Method for manufacturing metal strip and workbench

Abstract

The invention relates to a method for producing a metal strip (10), comprising the following steps: arranging an end portion (13) of a first metal strip element (11) and an end portion (14) of a second metal strip element (12) on a planar support (21) juxtaposed in a longitudinal direction, each of the first and second elements having a longitudinal side (11B, 11C, 11B, 11C, 11B, 11C, 11B, 11C, 11B, 11C, 11D, 11C, 11D, 11C, 11D, 11C, 11D, 11C, 11D, 11C, 11D); the first element and the second element each terminate by a transverse end face (11C, 12C), aligning the longitudinal side faces of the first element and the second element such that the longitudinal side faces of the first element and the second element extend in a line with each other, and wherein the longitudinal side faces of the first element and the second element extend in a line with each other, and wherein the longitudinal side faces of the first element and the second element each terminate by a transverse end face (11C, 12C). The first metal strip element and the second metal strip element are butt-welded so as to form a continuous weld seam extending along the transverse end faces (11C, 12C) over the entire width of the elements.

Description

Technical Field

[0001] The invention relates to the field of manufacturing metal strips for the construction of sealing films, in particular for sealed and thermally insulating cans.

[0002] The present invention relates in particular to the field of membranes for sealed and thermally insulated tanks for cryogenic storage and / or transport of liquids, such as tanks for transporting liquefied natural gas (LNG) at about -162°C at atmospheric pressure, liquid hydrogen (LH2O) at -253°C at atmospheric pressure, and liquid hydrogen (LNG) at about -162°C at atmospheric pressure. 2 ), ammonia (NH 3 ), or liquefied petroleum gas (LPG) at a temperature between -50°C and 0°C, for example. These tanks can be installed on land or on floating structures. In the case of floating structures, the tanks can be used to transport liquefied gas or to receive liquefied gas used as propulsion fuel for floating structures. In the case of land tanks or port storage structures, the latter can be placed on the ground or on the seabed and can be partially or completely buried. Background Art

[0003] Methods are known for producing metal strips having a longitudinal length of between 30 and 40 meters for the construction of sealing and thermally insulating tank films.

[0004] The production of such a metal strip is described, for example, in document FR 2 148 366. For the production of sealing and insulating tank films, the required precision in the straightness of the metal strip is very high.

[0005] The strip is stored in a coiled state on an axis perpendicular to the longitudinal direction. The strip is unwound and stretched on a straightening table to prevent the “blade” from deforming, and then placed on a shearing table to straighten it by cutting the longitudinal edges of the strip.

[0006] The length of each of the straightening station and the shearing station is suitable for receiving a metal strip having a length of about 30 to 40 meters. Summary of the invention

[0007] The idea of ​​the present invention is to provide a manufacturing method that can manufacture metal strips of very long lengths, for example, metal strips of 50 to 80 meters (inclusive) in length, in a small space.

[0008] Of note is the use of a manufacturing table having a length less than the length of the metal strip being manufactured (eg, a manufacturing table having a length less than 40 meters) to manufacture very long lengths of metal strip.

[0009] One embodiment of the present invention provides a method for manufacturing a metal strip, the method comprising the following steps:

[0010] - arranging an end portion of a first metal strip element and an end portion of a second metal strip element on a planar support, the end portion of the first metal strip element and the end portion of the second metal strip element being juxtaposed in the longitudinal direction, each of the first metal strip element and the second metal strip element having two opposite main faces connected by two longitudinal side faces, the first metal element and the second metal element both having the same width, the end portion of the first metal strip element and the end portion of the second metal strip element being terminated by a respective transverse end face; such that a main face of each of the first metal strip element and the second metal strip element is at least partially placed on the planar support and the transverse end face of the end portion of the first metal strip element extends in the vicinity of the transverse end face of the end portion of the second metal strip element;

[0011] - aligning the longitudinal side of the first metal strip element and the longitudinal side of the second metal strip element so that the longitudinal side of the first metal strip element and the longitudinal side of the second metal strip element extend in line with each other;

[0012] - butt welding the first metal strip element and the second metal strip element so as to form a continuous weld along the transverse end faces over the entire width of the metal strip elements.

[0013] Thanks to these characteristics, it is possible to manufacture metal strips of very long lengths by welding together a plurality of metal strip elements. Furthermore, the method allows the use of a manufacturing table of a length suitable for completely receiving a single metal strip element. Thus, it is not necessary to have a straightening and / or shearing table suitable for receiving the metal strip of the final length obtained according to the manufacturing method.

[0014] The longitudinal edge of the obtained metal strip is preferably cut at least in the longitudinal direction of the metal strip along a region extending from a position located on one side of the weld seam to a position located on the other side of the weld seam.

[0015] Therefore, after said welding has been carried out, the longitudinal edges of the portion of the metal strip comprising the weld seam are cut. This has the advantage of eliminating the initial and final areas of the weld which may contain welding defects.

[0016] Implementations of this method may have one or more of the following features.

[0017] In one embodiment, the end portions are arranged such that a transverse face of the end portion of the first metal strip element extends to a distance from a transverse end face of the end portion of the second metal strip element that is less than or equal to half the thickness of one of the metal strip elements.

[0018] In a further embodiment, the end portions are arranged such that a transverse face of the end portion of the second metal strip element overlaps the end portion of the first metal strip element by a distance less than or equal to three times the thickness of one of the metal strip elements.

[0019] Therefore, in practice, the end portion of the first metal strip element and the end portion of the second metal strip element are arranged so that the transverse end faces of the first metal strip element and the second metal strip element extend facing each other and are spaced apart from each other by a space: the size of the space in the longitudinal direction of the metal strip element is less than or equal to half the thickness of one of the metal strip elements, for example, the size of the space in the longitudinal direction of the metal strip element is less than or equal to half the thickness of the metal strip element with the larger thickness of the two metal strip elements, or the end portion of the first metal strip element and the end portion of the second metal strip element are arranged so that: the distance by which the end portion of the second metal strip element overlaps with the end portion of the first metal strip element is less than or equal to the thickness of one of the metal strip elements, for example, the distance by which the end portion of the second metal strip element overlaps with the end portion of the first metal strip element is less than or equal to three times the thickness of the metal strip element with the larger thickness of the two metal strip elements.

[0020] One embodiment of the method further includes:

[0021] - Paying out the roll carrying said first metal strip element.

[0022] One embodiment of the method further includes:

[0023] - Partially cutting the first metal strip element along its longitudinal sides using two tools, the two tools being arranged on a path for feeding the end portion of the first metal strip element to a position where the cutting stops, the position being located at a certain distance from the transverse end face of the first metal strip element, the first metal strip element being intended to be arranged in the vicinity of the second metal strip element.

