JP2022550346A - Method for repairing walls of tanks for transporting and/or storing liquefied natural gas - Google Patents

Abstract

The present invention is a method for repairing a wall (4) of a tank for transporting and/or storing liquefied natural gas, the tank wall (4) comprising at least one membrane (6) and a plurality of reinforcements. comprising a material (12), the membrane (6) comprising a plurality of corrugations (7), at least one of the plurality of corrugations (7) having at least one stiffener (12) disposed thereon; The method comprises at least one step of cutting a stiffener (12); replacing a stiffener portion (23) with a replacement portion (27); and inserting a sleeve (28) into said replacement portion (27). and a method.

Description

The present invention relates to the field of transport tanks with corrugated membranes, in particular closed and insulated tanks used for liquefied gases, for storing and/or transporting fluids.

The present invention is for example for transporting liquid petroleum gas (LPG) at temperatures from -50°C to 0°C, or liquid natural gas (LNG) at about -162°C at atmospheric pressure. It relates to the field of closed and insulated tanks for storing and/or transporting liquids at low temperatures, such as tanks for transporting. These tanks can be installed on land or on floating structures. In the case of floating structures, the tanks may be intended to transport liquefied gases or to contain liquefied gases used as fuel for propulsion of the floating structure.

The closed and insulated tanks used for cryogenic storage of such liquids typically consist of insulation and a membrane composed of a plurality of corrugations in contact with the liquid cargo. Between the insulation and the membrane, stiffeners that conform to the shape of the membrane corrugations may be nested inside the membrane corrugations. The stiffener then has the function of mechanically supporting the corrugations of the membrane against the mechanical pressure exerted on the tank. The stiffeners are assembled, for example by connecting pieces, to form a fixed assembly.

One drawback of such tank walls is repairing the tank wall, and more particularly the reinforcement that may or may not be inserted into one of the corrugations of the membrane. It is in. Specifically, because the tank wall elements are nested on top of each other, access to each of said tank wall elements usually requires dismantling at least a portion of the tank wall.

The object of the present invention is therefore to overcome this drawback by proposing an optimized repair method that does not require excessive dismantling of the tank wall.

Accordingly, one subject of the present invention is a repair method for repairing a liquefied natural gas transportation and/or storage tank wall, the tank wall comprising at least one membrane and a plurality of stiffeners, the membrane comprising: a plurality of corrugations, at least one stiffener disposed in at least one of the plurality of corrugations, the stiffener extending in the main direction of elongation and defining a cavity in the stiffener; with its main direction of elongation such that, during the repair method, the stiffener forms at least a first stiffener portion and a second stiffener portion separable from the tank wall in at least one step. In another step the first stiffener portion and the second stiffener portion are replaced with at least two replacement portions, and in another step the sleeve is replaced with the at least two replacement portions. A repair method that is inserted into a cavity.

The tank may in particular be a tank of a liquefied natural gas carrier, said ship then comprising several tanks for storing and/or transporting said gas.

The tank wall may then comprise at least one thermal insulation, in particular at least one thermal insulation layer, which provides the tank with the necessary thermal insulation for transporting liquid natural gas. The membrane comprises a plurality of corrugations disposed on its surface. Such a membrane configuration withstands the pressures that develop within the tank, particularly thermal contraction as the tank cools, hydrostatic pressure due to liquid cargo loading, and dynamic pressure due to cargo movement, especially as a result of expansion. Give it more power. The corrugations of the membrane therefore allow the membrane to deform in order to withstand these pressures.

More specifically, the plurality of corrugations of the membrane are arranged in a first series of corrugations and a second series of corrugations that are perpendicular to each other and whose intersections form nodes. The plurality of stiffeners of the tank wall are then arranged as a first series of stiffeners and a second series of stiffeners, which are perpendicular to each other and respectively the first series of corrugations and the second series of corrugations. , extending within a series of corrugations of A cruciform connecting piece is then placed between each of the stiffeners of the first series of stiffeners and the second series of stiffeners, more specifically below the nodes of the membrane. The cruciform connecting piece located below the node thus has the purpose of connecting the stiffeners of the first series of stiffeners and the second series of stiffeners to each other, thus each of the stiffeners It will be appreciated that it extends to the bottom of the cavity.

