Abstract: The process comprises forming a mixture containing a thermoplastic material and a cross-linking agent and causing the mixture to enter a die head. A pressure is exerted on the mixture in the die head along the axis of the die head so as to sinter the mixture. The die head is heated to a temperature lower than the temperature at which the cross-linking agent becomes substantially decomposed so as to cause fusion of the mixture and produce a formed material. The formed material is passed through a bath of molten salt downstream of the die head. The temperature of the molten salt is such as to achieve the decomposition of the cross-linking agent and the cross-linking of the formed material. A device is described for carrying out the process.

Abstract: This apparatus having two pouring channels comprises a support which is movable in a direction perpendicular to the axis of the mould in synchronism with the carriage which carries the two pouring channels and to the same extent of travel as the carriage so as to support the free end of the two channels when the centrifugal casting machine and the carriage are moved away from each other. The support is rigid with the centrifugal casting machine as concerns movement in translation in a direction parallel to said axis and is provided with transverse shifting means synchronized with the means for shifting the carriage.

Abstract: The support jack comprises a cylinder and a piston which define therebetween a variable-volume chamber. An inlet aperture and an outlet aperture for control fluid are provided for the chamber. Escape passageways are provided in evenly-spaced relation about the rod of the piston and put the chamber in communication with the annular space between the fixed and moving component parts of the jack and open radially onto said space. These passageways create pressure drops which are higher than the pressure drops due to the annular space.

Abstract: This process for manufacturing spheroidal graphite cast iron pipes by centrifugal casting has the feature that the rate of the cooling of the liquid iron just centrifugally cast in a tubular layer is increased from a zone of the layer spaced away from the mould to the free inner surface of this tubular layer while the cooling of the liquid iron in the vicinity of the surface of the mould is slowed down.

Abstract: The device is provided for a coupling which comprises an annular sealing element interposed and compressed radially between the socket of one pipe element and the male end of the other pipe element. The pipe elements are capable of having an angular deviation therebetween. The device comprises an annular shoulder integral with the male end which shoulder is disposed, in the assembled state of the coupling, between an inner flange at the entrance of the socket and the sealing element. A split ring surrounds the male end between the flange and the shoulder. Screws engaged with and extending through tapped passages arranged circumferentially around and carried by the flange bear against a face of the shoulder so as to apply the ring against the shoulder.

Abstract: A process for effecting an annealing treatment of a spheroidal or lamellar graphite cast iron pipe. While the pipe is driven in rotation about the axis of the pipe, it is suspended substantially horizontally as it issues from the centrifugal casting machine and the pipe is partly immersed in a bath of metal at the desired temperature. An installation for carrying out this process comprises an elongate vessel having a horizontal axis and containing a bath of molten metal at the required temperature. A withdrawable device is provided outside the bath for suspending the pipe in a substantially horizontal position and plunging the pipe partly in the bath while driving the pipe in rotation about the axis of the pipe.

Abstract: The coupling of two tubular elements is achieved by welding them together by energization of an electrical resistance element, the one element comprising a male end, the other a socket end. The coupling operation is carried out by means of a composite connecting piece comprising two rings which are fitted on one another, one acting as a support for a bifilar electrical resistance element and the other as a sheath. The electrical resistance element is thus uniformly coated in plastic material and is accurately centered, thereby ensuring uniform heating and welding. This coupling method is for use in coupling discharge pipelines for waste water and rain water and for conduits for industrial fluids.

Abstract: The machine comprises an openable moulding box which has a perforated top side and is in the form of two separable semi-moulds. A sand blowing head is movably connected to the machine stand by at least one pair of parallel connecting elements which form a deformable parallelogram structure. The head is capable of being moved away from the perforated top side or against the latter for blowing a mixture of sand and binder into the interior of the mould.

Abstract: The process modifies the thickness of the wall of a tube of thermoplastic material which issues at constant speed from an extruder and is driven downstream of and in the extension of the extruder by a drawing machine. The drawing machine has motorized rolling members which frictionally drive the tube and permit modifying the speed at which the tube is driven. The thickness of the wall is modified by producing a relative movement of translation between the extruder and drawing machine while maintaining the speed of rotation of the rolling members.

Abstract: The valve closure element has an annular peripheral groove opening outwardly onto the periphery of the closure element. An annular sealing element has an annular heel portion disposed in the groove. The latter has an inner end face whose diameter is less than the inside diameter of the heel portion. The groove is defined laterally by two confronting annular faces of the closure element which have a substantially rectilinear generatrix and grip the heel portion so as to prevent relative movement of the heel portion and closure element.

Abstract: A process for controlling a vessel for a repeated pouring of a liquid under low pressure into blind sand moulds. The process comprises after each pouring, lowering the liquid in the pouring tube only to a level which is equal to or substantially equal to a constant predetermined level in the vicinity of the outlet of the tube. According to the invention, the level of the liquid in the tube and the pressure of the driving gas prevailing in the vessel are measured directly and the inlet and exhaust of the driving gas are controlled as a function of these measurements so as to ensure, for all the pourings, a pressure rise time and a pressure drop time which are predetermined and substantially constant. A device is described for carrying out this process.

