• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
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    • 专利摘要:
    TECHNIQUES FOR PIPE COATING. The present invention relates to a method of coating a pipe field joint to accelerate the cycle time which comprises positioning a molding tool around the field joint to define a mold cavity and inject the plastic material into of the mold cavity through and a plurality of ports on the molding tool, spaced along the mold cavity. The material is injected through different ports as the mold cavity is filled, specifically through at least one first port to advance a melting front within the mold cavity, and subsequently through at least a second spaced port from the first door, preferably when the melting front passes the second door. The first and second molding tools can be placed in succession around the field joint to create internal and external coatings on the field joint. An insertion device can be positioned in a mold cavity to be embedded in the injected plastic material.
    公开号:BR112013000304B1
    申请号:R112013000304-9
    申请日:2011-07-04
    公开日:2021-02-02
    发明作者:Philippe Hoffmann
    申请人:Acergy France SAS；
    IPC主号:
    专利说明:

    [0001] The present invention relates to pipe coating, in particular apparatus and techniques for coating field pipe joints and pipes provided with field joints covered by said techniques.
    [0002] Pipes used in the oil and gas industry are generally formed of steel pipe lengths - 'pipe joints' - welded joints end to end as the pipe is launched. It is also common to manufacture a terrestrial tube rod on a spool base and to transport the prefabricated tube on the platform offshore for launch, for example, in a spool launch operation in which the tube rods are welded together and stored in a compact form rolled up in the submarine pipeline launch barge.
    [0003] To mitigate corrosion of the pipe and optionally also to isolate the fluids that the pipe in use, the pipe joints are pre-coated with protective coatings which, optionally, are also thermally insulating. Many variations are possible in the structure and composition of the coating to obtain the necessary protective or insulating properties. However, polypropylene (PP) is most commonly used to coat the pipe joints from which pipes are produced. For example, a so-called three-layer PP (3LPP) coating can be used for corrosion protection and a so-called five-layer PP (5LPP) coating can be used for additional thermal insulation. Additional layers are possible.
    [0004] A type 3LPP coating typically comprises an epoxy primer applied to the clean outer surface of the steel pipe joint. As the primer cures, a second thin layer of PP is applied to bond with the primer and then a third, thicker layer of extruded PP is applied over the second layer for mechanical protection. A 5LPP type coating adds two additional layers, that is, a fourth layer of PP modified for thermal insulation, for example, PP of syntactic glass (GSPP) or a foam, surrounded by a fifth layer of extruded PP for mechanical protection of the fourth insulating layer.
    [0005] A short length of pipe is left uncoated at each end of the pipe joint to facilitate welding. The resulting 'field gasket' must be coated with a field gasket coating to mitigate corrosion and to maintain any level of insulation may be required for piping purposes.
    [0006] Where a pipe is launched on an offshore platform, welding and field joint lining are commonly carried out on board the submarine pipeline launch barge such as the pipeline launch barge that launches the resulting tube column using either the S-launch method or the J-launch method.
    [0007] In the S-launch method, the tube column is mounted on the barge deck on a horizontal drive line with multiple welding stations. The tube column is launched from the barge onto a tube guide comprising a succession of rollers, from which the tube column curves downwards through the water to a landing point on the ocean floor. The field joint coating is carried out upstream of the pipe guide, in one or more coating stations or 'incrementing stations to which the pipe column is advanced step by step after welding.
    [0008] Field joint lining is also used during J-release installation, in which the pipe joints are launched in a near-vertical orientation in a welding tower at the end of the pipe column. The coating of the field joint is carried out downstream of the welding station in the tower, just before the tube column is launched downwards from the barge to the seabed.
    [0009] In principle, the S-launch method allows pipelines to be launched faster than the J-launch method, but the J-launch method is necessary in challenging pipeline launch situations where water depth and strong currents make the S-launch method impractical, without providing great stresses to the pipeline.
    [00010] Whether using the S-launch method or the J-launch method, the speed of launching pipelines depends on minimizing the execution time of all operations on the critical path. Considering the processing steps of the welding and coating sequences, it is particularly important that neither the welding nor the coating takes longer than is necessary or that one process takes substantially longer than the other. Otherwise, there would be a 'bottleneck' in the pipeline installation process.
    [00011] The fastest possible welding speed using the S-launch method means that a shorter time period is available for field joint lining in the S-launch method than in the J-launch method. The said short time available for field joint lining in the S-launch method previously favored a cast-molded polyurethane (CMPU) technique that relies on curing rather than cooling to solidify the lining. This allows for a cycle time of about five minutes, which largely corresponds to the welding cycle time operations in the S-launch method and thus removes the coating operation from the critical one.
    [00012] In CMPU techniques, the exposed surface of the pipe at the welded ends that touch the pipe joints is cleaned and an initiator is applied. A mold is then positioned to embed the field joint and a two-component urethane material is melted into the defined annular cavity within the mold around the field joint. The urethane material then cures, cross-links and solidifies to form polyurethane (PU) in an irreversible chemical reaction.
    [00013] When the PU has cured to a self-supporting extension, the mold is removed to leave a field joint lining in place around the weld region. Curing can continue afterwards as the PU coating approaches its setting resistance.
    [00014] The mold used in a CMPU operation does not need to withstand high pressures and can only be of a compact, light and simple configuration.
    [00015] The speed of the chemical reaction involved in curing CMPU is largely independent of heating or the size or thickness of a field joint coating, and there is no need for cooling time to consolidate the coating. In contrast, the heat generated by the exothermic curing reaction helps to speed up the reaction. Although heating can promote the curing reaction, it cannot reverse the curing reaction as the PU is thermally consolidating: the excessive temperature would merely degrade the PU instead of melting it.
    [00016] An example of a CMPU technique is described in DE 102007018519 in relation to a gas pipe or other essentially static pipe, where the coating is not carried out as part of a continuous manufacturing process from station to station in the method mode S-launcher for pipeline launching or land-based manufacturing operations. There is, therefore, much less pressure time than is found in offshore platform or tube-making operations.
    [00017] DE 102007018519 describes a formwork element for applying a coating joint material to a weld region of a coated steel tube. The formwork element forms a mold that encloses the weld region of the tube and defines an annular cavity around the weld region. A coating material such as PU is admitted into the cavity through one or more supply ports at the bottom of the formwork element. In addition, one or more vents are provided at the top of the formwork element to allow air to escape as the cavity is filled with PU. The PU that enters the cavity through the supply port (s) fills the cavity upwards from the bottom, rising in the direction of the ventilation (s) and consequently advancing circumferentially around the tube until the cavity is full.
    [00018] Although continuous filling of the cavity from the bottom supply port (s) from above is preferred in DE 102007018519, larger tubes may require additional supply ports aligned in cross section with the, or each, port bottom fill and spaced around the circumference of the formwork element. Said additional supply ports provide supplemental injection of PU in a circumferential "cascade" arrangement to allow consistent and homogeneous filling from the bottom upwards of the cavity before the PU cures.
    [00019] Bottom-up filling is commonly used in a CMPU technique such as that of DE 102007018519 due to the fact that a thermal consolidation resin such as urethane has low viscosity before it cures to form PU. Consequently, there is a high risk of bubbles being trapped in the material during injection due to turbulence. This risk is mitigated by gently injecting and filling the mold progressively in a way that discourages blistering. Filling the bottom upward also encourages any bubbles that may form to rise to the top of the injected liquid before it cures, to vent with the air that is expelled as the mold cavity fills.