[0024] Therefore, before welding the first metal strip element to the second metal strip element, the longitudinal edge of the first metal strip element can be partially cut. Due to this partial cutting, the start and end points of the butt welding area along the longitudinal side of the welded metal strip can be cut after welding to eliminate welding defects, thereby improving the mechanical strength of the welded metal strip.

[0025] In one embodiment, the two cutting tools are placed face to face and are immovable. The metal strip element is driven and moves in the longitudinal direction. The planar support then comprises means for moving the metal strip element, for example a conveyor, which means for moving the metal strip element may be provided with: a suction system for obtaining a suction effect for holding the metal strip element; or an attachment system fixed to the end portion of the metal strip element.

[0026] In one embodiment, the two cutting tools are placed face to face and can move in the longitudinal direction. The cutting tools are for example mounted to be movable on rails parallel to the longitudinal axis of the manufacturing table.

[0027] In one embodiment, the method further comprises:

[0028] - Winding the cut end portion of the first metal strip element around a winding axis perpendicular to said longitudinal direction.

[0029] This step makes it possible to release the planar support, allowing it to receive the second metal strip element.

[0030] In one embodiment, before the welding step, a portion of the second metal strip element is also cut along the longitudinal side of the second metal strip element, and the cut portion of the second metal strip element extends from the transverse end face of the second metal strip element to a position where the cutting is stopped, and the position where the cutting is stopped is located at a certain distance from the transverse end of the second metal strip element, and the transverse end of the second metal strip element is intended to be arranged near the first metal strip element.

[0031] In one embodiment, the planar support comprises a metal plate, towards which the transverse end faces of the first and second metal strip elements arranged adjacent to each other extend during the welding step.

[0032] In one embodiment, the method comprises the following steps:

[0033] - pressing the end portion of the first metal strip element and the end portion of the second metal strip element against the planar support by bearing on the planar support opposite main faces on either side of transverse end faces arranged adjacent to each other.

[0034] In one embodiment, the step of pressing the end portions of the first and second metal strip elements against the planar support uses a clamping device, which includes a metal support part that presses on the main faces of the metal strip elements on both sides of the lateral end faces of the metal strip elements arranged adjacent to each other.

[0035] In one embodiment, the method further comprises:

[0036] - Spot welding is performed before producing a continuous weld.

[0037] In one embodiment, the continuous weld is produced by a method selected from the following methods: TIG arc welding, micro plasma welding, extrusion seam welding, chewing friction welding.

[0038] In one embodiment, the length of each metal strip element is greater than 25 meters.

[0039] In one embodiment, each metal strip element has a constant thickness.

[0040] In one embodiment, the first metal strip element and the second metal strip element have the same thickness.

[0041] In one embodiment, the cutting is stopped at a distance between 1 meter and 3 meters from the transverse end face of the cut first metal strip element or the second metal strip element, wherein 1 meter to 3 meters are inclusive.

[0042] In one embodiment, the metal strip element used has a coefficient of expansion of typically 1.10 -6 K -1 To 2.10 -6 K -1 The metal strip element used is made of an iron-nickel alloy with a coefficient of expansion between 7.10 and 10. -6 K -1 and 9.10 -6 K -1 It is made of iron-manganese alloy with a value between (including the endpoint values).

[0043] In one embodiment, each metal strip element has a thickness between 0.5 mm and 1 mm, inclusive.

[0044] In one embodiment, the manufacturing method further comprises the step of bending the longitudinal edges of the metal strip.

[0045] In one embodiment, the present invention further provides a workbench for manufacturing a metal strip, the workbench comprising:

[0046] a planar support adapted to receive an end portion of a first metal strip element and an end portion of a second metal strip element, the end portion of the first metal strip element and the end portion of the second metal strip element being juxtaposed in the longitudinal direction, each of the first metal strip element and the second metal strip element having two opposite main faces connected by two longitudinal side faces, the end portion of the first metal strip element and the end portion of the second metal strip element each terminating by a respective transverse end face, the transverse end face of the first metal strip element extending in the vicinity of the transverse end face of the second metal strip element,

[0047] - an alignment device for adjusting the relative position of the longitudinal side of the first metal strip element and the longitudinal side of the second metal strip element so that the longitudinal side of the first metal strip element and the longitudinal side of the second metal strip element extend in line with each other,

[0048] - A welding bench for butt-welding the two metal strip elements by means of a continuous weld extending along the transverse end faces over the entire length of the metal strip elements.

[0049] The workbench preferably comprises two cutting tools adapted to cut the longitudinal edge of the obtained metal strip at least along a region extending in the longitudinal direction of the metal strip from one side of the weld seam to the other side of the weld seam.

[0050] In one embodiment, the planar support comprises a groove adapted to receive an end portion of the metal strip element.

[0051] In one embodiment, the alignment device comprises, on the one hand, a fixed main component, which includes a bottom wall and a first longitudinal side wall defining the groove, and, on the other hand, a movable side component, which includes a second side wall facing the first side wall, the movable side component of the alignment device being suitable for laterally clamping the end portion of the metal strip element placed in the groove along a transverse direction perpendicular to the longitudinal direction.

[0052] In one embodiment, the movable side portion of the alignment device is suitable for sliding in the main body of the alignment device in the transverse direction between an open position and a clamping position, in which the second side wall is arranged at a distance from the first side wall that is strictly greater than the width of the metal strip element, and in the clamping position, the second side wall is arranged at a distance from the first side wall that is less than or equal to the width of the metal strip element.

[0053] In one embodiment, the manufacturing table comprises clamping means adapted to press the two metal strip elements against the planar support by bearing on the supporting plane opposite main faces on either side of transverse end faces arranged adjacent to each other.

[0054] In one embodiment, the clamping means take the form of a first metal plate having through slots intended to extend transversely, said through slots facing the transverse end faces of the metal strip element received on the planar support, arranged adjacent to each other.

[0055] In one embodiment, the manufacturing table comprises a second plate forming part of the planar support and intended to be arranged facing the transverse end face located adjacent the metal strip element.

[0056] In one embodiment, the second plate is made of ceramic or metal, more specifically, the second plate is made of copper and its alloy or stainless steel.

[0057] In one embodiment, the welding stand comprises a welding head and a guide rail, the welding head being adapted to slide along the rail so that the welding head moves in the groove of the first metal plate.

[0058] One embodiment of the present invention also provides a metal stripe, which is suitable for producing a sealing film for a sealed and insulated tank, the metal stripe comprising a metal strip obtained from two metal strip elements according to the above method, both metal strip elements having a constant thickness over the entire length of the metal strip element, the metal stripe having a planar central portion and two side edges bent substantially perpendicularly to the planar central portion in the width direction of the metal stripe, the two side edges having a smaller width than the planar central portion.

