DIE FOR CASTING JUNCTIONS OF A COATING OF A PIPELINE

Abstract

A die for casting junctions of a coating of a pipeline is configured to be coupled to the pipeline to form an annular shaped closed compartment about a tubular joint portion comprising a tubular wall, which extends about a designated axis; a plurality of centering devices configured to align the axis of the tubular wall with a longitudinal axis of the pipeline; two annular walls arranged respectively at the opposite ends of the tubular wall; and two pluralities of vent openings arranged along the tubular wall respectively at each of the annular walls; and at least one feeding port configured to supply polymer material into the closed compartment.

Claims

1-13. (canceled)

14. A die comprising: a tubular wall which extends about an axis; a plurality of centering devices configured to align the tubular wall such that the axis of the tubular wall with a longitudinal axis of a pipeline; a first annular wall arranged at one end of the tubular wall; a first plurality of vent openings arranged along the tubular wall within a first designated distance of the first annular wall; a second annular wall arranged at an opposite end of the tubular wall; a second plurality of vent openings arranged along the tubular wall within a second designated distance of the second annular wall; and at least one feeding port configured to supply polymer material into an annular-shaped closed compartment formed about a tubular joint portion of the pipeline when the die is coupled to the pipeline.

15. The die of claim 14, wherein each of the vent openings comprises: a hole defined by the tubular wall, and an insert of porous material which is configured to enable air to pass through the hole and stop a flow of the polymer material.

16. The die of claim 14, wherein the first plurality of vent openings and the second plurality of vent openings are uniformly distributed along respective areas arranged between the first annular wall and the second annular wall relative to the axis of the tubular wall.

17. The die of claim 14, wherein the first annular wall and the second annular wall are each made of a silicon elastic material with a hardness from 50 Shore A to 70 Shore A.

18. The die of claim 17, wherein the first annular wall and the second annular wall each comprise a base portion fixed to the tubular wall and an end portion configured to be deformed when the end portion comes into contact with the pipeline when the die is coupled to the pipeline.

19. The die of claim 18, wherein the first annular wall and the second annular wall each has a cross-section comprising two sides converging from the base portion of that annular wall towards the end portion of that annular wall.

20. The die of claim 18, wherein the first annular wall and the second annular wall each has a cross-section defining an opening.

21. The die of claim 20, wherein the plurality of centering devices comprise first centering devices and second centering devices, the first annular wall and the second annular wall are arranged between the first centering devices and the second centering devices relative to the axis of the tubular wall.

22. The die of claim 14, wherein the plurality of centering devices comprise a plurality of rollers rotatably supported by the tubular wall and configured to roll along an outer face of the pipeline.

23. The die of claim 14, wherein the feeding port is arranged between the first annular wall and the second annular wall relative to the axis of the tubular wall.

24. The die of claim 14, wherein the tubular wall comprises at least two sectors hinged to each other and configured to be closed about the pipeline.

25. The die of claim 24, wherein the two sectors each comprise a first coupling face and a second coupling face configured to shape couple to the other sector to prevent mutual sliding of said sectors in a radial direction.

26. The die of claim 25, wherein the first coupling face defines a groove parallel to the axis of the tubular wall and the second coupling face defines a relief parallel to the axis of the tubular wall and complementary to the groove

Description

BRIEF DESCRIPTION OF THE FIGURES

[0038] Further characteristics and advantages of the present disclosure will become clear from the following description of a non-limiting embodiment, with reference to the figures in the appended drawings, wherein:

[0039] FIG. 1 is a section view, with parts removed for clarity, of a die for casting junctions of a coating of a pipeline;

[0040] FIG. 2 is a section view, with parts removed for clarity, of a pipeline provided with a junction cast by the die in FIG. 1;

[0041] FIG. 3 is a perspective view, with parts removed for clarity, of the die in FIG. 1; and

[0042] FIG. 4 is a section view, with parts removed for clarity, and on an enlarged scale, of a detail of the die in FIG. 1.

DETAILED DESCRIPTION

[0043] A section of pipeline 1 is globally represented, with reference to FIG. 1, extending along a longitudinal axis A and about which a die 2 is arranged. In this case, the section of pipeline 1 illustrated shows two sections of pipe 3 joined to each other by welding. Each section of pipe 3 comprises a steel cylinder 4; and a coating 5 of polymer material, which serves to protect and insulate the steel cylinder 4, and can be made in one single layer or in a plurality of layers. The opposite free ends of each section of pipe 3 are without the coating 5 to enable the steel cylinders 4 to be welded to each other and define a welding seam 7. The section of pipeline 1, which extends axially between two end edges of the existing coatings 5, is a tubular joint portion 8.