    [00020] A field joint CMPU coating has disadvantages. The key disadvantages arise from the dissimilarity between PP and PU, which sabotages the bond strength between the pipe lining and a field joint lining. This introduces a risk that cracks may occur at the interface between the pipe liner and a field joint liner. Any cracks can allow water to reach the outer surface of the tube, thus corroding the tube. The ingress of water can also reduce the adhesion of the coating to the pipe and can additionally degrade the coating, particularly due to the hydrolysis of the PU under heat emanating from inside the pipe in use; this is particularly significant under conditions of high water pressure. Degradation or loss of adhesion of the coating will tend to allow additional corrosion of the pipe and may also reduce its thermal insulation.
    [00021] Said disadvantages of a CMPU field joint coating can be mitigated by instead of using PP as a field joint coating in an injection molded polypropylene (IMPP) process. In an IMPP process, the exposed ends of contact with the tube are cleaned, started and heated, for example, using induction heating or gas flames. The chamfers exposed at the ends of the tube liners are also heated. The field joint is then closed by a mold that defines an annular cavity around the field joint. Molten PP is injected into the cavity under high pressure. Once the PP has cooled to a self-supporting extension, the mold is removed, leaving a PP tube around the field joint as a field joint liner. Said tube is continuous with the tubular liner surrounding the tube joints, so that the same material or compatible liner material extends the entire length of the tube column.
    [00022] An IMPP field joint lining generally has mechanical and thermal properties similar to that of a PP lining tube. Also, the pipe lining and a field joint lining are sufficiently compatible so that they fuse together at their mutual interfaces, resisting breakage and consequently providing a longer service life. The working temperature of PP is also markedly higher than PU.
    [00023] A fused thermoplastic such as PP used in an IMPP process is typically, in orders of magnitude, more viscous than an uncured thermal consolidation resin such as urethane used in a CMPU process. The difference in viscosity is from a few centipoise for a urethane resin to several hundred poise for the molten PP. Consequently, bubble formation is not a concern in an IMPP process and therefore the direction of filling the cavity, whether from bottom to top or from top to bottom, is much less important than in a CMPU process.
    [00024] A typical prior IMPP process involves injecting PP into one end of a mold enclosing the field joint area such as a jacket. The constant flow of injected molten product introduces heat continuously and maintains the temperature throughout the field joint throughout the duration of the injection process. This reduces cooling and, consequently, the solidification of the PP.
    [00025] In this regard, reference is made to figures 1a to 1c of the drawings that show how an IMPP operation can be used to coat a pipe field joint in a barge launch line or in a field. terrestrial manufacturing such as a cylinder base / support. Here, the molding tool 31 circles the welded field joint created between touching pipe joints 34, where a circumferential weld 36 fixes the pipe joints 34 to each other.
    [00026] Each pipe joint 34 is coated, for example, with a 5LPP coating 38, and said coating 38 ends flush with the end of each pipe joint 34 with a typically chamfered end shape. An annular space, therefore, is found between the opposite ends of the liner 38 around the weld 36, where the exposed outer surfaces of the pipe joints 34 need to be coated. For this purpose, the molding tool 31 is fixed around the field joint, extending from one coating 38 to the other and overlapping said coatings 38 to define a mold cavity 40 including the annular space between the coatings 38 Molten PP 58 or other thermoplastic material is injected into the mold cavity 40 to form a field joint coating.
    [00027] The molding tool 31 comprises a tube 42 of generally circular cross-section, which is suitably divided longitudinally into two halves. Opposite end portions of the tube 42 sit against the linings 38 of the respective tube joints 34 and therefore have an internal diameter that corresponds to the outer diameter of the coated tube joints 34.
    [00028] The two halves of the molding tool 31 are fastened together to surround the field joint and still withstand internal pressure within the molding tool 31 in use. The molding tool 31 is therefore maintained in a sealing engagement with the linings 38 of the tube joints 34. Inward seals 52 are provided on the end portions of the molding tool for this purpose. Stiffening rings 54 circling the end portions of the molding tool 31 also help to maintain structural integrity and sealing.
    [00029] The tubular wall of the molding tool 31 is penetrated by a gate 56 near one end to inject molten PP 58 into the mold cavity 40. The molten PP 58 is supplied via a pressure line 60 under pressure from a supply tank or machine 62. A vent 67 allows air to escape as the mold cavity 40 is filled with molten PP 58. The molding tool 31 is also provided with a cooling system comprising a jacket water created by water tubes 69 arranged in or on the tubular wall of the molding tool 31.
    [00030] Before the injection molding operation begins, the bare, uncoated outer surfaces of the tube joints 34 are cleaned, primed and heated, as are the beveled end surfaces of the liners 38.
    [00031] In figure 1a, the injection molding operation started by injecting molten PP 58 through port 56 near one end of the mold cavity 40. The injected melt has already filled that end of the mold cavity 40 and the front of melt 70 is progressing along the mold cavity 40 towards the other end of the mold cavity 40. Figure 1b shows the further progress of the melt front 70 as the molten PP 58 continues to be injected through port 56 and figure 1c shows the mold cavity 40 completely filled with the injected melt.
    [00032] It will be seen from figures 1a to 1c that the outer perimeter of the injected melt soon starts to freeze to form solid PP 59. Freezing occurs more quickly where the injected melt comes into contact with the cooler, conductive surfaces of the molding tool 31 and tube 34. However, the inner core of the injected fusion remains as molten PP 58 through the injection process until the mold cavity 40 has been filled.
    [00033] Continuous injection of molten PP 58 continues to add heat to the system, and thus does not allow the melt core to start cooling and solidification until the entire mold cavity 40 has been filled and the injection can therefore cease. Even after the mold cavity 40 has been filled and the injection ceases, the molding tool 31 must remain in place until the injected melt has cooled and solidified to a self-supporting extent. Only then can the two halves of the molding tool 31 be separated and removed from the field joint for reuse in a subsequent field joint.
    [00034] Consequently, when using existing techniques, the IMPP coating in a single station has a typical cycle time of eight to ten minutes, which cannot compete with the short cycle time of the CMPU coating. Consequently, the IMPP coating is not suitable for use especially in the S-launch method of pipe installation methods. Unlike CMPU, the injected molten PP must be allowed time to cool and the said cooling time is strongly dependent on the size and depth of the mold cavity that defines a field joint coating. Although the mold can be water-cooled as shown to accelerate cooling, forced cooling can reduce the quality of a field joint lining and it is still too long for the PP to solidify to the extent necessary to resist flattening or other deformation when the tube column passes over the tube guide rollers.
    [00035] IMPP coating can be used in J-launch methods where there is more time to coat the field joint, where a field joint coating will cool quickly with immersion in water and where a field joint coating will find less site of deformation during launch. However, the IMPP coating is on a critical path in S-launch methods and introduces a disadvantageous delay.
    [00036] The IMPP coating also suffers from the viscosity of the molten PP and consequently from the need to pump and contain the PP at high molding pressures. This adds to the volume and cost of the mold and the injection equipment that feeds the molten PP into the mold.
    [00037] It is in connection with this background that the present invention was produced. The present invention aims to reduce the cycle time of an IMPP coating operation, thereby allowing the benefits of IMPP to be enjoyed without experiencing a substantial increase in cycle time compared to an IMPU coating operation. The time-saving coating techniques of the present invention can be applied with benefit in the J-launch methods, but for reasons that will become apparent from the above, they have the greatest benefits when used in the S-launch methods. . The present invention, therefore, will be described in the context of the S-launch method operations but it should be noted that the present invention can be of benefit in the J-method launch operations and also in onshore pipeline fabrication and during winding and winding, where there is also a need to shorten the IMPP coating cycle.
