Fluid pipe repair method and fluid pipe repair structure

Abstract

To provide a fluid pipe repair method suitable for a situation where a fluid spouts from a leakage hole of a fluid pipe, and to provide a fluid pipe repair structure.SOLUTION: In a fluid pipe repair method, a drain plug 102 is pressed to a water pipe K while covering a leakage hole K1 of the water pipe K through an annular seal material 101 which encloses the leakage hole K1. Then, the drain plug 102 is fixed to the water pipe K in a state that a fluid leaking from the leakage hole K1 is discharged from the drain plug 102.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a method and structure for repairing a fluid pipe such as a water pipe. [Background technology]

[0002] Fluid pipes (such as water pipes) installed outdoors, such as on water pipe bridges, can become weaker due to corrosion, leading to leaks. If the corroded area of ​​the pipe succumbs to water pressure and a leak hole forms, water or other fluids can leak out of the hole, requiring repairs.

[0003] Patent Document 1 discloses a technique for repairing and reinforcing corroded areas of pipes before they succumb to water pressure and cause water leaks. However, this technique cannot be used after a water leak has occurred. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-116734 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a method and structure for repairing a fluid pipe that is suitable for situations in which fluid gushes out from a leak hole in the fluid pipe. [Means for solving the problem]

[0006] The fluid pipe repair method disclosed herein involves pressing a drain plug against the fluid pipe while covering the leak hole through an annular sealing material that surrounds the leak hole, and fixing the drain plug to the fluid pipe while discharging fluid leaking from the leak hole through the drain plug. [Brief explanation of the drawings]

[0007] [Figure 1]1 is a side view of the water pipe K as seen from a line of sight parallel to the pipe diameter direction perpendicular to the pipe axis direction AD, and a partial cross-sectional view of the A1-A1 portion. [Figure 2] 1 is a side view showing a state in which the drain plug 102 is temporarily fixed to the water pipe K by the fixing device 104 of the first embodiment. FIG. [Figure 3] 10 is a front view of the drain plug 102 temporarily fixed to the water pipe K by the fixing device 104, seen from a line of sight parallel to the pipe axis direction. FIG. [Figure 4] Cross-sectional view of the A2-A2 portion in Figure 2. [Figure 5] A cross-sectional view of the A3-A3 portion in Figure 4. [Figure 6] 2 is a cross-sectional view of the A2-A2 portion showing the state after putty 107 has been applied. [Figure 7] 10 is a cross-sectional view taken along a line parallel to the pipe axis, showing the state in which the drain plug 102 is fixed with the reinforcing sheet 106. FIG. [Figure 8] FIG. 10 is a cross-sectional view showing a state in which the drain plug 102 is closed by the plug 105. [Figure 9] FIG. 10 is a side view showing the state in which the drain plug 102 is closed by the plug 105. [Figure 10] FIG. 10 is a side view showing a state in which the drain plug 102 is closed by the plug 105 in the second embodiment. [Figure 11] 10A and 10B are perspective and cross-sectional views showing a repair method and repair structure for a water pipe K according to a third embodiment. [Figure 12] 10 is a cross-sectional view parallel to the axial direction of the fluid pipe, showing the reinforcement structure of the fluid pipe of the fourth embodiment. FIG. [Figure 13A] 10 is a cross-sectional view perpendicular to the axial direction of the fluid pipe, showing the reinforcement structure of the fluid pipe of the fourth embodiment. FIG. [Figure 13B] 10 is a cross-sectional view parallel to the axial direction of the fluid pipe, showing the reinforcement structure of the fluid pipe of the fourth embodiment. FIG. [Figure 14] 10 is a flowchart showing a method for reinforcing a fluid pipe according to a fourth embodiment. [Figure 15A] FIG. 13B is a view corresponding to FIG. 13A and showing a modified example of the reinforcing structure of the fluid pipe of the fourth embodiment. [Figure 15B] FIG. 13C is a view corresponding to FIG. 13B and showing a modified example of the reinforcing structure of the fluid pipe of the fourth embodiment. [Figure 16A] FIG. 13B is a view corresponding to FIG. 13A and showing a modified example of the reinforcing structure of the fluid pipe of the fourth embodiment. [Figure 16B] FIG. 13C is a view corresponding to FIG. 13B and showing a modified example of the reinforcing structure of the fluid pipe of the fourth embodiment. [Figure 17] 10 is a cross-sectional view parallel to the pipe axis direction of the fluid pipe, showing the reinforcing structure of the fluid pipe of the fifth embodiment. FIG. [Figure 18] 10 is a cross-sectional view parallel to the axial direction of the fluid pipe, showing the reinforcing structure of the fluid pipe of the sixth embodiment. FIG. [Figure 19] 10A and 10B are a perspective view and a cross-sectional view perpendicular to the pipe axis direction, showing modifications of the reinforcement structures of the fourth to sixth embodiments. [Figure 20] FIG. 10 is a perspective view showing a modified example of the reinforcement structure of the fourth to sixth embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0008] First Embodiment A method and structure for repairing a fluid pipe (water pipe K) according to a first embodiment of the present disclosure will be described with reference to the drawings.