The present invention seeks to cut a tank wall reinforcement, eg a damaged tank wall reinforcement, to form at least two reinforcement sections, a first reinforcement section and a second reinforcement section. The stiffener part is then separable as long as it is removed from the tank wall. A sleeve is threaded through the cavity of the replacement part to allow alignment of said replacement part in the main direction of extension of the stiffener. The sleeve is more particularly arranged above the cavity of the replacement parts and forms a mechanical connection between the two replacement parts. It will therefore be appreciated that the replacement part used during the present method is intended to replace one original unitary damaged reinforcement, ie, an individual reinforcement prior to cutting.

The invention finds a favorable application in that it allows repairing at least one of the tank wall reinforcements without having to dismantle the tank wall. Alternatively, the invention finds suitable application as long as it allows repairing at least one of the stiffeners while the tank wall is being assembled. The features listed below for single stiffeners apply mutatis mutandis to multiple stiffeners from which the tank wall is constructed.

According to the tank wall repair method, the plurality of stiffeners comprises adjacent stiffeners adjacent to the stiffener to be cut, the adjacent stiffeners being aligned along the main direction of elongation, and during the method Alternatively, the sleeve is threaded through the adjacent stiffener prior to placement of the replacement part.

The plurality of stiffeners of the tank wall are organized as a first series of stiffeners and a second series of stiffeners. Thus, by adjacent reinforcements is meant reinforcements located next to cut reinforcements in the original first series of reinforcements or the original second series of reinforcements. be. Adjacent stiffeners therefore exhibit the same structural properties as a plurality of stiffeners, and sleeves are therefore inserted into the cavities of said adjacent stiffeners. It will also be appreciated that adjacent reinforcements are different from damaged reinforcements and, as a result, said adjacent reinforcements are not intended to be replaced with replacement parts.

According to the tank wall repair method, the sleeve is fixed to the adjacent stiffener.

More specifically, the sleeve is temporarily secured to the adjacent stiffener before subsequent steps of the repair method are performed. This fixation of the sleeves to the adjacent stiffeners is preferred inasmuch as it holds the elements together and facilitates repair work on the tank wall. Securing of the sleeve to the adjacent stiffener may be accomplished using sleeve securing means in the form of, for example, Teflon screws or washers.

According to the tank wall repair method, sleeves are inserted into the cavities of these replacement parts after their placement in the tank wall.

According to an alternative tank wall repair method, the sleeve is translated from the adjacent reinforcement into the cavity of the replacement part in the main direction of extension of the reinforcement.

According to the tank wall repair method, the sleeve is fixed within the cavity of the replacement part.

More specifically, the sleeve is securely fixed within the cavity of the replacement part. Securing the sleeve within the cavity of the replacement part is accomplished by securing means, which may be, for example, Teflon screws or washers. Alternatively, securing the sleeve within the cavity of the replacement part can be done by deforming one end of one of the replacement parts to crimp the sleeve. As a further alternative, securing the sleeve within the cavity of one of the replacement parts is by forming an end stop in one of the replacement parts by adding external metallic material using a welding operation. can be done.

According to the tank wall repair method, adjacent stiffener cavities are closed to prevent translation of the sleeve therein.

In other words, the cavity of the adjacent stiffener is partially closed at its end facing the severed stiffener, and this operation can be carried out before securely fixing the sleeve in the cavity of the replacement part. It is possible. For this purpose, a closure device, which may for example take the form of an adhesive, may be applied to at least partially close the cavities of the reinforcement according to the conditions mentioned above.

According to the tank wall repair method, prior to the step of cutting the reinforcement, the portion of the membrane located facing the reinforcement is removed.

In other words, the stiffener forming the object of implementation of the tank wall repair method is exposed, this step being necessary for the implementation of the subsequent steps of said method. Removal of parts of the membrane may be done, for example, by mechanically cutting said membrane or by using a laser.

According to the tank wall repair method, a membrane repair patch is fixed facing the stiffener.