    [00038] From a first aspect, the present invention is based on a method of coating a joint of a tube during the manufacture of the tube from sections of tube, comprising: positioning the molding tool around the joint for defining a mold cavity around the tube, the molding tool provided with first and second doors spaced from one another; injecting the molten thermoplastic material through the first port into a first portion of the mold cavity to advance the melting front in the mold cavity towards the second port; subsequently injecting molten thermoplastic material through the second port into the second portion of the mold cavity in the vicinity of the first portion; accelerate the cooling of the injected material in the first portion of the mold cavity with respect to the cooling of the injected material in the second portion of the mold cavity; and removing the molding tool from the field joint after the material injected into the mold cavity has cooled to a self-supporting extension.
    [00039] The cooling of the injected material in the first portion of the mold cavity can be accelerated in several ways, for example: by reducing the injection coefficient, or stopping the injection, through the first port and still inject through the second port; and / or when cooling the molding tool or tube in the region of the first portion. Cooling can be applied locally to the molding tool or to the tube in a cooling position that is moved according to the movement of the melting front. These measures allow the thermoplastic material injected through the first port to cool while the thermoplastic material is being injected through the second port.
    [00040] For homogeneity and strength, it is preferred that the molten plastic material is injected through the second door after the melting front passes through the second door. Until the fusion front passes through the second door, the second door is preferably kept closed.
    [00041] When injecting sequentially into the injection ports or ports spaced along the mold, the first portion or segment between the first and second ports is allowed to start cooling as soon as the first port is closed. The process is repeated for subsequent ports. Consequently, the length of the internal melting zone is reduced. The overall cooling time is thus reduced and also the length over which a field joint lining remains relatively soft is reduced.
    [00042] The thermoplastic material can be injected through the first door located between other doors to advance the melting front from the first door towards the other doors. It is possible to progressively advance the melting front from one end of the mold cavity to the other end of the mold cavity or to advance two melting fronts in opposite directions along or around the mold cavity.
    [00043] The molten thermoplastic material is suitably injected through a plurality of angularly spaced first and second doors around the field joint. In one example, the first and second doors are generally spaced longitudinally in a direction parallel to the tube; the second portion of the mold cavity is generally arranged longitudinally beside the first portion; and the fusion front advances along the tube from the first door towards the second door. However, the melting front can also advance circumferentially within the mold cavity with respect to the tube.
    [00044] In said example, an annular melting front is preferably generated within the mold cavity. This can be achieved by injecting the molten thermoplastic material through a group of angularly spaced first ports around the tube and subsequently injecting the molten thermoplastic material through a group of angularly spaced second ports around the tube and generally spaced longitudinally from the first door group. It is preferred that the injection takes place substantially simultaneously between the doors of each group. When the fusion front progresses longitudinally in the cavity, a second group of angularly spaced doors around the field joint opens, causing the fusion front to progressively progress along the cavity.
    [00045] It is also preferred in this example that the first portion of the mold cavity is positioned downstream of the second portion of the mold cavity in the direction of manufacture. This exposes the coldest and therefore hardest part of a field joint coating first to the stresses of the supports and tensioners during the casting steps after the coating operation.
    [00046] In another example, insofar as the first and second doors are angularly spaced around the tube; the second portion of the mold cavity is generally arranged circumferentially next to the first portion; and the fusion front advances around the tube from the first port towards the second port. However, the melting front can also advance longitudinally within the mold cavity with respect to the tube.
    [00047] In this example, the molten thermoplastic material can be injected through a group of first longitudinally spaced doors along the molding tool and the molten thermoplastic material can be injected subsequently through a group of second longitudinally spaced doors along the tool molding and generally spaced circumferentially from the first door group. If the first door or each is arranged on the molding tool at a level below the level of the or each second door, this helps to cool and harden the underside of a field joint coating first. This can be advantageous in that the underside of a field joint liner will withstand the load of the tube when it encounters the tube supports after the coating operation.
    [00048] To deal with the shrinkage during the cooling of the plastic material, it is advantageous for the mold cavity to be radially deeper than the radial thickness of a coating on the tubes joined by the field joint. For example, the molding tool may comprise end sections of relatively small internal diameter and a central section of relatively large internal diameter.
    [00049] Optionally, the present invention may involve positioning an insertion device to be within the mold cavity and injecting the plastic material into the mold cavity to embed the insertion device in the plastic material. In this case, it is preferred to maintain a space between a body of the inserter and the pipe joints joined by the field joint to allow the plastic material to flow around the inserter as the mold cavity fills. This can be achieved with spacing formations in the inserter. It is also preferred that the plastic material flows through a body of the inserter as the mold cavity fills. Passages such as holes can be provided in the body of the inserter for this purpose. This ensures that the plastic material surrounds the inserter in close contact and fills the mold.
    [00050] Where used, an insertion device can be of a different material for the plastic material injected into the mold cavity. For example, the material of the inserter may be relatively insulating compared to the plastic material injected into the mold cavity. Said difference can be used to fabricate the insulating properties of a field joint coating.
    [00051] The method of the present invention may also comprise: positioning a first molding tool around the field joint to define a first mold cavity; injecting the plastic material into the first mold cavity to create an internal coating on the field joint; positioning the second molding tool around the field joint to define the second mold cavity around the inner liner; and injecting the plastic material into the second mold cavity to create an external coating on the field joint.
    [00052] Different plastic materials can be injected into the first and second mold cavities. For example, a relatively insulating plastic material can be injected into the first mold cavity and a relatively strong plastic material can be injected into the second mold cavity. Again, this difference can be used to fabricate the insulating properties of a field joint coating.
    [00053] The molding tool can move with the tube and still inject and / or cool molten plastic material, in which case the molding tool can pass over a tube support such as a roll or rail associated with a tube guide before the molding tool is removed from the tube.
    [00054] Where the field joint passes over a support after removing the molding tool from the tube, the support adequately connects a relatively hot part of the injected material by resting on a relatively cold part of the injected material and / or on a adjacent pipe lining. It is also possible to interpose padding between the support and the tube to keep the field joint free of the support.
    [00055] The present invention can also be expressed in terms of apparatus for coating a pipe joint during manufacture of the pipe from pipe sections, the apparatus comprising: a molding tool that can be positioned around the joint to define the mold cavity and which is provided with first and second ports through which the molten thermoplastic material can be injected into the mold cavity, said ports being spaced apart from one another; and a control unit arranged to control a coating process involving the molding tool; and the apparatus being arranged to inject molten thermoplastic material through the first port into a first portion of the mold cavity to advance the melting front in the mold cavity towards the second port, and subsequently to inject molten thermoplastic material through the second port to within the second portion of the mold cavity in the vicinity of the first portion; and to accelerate the cooling of the injected material in the first portion of the mold cavity with respect to the cooling of the injected material in the second portion of the mold cavity.
    [00056] The control unit adequately controls the filling of the mold cavity when acting on the valves associated with the ports, each port provided with a respective valve under the individual control of the control unit.
    [00057] The molding tool can be provided with at least one ramp surface on its underside to elevate the molding tool on a pipe support such as a roller or rail associated with a pipe guide, as far as the tube and the molding tool move with respect to the support.
