is provided, at one or both ends, with an integral socket. The biaxially oriented thermoplastic pipe is subjected to a socket-forming operation comprising the steps of fixing both axial ends of the unheated end part of the pipe, heating the fixed end part to a suitable socket-forming temperature in one or more steps, and expanding the axially fixed end part with the aid of a fluid pressure in the interior of the end part and/or a vacuum on the outer side of the end part, which expansion may begin as early as during the heating of the end part.

Abstract: A method for producing a tube section from thermoplastic material, in which a tube section is extruded by means of an extruder which is provided with an extruder die having an inner core, which inner core defines an axial hollow space in the tube section, the tube section coming out of the extruder die downstream of the extruder die being internally cooled by means of an internal cooling member and externally cooled by means of an external cooling device. Immediately after the tube section leaves the extruder die, the internal cooling member brings about internal cooling of the tube. The external cooling device is positioned downstream of the internal cooling member, so that the external cooling of the tube section is brought about after the internal cooling.

Abstract: A pipe of layers of thermoplastic polyolefins of the same type, however with different properties, which are connected inseparably with one another, an outer first layer and a second layer, adjoining the first layer on the inside, consisting of a material, which has not been cross-linked, the second layer approximately having the FNCT the value or the NPT value of a one-layer standard pressure pipe and the first layer having an FNCT or NPT value, which is higher by a factor of at least 3 than that of the second value. Moreover, a third layer is provided, which adjoins the second layer on the inside, also consists of material that is not cross-linked and has a PNCT, which is higher by a factor of at least 3 than that of the second layer and an NPT layer, which is higher by a factor of at least 2 than that of the second layer.

Abstract: A method of forming a socket on a pipe of thermoplastic material is disclosed. In the process, an end section of the pipe is heated in a heating station. Then, the pipe is transferred to a socket-forming station having a socket-forming mandrel. This is followed by the socket-forming mandrel being introduced into the pipe end section, heated to a suitable socket-forming temperature, and the end section being formed into a socket. Prior to the pipe end section being heated in the heating station, a support is introduced into the end section in order to internally support the end section. The support remains in the end section after the socket-forming mandrel is introduced into the pipe and in the process the support is pushed deeper into the pipe.

Abstract: A coupler for a pipe or hose section has a coupling body, at least one coupling piece integrally formed therewith and a pressing sleeve, which can be previously joined to the coupling body. The coupling body and the pressing sleeve can be previously joined by a locking or interlocking connection.

Abstract: The invention relates to a method for forming an article comprising closed-cell microfoam from thermoplastic, wherein at least one molten thermoplastic comprising a foaming agent is subjected under pressure to a forming operation and, after the pressure has been at least partially released is cooled, wherein the amount of foaming agent is substantially identical to the amount corresponding to that quantity of gas released by the foaming agent which is comprised by a close-packed structure of the foam cells having a specific foam-cell diameter, substantially uniform throughout the foam, at the pressure prevailing during cool-down.

Abstract: Apparatus and method for producing a hollow plastic section by extrusion through a die in a horizontal direction. The die has an inner mandrel which forms the cavity in the section. A first sealing plug and a second sealing plug, which sealing plugs are situated at a distance from one another downstream of the inner mandrel are attached to the inner mandrel. The sealing plugs are designed, during operation of the apparatus, to lie in the hollow section, such that they are sealed against the section, so that the sealing plugs and the section delimit a compartment in the cavity of the section. The compartment is filled with a liquid during operation of the apparatus. Vent means are located in the compartment for receiving and discharging gases or vapor which collects at the highest point of the compartment.

Abstract: Method for treating an extruded plastic section having a hollow space and installation suitable for carrying out such a treatment. The installation includes an extruder which has a core for forming the hollow space in the section and, at a distance downstream from the extruder in the extrusion direction of the section, a closing means having a rigid circumferential wall. The installation also has a first conduit connected to a supply orifice which is provided in the circumferential wall of the closing means, a fluid feeder connected to the first conduit and a second conduit connected to a discharge orifice. The discharge orifice is upstream of the supply orifice to provide a fluid film flowing opposite to the extrusion direction between the circumferential wall of the closing means and the extruded section.