In other words, the final step of the tank wall repair method is to attach the membrane repair patch facing the at least one stiffener forming the object of the repair method. It will therefore be understood that the fixation of the membrane repair patch is performed after the replacement part has been installed on the tank wall. In other words, the repair patch is placed as a replacement for the portion of the membrane previously removed during the repair method.

The invention also provides at least two replacement parts, said at least two replacement parts intended to replace at least one stiffener of a tank wall, and two replacement parts. and at least one sleeve intended for mechanical connection. The repair kit may also include a repair patch that can cover the replacement part.

The repair kit is involved in implementing the tank wall repair method. It will therefore be appreciated that the two replacement parts of the repair kit are intended to replace both or part of a single original unitary damaged reinforcement of the tank wall. In other words, the replacement kit according to the invention is used to replace a single original tank wall reinforcement.

According to one aspect of the kit, the sleeve is configured to be received in the upper portion of the cavity of the replacement part, the upper portion of the cavity being triangular in shape.

According to another aspect, the sleeve has a circular cross section.

According to one feature of the invention, the repair kit comprises at least one fixing means for fixing the sleeve to the replacement part.

According to one aspect of the invention, the repair kit comprises at least one closure device configured to close a reinforcement cavity adjacent one of the replacement parts.

More specifically, adjacent reinforcements are aligned in the main direction of elongation of the reinforcement that is the object of the repair method, i.e. the severed reinforcement. The cut stiffener thus comprises a replacement part.

The invention also relates to a liquefied natural gas transport and/or storage tank for ships comprising a tank wall and at least one repair kit according to any one of the preceding features, the replacement part being fixed to the tank wall by a sleeve. and the replacement part is covered by at least one repair patch.

Other characteristics, details and advantages of the present invention will emerge on the one hand from reading the following description and on the other hand from some exemplary embodiments given as non-limiting indications with reference to the accompanying schematic drawings. more clearly revealed.

1 is a perspective side view of a liquid gas carrier having four tanks equipped with the present invention; FIG. FIG. 4 is an enlarged view of the tank wall showing a portion of the insulation, a plurality of stiffeners, and the membrane; FIG. 4 is an enlarged view of one of the tank wall reinforcements cut into a first stiffener portion, a second stiffener portion and a third stiffener portion; 4 is an enlarged view of the stiffener of FIG. 3 with three replacement parts; FIG. 1 is a perspective view of a sleeve according to the invention; FIG. Figure 6 is an enlarged view of the stiffener of Figure 4 with the sleeve of Figure 5 inserted; 7 is an enlarged view of a repair patch placed on the stiffener of FIG. 6; FIG. Figure 6 is an enlarged view of the stiffener of Figure 3 with the first stiffener portion, the second stiffener portion, and the third stiffener portion removed, and the sleeve of Figure 5 in accordance with a second embodiment of the present invention; Shown are threaded adjacent stiffeners. FIG. 9 is an enlarged view of the adjacent stiffener of FIG. 8 with the sleeve of FIG. 5 inserted, showing the securing means; FIG. 8 is an enlarged view of the stiffener of FIG. 8 incorporating a replacement portion with a sleeve previously inserted into the adjacent stiffener of FIG. 7 translating into it;

Features, modifications and various aspects of embodiments of the invention may be combined with each other in various combinations unless they are mutually exclusive or mutually exclusive. In particular, only the selection of features described below in isolation from other features described if the selection of features provides a technical advantage or is sufficient to distinguish the invention from the state of the art. A variant of the invention can be envisaged comprising:

In the following part of the description, longitudinal or transverse labels refer to the direction of the membrane according to the invention. The longitudinal direction L corresponds to the axis of the membrane along which the membrane mainly extends, while the transverse direction, as far as the transverse direction T is concerned, is in particular a parallel straight line perpendicular to the longitudinal direction L of the membrane, i.e. a line intersecting the longitudinal direction. handle. One of the directions, indicated by the arrow referenced V, corresponds to the film thickness.

The directions mentioned above can be seen in the orthonormal frame of the reference LVT shown in the figure.

Figure 1 shows a ship 1, for example a methane tanker, comprising four tanks 2 for storing gas in liquid state, in particular liquid natural gas. The tanks 2 are separated from each other by double transverse bulkheads 3, also called cofferdams. Each of the tanks 2 is in contact with the liquid cargo and is fixed to the tank wall 4 and, inter alia, the insulation 5 visible in FIG. formed from a tank wall 4 with at least one membrane 6 intended for.