[0009] The method for repairing a water pipe K in this embodiment is a method for repairing a water pipe K in a situation where a leak hole K1 is formed in the water pipe K and a fluid (water) is leaking from the leak hole K1, as shown in Fig. 1. The method for repairing a water pipe K uses an annular sealing material 101 and a drain plug 102, as shown in Figs. 2 to 5.

[0010] The sealing material 101 is disposed between the outer circumferential surface of the water pipe K and the drain plug 102, and surrounds the leak hole K1 of the water pipe K. The sealing material 101 is annular as shown in Fig. 5. The sealing material 101 can be made of a material such as rubber or sponge, as long as it has a sealing function.

[0011] The drain plug 102 has a cylindrical portion 121 having a discharge path 120 (see FIGS. 4 and 5) that receives fluid leaking from the leak hole K1 and discharges it to the outside, and a flange portion 122 that faces the outer circumferential surface of the water pipe K at the base end of the cylindrical portion 121. The flange portion 122 faces the outer circumferential surface of the water pipe K, including the leak hole K1, and covers the outer circumferential surface of the water pipe K, including the leak hole K1. The flange portion 122 has a larger outer diameter than the cylindrical portion 121, but the entire circumference of the flange portion 122 does not need to be larger than the cylindrical portion 121. For example, as shown in FIG. 4, when the drain plug 102 is fixed to the water pipe K, the discharge path 120 in the flange portion 122 faces the leak hole K1. An external pipe 103 (pipe or hose) for discharging the fluid can be connected to the cylindrical portion 121. The discharge path 120 in the cylindrical portion 121 is configured to be closable. Specifically, the tip of the drain passage 120 of the tubular portion 121 is formed as a threaded hole, and a threaded male external pipe 103 (such as a threaded steel pipe) is screwed into this threaded hole, thereby enabling the external pipe 103 to be connected to the drain plug 102. Furthermore, the drain passage 120 can be closed by removing the external pipe 103 and screwing a plug 105 that matches the threaded hole, as shown in FIGS. 8 and 9 . In the first embodiment, the flange portion 122 has a rectangular shape when viewed from a line of sight parallel to the axis C1 of the drain passage 120, as shown in FIG. 5 . However, the shape is not limited thereto and may be a circular or elliptical shape. Furthermore, as shown in FIGS. 3 and 4 , the inner surface of the flange portion 122 that faces the water pipe K (the surface on the water pipe K side) is curved in an arc shape when viewed from a position parallel to the pipe axis direction AD of the water pipe K. However, the shape is not limited thereto and the inner surface of the flange portion 122 (the surface on the water pipe K side) may be flat.

[0012] In the first embodiment, as shown in Fig. 8, the drain plug 102 is fixed to the water pipe K using a reinforcing sheet 106 and an adhesive. However, if the adhesive becomes wet with a fluid (water) before it hardens, it will not adhere properly. Note that in the drawings of the first to third embodiments, the adhesive is present at least at the interface of the reinforcing sheet 106, but is not shown because it is thin.

[0013] Therefore, before fixing the drain plug 102 with an adhesive, as shown in FIGS. 2 to 4 , the drain plug 102 is temporarily fixed to the water pipe K with a non-adhesive fixing device 104. The non-adhesive fixing device 104 of the first embodiment includes a magnet portion 140 that is attached to the water pipe K and a presser 141 that can press the drain plug 102 against the water pipe K using the magnet portion 140 as a foothold. The magnet portion 140 is a headed bolt with a magnet built into its head. The presser 141 has a plate-shaped portion and includes an external pipe insertion portion 142 that is a hole or notch sized to pass through the external pipe 103 connected to the drain plug 102, and at least two magnet portion fixing portions 143 that are provided at positions that sandwich the external pipe insertion portion 142. The magnet portion fixing portions 143 are holes or notches through which the headed bolt, which is the magnet portion 140, can be passed and fixed with a nut. The number of magnet part fixing portions 143 is two in this embodiment, but can be changed as appropriate. The number of magnet part fixing portions 143 may be three, four or more. It is preferable that a pair of magnet parts 140 are arranged at positions symmetrical with respect to the discharge path 120.