[0044] The die 2 is coupled to the pipeline 1 at the coatings 5 so as to define, in use, a closed compartment 9 at the tubular joint portion 8. The die 2 comprises a tubular wall 10, which extends along a designated or given axis A1; a plurality of centering devices 11 configured to substantially align the axis A1 with the longitudinal axis A of the pipeline 1; a first and a second annular wall 12 arranged respectively at the opposite ends of the tubular wall 10; and a first and a second plurality of vent openings 13 arranged along the tubular wall 10, at the first and second annular walls 12, respectively; and at least one feeding port 14 made of polymer material in the closed compartment 9 defined by the die 2 and by the tubular joint portion 8. In greater detail, the closed compartment 9 also extends partly at the opposite ends of the coatings 5 so as to enable welding to be made between the injected polymer material and the coatings 5, and it is delimited by opposite bands from the annular walls 12. That is, after hardening, the injected polymer material forms a protective sleeve 15, which is securely connected to the tubular joint portion 8 and to the pre-existing coatings 5, better illustrated in FIG. 2.

[0045] With reference to FIG. 3, the tubular wall 10 comprises at least two cylindrical sectors 16 hinged to each other so as to be able to be closed about the pipeline 1. More precisely, only one sector 16 is illustrated in FIG. 3, and it is understood that the sector 16 (which is not illustrated) is substantially complementary to the sector 16 shown, without the feeding port 14, which is made in only one of the sectors 16. Each sector 16 presents an outer face 17; an inner face 18; and two coupling faces 19 and 20 adjacent to the outer face 17 and to the inner face 18.

[0046] Each sector 16 comprises gripping elements 21 arranged along the outer face 17, which serve to connect the sector 16 to sector movement and control devices (not shown in the Figures).

[0047] The coupling faces 19 and 20 of a sector 16 are shaped so as to achieve respective shape couplings with the coupling faces 20 and 19 of the other sector 16 to prevent the mutual sliding of the sectors 16, in particular in a radial direction.

[0048] The coupling face 19 presents a groove 22 parallel to the axis A1, while the coupling face 20 presents a relief 23 parallel to the axis A1, substantially complementary to the groove 22.

[0049] In use, when the sectors 16 are mutually coupled, the reliefs 23 engage the grooves 22 preventing radial and axial slidings between the sectors 16, also when the polymer material injection pressures are relatively extremely high.

[0050] The centering devices 11 are positioned at the opposite distal ends of the die 2 (FIG. 1) and substantially comprise rollers, which are rotatably mounted onto the die 2, enabling a relative movement between the die 2 and the pipeline 1. in particular, the centering devices 11, in other words, the rollers, are arranged two by two, diametrically opposite.

[0051] With reference to FIGS. 1 and 4, each vent opening 13 is housed in a through hole 24 made in the tubular wall 10 and comprises an insert 25 of porous material, which is configured to enable the air to pass and stop the flow of the polymer material. The inserts 25 of porous material can be of the type produced by the Company COMAT SRL, known by the trade name of Valvole Aria Van.

[0052] The vent devices 13 are distributed, in particular uniformly distributed, along respective annular areas arranged at the annular walls 12 and between the two annular walls 12 with reference to the axis A1.

[0053] With reference to FIG. 3, each annular wall 12 is made up of two sections, only one of which is illustrated in FIG. 3. complementary to each other to form a ring of elastic material, in particular silicon and, in particular, with a hardness from 50 to 70 Shore A.

[0054] With reference to FIG. 4. each annular wall 12 extends in a radial direction from the tubular wall 10 towards the axis A1 and plays mainly a sealing role, axially delimiting the closed compartment 9 by opposite bands. Each annular wall 12 comprises a base portion 26 drowned in the tubular wall 10 and an end portion 27 configured to be deformed when it comes into contact with the pipeline 1, in this case when it comes into contact with the coating 5, when the die 2 is anchored to the pipeline 1.

[0055] In particular, the annular wall 12 presents a cross-section comprising two sides 28 converging from the base portion 26 towards the end portion 27.

[0056] Furthermore, the annular wall 12 presents a cross-section having a central opening 29, which gives the annular wall 12 greater elasticity in an axial direction.

[0057] With reference to FIG. 1, the temperature of the die 2 is controlled by a system 30 comprising a control unit 31 and a plurality of sensors 32, only one of which is shown in FIG. 1, and a temperature control device 33, which is able to circulate a liquid at a controlled, varying temperature, according to the polymer material injection phase, inside cavities (not shown).

[0058] With reference to FIG. 1, in use, the polymer material is injected into the closed compartment 9 of the die 2 through the feeding port 14, forming two fronts 34, which move gradually into the closed compartment 9, in opposite and parallel directions to the longitudinal axis A, towards the opposite ends of the die 2 and partly in a circumferential direction. In this phase, the air in the closed compartment 9 is expelled through the vent openings 13. The gradual advancing of the fronts 34 towards the opposite ends of the die 2 causes the polymer material to arrange itself at the vent openings 13 as shown, for example, in FIG. 4, thus stopping the air still trapped inside the closed compartment 9 from escaping through the vent openings 13.

[0059] With reference to FIG. 4, the air trapped between the front 34 of the polymer material, the pre-existing coating 5, the tubular wall 10 and the annular part 12 is expelled thanks to the deformation of the annular wall 12 determined by the increase in pressure of the air and by the closure of the vent openings 13. Consequently, the annular wall 12 can also act, if necessary, as a vent for the air trapped inside the closed compartment 9.

[0060] The present disclosure clearly includes further variations, which are not described in detail, without going beyond the protective scope of the following claims. Accordingly, various changes and modifications to the presently disclosed embodiments will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.