The membrane 6 visible in FIG. 2 is a sheet of corrosion-resistant material, in particular stainless steel, having a thickness, measured in the vertical direction V of the membrane 6, of for example 0.5 mm to 1.5 mm, preferably 1.2 mm. . The membrane may also have a length, measured in the longitudinal direction L of membrane 6, between 680 mm and 3060 mm. Finally, membrane 6 may have a width measured in transverse direction T of membrane 6 of 680 mm to 1030 mm.

The membrane 6 has a plurality of first series of corrugations 8 parallel to each other and extending along the longitudinal direction L of the membrane and a plurality of corrugations 8 parallel to each other and extending along the transverse direction T of the membrane 6 . It comprises a plurality of corrugations 7 arranged as a second series of corrugations 9 .

A first series of corrugations 8 and a second series of corrugations 9 extend primarily in directions perpendicular to each other and form nodes 10 at their intersections. Node 10 protrudes vertically from plane AB inscribed by membrane 6 . What is meant by corrugations 7 are deformations of the surface of the membrane 6 in the vertical direction V. FIG.

The membrane 6 also comprises a flat portion 11 of rectangular shape, the two sides of which extending in the longitudinal direction L of the membrane 6 are bounded by two first series of corrugations 8 and the lateral direction of the membrane 6 Its two sides extending to T are defined by two second series of corrugations 9 . The collection of flats 11 thus defines the undeformed surface of the membrane 6 which extends in the plane AB of the membrane 6 and contacts the insulation 5 of the tank wall 4 when the membrane is attached to the insulation 5. form.

FIG. 2 also demonstrates the presence of stiffeners 12 arranged as first stiffener 13 and second stiffener 14 . In the following portion of the detailed description, when the features mentioned apply to both the first stiffener 13 and the second stiffener 14, the first stiffener 13 and the second stiffener 14 are referred to as stiffeners Collected under the name 12. Nevertheless, the invention is not limited to a plurality of stiffeners 12 and is applicable whenever it is necessary to carry out the repair method on at least one stiffener 12 of the tank wall 4 .

The first stiffeners 13 are aligned to form at least a first series of stiffeners 15 extending in the longitudinal direction L of the membrane 6 . The second stiffeners 14 are aligned to form at least a second series of stiffeners 16 extending in the transverse direction T of the membrane 6 . Thus, the first series of reinforcements 15 and the second series of reinforcements 16 intersect, in particular perpendicularly intersect.

A first stiffener 13 is arranged in the first series of corrugations 8 of the membrane 6 . The first stiffener 13 is nested inside the deformation of the corrugations 7 , the shape of the first stiffener 13 conforming to that of the corrugations of the first series of corrugations 8 of the membrane 6 . Complementary shapes are understood.

A second stiffener 14 is arranged in the second series of corrugations 9 of the membrane 6 . The second stiffener 14 is thus nested inside the deformations of the corrugations 7 and the shape of the second stiffener 14 conforms to the corrugations of the second series of corrugations 9 of the membrane 6 . It will be appreciated that it complements the shape of portion 7 .

It will also be appreciated that the intersections of the first series of stiffeners 15 and the second series of stiffeners 16 are located below the nodes 10 of the membrane 6 .

The stiffener 12 comprises an outer wall 17 defining a cavity 18 . It will therefore be understood from the above that the outer wall 17 gives the stiffener 12 a shape such that the stiffener 12 can be arranged on the corrugations 7 of the membrane 6 according to the characteristics described above.

The connecting pieces 21 are arranged on the first stiffener 13 and the second stiffener 14 of the membrane 6 such that they are connected to each other under the series of corrugations 8 , 9 of the membrane 6 . A connecting piece 21 is thus arranged along the node 10 of the membrane 6 and inserted into each of the cavities 18 of the stiffener 12 . The connecting piece 21 may be, for example and without limitation, a cruciform shape 22 . Accordingly, the assembly of stiffeners 12 forming the first series of stiffeners 15 and the second series of stiffeners 16 are arranged between the membrane 6 of the tank wall 4 and the insulation 5 as described above. It will be understood to form a fixed assembly.