[0059] One embodiment of the present invention also provides a sealing membrane for a sealed and insulated tank, the sealing membrane comprising a repeating structure, the repeating structure alternately comprising the metal strakes as described above and elongated welding flanges, the welding flanges being connected to a supporting surface of the sealing membrane and protruding relative to the supporting surface, the welding flanges extending parallel to the metal strakes over at least a portion of the length of the metal strakes, the planar center portion of the metal strakes being placed on the supporting surface, the side edges of the metal strakes being arranged to abut against adjacent welding flanges and being welded to the welding flanges in a sealing manner.

[0060] One embodiment of the present invention also provides a sealed and insulated tank, which is integrated into a supporting structure, the supporting structure comprising a plurality of supporting walls, the tank comprising a plurality of tank walls, each tank wall being fixed on a corresponding supporting wall, the tank wall comprising an insulating barrier retained on the supporting wall, the insulating barrier having a planar supporting surface parallel to the corresponding supporting wall and a sealing film as described above.

[0061] One embodiment of the present invention further provides a ship for transporting fluid, the ship comprising a catamaran and a tank disposed in the catamaran.

[0062] One embodiment of the present invention also provides a fluid transportation system, which includes a ship, an insulating pipe arranged in a manner to connect a tank of the ship to a floating storage facility or an onshore storage facility, and a pump for pumping fluid from the floating storage facility or the onshore storage facility to the tank of the ship or from the floating storage facility or the onshore storage facility to the tank of the ship through the insulating pipe.

[0063] One embodiment of the present invention also provides a method of loading or unloading a vessel, wherein fluid is transferred from a floating storage facility or an onshore storage facility to a tank of a vessel or from a tank of a vessel to a floating storage facility or an onshore storage facility through an insulated pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The invention will be better understood and other objects, details, features and advantages of the invention will become more apparent in the course of the following description of certain embodiments of the invention given by way of non-limiting illustration only and with reference to the accompanying drawings.

[0065] Figure 1 A schematic perspective view of a portion of a workbench for producing metal strips is shown.

[0066] Figure 2 Shows Figure 1 Schematic diagram of the cross section of the workbench used to manufacture metal strips along line AA.

[0067] Figure 3 Shows Figure 2 Enlarged schematic diagram of detail B.

[0068] Figure 4 Shows Figure 1 Schematic diagram of part of the manufacturing table viewed from above.

[0069] Figure 5 The four steps of the method for manufacturing a metal strip are schematically shown.

[0070] Figure 6Schematically shown are sectional views of the configuration of an end portion of a metal strip element during seam welding and a cross section of the metal strip obtained after such welding.

[0071] Figure 7 is a schematic cross-sectional view of a methane tanker tank and the terminal used to load / unload the tank. DETAILED DESCRIPTION

[0072] The accompanying drawings show a part of a workbench for manufacturing metal strips and the various steps of its manufacture. The same or corresponding elements shown in the drawings will be marked with the same reference numerals and will not be described in detail each time.

[0073] exist Figure 1 , Figure 2 and Figure 3 1 shows a partial view of an embodiment of a workbench 20 for producing a metal strip 10 .

[0074] This manufacturing table 20 enables the use of a method for manufacturing very long metal strips 10 , for example with a length greater than or equal to 50 meters.

[0075] In the method for producing a metal strip described here, a metal strip 10 is produced from a plurality of metal strip elements 11 , 12 , for example at least two metal strip elements.

[0076] The case where the metal strip 10 is manufactured from the first metal strip 11 and the second metal strip element 12 will be described below.

[0077] Each metal belt element 11 , 12 is in the shape of a belt having an elongated shape in the longitudinal direction D1 , D2 , and each metal belt element 11 , 12 has a straight profile in a direction perpendicular to the longitudinal direction.

[0078] It has two opposite main faces 11A, 12A, which are connected by two longitudinal side faces 11B, 12B and two transverse end portions 11C, 12C ( Figure 1 and Figure 6 ).

[0079] Each metal strip element 11, 12 has a length in the longitudinal direction D1, D2 of typically about 25 to 40 meters, for example 35 meters, and has a width slightly greater than 540 mm in a direction extending perpendicularly to the longitudinal direction and parallel to the main faces 11A, 12A of the metal strips 11, 12. The width of the metal strip elements is, for example, between 540 mm and 560 mm (both inclusive).

[0080] The reference thickness of the metal strip elements 11 , 12 is approximately 0.7 mm, for example between 0.5 mm and 1 mm (inclusive).

[0081] Each metal strip element has a uniform and constant thickness over the entire length of each metal strip element. This thickness is equal to its reference thickness with a tolerance strictly less than 5%, i.e. for a reference thickness of 0.7 mm, the tolerance is 0.035 mm. Thus, the thickness of each metal strip element varies locally by less than 5% of the reference thickness of the metal strip element. Here, the thickness of each metal strip element preferably varies locally by less than 4%, 3%, 2% or 1% of its reference thickness.

[0082] The first metal strip element and the second metal strip element preferably have the same width and thickness. Their lengths may be the same or different.

[0083] Each of the first metal strip element and the second metal strip element is made of a metal, such as an iron-nickel alloy, whose coefficient of expansion is generally less than 2.10 -6 K -1 , for example in 1.10 -6 K -1 To 2.10 -6 K -1 For example, it is In another embodiment, each metal strip element is made of an iron-manganese alloy having a coefficient of expansion of 7.10 -6 K -1 and 9.10 - 6 K -1 This alloy is usually lower in cost.

[0084] The method of manufacturing the metal strip 10 comprises the following steps:

[0085] - arranging the end portion 13 of the first metal strip element 11 and the end portion 14 of the second metal strip element 12 on the planar support 21,

[0086] - aligning the longitudinal side 11B of the first metal strip element 11 and the longitudinal side 12B of the second metal strip element 12 so that the longitudinal side 11B of the first metal strip element 11 and the longitudinal side 12B of the second metal strip element 12 extend in line with each other,

[0087] - Butt welding the first metal strip element 11 and the second metal strip element 12 to form a continuous weld seam extending along the transverse end faces 11C, 12C over the entire width of the first and second metal strip elements.

[0088] In practice, each metal strip element 11 , 12 is initially stored in the form of a roll, wherein the metal strip element is wound on itself around an axis extending in the width direction of the metal strip element.

[0089] The method therefore comprises a preliminary step in which a roll carrying the first metal strip element 11 is paid out.

[0090] The metal strip element 11 may immediately after unwinding exhibit a so-called "sabre blade" deformation, in which the two longitudinal edges of the metal strip element bend in the same direction. Using such a metal strip element without correcting this deformation makes it impossible to produce a metal strip with a straightness and dimensional accuracy that corresponds to the level of accuracy required for the manufacture of sealing films.