Abstract: The device comprises an annular case having a first portion which projects from the wall and a second portion which is embedded in the wall. A tubular element connected to two pipes of the piping defines a passage through the case. The tubular element has a first section and a second section respectively located in the first portion and second portion of the case. The tubular element is of a material which is rigid at ordinary temperature and softens under the action of heat. At least the first section is of a fusible material having a distinct point of fusion. The first portion of the case is provided with means for instantaneously closing the passage as soon as the first section has disappeared. The second portion of the case is filled with a material which swells radially under the action of heat.

Abstract: A low-pressure metal repetitive casting apparatus comprising a large capacity fluidtight vessel containing liquid metal to cast, in particular a high melting point metal; an upwardly open supply pipe partly extending into the vessel through a wall of the vessel and having a lower end immersed in the metal; a source of gas under pressure; a device for selectively putting the source in communication with the interior of the vessel and closing off said communication; and a series of blind sand moulds each defining at least one mould cavity, a main runner whose sectional size is in the neighborhood of the sectional size of the supply pipe and communicates with the mould cavity and has a lower open end portion capable of being adapted for connection to an upper end portion of the supply pipe, and at least one secondary runner which puts the main runner in communication with the mould cavity and has a cross-sectional area so calibrated that, during the casting, the solidification time of the secondary runner is sli

Abstract: The installation comprises a first core support pivotable about a fixed axis between a horizontal position and vertical position. The core is mounted on the first support. A second core support having a horizontal axis is provided with a core gripping device and is movable between the first core support, in which it receives the core from the first core support in the vertical position of the first support, and the socket end of a centrifugal casting mould. The two supports are provided with a device for mutually centering the two supports when transferring the core from one support to the other.

Abstract: The process is of the type comprising continuously shaping a mixture of thermoplastic material and crosslinking agent by pressure and then effecting the cross-linking by the cross-linking agent. The cross-linkable mixture is placed inside a sintering zone in which it is subjected to the action of pressure and a sintering temperature at the same time as it is put into shape. It is then conveyed without modification of shape by means of the same pressure to a zone where the cross-linking is effected by a rise in temperature. The device comprises in the following order, along a common axis, a device supplying the cross-linkable mixture, a sintering die and a cross-linking die. These dies define a continuous space in which the pressure is exerted and each comprise heating means.

Abstract: The installation comprises two centrifugal casting moulds which are roughly parallel to each other and are movable by rotation of a common support between a mould preparing station, a pouring station and a pipe extracting station, which stations are disposed in such maner that one of the moulds is in the axial extension of the pouring station when the other mould is in the axial extension of the extracting station and vice-versa. The two moulds are carried by rollers mounted on the common support and the latter comprises a horizontal platform which is rotatable about a central vertical axis relative to which the two moulds are symmetrically arranged.

Abstract: The insulated pipe comprises an inner pipe and a foam of thermally insulating plastics material which adheres to the inner pipe and to an outer protective layer. The foam material covers the major part of the inner pipe but terminates at a distance from each end thereof in a portion having an inclined surface of frustoconical shape. The outer protective layer comprises a cover which is relatively rigid and terminates before reaching each frustoconical surface and a protective case for each frustoconical surface of the foam material. The case is at one end fixed to the cover and at the other end integral with the inner pipe. The case has sufficient elasticity to allow the foam to follow the expansion of the inner pipe while the cover remains immobilized.

Abstract: The device comprises a case of a material non-deformable under the effect of heat and mounted on the wall around at least a part of the tube. A mass of material capable of swelling under the effect of heat is enclosed in the case. An element of a material which is substantially non-fusible at temperatures which are developed in the course of a fire has a part which is planar and perpendicular to a radial direction relative to the tube and is movable and slidable in said radial direction in the case. The element normally bears on the outer surface of the tube and the mass of swelling material is disposed on the opposite side of the element to the tube.

Abstract: The method comprises applying on the surface of each of the parts a thin layer of a curable first mixture containing a first resin which cures slowly and is slightly exothermic and has a good adherence to said surfaces. A curable second mixture is then introduced in a space defined by the layers of the first mixture in the final position of the two parts. The second mixture contains a second resin which cures rapidly and is sufficiently exothermic to promote the curing of the first resin and normally has after curing a poor adherence to said surfaces but a good adherence to the first resin.

Abstract: The valve closure element has an annular peripheral groove opening outwardly onto the periphery of the closure element. An annular sealing element has an annular heel portion disposed in the groove. The latter has an inner end face whose diameter is less than the inside diameter of the heel portion. The groove is defined laterally by two confronting annular faces of the closure element which have a substantially rectilinear generatrix and grip the heel portion so as to prevent relative movement of the heel portion and closure element.