A method for repairing the tank wall 4 will now be described with reference to FIGS. More particularly, the repair method enables a simplified repair of the tank wall 4, for example repair of at least one of the reinforcements 12 of said tank wall 4, to be carried out. In the following part of the description, the method is performed for at least one of the stiffeners 12 of the first series of stiffeners 15 and/or at least one of the stiffeners 12 of the second series of stiffeners 16. It will be appreciated that Thus, the longitudinal direction L of the membrane 6 in the case of the first stiffener 13 and the transverse direction T of the membrane 6 in the case of the second stiffener 14 are grouped together under the name main direction of elongation of the stiffener. Defined.

The first step in the method for repairing the tank 2 consists in giving the operator access to the reinforcement 12 which forms the object of the repair method. To do this, the portion P visible in FIG. 2 of the membrane 6 lying facing said stiffener 12 is removed, for example by mechanical cutting or by using a laser.

As an alternative not shown, the repair method may be performed during assembly of the tank wall before the membrane is installed over the stiffeners that make up the tank wall, at which time a portion of the membrane is removed. It should be considered that the first step to do is not performed.

After the stiffener 12 is exposed, the second step of the repair method is to form the stiffener portion 23, more specifically at least the first stiffener portion 24 and the second stiffener portion 25, by: It is to cut the reinforcing member 12 in a direction transverse to its main direction of elongation. In the illustrated example, a third stiffener portion 26 is also formed, but it will be appreciated that the method may be applied to more or less stiffener portions 23 . During the second step of the method, when the stiffener 12 is cut, one original unitary stiffener 12 of the tank wall 4 is divided into the first stiffener portion 24, the second stiffener portion 25, and the stiffener portion 25. It will also be appreciated that this one original stiffener 12 is cut to become the third stiffener portion 26 .

Consequently, this results in, according to the example shown in FIG. A stiffener portion 26 is obtained. By separable from the tank wall 4 is meant that the stiffener parts 24 , 25 , 26 are intended to be permanently removed from the tank wall 4 and replaced by a replacement part 27 .

Alternatively, although this is not shown, at least one of the stiffener portions 24 , 25 , 26 is attached to the tank wall after at least one of the stiffener portions 24 , 25 , 26 has been replaced with at least one replacement portion 27 . It may be removable as long as it can be reattached.

According to a first embodiment of the method visible in FIG. 4, after the first stiffener portion 24, the second stiffener portion 25 and the third stiffener portion 26 have been removed, the replacement portion 27 is: It is attached to replace said first stiffener portion 24 , second stiffener portion 25 and third stiffener portion 26 . It will therefore be appreciated that all three replacement portions 27 are aligned in the direction of elongation of the stiffener 12 . It will also be appreciated that the replacement part 27 is intended to replace one unitary original reinforcement 12 of the tank wall 4 .

Then, in an additional step, a sleeve 28 visible in FIG. 5 is threaded through at least two cavities 18 of the two replacement parts 27 . In the example shown in FIG. 6 the sleeve 28 is threaded through three cavities 18 of three replacement parts 27 .

The sleeve 28 has an elongated shape and a first end 29 and a second end 30 which are opposite ends at each end of the sleeve 28 . Insertion of the sleeve 28 as described above is primarily effected by a translation of the main direction of elongation of the stiffener 12 from the second end 30 to the first end 29, which is therefore associated with the first The insertion direction I1 is considered. Therefore, the sleeve 28 has the function of at least preventing movement between the replacement parts 27 in the direction perpendicular to the extension direction of the reinforcing member 12 .

Furthermore, in this first embodiment, a second end 30 of said sleeve 28 outside the volume defined by the cavity 18 of one of the series of replacement portions 27 is located at one end of the series of replacement portions 27 . , the sleeve 28 may be inserted according to the previous insertion characteristics. As a result, this allows the attachment of means 31 for fixing the sleeve 28 at its second end 30 . Fixing means 31 may be, for example and without limitation, Teflon screws or washers. The fixing means 31 have the purpose of reliably preventing movement of the sleeve 28 in the above-mentioned translational movement, at least in the first insertion direction I1, in this example by forming an end stop for the replacement part 27 . Alternatively, the fixing means 31 may be a deformation of one of the replacement parts 27 so as to prevent movement of the sleeve 28, or an abutting end stop so that the sleeve 28 remains free. It may be an addition to one of the replacement parts 27 of forming metal material.