    [00058] The inventive concept extends to a submarine pipeline launch barge comprising the piping production facilities of the present invention or the apparatus of the present invention, or operating any of the methods of the present invention. The inventive concept additionally extends to a pipe or field joint for the pipe, produced by the submarine pipeline launch barge of the present invention, by the pipe production facilities of the present invention or by the apparatus of the present invention, or by carrying out any one of the methods of the present invention.
    [00059] Reference has already been made to figures 1a to 1c of the attached drawings to describe the prior art. In order that the present invention can be more readily understood, reference will now be made, as an example, to the rest of the drawings in which: figure 2 is a schematic side view of a launch barge configured for the operation of the launch method - S, showing a typical context for the coating techniques of the present invention; figure 3 is a schematic cross-sectional view on line III-III of figure 4a, showing the molding tool according to the present invention positioned around a field joint; figures 4a to 4c are schematic detailed views in longitudinal section of the molding tool and field joint in line IV-IV of figure 3, showing the progression over time of a sequential injection molding operation according to the present invention; figures 5a and 5b are detailed schematic views in longitudinal section of an alternative molding tool positioned around a field joint, showing the progression over time of another sequential injection molding operation according to the present invention; figures 6a and 6b are seen in schematic cross section of another molding tool according to the present invention positioned around a field joint, showing the progression over time of an additional sequential injection molding operation according to the present invention; figure 7 is a schematic side view of upstream and downstream coating stations on a launch line on a barge as shown in figure 2; figures 8a and 8b are schematic detailed views in longitudinal section of different molding tools around a field joint in a variant of the present invention in which successive molding operations are carried out at the upstream and downstream coating stations shown in the figure 7; figure 9 is a schematic detailed view in longitudinal section of the molding tool around a field joint in a further variant of the present invention in which an insertion device is embedded in injection molded plastics; figure 10 is a detailed side view of a tube guide arrangement of a launch barge, in which the rollers are replaced by continuous rail supports; figure 11 comprises enlarged side and end views of a rail support shown in figure 10; figure 12 is a schematic side view of a field joint passing over a rail support, showing measures to protect a field joint covering; and figure 13 is a schematic side view of a field joint passing over a rail support, showing another measure to protect a field joint covering.
    [00060] Referring first to the schematic view of figure 2 of the drawings, the submarine pipeline launch barge 10 is configured for the S-launch installation method and moves from left to right as illustrated during an operation pipeline launch. Barge 10 carries a supply of pipe joints 12 on its deck 14 which are welded together at one or more welding stations 16 to form a column of pipe 18 that moves in the stern direction with respect to barge 10 along the line Of launching. Welds are tested at one or more test stations 20 located downstream (that is in the stern direction) of welding stations 16 and are then coated at one or more coating stations 22 located downstream of test stations 20. welding stations 16, test stations 20 and coating stations 22 are thus found on the launch line along which the tube column 18 moves as it is assembled, checked and coated before being launched from barge 10 into sea 24.
    [00061] The tube column 18 is supported by a tensioning system 26 located downstream of the coating stations 22. The tube column 18 is launched from the barge 10 onto a tube guide 28 extending towards the stern of the barge 10, located downstream of the tensioner system 26. The tube guide 28 comprises rollers 30 that support the excess curvature of the tube column 18 as it enters the sea 24. The tube column 18 hangs from the guide -tubes 28 in a shallow S shape under tension acting between the tensioner system 26 and a landing point on the ocean floor (not shown).
    [00062] It is evidently possible for the tube column to experience a much greater deviation through the excess curvature than shown in figure 2, especially in the so-called steep operations of the S-launch method in which the departure angle of the column of tube is close to the vertical as it leaves the tube guide.
    [00063] The present invention is mainly related to coating operations carried out at coating stations 22 on the launch line, which will now be described with reference to figures 3 to 6 of the drawings.
    [00064] Figures 3 and 4a to 4c of the drawings show a molding tool 32 according to the present invention, circling the welded field joint of a pipe in a coating station 22.
    [00065] As in the prior art arrangement of figures 1a to 1c, the field joint in figures 4a to 4c is created between the touching pipe joints 34 where the circumferential weld 36 fixes the pipe joints 34 to each other. Each tube joint 34 is coated, for example, with a 5LPP coating 38, and said coating 38 ends flush with the end of each tube joint 34 with a typically beveled end shape. An annular space is found between the opposite ends of the liner 38 around the weld 36, where the exposed outer surfaces of the pipe joints 34 need to be coated. For this purpose, the molding tool 32 is fixed around the field joint, extending from one coating 38 to the other and overlapping said coatings 38 to define a mold cavity 40 including the annular space between the coatings 38 , into which molten thermoplastic material such as PP is injected as a field joint coating.
    [00066] The molding tool 32 comprises a tube 42 of generally circular cross-section, divided longitudinally into a cross-sectional diameter in two halves. Opposite end portions 44 of the tube 42 sit against the liners 38 of the respective tube joints 34 and thus have an internal diameter that corresponds to the outer diameter of the coated tube joints 34. A central portion 46 of the tube 42 aligned with the space between the liners 38 it has a larger internal diameter that exceeds the outer diameter of the coated pipe joints 34. This enlarges the mold cavity 40 to allow the retraction of the injected plastic material as it cools.
    [00067] The two halves of the molding tool 32 are assembled together to surround the field joint. Where they meet, the two halves are provided with flanges 48 which are held together by external clips 50 shown schematically in figure 3. The clips 50 hold together the two halves against internal pressure inside the molding tool 32 in use; they also hold the molding tool 32 in sealing engagement with the linings 38 of the tube joints 34. Inward seals 52 are provided on the end portions 44 of the molding tool for this purpose, as can be seen in figures 4a to 4c. Stiffening rings 54 circling the end portions 44 of the molding tool 32 also help to maintain structural integrity and sealing.
    [00068] The tubular wall of the molding tool 32 is penetrated by a port structure 56 for injection into the mold cavity 40 of molten PP 58 supplied via the supply line 60 under pressure from a supply reservoir or machine 62 A total of nine ports 56 are shown in the example in figures 3 and 4a to 4c; said doors 56 are arranged in three axially spaced circumferential groups, each group comprising three doors 56 equiangularly spaced around the circumference of the tubular wall. The door groups 56 are substantially evenly spaced, but they are together displaced towards one end of the molding tool 32, the end being downstream with respect to the barge launch line 10.
    [00069] Each port 56 is provided with a respective valve 64 that controls the injection of molten PP 58 through that port 56. Valves 64 are controlled by a central control unit 66 shown in figure 3 and they can be operated independently one on the other. To simplify the illustration, handle valve elements 68 are shown schematically on valves 64 of figures 4a to 4c; other types of valves are, of course, possible.
    [00070] A vent 67 at an end upstream of the tubular wall of the molding tool 32 allows air to escape as the mold cavity 40 is filled with molten PP 58. The molding tool 32 is also provided with a optional cooling system comprising a water jacket created by water pipes 69 arranged in or on the tubular wall of the molding tool 32.
    [00071] In this example, the cooling system is supplemented by an optional cooling tube device 71 which is positioned inside the tube to cool the melt by accelerating the conduction of heat through the tube wall. The tube cooling device 71 is movable longitudinally along the tube to apply cooling where it is needed.