[0091] In practice, the required accuracy is about 0.5 mm per meter (this is not cumulative). This means that over the entire length of the metal strip, the longitudinal edges of the metal strip must not deviate by more than 0.5 mm from a theoretical ideal straight line extending between the longitudinal ends of said longitudinal edges.

[0092] In order to correct this deformation, the method for manufacturing a metal strip comprises a step of stretching the first metal strip element 11 .

[0093] Therefore, the first metal strip element 12 is preferably stretched under tension in a straightening device. This straightening device is well known to the person skilled in the art and will not be described in detail here. The straightening device comprises, for example, two self-clamping jaw parts, one of which is rigidly fixed to a fixed frame of the straightening device and the other of which is movable because it is part of a part that can slide on the frame. The end portion 13 of the first metal strip element 11 is placed in the self-clamping jaw part and the movable self-clamping jaw part slides in such a way that a longitudinal traction force is exerted on the first metal strip element 11. This longitudinal traction force is slightly greater than the elastic deformation limit of the metal strip element.

[0094] Once straightened by stretching, the first metal strip element 11 lies flat on a planar support 21 of a production table 20 (see Figure 5 Schematic diagram a) in FIG. 1 ). The first metal strip element can be rewound when leaving the straightening device in order to transfer it to the production table 20 and unrolled to lie flat on the planar support 21 of the production table 20 .

[0095] The planar support 21 comprises a planar receiving surface which can receive the first metal strip element or the second metal strip element ( Figure 5 Schematic diagram in a)).

[0096] The planar support 21 extends along a longitudinal axis L. The metal strip elements are placed on the planar support 21 such that the longitudinal directions D1 , D2 of the metal strip elements 11 , 12 extend along the longitudinal axis L of the planar support.

[0097] The manufacturing method then preferably comprises the step of partially cutting the first metal strip element 11 along its longitudinal side 11B until a cutting stop position AD which is located at a distance from a transverse end face 11C of the first metal strip element 11 which is intended to be arranged in the vicinity of the second metal strip element 12.

[0098] Figure 5 The schematic diagram b) in FIG. 1 schematically illustrates this cutting step.

[0099] The longitudinal edges in the first metal strip element 11 are cut by means of two cutting tools 22 arranged on a path for feeding the end portion 13 of the first metal strip element 11 .

[0100] exist Figure 5 In the example shown, two cutting tools 22 are placed face to face and cannot be moved. Each cutting tool 22 comprises, for example, a shearing tool with two circular cutters. The cutting tools 22 are located at the longitudinal ends of the planar support 21 of the manufacturing table.

[0101] Here, the first metal strip element 11 is moved by a conveyor which can be equipped with: a suction system for obtaining a suction effect to hold the metal strip element; or with attachment means fixed to the end portion of the metal strip element. It is thus translated longitudinally along the longitudinal axis L of the planar support 21 parallel to the longitudinal direction D1 of the first metal strip element 11 until the cutting tool reaches the cutting stop position AD ( Figure 5 Schematic diagram in c)).

[0102] The cutting stop position AD is located, for example, at a distance from the transverse end face 11C of the first metal strip element 11 of between 1 meter and 3 meters (inclusive).

[0103] For this purpose, the cutting tool is located in the longitudinal direction L of the production table downstream of the welding carriage 50 in the direction of movement of the first metal strip element.

[0104] Alternatively, the two cutting tools can be placed face to face and movable in the longitudinal direction. The two cutting tools 22 are, for example, mounted on a frame that can be translated along a track extending along a planar support, which extends along the longitudinal axis L of the support plane 21. They can be translated unidirectionally along the longitudinal direction L of the manufacturing table, or bidirectionally along this longitudinal direction.

[0105] In this case, the table may or may not contain means for moving the metal strip element.If the table does not contain such means, the two cutting tools may be moved at least between the two ends on either side of the welding stand.

[0106] When the longitudinal edge of the first metal strip element 11 is cut, the cut portion of the first metal strip element is preferably rewound on a winding axis perpendicular to the longitudinal direction D1 of the first metal strip element 11. Figure 5 The schematic diagram c) is shown in FIG.

[0107] Thus, at the end of this cutting step, the first metal strip element 11 comprises the rewound cut portion and the portion of the first metal strip element 11 between the cutting stop position AD and the nearest transverse end face 11C, wherein the longitudinal edge of this transverse end face has not yet been cut and is arranged on the main support 21. This latter portion constitutes the end portion 13 of the first metal strip element 11.

[0108] The space occupied by the first metal strip element 11 on the planar support 21 is limited by its end portion 13. The second metal strip element 12 can then be arranged flat on the planar support 21 ( Figure 5 Schematic diagram in c)).

[0109] The method preferably comprises a preliminary step in which a coil formed from the second metal strip element 12 is paid out.

[0110] The method of manufacturing a metal strip preferably also comprises the step of stretching the second metal strip element 12 to prevent any "sabre blade" deformation thereof.

[0111] Therefore, the second metal strip element 12 is preferably stretched in the straightening device under a tensile force as described above.

[0112] Once straightened by stretching, the second metal strip element 12 is placed on a planar support 21 of a production table 20 (see Figure 5 c) in FIG. 1 ). The second metal strip element 12 can be rewound when leaving the straightening device for transfer to the production table 20 and then unwound for placement on the planar support 21 .

[0113] The second metal strip element 12 is placed beside the first metal strip element so that the end portion 13 of the first metal strip element is longitudinally aligned with the end portion 14 of the second metal strip element 12. The longitudinal direction D1 of the first metal strip element 11 and the longitudinal direction D2 of the second metal strip element 12 are then parallel.

[0114] One of the respective main faces 11A in the first metal strip element 11 and the respective main faces 12A in the second metal strip element 12 rests at least partially on a receiving surface of the manufacturing table 20. In particular, portions of the main faces 11A, 12A belonging to end portions of the first metal strip element and the second metal strip element rest on a planar support 21.

[0115] The lateral end 11C of the end portion 13 of the first metal strip element 11 extends to the vicinity of the lateral end face 12C of the end portion 14 of the second metal strip element 12 .

[0116] More precisely, two configurations are envisaged in which the transverse end face 11C of the first metal strip element and the transverse end face 12C of the second metal strip element extend adjacent to each other.

[0117] In a first possible configuration, the transverse face 11C of the end portion of the first metal strip element extends to a distance from the transverse end face of the end portion of the second metal strip element that is less than or equal to half the thickness of each metal strip element.

[0118] More precisely, the transverse end face 11C of the first metal strip element 11 extends towards the transverse end face 12C of the second metal strip element 12 in such a manner that the transverse end face 11C of the first metal strip element 11 is in contact with the transverse end face 12C of the second metal strip element 12 or the transverse end face 11C of the first metal strip element 11 is spaced from the transverse end face 12C of the second metal strip element 12 by a distance less than or equal to half the thickness of each metal strip element. Figure 3 shown.