Abstract: A method for forming a socket on a pipe of biaxially oriented polyvinyl chloride including: placing a support in an end section of the pipe, heating the pipe in the region of the end section; deforming the pipe to produce a socket in the region of the heated end section, the heated end section being supported internally while the socket is being formed; cooling the pipe in the region of the end section, the end section being supported internally during the cooling operation; and removing the support from the pipe. For the purpose of heating the internally supported end section of the pipe, the end section is first heated until the end section has reached, substantially homogeneously, the glass transition temperature of polyvinyl chloride and is then further heated until the end section has reached, substantially homogeneously, a temperature near, preferably just above, the orientation temperature of polyvinyl chloride.

Abstract: Method and device for manufacturing biaxially oriented tubing from thermoplastic material. The method includes forcing the tube over a mandrel at an orientation temperature of the plastic material, which mandrel includes an expansion part which produces expansion in the circumferential direction of the tube, and downstream of the mandrel the exertion of an axial pulling force on the tube, in the course of which the tube encounters a resistance which counteracts the movement of the tube over the mandrel. The method also includes the exertion of an influence sector-wise in an adjustable manner in the circumferential direction of the tube on the resistance which counteracts the movement of the tube over the mandrel. In an advantageous embodiment, the temperature of the plastic material of the tube is influenced sector-wise in an adjustable manner, viewed in the circumferential direction of the tube. The measures according to the invention lead to better control over the manufacture of biaxially oriented tubing.

Abstract: A tube is extruded from a thermoplastic material and is then forced over a mandrel at an orientation temperature of the material. The mandrel has an expanding section that expands the tube in its circumferential direction. A tube speed controller upstream of the expanding section of the mandrel exerts an axial force on the tube, and a puller downstream of the mandrel exerts an axial pulling force on the tube. Upstream of the tube speed controller, an outer layer of a wall of the tube is brought to a temperature below the orientation temperature. That outer layer is thick enough to withstand the force exerted by the tube speed controller.

Abstract: A tubular profile made of thermoplastic material is formed by extrusion from an extruder. Downstream from the extruder, the tubular profile is cooled both externally and internally by an external cooling unit and an internal cooling unit mounted on the extruder. A tensile force is exerted on the cooled tubular profile downstream from the cooling units by a pulling device. When the extruder is set in operation to start the production of the tubular profile, the internal cooling unit is left out. When the pulling device applies the tensile force on the extruded and externally cooled tubular profile, the internal cooling unit is introduced into the tubular profile from the open end of the tubular profile and is mounted on the extruder.

Abstract: Method and devices for manufacturing biaxially oriented tubing from thermoplastic material. The method includes forcing the tube over a mandrel at an orientation temperature of the plastic material, which mandrel includes an expansion part which produces expansion in the circumferential direction of the tube. The forcing over the mandrel is achieved by exerting a pushing force on the tube upstream of the expansion part of the mandrel by a pushing device acting upon the outside of the tube, and by exerting a pulling force on the tube downstream of the mandrel. The pushing device acts upon the tube at a distance upstream of the mandrel, and the tube is supported between the place where said pushing device acts and the expansion part of the mandrel.

Abstract: A method for manufacturing biaxially oriented tubing from a thermoplastic material. The method includes forcing the tube over a mandrel at an orientation temperature of the plastic material, which mandrel is an expansion part which produces expansion in the circumferential direction of the tube. Downstream of the mandrel an axial pulling force is exerted on the tube, and the biaxially oriented tube is cooled down. At a distance downstream of the mandrel, the tube is drawn through a calibration opening bounded by a calibration device, the calibration opening being such that it produces a reduction in the external dimensions of the tube. Accurate regulation of the external dimensions of the tube is provided by regulating the distance between the mandrel and the calibration device, in particular depending on the external dimensions of the tube measured downstream of the calibration device.

Abstract: A thermoplastic saddle (6) for renovating or repairing a pipeline (1) with a branch pipe (2). The saddle comprises two saddle parts (20, 22) being movable with respect to each other. The first saddle part (20) comprises a flexible saddle plate (6') and a first connecting part (21) being integral therewith. The second saddle part (22) comprises a branch (8) provided with a second connecting part (23). The part (21) tapers towards its open free end (12') and the second connecting part has a spherical circumference (23a). The position of connecting parts (23, 23a) with respect to connecting part (21) ensures that branch (8) is retained in connecting part (21) if said branch is subjected to pulling forces. In a renovated or repaired pipeline (1) the saddle is fixed by fixing means preferably an expanded plastic fixing sleeve (13). However, fixation by a glued connection (112) and/or sealed connection (113) is also possible.