    [00072] The tube cooling device 71 can be a refrigerated tube cleaner, but in the present example it simply comprises a spray head 73. The spray head 73 sprays water radially outward against the inner circumference of the tube wall to cool the molten PP 58 in the mold cavity 40 on the other side of the tube wall. In this way, the water is projected onto a disc that is in a plane orthogonal to the central longitudinal axis of the tube. The spray head 73 is supported by an axis 75 which is on the central longitudinal axis of the tube and which supplies the spray head 73 with water under pressure.
    [00073] Axis 75 is movable longitudinally with respect to the tube to move the spray head 73 in a corresponding mode. A support provided with wheels 77 mounted on the axle next to the spray head 73 allows said longitudinal movement, while keeping the spray head 73 centered within the inner circumference of the tube wall.
    [00074] It is possible for the cooling to be applied locally to the walls of the mold cavity 40 and for the cooling effect to be applied progressively or in stages along the length of the molding tool 32 and / or the tube to suit the desired progression and cooling the melt within the mold cavity 40. In this context, the spray head 73 applies cooling in a advantageously located manner so that an appropriate melting region can be cooled while an adjacent melting region remains internally melted by virtue of continued injection of molten PP 58. This allows molten PP 58 to continue to flow without excessive viscosity and without introducing excessive discontinuity in the melt cooling.
    [00075] Before the injection molding operation begins, the bare, uncoated outer surfaces of the tube joints 34 are cleaned, primed and heated, as are the beveled end surfaces of the liner 38.
    [00076] In figure 4a, the injection molding operation started when opening the valves 64 of the first circumferential group of ports 56 at one end of the mold cavity 40. The result is an annular melting front 70 that has already filled that end of the mold cavity 40 and is now progressing along the mold cavity 40 towards the other end of the mold cavity 40. The outer perimeter of the injected melt has started to freeze to form solid PP 59, but the inner core of the injected melt remains as molten PP 58 while the injection continues through the first circumferential group of ports 56. Valves 64 of the second and third circumferential groups of ports 56 remain closed at this stage.
    [00077] Freezing of the injected melt to form solid PP is aided by the water tubes 69 of the molding tool 32 which cool the radially outer side of the mold cavity 40 and by the spray head 73 of the tube cooling device 71 which cools the radially inner side of the mold cavity 40 by means of the tube wall. In this regard, it will be noted that the spray head 73 is initially aligned with the end downstream of the mold cavity 40 with respect to the barge launch line 10. Similarly, it might be possible, but perhaps less effective, to enable or disable the flow of cooling water through some certain water pipes 69 or if the relative flow of cooling water through different water pipes 69 is varied to concentrate the cooling in certain parts of the molding tool 32.
    [00078] In figure 4b, the fusion front 70 has passed the second circumferential group of ports 56. Now, the valves 64 of the first circumferential group of ports 56 close and the valves 64 of the second circumferential group of ports 56 open. This cascade technique further impels the melt front 70 along the mold cavity 40 and still maintains the melt homogeneity. In this regard, it is advantageous that the valves 64 of the second circumferential port group 56 only open when the fusion front 70 has passed through them; otherwise, there would be two melting fronts that can weld with dissimilar crystalline structures where they come together, which can introduce a weakness in the finished coating of the field joint.
    [00079] Meanwhile, as the valves 64 of the first circumferential group of ports 56 have closed, the fusion introduced through that first circumferential group no longer receives heat input and so it is allowed to start cooling immediately while the fusion injection continues at some other point in the mold cavity 40. Cooling of the melt introduced through the first circumferential group of doors 56 is promoted by the optional application of local cooling. In this regard, the spray head 73 of the tube cooling device 71 now applies cooling locally to a position relative to the downstream of the second circumferential group of ports 56 with respect to the barge 10 launch line. the fusion core next to the first circumferential group of ports 56 began to freeze to form solid PP 59.
    [00080] In figure 4c, the injection molding operation is almost complete. When the fusion front 70 has passed the third circumferential port group 56 near the opposite end of the mold cavity 40, the valves 64 of the second circumferential port group 56 close and the valves 64 of the third circumferential port group 56 open. The molten PP 58 injected through the third circumferential group of ports 56 fills the remainder of the mold cavity 40 while melting in the region of the second circumferential group of ports 56 is able to initiate cooling rapidly. In the meantime, the merger in the region of the first circumferential group of doors 56 has already cooled significantly as it approaches its last resistance.
    [00081] Once again, the cooling of the merger introduced through the second circumferential group of ports 56 is promoted by the optional application of local cooling. In this regard, the spray head 73 of the tube cooling device 71 now applies cooling locally to a position relative to the downstream of the third circumferential group of ports 56 with respect to the barge 10 launch line. the fusion core near the second circumferential group of ports 56 began to freeze to form solid PP 59.
    [00082] When the mold cavity 40 has been filled and the entire melt inside has solidified to a self-supporting extent, the clamps 50 are released to separate and remove the two halves of the molding tool 32 from the field joint. As it consolidates, the injection-molded material will retract, but the over-sized central portion 46 of the molding tool 32 allows it to retract so that the outside diameter of the finished field joint lining approaches the diameter outside of the coated pipe joints 34 on either side of the field joint.
    [00083] The sequential injection molding operation described above has several advantages in the context of field pipe joint lining. It allows rapid cooling of thermoplastic material, reducing cycle time to a level compatible with S-launch installation methods although it is emphasized that the process is also suitable for installation in J-launch methods and for pipe fabrication including winding / winding operations. In addition, the process of the present invention produces a high quality field joint coating. Also, it allows for lower molding pressure and therefore lower gripping strength as the viscous melting need only travel a short distance between ports 56 instead of traversing the mold cavity 40 as a whole.
    [00084] Other arrangements of ports 56 and valves 64 are possible, not only in the number of ports 56, but also in their relative arrangement around the tubular wall of the molding tool 32: for example, ports 56 of neighboring circumferential groups can be angularly displaced with respect to each other. Variations are also possible in the sequence of operation of valves 64: for example, valves 64 of a circumferential group do not need to open simultaneously, but their opening can be staggered, for example, by delaying the opening of valve 64 on a port 56 until the fusion front 70 from the other, previously opened door 56 has passed through it.
    [00085] Valves 64 can open and close at a predefined time of execution based on the assumption that the melting front 70 will move a certain distance over a given time. It is also possible to open and close the valves 64 in response to detecting the position of the melting front 70, for example, using temperature sensors or pressure sensors (not shown) in the molding tool 32.
    [00086] It may be beneficial to advance the melting front 70 through the mold cavity 40 in a direction of movement of the barge 10 during the launch of pipelines, or in an upstream direction with respect to the launch line of the barge 10. This ensures that the coldest and therefore strongest part of a field joint liner is the first to find the rollers 30 of the tube guide 28, which gives more time for the hottest parts of a field joint liner to cool and solidify before they meet the rollers 30.
    [00087] Figures 5a and 5b show an alternative sequential injection molding arrangement using the molding tool 33 in which a first circumferential group of ports 56 is arranged between a pair of second circumferential groups of ports 56. Similar numbers are used for similar parts. Here, the injected fusion is provided with two melting fronts 70 which advance in opposite longitudinal directions from the first circumferential group of doors 56 towards and in addition to a respective of the second circumferential groups of doors 56.