[0119] In a second possible configuration, the end portion 14 of the second metal strip element 12 slightly overlaps the end portion 13 of the first metal strip element by a distance less than or equal to three times the thickness of each metal strip element. Figure 6 In this second configuration, the transverse end face 11C of the first metal strip element and the transverse end face 12C of the second metal strip element are separated by a distance measured in the longitudinal direction of the metal strip elements and which is less than or equal to three times the thickness of one of the metal strip elements.

[0120] The transverse end faces 11C, 12C of the two metal strip elements are preferably straight, that is to say perpendicular to the main faces of the metal strip elements, such as Figure 3 and Figure 6 Furthermore, in both envisaged configurations, the transverse end face 11C of the first metal strip element 11 and the transverse end face 12C of the second metal strip element 12 are separated by a distance measured in the longitudinal direction of the metal strip elements and which is less than or equal to three times the thickness of one of the metal strip elements.

[0121] The transverse end faces 11C, 12C of the two metal strip elements are preferably arranged in contact with each other.

[0122] This configuration is used, for example, for TIG welding, plasma welding or mastication friction welding.

[0123] The planar support 21 also comprises recesses 24 suitable for receiving the end portions 13 , 14 of the metal strip elements 11 , 12 .

[0124] In order to accurately position the end portion of the first metal strip element 11 and the end portion of the second metal strip element 12 in line with each other, the method comprises the steps of aligning the longitudinal side 11B of the first metal strip element and the longitudinal side 12B of the second metal strip element so that the longitudinal side 11B of the first metal strip element and the longitudinal side 12B of the second metal strip element extend in line with each other.

[0125] To this end, the manufacturing device 20 includes an alignment device 30, which is used to adjust the relative positions of the longitudinal side 11B of the first metal strip element 11 and the longitudinal side 12B of the second metal strip element 12 so that the longitudinal side 11B of the first metal strip element 11 and the longitudinal side 12B of the second metal strip element 12 extend in line with each other.

[0126] Figure 4 A portion of a planar support 21 is shown which is intended to extend below the end portions 13 and 14 of the first and second metal strip elements 11, 12. This portion of the planar support comprises two complementary portions 31, 32 which together form an alignment device 30.

[0127] More specifically, the alignment device 30 here: on the one hand, includes a fixed main component 31, which includes a first side wall 31A and a bottom wall 31B, and the first lateral outer surface 33 and the central outer surface 34 of the bottom wall 31B define the groove 24; on the other hand, the alignment device 30 includes a movable side component 32, which includes a second side wall 32A and a second outer surface 35, and the second outer surface 35 faces the first lateral outer surface 33 of the first side wall 31A to define the groove 24.

[0128] The mobile side parts 32 of the alignment device 30 are adapted to laterally clamp the end portions 13 , 14 of the metal strip elements 11 , 12 placed in the grooves 24 in a transverse direction perpendicular to the longitudinal direction L of the production table.

[0129] The mobile side part 32 of the alignment device 30 is here adapted to slide in the transverse direction in the fixed main part 31 of the alignment device 30. To this end, the mobile side part 32 comprises a series of pins 36 projecting from the second side wall 32A in the direction of the fixed main part 31, the fixed main part comprising in its bottom wall 31B a housing 37 open in the direction of the pins 36, the housing 37 being adapted to receive the pins 36 sliding in the housing 37.

[0130] Thus, the movable side part 32 is adapted to slide between an open position in which the second side wall is arranged at a distance from the first side wall strictly greater than the width of the metal strip element, and a clamped position in which the second side wall is arranged at a distance from the first side wall equal to the width of the metal strip element.

[0131] In order to align the end portion of the first metal strip element and the end portion of the second metal strip element, the moving part 32 of the alignment device 30 is slid to clamp the longitudinal sides 11B, 12B of the two metal strip elements between the lateral outer faces 33, 35 of the side wall 31A of the fixed main part 31 and the second side wall 32A of the moving part 32 of the alignment device 30. This ensures that the longitudinal sides 11B, 12B of the two metal strip elements extend in line with each other and that the end portions 13, 14 of the two metal strip elements are fully aligned.

[0132] The step of butt welding the first metal strip element 11 and the second metal strip element 12 can be performed in various ways. Figure 5 This is schematically shown by arrow W in the schematic diagram c).

[0133] The continuous weld seam is produced, for example, by a process selected from the following: TIG (Tungsten Inert Gas) arc welding, plasma or microplasma welding, extrusion seam welding, mastication friction welding.

[0134] exist Figures 1 to 3 In the example shown, the welding is TIG arc welding or plasma welding.

[0135] In order to ensure accurate welding of the two metal strip elements, the method comprises the step of pressing the end portion 13 of the first metal strip element 11 and the end portion 14 of the second metal strip element 12 against the planar support 21 by bearing on the opposite main faces 11A, 12A on both sides of the mutually adjacent transverse faces 11C, 12C.

[0136] This step makes it possible to ensure a correct positioning of the end portion of the metal strip element during the welding process, thereby preventing defects associated with thermal deformation of the metal strip element during the welding process due to heating of the material during the welding process.

[0137] In practice, the step of pressing the end portion of the first metal strip element and the end portion of the second metal strip element against the planar support is performed using a clamping device 40 comprising a metal bearing part 41 which bears on the main faces of the metal strip elements 11, 12 on both sides of the lateral end faces of the metal strip elements arranged adjacent to each other.

[0138] Figure 1 and Figure 3 An example of such a clamping device 40 is schematically shown. The metal support part is formed by a first plate provided with an intermediate groove 42 .

[0139] The length of the first plate is greater than the length of the metal strip elements 11 , 12 measured in the transverse direction.

[0140] The ends of the first plate of the clamping device 40 are placed on the first side wall 31A and the second side wall 32A of the alignment device 30 and pressed against them by a cylinder system (not shown) rigidly fixed to the alignment device 30 or to the welding stand 50. The depth of the groove 24 formed by the alignment device 30 is preferably greater than or equal to the thickness of each belt element.

[0141] Thus, when the first plate of the clamping device 40 is pressed onto the alignment device after the alignment step, the first plate clamps the end portions 13 , 14 of the metal strip element 11 , 12 against the bottom of the groove 24 .

[0142] The slot 42 in the first plate extends beyond the outer faces of the first 31A and second 32A side walls of the alignment device 30 and thus beyond the longitudinal sides 11B, 12B of the metal strip elements 11, 12, which allows completely free access to the transverse end faces 11C, 12C of the metal strip elements 11, 12. The slot 42 preferably has beveled side edges diverging in a direction away from the support plane.

[0143] The first plate is a metal plate, preferably made of a metal with high thermal conductivity, such as copper and its alloys. This can limit the heating of the end portion of the metal strip element by facilitating the discharge of heat.