[0014] As shown in FIGS. 2 to 5, the drain plug 102, to which the magnet portion 140 and the presser 141 are attached, is pressed against the water pipe K in a state where it covers the leak hole K1. At this time, the sealant 101, which is disposed between the drain plug 102 and the water pipe K, is positioned to surround the leak hole K1 of the water pipe K. The magnet portion 140 is attracted to the water pipe K while the fluid (water) leaking from the leak hole K1 is discharged from the drain plug 102 through the external pipe 103. The water pipe K is a pipe made of a magnetic material to which the magnet portion 140 can be attracted. In this way, the drain plug 102 is temporarily fixed to the water pipe K by the fixing device 104. In order to press the drain plug 102 against the water pipe K without discharging the fluid (water) leaking from the leak hole K1, it is necessary to apply a pressing force stronger than the pressure of the fluid (water) leaking from the leak hole K1. However, in this embodiment, the fluid (water) leaking from the leakage hole K1 is discharged from the drain plug 102 through the external pipe 103, so the force required for the magnet part 140 to press the water pipe K can be reduced compared to when no fluid is discharged, making it easier to temporarily fix the drain plug 102.

[0015] Next, with the drain plug 102 temporarily fixed to the water pipe K by the fixture 104, putty 107 is applied between the water pipe K and the drain plug 102, as shown in FIG. 6 . The putty 107 may have any adhesive properties. In this embodiment, Unitec Corporation's "Rector Seal" (EP-400, EP-200, or EP-200W) product is used. In this embodiment, the putty 107 is an epoxy resin adhesive putty mixed with a hardener, but other putty materials may also be used as appropriate. In this embodiment, as shown in FIG. 6 , the putty 107 is applied from a position covering the inner surface S1 of the drain plug 102 facing the outer periphery of the water pipe K, through a position covering the side surface S2 of the drain plug 102, and to a position covering the outer surface S3 of the drain plug 102, enveloping the drain plug 102 from both radial sides of the water pipe K and hardening. The fluid (water) leaking from the leak hole K1 continues to be discharged from the drain plug 102 through the external pipe 103.

[0016] After the putty 107 has hardened, the magnet portion 140 is removed from the water pipe K, thereby releasing the temporary fixation of the drain plug 102 to the water pipe K by the fixture 104. Although the fixation by the fixture 104 is released, the drain plug 102 is still fixed to the water pipe K by the putty 107.

[0017] Next, as shown in FIG. 7 , the drain plug 102 is fixed to the water pipe K using a reinforcing sheet 106 and adhesive. The reinforcing sheet 106 covers the entire outer periphery of the water pipe K and also covers the drain plug 102. The reinforcing sheet 106 is adhered and fixed to the outer periphery of the water pipe K and the drain plug 102 using the adhesive. The adhesive may be applied to the outer periphery of the water pipe K and the drain plug 102 before the reinforcing sheet 106 is laid over them, or the adhesive-impregnated reinforcing sheet 106 may be wrapped around the outer periphery of the water pipe K and the drain plug 102. The drain plug 102 may be covered with the reinforcing sheet 106 by first drilling a hole in the reinforcing sheet 106 corresponding to the drain plug 102, passing the drain plug 102 through the hole, and then wrapping the reinforcing sheet around the water pipe K, or by covering the drain plug 102 with the ends of multiple reinforcing sheets. The reinforcing sheet 106 may also have a hole corresponding to the drain plug 102 and a slit extending from the hole to the end of the reinforcing sheet 106, with the slit being opened to cover the drain plug 102. When the reinforcing sheet is used to cover the entire outer periphery of the water pipe K, the reinforcing strength can be increased by overlapping the ends of the reinforcing sheet. The reinforcing sheet also covers the putty.

[0018] The reinforcing sheet 106 may be a fiber sheet, and examples of the fiber sheet include a carbon sheet, a glass fiber sheet, etc. In this embodiment, a carbon fiber sheet is used, but this can be changed as appropriate. The adhesive has the function of fixing the interface between the reinforcing sheet and the water pipe K (fluid pipe) upon hardening. Examples of adhesives include adhesives whose main component is a curing agent-mixed acrylic resin, epoxy resin, or silicone rubber, as well as adhesives whose main component is a UV-curable acrylic resin or epoxy resin.