    [00088] At and shortly after the start of the injection molding operation as shown in figure 5a, the valves 64 of the first circumferential group of ports 56 are opened and the valves 64 of the second circumferential groups of ports 56 are closed. Conversely, figure 5b shows the almost complete injection molding operation. When the melting fronts 70 passed through the second circumferential group of ports 56 near the opposite ends of the mold cavity 40, the valves 64 of the first circumferential group of ports 56 close and the valves 64 of the second circumferential groups of ports 56 open. In figure 5b, molten PP 58 injected through the second circumferential groups of ports 56 filled the rest of the mold cavity 40 while melting in the central region of the mold cavity 40 next to the first circumferential group of ports 56 was able to start cooling quickly as soon as the valves 64 of that group of ports 56 close. Consequently, the melt in the central region of the mold cavity 40 started to freeze to form solid PP 59.
    [00089] Although the tube cooling device 71 of figures 4a, 4b and 4c has been omitted from the modality shown in figures 5a and 5b, it will be apparent that localized cooling can be applied through the tube wall by similar means if required.
    [00090] Figures 6a and 6b show an additional sequential injection molding arrangement using the molding tool 35 whose tubular wall is penetrated by a structure of doors 56 which are angularly spaced from one another in a circumferential arrangement. A total of five doors 56 are shown in the example of figures 6a and 6b in an arrangement that is symmetrical over a vertical longitudinal central plane of the molding tool 35. Said doors comprise a first door 56 arranged centrally at the bottom of the molding tool 35 , a pair of second ports 56 above the level of the first port and a pair of third ports 56 above the level of second ports 56.
    [00091] As before, each port 56 is provided with a respective valve 64 (shown for ease of illustration as a loop valve element) that controls the injection of molten PP 58 through that port 56. Valves 64 are controlled by a central control unit such as the one shown in figure 3.
    [00092] Vent 67 at the top of the tubular wall of the molding tool 32 diametrically opposite the first port 56 allows air to escape as the mold cavity 40 is filled with molten PP 58. The molding tool 32 is also provided with an optional cooling system comprising a water jacket created by water pipes 69 arranged in or on the tubular wall of the molding tool 32.
    [00093] In figure 6a, the injection molding operation started by opening the valve 64 of the first port 56 at the bottom of the mold cavity 40. This created melting fronts 70 which are shown here progressing circumferentially in opposite angular directions around of the tube joints 34 in the mold cavity 40, clockwise and counterclockwise. The outer perimeter of the injected fusion started to freeze to form solid PP 59, but the inner core of the injected fusion remains as molten PP 58 while injection continues through the first port 56. The valves 64 of the second and third ports 56 remain closed at this stage.
    [00094] Freezing of the injected melt to form solid PP is aided by the water tubes 69 of the molding tool 32 which cool the radially outer side of the mold cavity 40.
    [00095] In figure 6b, the melting fronts 70 have passed the second ports 56. Now, the valve 64 of the first port 56 closes and the valves 64 of the second ports 56 open. Said cascade technique further impels the melting fronts 70 around the mold cavity 40 and still maintains the melting homogeneity. As before, it is advantageous for the homogeneity of the fusion that the valves 64 of the second circumferential group of ports 56 only open when the fusion front 70 has passed through them.
    [00096] In the meantime, as the valve 64 of the first port 56 has closed, the fusion introduced through that first port 56 no longer receives heat input and so it is allowed to start early cooling while the fusion injection continues at some other point in the mold cavity 40.
    [00097] The cooling of the fusion introduced through the first port 56 is promoted by the optional application of local cooling. In this regard, figure 6b shows how the cooling system can be supplemented by an optional cooling tube device 79 which is positioned within the tube to cool the melt by accelerating heat conduction through the tube wall. The tube cooling device 79 comprises the spray head which is pivotable on the central longitudinal axis of the tube to apply cooling where it is needed. The spray head can, for example, oscillate to spray an arc that increases as the melting fronts 70 progress around the mold cavity 40. The spray head sprays water radially outward against the inner circumference of the wall of the mold. tube to cool molten PP 58 in the mold cavity 40 on the other side of the tube wall. This applies cooling in a locally advantageous manner so that an appropriate fusion region can be cooled while an adjacent fusion region remains internally fused due to the continued injection of molten PP 58.
    [00098] As before, it may also be possible to enable or disable the flow of cooling water through a certain water pipe 69 or to vary the relative flow of cooling water through different water pipes 69 to concentrate cooling in certain molding tool parts 32.
    [00099] Figures 7, 8a, 8b and 9 show other variants of the present invention. They are shown together with ports 56 and valves 64 arranged for sequential injection molding as in figures 3 and 4a to 4c, but they can be used regardless of sequential injection molding if necessary.
    [000100] The variant shown in figures 7, 8a and 8b is specific to the S-launch method and contemplates successive coating stations 22 ', 22 "in a launch line working simultaneously on successive pipe joints 34, as shown in the figure 7. An upstream coating station 22 'applies a thin, internal injection molded coating that cools and hardens quickly, particularly as it has a low volume in relation to its surface area. downstream 22 "applies an external thin injection molded coating on top of the internal coating, which similarly cools and hardens quickly. Together, the thickness of the inner and outer linings, after shrinking, substantially equals the thickness of the pipe liner joint.
    [000101] For this purpose, different molding tools are used in the different coating stations 22 ', 22 ". The upstream coating station 22' is provided with a first molding tool 72 shown in figure 8a provided with a thick wall 74 in its central portion and a corresponding small inner diameter that is less than the outer diameter of the coated pipe joints 34. This produces a thin inner lining in a first sequential injection molding operation. molding 78 shown in figure 8b used in the downstream coating station 22 "is almost the same as the molding tool 32 shown in figures 3 and 4a to 4c, with a thinner wall 80 in its central portion and a correspondingly larger internal diameter width that is greater than the outside diameter of the coated pipe joints 34. Here, the second molding tool 78 is shown before starting a second molding operation. sequential injection to superimpose the additional thin outer lining on the inner lining 76 already formed in the upstream lining station 22 '.
    [000102] The internal and external coatings can be of the same material, such as PP, or they can be of different materials to optimize properties such as insulation. For example, the inner lining can be GSPP for insulation and the outer lining can be solid PP for protection and increased heat capacity.
    [000103] Referring next to figure 9 of the drawings, it shows a variant of the present invention in which an insertion device 82 is positioned in the mold cavity 40 to be embedded in molten plastic during the sequential injection molding operation. However, it is reiterated that inserter 82 can be used independently of sequential injection molding if necessary. Insertion device 82 is a thermoplastic tube (for example, of solid PP or GSPP) in two or more sections that are brought together around the prepared and heated field joint; the inserter 82 itself can be heated and initiated to promote adhesion of the fusion to the inserter 82.
    [000104] In the same way as the arrangement shown in figure 7, the insertion device 82 can be fixed to the field joint in an upstream station before a mold is positioned around the field joint and the insertion device in one downstream station.
    [000105] The inserter 82 comprises spacing tapered formations 84 that space the tubular body 86 of the inserter 82 from the bare exterior of the tube joints 34, and the annular recesses 88 around the tubular body 86 with which the sections of the inserter 82 can be connected around the field joint. The tubular body 86 of the inserter is also penetrated by holes 90 through which molten plastic can flow during molding, helping to fill the mold cavity 40 and ensuring a strong mechanical connection between the hardened melt and the inserter 82.