[0144] The welding is performed using a welding stand 50 . The welding stand 50 includes a welding head 53 and a guide rail 51 .

[0145] The guide rail 51 extends toward the slot 42 in the first plate 41 of the clamping device 40. The guide rail 51 is supported, for example, by a wall 54 protruding from the first side wall 31A of the fixed main part 31 of the alignment device 30 and from the second side wall 32A of the movable side part 32. The welding head 53 includes an electrode 52 of, for example, a TIG or plasma welding gun for welding. The welding head 53 and its electrode 52 are adapted to slide along the guide rail 51 so that the electrode 52 moves in the slot 42 in the metal first plate 41 ( Figure 3 ).

[0146] Prior to producing the continuous weld, the method may include a spot welding step. Preferably, the spot welding is performed every 5 cm at most.

[0147] This step makes it possible to limit the deformation of the end portions 13 , 14 of the metal strip elements 11 , 12 during definitive welding.

[0148] For welding the metal strip elements 11, 12, the planar support 21 of the manufacturing table 20 preferably comprises a second plate 60. The second plate 60 is, for example, part of the bottom wall 31B of the fixed main part 31 of the alignment device 30 ( Figure 3 ).

[0149] The second plate 60 is housed in this bottom wall 31B and is flush with the central outer face 34 of the groove 24. It is placed facing the groove 42 in the first plate 41 and the guide rail 51 of the welding stand 50.

[0150] Thus, the lateral end faces of the first metal strip element 11 and the second metal strip element 12 arranged adjacent to each other extend towards the metal sheet during the welding step.

[0151] The second plate is made of ceramic or metal, preferably of a metal with high thermal conductivity, such as copper and its alloys. This can limit the heating of the end portion of the metal strip element by facilitating the removal of heat during welding. When copper or a copper-based alloy is used, a groove (not shown) in line with the area to be welded must be provided on the second plate.

[0152] The weld is formed by melting a portion of each metal strip element adjacent the transverse end faces of each metal strip element, with or without the addition of filler metal.

[0153] Once the two metal strip elements 11, 12 are welded together to form the metal strip 10, the longitudinal edges of the obtained metal strip are cut at least along a region extending in the longitudinal direction of the metal strip 10 from one side of the weld to the other side of the weld. Figure 5 This is schematically shown in the schematic diagram d).

[0154] The advantage of this cutting of the longitudinal edge of the metal strip 10 at the level of the weld seam, after the weld seam has been formed, is that it is possible to eliminate any welding defects that occurred at the beginning and end of the welding step, and therefore to eliminate defects in the immediate vicinity of the longitudinal sides 11B, 12B of the metal strip element. The remaining portion of the longitudinal edge of the second metal strip element is then cut. This cutting is performed using the cutting tool 22 described above.

[0155] In the embodiment described here, the longitudinal edge of the metal strip is cut from the stop cutting position of the first metal strip element to the position on the other side of the weld seam, for example to the free end of the metal strip element 10 .

[0156] Alternatively, before the welding step, the longitudinal edge of a portion of the second metal strip element is also cut along its longitudinal side, the cut portion of the second metal strip element extending from the transverse end face of the second metal strip element to a position where the cutting is stopped, the position where the cutting is stopped is located at a distance from the transverse end face of the second metal strip element, which is intended to be arranged near the first metal strip element. The stop position is also located at a distance (preferably between 1 meter and 3 meters, inclusive) from the transverse end face of the second metal strip element, which is intended to be arranged near the first metal strip element.

[0157] In this case, after welding the metal strip elements, the longitudinal edges of the obtained metal strip are cut between the position at which the cutting of the first metal strip element stops and the position at which the cutting of the second metal strip element stops.

[0158] The metal strip 10 obtained is, for example, wound around a transverse axis perpendicular to its longitudinal direction D1 , D2 .

[0159] The thickness of the metal strip 10 obtained is uniform and constant over its entire length, except for small local overthicknesses that may be introduced by the weld seams.

[0160] In a subsequent step of the manufacturing method, a step of bending the longitudinal edges of the metal strip can be performed. This step is carried out directly in the can. This makes it possible to form a strake that can be used to manufacture a sealing membrane for a can as described in the introduction.

[0161] The manufacturing method has the advantages of being simple and economical. In addition, chemical strength tests on the 40 mm wide and 0.7 mm thick metal strip obtained after the above butt welding showed that the mechanical strength was 13 kN, i.e. 20% greater than the mechanical strength of the 40 mm wide metal strip obtained by 1 mm / 0.7 mm fillet welding.

[0162] In addition, plasma welding tests conducted using a high current of 50A, a low current of 30A, a low current of 70% low current / high current time ratio, a speed of 35cm / minute, and a frequency of 4Hz produced good quality welds with little overthickness and no deformation at the weld joint between the first metal strip element and the second metal strip element.

[0163] TIG welding tests conducted using 45A high current, 20A low current, 45% low current / high current time ratio, 20 cm / minute speed, and 10 Hz frequency also produced good quality welds with little overthickness and no deformation at the joint between the first metal strip element and the second metal strip element.

[0164] In a further embodiment of the production method, the welding is an extrusion butt welding, for example performed by extrusion seam welding. Figure 6 The end portion 13 of the first metal strip element and the end portion 14 of the second metal strip element are schematically shown, as well as two electrodes 70 in the form of wheels (copper disks or knurled wheels) rotating in opposite directions. In addition to heating the longitudinal edges by passing high-frequency current through the longitudinal edges, the two electrodes also apply a compressive force to the longitudinal edges and achieve continuous welding. The planar support comprises a channel for the electrodes to pass through, located below the metal strip elements.

[0165] Extrusion butt welding can obtain Figure 6 The metal strip 10 is shown.

[0166] The metal strip 10 produced by this method is intended for use in constructing sealing membranes for sealed and thermally insulating tanks.

[0167] To this end, the metal strip obtained by the above-described method is used to form a metal strip with a raised edge, which is intended to produce a sealing membrane inside a can.

[0168] The metal strake is a metal strip obtained by the above method from two metal strip elements, each metal strip element having a constant thickness over its entire length.

[0169] The metal strake has a planar center portion and two side edges bent substantially perpendicularly to the planar center portion in its width, and the width of the two side edges is smaller than the width of the planar center portion.

[0170] The raised edge of the metal strake can be obtained from the metal strip by using a bending device comprising three rollers on each side of the metal strip. The rollers apply pressure to the metal strip, deforming it to produce the raised edge. The finished sealing film comprises a continuous layer of metal strake with a raised edge.

[0171] The raised edges of the metal strakes are welded to parallel welded supports fixed to the underlying thermal insulation barrier.

[0172] The successive layers thus have a repeating structure comprising alternately metal strakes as described above and elongated welding flanges forming welding supports.