[0019] As shown in Figure 7, the state in which the fluid (water) leaking from the leak hole K1 is discharged from the drain plug 102 via the external pipe 103 continues until the adhesive that secures the reinforcing sheet 106 hardens. After the adhesive that secures the reinforcing sheet 106 hardens, the drain plug 102 is closed to stop the discharge of the fluid from the drain plug 102, as shown in Figures 8 and 9. In this embodiment, the discharge of the fluid from the drain plug 102 is stopped by removing the external pipe 103 from the drain plug 102 and inserting a plug 105 into the drain plug 102. The drain plug 102 is fixed in place, covering only a portion of the outer circumferential surface of the water pipe K, including the leak hole K1. This means that it is not a valve provided in a housing device that hermetically encloses the entire water pipe K. Furthermore, the inside of the drain plug 102 is connected to the inside of the water pipe K, while the outside of the drain plug 102 is not filled with fluid.

[0020] Second Embodiment A method and structure for repairing a fluid pipe (water pipe K) according to a second embodiment of the present disclosure will be described. In the second embodiment, a fixing device 204, which is a band that can be wrapped around the water pipe K (fluid pipe), is used instead of the fixing device 104 in the first embodiment. As shown in FIG. 10 , the fixing device 204 (band) is wrapped around the water pipe K together with the flange portion 122 of the drain plug 102, thereby fixing the drain plug 102 to the water pipe K. In the second embodiment, instead of releasing the temporary fixing of the drain plug 102 by the fixing device 104 as in the first embodiment, the fixing device 204 and the drain plug 102 are covered with a reinforcing sheet 106 and fixed with an adhesive. This is effective when the reinforcing sheet 106 and the fixing device 204 can be wrapped around the entire circumference of the water pipe K. Note that a putty 107 may be used, or the putty 107 can be omitted.

[0021] <Third embodiment> A repair method and repair structure for a fluid pipe (water pipe K) according to a third embodiment of the present disclosure will be described. The water pipe K to which the repair method and repair structure of the third embodiment apply is a case in which an axial rib structure R1 extending in the pipe axis direction AD is integrally formed with the water pipe K, as shown in FIG. 11 . The third embodiment is substantially the same as the first embodiment, except that the reinforcing sheet 106 cannot cover the entire outer circumferential surface of the water pipe K. Therefore, the reinforcing sheet 106 covers only a portion of the outer circumferential surface of the water pipe K. Furthermore, the band (fixing device 204) of the second embodiment cannot be used, but instead, a fixing device 104 having a magnet portion 140 is used.

[0022] <Modification> (1) In the first embodiment, the holding tool 141 of the fixing tool 104 is temporarily fixed in a state in which it extends in the circumferential direction of the water pipe K, but this is not limiting. For example, the holding tool 141 may be temporarily fixed in a state in which it extends in the pipe axis direction AD of the water pipe K.

[0023] (2) In the second embodiment, since the fixing tool 204 is used, the putty 107 may be used or the putty 107 may be omitted.

[0024] (3) In the first to third embodiments, the method of wrapping the reinforcing sheet 106 and adhesive around the water pipe K, and the adhesive and attachment method used can be the same as those described in the fourth to sixth embodiments below, and the materials can be used.

[0025] As described above, although not particularly limited, as in the first to third embodiments, a method for repairing a fluid pipe may involve pressing a drain plug 102 against the water pipe K (fluid pipe) in a state covering the leak hole K1 via an annular sealing material 101 that surrounds the leak hole K1, and fixing the drain plug 102 to the water pipe K while discharging fluid leaking from the leak hole K1 from the drain plug 102. In this way, the drain plug 102 is fixed to the water pipe K while the fluid is discharged through the drain plug 102, so it is possible to avoid resisting the pressure of the leaking fluid and the drain plug 102 can be fixed to the fluid pipe relatively easily.

[0026] Although not particularly limited, the drain plug 102 may be fixed to the water pipe K by adhesive and a reinforcing sheet 106 that covers at least a part of the outer circumferential surface of the water pipe K, as in the first to third embodiments. When the drain plug 102 is fixed to the water pipe K using the reinforcing sheet 106 and adhesive, there is a risk that the leaking fluid will inhibit the hardening of the adhesive, or that the pressure of the leaking fluid will cause the adhesive to peel off before it hardens. However, by discharging the leaking fluid from the drain plug 102, it is possible to make it difficult for the pressure of the fluid to act on the adhesive and to prevent the fluid from coming into contact with the adhesive, so that the drain plug can be fixed appropriately even when the reinforcing sheet 106 and adhesive are used.