    [000106] Insertion device 82 reduces the volume of the melt and increases the proportion of the melt interface surface or area with respect to its volume, for the benefit of the cooling time. The insertion device 82 serves as a heat sink that promotes the cooling of the melt; the insertion device also reinforces a field joint lining to help it survive the forces of tensioning and launching on the tube guide 28. Also, if produced from an insulating material such as GSPP, the insertion device 82 can check the desired insulation properties in the field joint lining.
    [000107] Figures 10 to 13 show how the rollers 30 of a tube guide 28 can be replaced by continuous track supports 92, which have the benefit of spreading the load of the tube column 18 over a large contact area. In this way, a field joint coating can be allowed to reach the supports 92 before all or part of a newly coated region has reached full hardening. A similar effect can be achieved by enlarging the radius of the rollers 30, or with straps that run over the paired rollers of the tube guide 28. The continuous track supports 92 shown in figures 10 to 13 can therefore be replaced by a roller 30 or by a series of rollers, with or without running over them.
    [000108] The cycle time of the general launch line can be reduced by spreading the cooling time over more than one cycle. In an S-launch method operation, this involves allowing cooling to take place on one, two or three rollers 30 or other supports 92 after coating station 22. To achieve this the tube column 18 must be supported over the length of a field joint lining or at least over the length of the still soft part of a field joint lining. Thus, the radius of a roller 30, the length of a belt section connecting the rollers or the length of a continuous rail support 92 must be such as to support an already cooled part of a field joint covering and / or in the adjacent pipe liner 38, effectively to bond any still soft part of a field joint liner.
    [000109] Figure 10 shows a series of continuous track supports 92 spaced along and aligned with the longitudinal axis of the tube column 18, while figure 11 shows one of the continuous track supports 92 of figure 9 in more detail. Figure 11 shows that the T-shaped structure 94 supports a pair of main wheels 96, one at each end of the structure 94. A rail 98 comprising flexible hinged connections 100 rotates around the main wheels 96 in a continuous loop aligned with the longitudinal axis of the tube column 18.
    [000110] An upper side of the rail handle 98 defines a support surface 102 for the tube column 18. The support surface 102 is supported along its length by auxiliary wheels 104 within the handle. As best seen in the end view of figure 11, the connections 100 of the rail 98 are concave plates in cross section so that the support surface 102 is longitudinally grooved to locate the tube column 18 laterally. In addition, the support surface 102 is approximately flat allowing less steep ramp portions at each end. The straight length of the support surface 102 is in the order of the length of the field joint: for example, about 750 mm.
    [000111] The main wheels 96 can turn passively with the rail 98, whose movement is directed by the movement of the tube column 18 in its direction of launch, directed in turn by the relative movement of the barge 10 and controlled by the tensioning system 26. Alternatively , at least one of the main wheels 96 can direct the movement of the rail 98 to correspond to the movement of the tube column 18 in its direction of launch, if a main wheel 96 is driven by a suitable electric or hydraulic motor (not shown).
    [000112] With reference now to figure 12, it shows schematically how a field joint lining 106 can be protected as the tube column 18 passes through a continuous rail support 92. Here, a joint lining field 106 is kept free of the support surface 102 of the rail 98 by flexible padding 108 arranged under the tube column 18. Padding 108 may, for example, be layered neoprene rubber. A pad 108 is disposed on each side of a field joint liner 106 and each pad 108 is suitably attached to the tube column 18 by a respective securing rope 110.
    [000113] The spacing between the padding 108 is such that the support surface 102 of the rail 98 connects the space between the padding and the rail portion 98 between the padding 108 does not come into contact with a field joint lining 106. Once a field joint liner 106 has been released from support 92, the fixing strings 110 are untied to remove padding 108 for reuse in protecting the next field joint liner to pass over support 92.
    [000114] Finally returning to figure 13, it shows schematically how the molding tool 112 can travel with the tube column 18 through a support 92, thus providing more time for the modeling and cooling operations to occur. Instead, this allows a field joint liner 106 within the molding tool 112 to pass through support 92 before liner 106 is cooled enough to resist damage or to be self-supporting, or even before liner 106 is complete.
    [000115] It will be seen that the molding tool 112 shown in figure 13 is provided with adaptations to assist its passage over the support 92. Said adaptations comprise longitudinal extensions 114 at each end of the molding tool 112 on its underside, whose extensions overlap the tube liner 38 adjacent to a field joint liner 106. Each extension 114 comprises a frustoconical ramp surface 116 that tapers upward and longitudinally from the center wall 118 of the molding tool 112 to the surface outer tube liner 38 under each extension 114.
    [000116] Once the molding tool 112 and a field joint liner 106 have been released from support 92 and a field joint liner 106 is sufficiently solid to survive additional tensioning or launching steps, the molding 112 is disassembled and removed from the pipe column 18. Additional launching steps may involve the field joint traversing additional rollers or other supports and can therefore use any of the aforementioned solutions to protect the field joint coating recently formed 106. The molding tool 112 can then be reassembled and reused to form a subsequent field joint coating on a tube column 18 upstream of support 92. Although an additional molding tool may be required in said system, the time available cooling capacity is advantageously increased by the duration of a pipe release cycle and possibly more, without the adversely affect the critical path.
    [000117] The thermoplastic material used for injection molding can be PP, polystyrene or other suitable thermoplastic material that is compatible with the coating applied to the pipe joints. Additives or modifiers can be employed, such as an elastomeric modifier such as EDPM (ethylene propylene diene monomer rubber) to provide appropriate flexibility and impact resistance, or glass, aramid or carbon fibers to increase strength and elastic modulus. Additives such as fibers can also reduce shrinkage and cooling speed.
    [000118] By virtue of the present invention, it is envisaged that the cooling time after injection can be reduced to three or four minutes. This allows the use of advantageous injection molding for field joint lining of compatible thermoplastics in time-critical applications such as S-launch method or J-launch method pipe installation operations and other operations tubing fabrication, without the disadvantages of incompatibility suffered by a coating material such as PU.
    权利要求:
    Claims (19)
    [0001]
    1. Method of coating a joint of a tube (18) during the manufacture of the tube (18) from sections of tube (12), characterized by the fact that it comprises: positioning the molding tool (32, 33, 35 , 72, 78, 112) around the joint to define a mold cavity (40) around the tube (18), the molding tool (32, 33, 35, 72, 78, 112) provided with first and second doors (56) spaced from one another; inject the molten thermoplastic material (58) through the first port (56) into a first portion of the mold cavity (40) to advance the melting front (70) into the mold cavity (40) towards the second port (56) ; subsequently injecting the molten thermoplastic material (58) through the second port (56) into the second portion of the mold cavity (40) in the vicinity of the first portion; accelerating the cooling of the injected material (58) in the first portion of the mold cavity (40) with respect to the cooling of the injected material (58) in the second portion of the mold cavity (40); and removing the molding tool (32, 33, 35, 72, 78, 112) from the joint after the material injected (58) into the mold cavity (40) has cooled to a self-supporting extension.
    [0002]
    2. Method, according to claim 1, characterized by the fact that it comprises accelerating the cooling of the injected material (58) in the first portion of the mold cavity (40) by reducing the injection coefficient, or ceasing injection, through the first port (56) and inject through the second port (56).
    [0003]
    Method according to claim 1 or 2, characterized in that it comprises injecting the molten thermoplastic material (58) through the second port (56) after the melting front (70) passes the second port (56).
    [0004]
    Method according to any one of claims 1 to 3, characterized by the fact that: the first and second doors (56) are generally spaced longitudinally in a direction parallel to the tube (18); the second portion of the mold cavity (40) is generally arranged longitudinally beside the first portion; and the melting front (70) advances along the tube (18) from the first port (56) towards the second port (56).