[0173] The surface of the lower thermal insulation barrier oriented toward the sealing membrane forms a surface for supporting the sealing membrane. Each welding flange is connected to the supporting surface and protrudes relative to the supporting surface.

[0174] The sealed and insulated tank is integrated into a support structure comprising a plurality of support walls. The tank comprises a plurality of tank walls, each of which is fixed to a corresponding support wall.

[0175] The supporting wall may in particular be formed by a hull or catamaran of a ship.The supporting wall usually forms part of a supporting structure comprising a plurality of walls defining the general shape of the tank, usually a polyhedral shape.

[0176] A sealed and insulated tank is formed by assembling a plurality of tank walls. For LNG, the tank wall generally includes, in order from the outside to the inside of the tank in the thickness direction, a secondary insulation barrier held on a supporting wall, a secondary sealing membrane resting on the secondary insulation barrier, a primary insulation barrier resting on the secondary sealing membrane, and a primary sealing membrane intended to be in contact with the liquefied natural gas contained in the tank.

[0177] When there are two sealing membranes, the primary sealing membrane can be made the same as or different from the secondary sealing membrane, and each of the two sealing membranes of the tank wall can be made as described above.

[0178] At the corner between the two tank walls, the secondary sealing membranes of the two tank walls and / or the primary sealing membranes of the two tank walls can be connected by a connecting ring in the form of a square tube. The connecting ring forms a structure that makes it possible to absorb the tensile forces caused by thermal contraction (especially thermal contraction of the metal elements forming the sealing membranes), deformation of the hull at sea, and movement of the cargo. A possible structure of the connecting ring is described in more detail in FR-A-2549575.

[0179] The secondary insulation barrier comprises a plurality of secondary insulation blocks and the primary insulation barrier comprises a plurality of primary insulation blocks. These insulation blocks have, for example, a parallelepiped general shape and can be anchored to the supporting wall in various ways, for example by anchoring members.

[0180] The supporting surface of the sealing membrane of each thermal insulation barrier is planar and parallel to the corresponding supporting wall.

[0181] Such membranes can be used for storage and / or transportation of cryogenic liquids, such as liquefied natural gas (LNG) at about -162°C at atmospheric pressure, liquid hydrogen (LH2O) at about -253°C at atmospheric pressure, and liquid hydrogen (LH3O) at about -162°C at atmospheric pressure. 2 ), ammonia (NH 3), or liquefied petroleum gas (LPG) at a temperature between -50°C and 0°C (inclusive). These tanks can be installed on land or on floating structures. In the case of floating structures, the tanks can be used to transport liquefied gas or to receive liquefied gas used as propulsion fuel for the floating structure. In the case of land tanks or port storage structures, the latter can be placed on the ground or on the seabed and partially or completely buried.

[0182] The tank wall may comprise only one sealing membrane and only one thermal insulation barrier, for example for storing LPG.

[0183] See also Figure 7 , a cross-sectional view of a methane tanker 70 shows a sealed and insulated tank 71 having a prismatic overall shape installed in a double hull 72 of the ship. The wall of the tank 71 comprises a primary sealing barrier intended to be in contact with the LNG contained in the tank, a secondary sealing barrier arranged between the primary sealing barrier and the double hull 72 of the ship, and two thermal insulation barriers arranged between the primary sealing barrier and the secondary sealing barrier and between the secondary sealing barrier and the double hull 72, respectively.

[0184] In a manner known per se, the loading / unloading pipeline 73 arranged on the top deck of the vessel can be connected by appropriate connectors to a marine or port terminal, or an LNG bunkering vessel, to transfer LNG cargo from or to the tank 71 .

[0185] Figure 7 An example of a marine terminal is shown, comprising a loading and unloading station 75, an underwater pipeline 76 and a land facility 77. The loading and unloading station 75 is a fixed offshore facility, comprising a mobile arm 74 and a tower 78 supporting the mobile arm 74. The mobile arm 74 carries a bundle of insulated flexible pipes 79 that can be connected to the loading and unloading pipeline 73. The orientable mobile arm 74 is suitable for methane tankers of all sizes. The connecting pipeline (not shown) extends into the tower 78. The loading and unloading station 75 enables the methane tanker 70 to be loaded and unloaded from the land facility 77, or to be loaded and unloaded to the land facility 77. The latter includes a liquefied gas tank 80 and a connecting pipeline 81 connected to the loading and unloading station 75 via an underwater pipeline 76. The underwater pipeline 76 enables the liquefied gas to be transported over a long distance, such as 5 kilometers, between the loading and unloading station 75 and the land facility 77, which enables the methane tanker 70 to remain at a great distance from the coast during the loading and unloading operation.

[0186] The pump on the ship 70, and / or the pump provided on the land facility 77, and / or the pump provided on the loading and unloading station 75 is used to generate the pressure required for conveying the liquefied gas.

[0187] The invention is applicable to tanks of ships 71 as well as to land tanks and port structures.

[0188] Although the invention has been described in connection with a number of specific embodiments, it is obvious that the invention is by no means limited to these embodiments and that the invention covers all technical equivalents and combinations of the means described, as long as the latter fall within the scope of the invention.

[0189] Use of the verb "comprise" or "include" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim.

[0190] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Claims

1. A method for manufacturing a metal strip (10), the method comprising the following steps: - arranging an end portion (13) of a first metal strip element (11) and an end portion (14) of a second metal strip element (12) on a planar support (21), the end portion (13) of the first metal strip element (11) and the end portion (14) of the second metal strip element (12) being juxtaposed in the longitudinal direction, each of the first metal strip element (11) and the second metal strip element (12) having two opposite main faces (11A, 12A) connected by two longitudinal side faces (11B, 12B), the first metal element and the second metal element both having the same width, the end portion (13) of the first metal strip element (11) and the end portion (14) of the second metal strip element (12) both being terminated by respective transverse end faces (11C, 12C), so that the main faces (11A, 12A) of each of the first metal strip element (11) and the second metal strip element (12) are at least partially placed on the planar support (21), and the transverse end faces (11C) of the end portion (13) of the first metal strip element (11) extend adjacent to the transverse end faces (12C) of the end portion (14) of the second metal strip element (12); - aligning the longitudinal side (11B) of the first metal strip element (11) and the longitudinal side (12B) of the second metal strip element (12) so that the longitudinal side (11B) of the first metal strip element (11) and the longitudinal side (12B) of the second metal strip element (12) extend in line with each other; - butt welding the first metal strip element (11) and the second metal strip element (12) so as to form a continuous weld along the transverse end faces (11C, 12C) over the entire width of the metal strip elements (11, 12); - The longitudinal edge of the obtained metal strip (10) is cut at least along a region extending in the longitudinal direction of the metal strip (10) from a position located on one side of the weld seam to a position located on the other side of the weld seam.