A repair patch 32 of the membrane 6 visible in FIG. 7 is then applied over the replacement part 27 . Thus, the repair patch 32 has longitudinal L and transverse T dimensions of the membrane 6 that are substantially identical to the longitudinal L and transverse T dimensions of the portion P removed during the first step. It will be understood.

Repair patch 32 can then be welded to the remainder of membrane 6 to re-establish that fluid tight seal.

According to a second embodiment of the invention, after the first stiffener portion 24, the second stiffener portion 25 and the third stiffener portion 26 have been removed from the tank wall, in an additional step: The sleeve 28 is threaded through the cavity 18 of the adjacent stiffener 33 adjacent to the severed stiffener 12, ie the stiffener forming the object of the repair method. By adjacent reinforcement 33 is meant a reinforcement positioned next to the cut reinforcement 12 and aligned in the direction of extension of the reinforcement 12 . Adjacent stiffeners 33 are also distinguishable in that they are not intended to be replaced by replacement parts 27; they are used only for one unitary stiffener 12 to be repaired. In other words, the cut stiffeners 12 and the adjacent stiffeners 33 form, although distinct, part of one of the original first series of stiffeners 15 or second series of stiffeners 16; They are directly connected to each other by one of the connecting pieces 21 connecting said series of stiffeners 15,16.

Accordingly, the sleeve 28 is positioned on the stiffener 12 such that the first end 29 faces the first stiffener portion 24 and protrudes from the volume defined by the cavity 18 of the adjacent stiffener 33 . A translation of the main extension direction in a second insertion direction I2 extending from the first end 29 towards the second end 30 inserts the adjacent stiffener 33 into the cavity 18 .

In one embodiment of the invention, seen in FIG. 9, means 31 for fixing the sleeve 28 may be provided at the first end 29 thereof. In this configuration, the fixing means 31 temporarily prevent movement of the sleeve 28 in the translation previously described in the second insertion direction I2. Thus, the fixing means 31 may in this example be screws or washers made of Teflon.

Another step in the method according to this second embodiment is to, as in the first embodiment, Replacing first stiffener portion 24 , second stiffener portion 25 , and third stiffener portion 26 with replacement portion 27 .

Following this step, as shown in FIG. 10, the means 31 for fixing the sleeve 28 arranged at its first end 29 are removed, said sleeve 28 being divided into two replacement parts 27 The stiffener 12 is translated in the first insertion direction I1 in the main direction of elongation so that it is at least inserted into the cavity 18 of the stiffener 12 . According to one example of the invention, the second end 30 faces an adjacent stiffener 33 such that means 31 for securing the sleeve 28 are available at said second end 30 of the sleeve 28 . one of the replacement parts 27 located outside the cavity 18 . Translational displacement of the sleeve 28 in the first insertion direction I1 and the second insertion direction I2 is thus reliably prevented and the fixing means 31 form an end stop for the replacement part 27 and the adjoining stiffener 33. .

An additional step of this second embodiment of the method may be closing the cavity 18 of the adjacent stiffener 33 at its end facing the severed stiffener 12 by means of a closing device 34 . In other words, the end of the cavity 18 of the adjacent reinforcement 33 located facing the second end 30 of the sleeve 28 carrying the fixing means 31 is closed. In this way, the fixing means 31 can be removed from the second end 30 of the sleeve 28 and the closure device 34 is placed in the cavity 18 of the stiffener 33 adjacent the sleeve 28 in the second direction of insertion I2. prevent parallel movement to

According to one example, the closure means 34 may take the form of an adhesive tape. According to another example of the invention, the closure means 34 may at least comprise a synthetic insert having a shape complementary to the shape of the cavity 18 of the adjoining stiffener 33 . The closing means 34 can then be placed inside or outside the cavity 18 of the adjacent stiffener 33 . Also, this closure means 34 may be forcibly assembled around the adjacent stiffener 33 or within the cavity 18 of said adjacent stiffener 33 , thus over or within the adjacent stiffener 33 . In order to ensure the mechanical integrity of said closure means 34, it is possible for said closure means 34 to be corrugated.