    [0005]
    5. Method according to claim 4, characterized in that it comprises injecting the molten thermoplastic material (58) through a group of first ports (56) angularly spaced around the tube (18) and subsequently injecting the thermoplastic material cast (58) through a group of second ports (56) angularly spaced around the tube (18) and generally spaced longitudinally from the first port group (56).
    [0006]
    Method according to any one of claims 1 to 3, characterized by the fact that: the first and second ports (56) are angularly spaced around the tube (18); the second portion of the mold cavity (40) is generally arranged circumferentially next to the first portion; and the melting front (70) advances around the tube (18) from the first port (56) towards the second port (56).
    [0007]
    Method according to any one of claims 1 to 6, characterized in that it comprises: positioning an insertion device (82) to be within the mold cavity (40); and embedding the insertion device (82) in the molten thermoplastic material (58) injected into the mold cavity (40).
    [0008]
    Method according to any one of claims 1 to 7, characterized in that it comprises: positioning the first molding tool (72) around the field joint to define the first mold cavity (40); injecting the plastic material (58) into the first mold cavity (40) to create an internal coating on the field joint; positioning the second molding tool (78) around the field joint to define the second mold cavity (40) around the inner liner; and injecting the plastic material (58) into the second mold cavity (40) to create an external coating on the field joint.
    [0009]
    Method according to any one of claims 1 to 8, characterized in that it comprises moving the molding tool (32, 33, 35, 72, 78, 112) with the tube (18) and injecting and / or cool molten plastic material (58).
    [0010]
    10. Apparatus for coating a joint of a tube (18) during manufacture of the tube (18) from sections of tube (12), the apparatus comprises: a molding tool (32, 33, 35, 72, 78 , 112) which can be positioned around the joint to define a mold cavity (40) and which is provided with a first port (56) through which the molten thermoplastic material (58) can be injected into the mold cavity ( 40); a means (60) for providing molten thermoplastic material (58); and a means (64) for injecting molten thermoplastic material (58) into the mold tool (32, 33, 35, 72, 78, 112); characterized by the fact that: the apparatus additionally comprises a control unit (66) arranged to control a coating process involving the mold tool (32, 33, 35, 72, 78, 112); the mold tool (32, 33, 35, 72, 78, 112) has a second port (56) through which molten thermoplastic material (58) can be injected into the mold cavity (40), the first and second port ( 56) being spaced apart from each other; and the apparatus is arranged to inject molten thermoplastic material (58) through the first port (56) into a first portion of the mold cavity (40) to advance the melting front (70) into the mold cavity (40) towards the second port (56), and subsequently to inject molten thermoplastic material (58) through the second port (56) into the second portion of the mold cavity (40) in the vicinity of the first portion; and to accelerate the cooling of the injected material (58) in the first portion of the mold cavity (40) with respect to the cooling of the injected material (58) in the second portion of the mold cavity (40).
    [0011]
    Apparatus according to claim 10, characterized by the fact that it is arranged to advance the melting front (70) along the mold cavity (40), in which the first and second doors (56) are spaced longitudinally in a direction parallel to the tube (18) and the second portion of the mold cavity (40) is disposed longitudinally next to the first portion of the mold cavity (40).
    [0012]
    Apparatus according to claim 10 or 11, characterized by the fact that it additionally comprises cooling means (71, 79) which is movable or reconfigurable to apply cooling locally in a cooling position that moves according to the movement of the melting front (70).
    [0013]
    13. Apparatus according to any of claims 10 to 12, characterized by the fact that the control unit (66) controls the filling of the mold cavity (40) when acting on the valves (64) associated with the ports (56 ), each port (56) provided with a respective valve (64) under individual control of the control unit (66).
    [0014]
    Apparatus according to any one of claims 10 to 13, characterized in that it additionally comprises an insertion device (82) positioned within the mold cavity (40) to be embedded in the plastic material (58) injected into the mold cavity (40).
    [0015]
    Apparatus according to any one of claims 10 to 14, characterized in that it comprises first and second molding tools (72, 78) positioned successively around the field joint to define first and second mold cavities respectively, the second molding tool (78) provided with a mold cavity internal diameter larger than that of the first molding tool (72) to overlap the outer coating in an internal coating produced by the first molding tool (72).
    [0016]
    16. Pipeline production installation characterized by the fact that it comprises the apparatus as defined in claim 14 or 15, in which the insertion device (82) is positioned at a field joint in an upstream station (16, 20, 22 ) and the molding tool (32, 33, 35, 72, 78, 112) is positioned around a field joint at the downstream station (16, 20, 22) with respect to a direction of movement of a pipe being produced by the installation.
    [0017]
    17. Pipeline production installation characterized by the fact that it comprises apparatus as defined in claim 15, in which the plastic material (58) is injected into the first mold cavity (40) in an upstream coating station (22) and plastic material (58) is injected into the second mold cavity (40) in a downstream coating station (22) with respect to a direction of movement of a pipe being produced by the installation.
    [0018]
    18. Submarine pipeline launch barge (10) characterized by the fact that it comprises piping production facilities as defined in claim 16 or 17 or the apparatus as defined in any of claims 10 to 15.
    [0019]
    19. Pipe or field joint for a pipe, characterized by the fact that it is produced by the submarine pipeline launch barge (10) as defined in claim 18, by the pipe production facilities as defined in claim 16 or 17, or by apparatus as defined in any of claims 10 to 15, or when carrying out the method as defined in any of claims 1 to 9.
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    同族专利:
    公开号 | 公开日
    EP2886288A1|2015-06-24|
    BR112013000304A2|2016-05-31|
    GB201011283D0|2010-08-18|
    EP2590794B1|2015-01-14|
    US20150375435A1|2015-12-31|
    GB2490153B|2013-10-02|
    US20130170913A1|2013-07-04|
    WO2012004665A3|2012-05-24|
    AU2011275454B2|2015-10-01|
    AU2011275454A1|2013-02-14|
    WO2012004665A2|2012-01-12|
    EP2886288B1|2017-11-01|
    GB2490153A|2012-10-24|
    US9046195B2|2015-06-02|
    NO2886288T3|2018-03-31|
    GB201106690D0|2011-06-01|
    US10160147B2|2018-12-25|
    EP2590794A2|2013-05-15|
    GB2481801A|2012-01-11|
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    法律状态:
    2017-10-10| B25D| Requested change of name of applicant approved|Owner name: ACERGY FRANCE SAS (FR) |
    2018-04-10| B06F| Objections, documents and/or translations needed after an examination request according art. 34 industrial property law|
    2019-10-01| B06U| Preliminary requirement: requests with searches performed by other patent offices: suspension of the patent application procedure|
    2020-07-28| B06A| Notification to applicant to reply to the report for non-patentability or inadequacy of the application according art. 36 industrial patent law|
    2020-11-24| B09A| Decision: intention to grant|
    2021-02-02| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 04/07/2011, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    GB1011283.7|2010-07-05|
    GB1011283.7A|GB2481801A|2010-07-05|2010-07-05|Techniques for coating pipes|
    GB1106690.9|2011-04-20|
    GB201106690A|GB2490153B|2010-07-05|2011-04-20|Techniques for coating pipes|
    PCT/IB2011/001859|WO2012004665A2|2010-07-05|2011-07-04|Techniques for coating pipes|
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