2. The method according to claim 1, wherein: The end portions (13, 14) are arranged such that a transverse face (11C) of the end portion (13) of the first metal strip element (11) extends to a distance from a transverse end face (12C) of the end portion (14) of the second metal strip element (12) that is less than or equal to half the thickness of one of the metal strip elements (11, 12).

3. The method according to claim 1, wherein: The end portions (13, 14) are arranged such that the end portion (14) of the second metal strip element (12) overlaps the end portion (13) of the first metal strip element (11) by a distance less than or equal to three times the thickness of one of the metal strip elements (11, 12).

4. The method according to any one of claims 1 to 3, further comprising: - Paying out the roll carrying said first metal strip element (11).

5. The method according to any one of claims 1 to 3, further comprising: - Partially cutting the first metal strip element (11) along its longitudinal side face (11B) using two tools (22), the two tools (22) being arranged on a path for feeding the end portion (13) of the first metal strip element (11) to a position (AD) where the cutting stops, the position being located at a certain distance from a transverse end face (11C) of the first metal strip element (11), the transverse end face of the first metal strip element (11) being intended to be arranged in the vicinity of the second metal strip element (12).

6. The method according to claim 5, wherein: The two cutting tools (22) are placed face to face and cannot be moved.

7. The method according to claim 5, wherein: The two cutting tools are placed face to face and are movable in the longitudinal direction.

8. The method according to claim 5, further comprising: - Winding the cut portions of the first metal strip element (11) around a winding axis perpendicular to the longitudinal direction.

9. The method according to any one of claims 1 to 3, wherein: Prior to the welding step, a portion of the second metal strip element is also cut along its longitudinal side, the cut portion of the second metal strip element extending from a transverse end face of the second metal strip element to a position where the cutting stops, the position where the cutting stops being located at a certain distance from the transverse end of the second metal strip element, the transverse end of the second metal strip element being intended to be arranged adjacent to the first metal strip element.

10. The method according to any one of claims 1 to 3, wherein: The planar support (21) comprises a metal plate (60) towards which the transverse end faces (11C, 12C) of the first metal strip element (11) and the second metal strip element (12) arranged adjacent to each other extend during the welding step.

11. The method according to any one of claims 1 to 3, comprising the steps of: - The end portion (14) of the first metal strip element (11) and the end portion (14) of the second metal strip element (12) are pressed against the planar support (21) by pressing opposite main faces (11A, 12A) against the planar support on both sides of lateral end faces (11C, 12C) arranged adjacent to each other.

12. The method according to claim 11, wherein: The step of pressing the end portion of the first metal strip element (11) and the end portion of the second metal strip element (12) against the planar support (21) uses a clamping device (40), which includes a metal supporting part (41) that presses on the main faces (11A, 12A) of the metal strip elements (11, 12) on both sides of the lateral end faces of the metal strip elements arranged adjacent to each other.

13. The method according to any one of claims 1 to 3, further comprising: - Spot welding is performed before producing a continuous weld.

14. The method according to any one of claims 1 to 3, wherein: The continuous weld seam is produced by a method selected from the following methods: TIG arc welding, microplasma welding, extrusion seam welding, chewing friction welding.

15. The method according to claim 5, wherein: The cutting stop position (AD) is located at a distance between 1 meter and 3 meters from the transverse end surface (11C) of the cut first metal strip element (11) or the transverse end surface (12C) of the second metal strip element (12), wherein 1 meter to 3 meters are inclusive.

16. A method according to the preceding claim, wherein: The metal strip elements (11, 12) used have a coefficient of expansion of typically 1.10 -6 K -1 To 2.10 -6 K -1 The metal strip elements (11, 12) used are made of an iron-nickel alloy having an expansion coefficient of 7.

10. -6 K -1 and 9.10 -6 K -1 Made of iron-manganese alloy with endpoint values ​​included.

17. A method according to any one of the preceding claims, wherein: The thickness of each metal strip element (11, 12) is between 0.5 mm and 1 mm, inclusive.

18. The method according to any of the preceding claims, further comprising the step of bending the longitudinal edges of the metal strip (10).

19. A workbench for manufacturing a metal strip, the workbench comprising: a planar support (21) adapted to receive an end portion (13) of a first metal strip element (11) and an end portion (14) of a second metal strip element (12), the end portions of the first metal strip element and the end portions of the second metal strip element being juxtaposed in the longitudinal direction, each of the first metal strip element and the second metal strip element having two opposite main faces (11A, 12A) connected by two longitudinal side faces (11B, 12B), the end portions of the first metal strip element and the end portions of the second metal strip element each terminating by a respective transverse end face (11C, 12C), the transverse end face (11C) of the first metal strip element (11) extending in the vicinity of the transverse end face (12C) of the second metal strip element (12), - an alignment device (30) for adjusting the relative position of the longitudinal side of the first metal strip element and the longitudinal side of the second metal strip element so that the longitudinal side of the first metal strip element and the longitudinal side of the second metal strip element extend in line with each other, a working platform (50) for butt-welding the two metal strip elements by means of a continuous weld extending along the transverse end faces over the entire length of the metal strip elements, - two cutting tools suitable for cutting the longitudinal edges of the obtained metal strip (10) at least along an area extending in the longitudinal direction of the metal strip (10) from a position located on one side of the weld to a position located on the other side of the weld.

20. A metal stripe, which is suitable for producing a sealing film for a sealed and insulated tank, the metal stripe comprising a metal strip (10) obtained from two metal strip elements (11, 12) according to the method described in any one of claims 1 to 3, both metal strip elements (11, 12) having a constant thickness over the entire length of the metal strip elements, the metal stripe having a planar central portion and two side edges bent substantially perpendicularly to the planar central portion in the width direction of the metal stripe, the two side edges having a smaller width than the planar central portion.

21. A sealing membrane for a sealed and insulated tank, the sealing membrane comprising a repeating structure, the repeating structure alternately comprising a metal strake according to claim 20 and an elongated welding flange, the welding flange being connected to a supporting surface of the sealing membrane and protruding relative to the supporting surface, the welding flange extending parallel to the metal strake over at least a portion of the length of the metal strake, the planar center portion of the metal strake being placed on the supporting surface, the side edges of the metal strake being arranged to abut against adjacent welding flanges and being welded to the welding flanges in a sealing manner.

22. A sealed and insulated tank, which is integrated into a supporting structure, the supporting structure comprising a plurality of supporting walls, the tank comprising a plurality of tank walls, each tank wall being fixed to a corresponding supporting wall, the tank wall comprising an insulating barrier retained on the supporting wall, the insulating barrier having a planar supporting surface parallel to the corresponding supporting wall and a sealing membrane according to claim 21.

23. A ship (70) for transporting fluids, the ship comprising a catamaran (72) and a tank (71) according to claim 22 arranged within the catamaran (72).

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