Alternatively, the closure device 34 may be attached prior to securely fixing the sleeve 28 within the cavity 18 of the replacement part 27 by the fixing means 31 .

Finally, as in the first embodiment of the invention, a repair patch 32 of membrane 6 visible in FIG. 7 is applied over replacement portion 27 . Repair patch 32 thus has the same structural characteristics as the first embodiment of the invention.

However, the invention should not be limited to the means and arrangements described and illustrated herein, but to any equivalent means and arrangements and to any technically practicable combination of such means. reach.

Claims (12)

A repair method for repairing a liquefied natural gas transportation and/or storage tank wall (4), said tank wall (4) comprising at least one membrane (6) and a plurality of stiffeners (12), Said membrane (6) comprises a plurality of corrugations (7), at least one of said plurality of corrugations (7) having at least one said stiffener (12) arranged thereon, said stiffener ( 12) comprises at least one outer wall (17) extending in the main direction of elongation and defining a cavity (18) of said stiffener (12), and during said repair method, in at least one step, said The stiffener (12) intersects its main direction of extension so as to form at least a first stiffener portion (24) and a second stiffener portion (25) separable from said tank wall (4). and in another step said first stiffener portion (24) and said second stiffener portion (25) are replaced by at least two replacement portions (27), in another step A repair method, wherein sleeves (28) are inserted into said cavities (18) of said at least two replacement parts (27). Said plurality of stiffeners (12) comprises adjacent stiffeners (33) adjacent said stiffeners (12) to be cut, said adjacent stiffeners (33) being positioned along said main direction of elongation. A repair method according to claim 1, wherein the sleeve (28) is threaded through the adjacent stiffener (33) prior to placement of the replacement portion (27) during the method. 3. The repair method of claim 2, wherein during the course of the repair method the sleeve (28) is secured to the adjacent stiffener (33). Claim wherein, in the course of said repair method, said sleeve (28) is inserted into said cavity (18) of said replacement part (27) after placement of said replacement part (27) on said tank wall (4). 4. The repair method according to item 1 or 3. In the course of said repair method, said sleeve (28) is parallel in the main direction of elongation of said reinforcement (12) from said adjacent reinforcement (33) into said cavity (18) of said replacement part (27). 5. The repair method of claim 4, wherein the repair method is moved. 6. Repair method according to claim 5, wherein during the course of the repair method the sleeve (28) is fixed in the cavity (18) of the replacement part (27). 7. Claims 2 and 6, wherein in the course of the repair method, the cavities (18) of the adjacent stiffeners (33) are closed to prevent translation of the sleeves (28) therein. Described repair method. In the course of said repair method, prior to said step of cutting said stiffener (12), a portion (P) of membrane (6) located facing said stiffener (12) is removed, Repair method according to any one of claims 1 to 7. 8. Repair method according to claim 7, wherein during the course of the repair method a repair patch (32) of the membrane (6) is fixed facing the stiffener (12). A repair kit for repairing a liquefied natural gas transportation and/or storage tank wall (4), comprising at least two replacement parts (27), said at least two replacement parts (27) being fitted with said tank wall ( 4) at least two replacement parts (27) intended to replace at least one stiffener (12) and at least one intended to mechanically connect said two replacement parts (27) sleeve (28) and at least one closure device (34) configured to close the cavity (18) of the reinforcement (33) adjacent one of said replacement parts (27). , repair kit. Repair kit according to claim 10, comprising at least one fixing means (31) for fixing said sleeve (28) with respect to said replacement part (27). A liquefied natural gas transport and/or storage tank for ships, comprising a tank wall (4) and at least one repair kit according to any one of claims 10 or 11, said replacement part (27 ) is fixed to said tank wall (4) by said sleeve (28) and said replacement part (27) is covered by at least one repair patch (32), for liquefied natural gas transportation and/or storage tank.

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