[0027] Although not particularly limited, as in the first to third embodiments, before fixing the drain plug 102 with an adhesive, the drain plug 102 may be fixed or temporarily fixed to the water pipe K with a non-adhesive fixing device (104, 204). Since the drain plug 102 is fixed or temporarily fixed to the water pipe K with the non-adhesive fasteners (104, 204), it may be possible to easily fix it with an adhesive.

[0028] Although not particularly limited, as in the first or third embodiment, the fixing device 104 may include a magnet portion 140 that is attracted to the water pipe K, and a pressing device 141 that can press the drain plug 102 against the water pipe K using the magnet portion 140 as a foothold. The fixing device 104 can be easily used for a water pipe K that can be attracted by the magnet portion 140, improving workability. In particular, the fixing device 104 can be used even when there is a restriction that prevents the entire periphery of the water pipe K from being used, such as when a rib (e.g., an axial rib structure R1) that supports the water pipe K is formed on the outer surface of the water pipe K.

[0029] Although not particularly limited, as in the first or third embodiment, while the drain plug 102 is temporarily fixed to the water pipe K by the fixing device 104, putty 107 may be applied between the water pipe K and the drain plug 102, and after the putty 107 has hardened, the fixing device 104 may be removed, and the drain plug 102 may be fixed by the reinforcing sheet 106 and adhesive. Because the hardened putty 107 holds the drain plug 102 in place until the drain plug 102 is fixed with the reinforcing sheet 106 and adhesive, workability can be improved. Furthermore, because the drain plug 102 is fixed to the water pipe K with the putty 107, reinforcing sheet 106, and adhesive, the fixing strength can be improved compared to when the drain plug 102 is fixed to the water pipe K with the reinforcing sheet 106 and adhesive.

[0030] Although not particularly limited, as in the second embodiment, the fixture 204 may be a band that can be wrapped around the water pipe K or the fluid pipe. The band allows for appropriate fixing or temporary fixing of the drain plug 102. This is particularly effective when the magnet portion 140 is not attracted to the fluid pipe.

[0031] Although not particularly limited, as in the first to third embodiments, the drain plug 102 may be closed to stop the discharge of fluid from the drain plug 102 after the adhesive has hardened. This reduces the pressure of the fluid acting on the adhesive before it hardens, allowing for proper adhesion.

[0032] Although not particularly limited, as in the first to third embodiments, the repair structure for a fluid pipe may include an annular sealing material 101 that surrounds a leak hole K1 formed in the outer peripheral surface of the water pipe K, a drain plug 102 that is fixed to the water pipe K with the sealing material 101 interposed therebetween in a state that covers only a portion of the outer peripheral surface of the water pipe K including the leak hole K1, and a fixing part (such as a reinforcing sheet 106, putty 107, fixing device 204, or adhesive) that fixes the drain plug 102 to the water pipe K, and the drain plug 102 has a discharge path 120 for discharging fluid leaking from the leak hole K1 to the outside, an external pipe 103 can be connected to the discharge path 120, and the discharge path 120 is configured to be closable. This is an appropriate configuration for blocking the leak hole K1 in the fluid pipe. In particular, until the drain plug 102 is properly fixed at the fixing part, fluid leaking from the leak hole K1 can be drained via the drain path 120 of the drain plug 102 and the connected external pipe 103, and after the fixing is completed, the drain path 120 can be closed.

[0033] Although not particularly limited, as in the first to third embodiments, the fixing portion may include a reinforcing sheet 106 and an adhesive, and the reinforcing sheet 106 may cover at least a portion of the outer surface of the water pipe K and the drain plug 102, and be adhesively fixed to the outer surface of the water pipe K and the drain plug 102 by the adhesive. According to this configuration, the reinforcing sheet 106 can reinforce the fluid pipe itself, and the drain plug 102 can also be fixed in place.

[0034] Although not particularly limited, the putty 107 may be placed between the outer circumferential surface of the water pipe K and the drain plug 102 as in the first to third embodiments. The putty 107 can increase the fixing strength of the drain plug 102.

[0035] Although not particularly limited, as in the first to third embodiments, the putty 107 may be arranged from a position covering the inner surface S1 of the drain plug 102 facing the outer peripheral surface of the water pipe K, through a position covering the side surface S2 of the drain plug 102, to a position covering the outer surface S3 of the drain plug 102, and then harden while enveloping the drain plug 102. This makes it possible to increase the fixing strength of the drain plug 102.

[0036] [Reinforcement structure and method for fluid pipes before leakage] Meanwhile, as a separate issue from the above disclosure, fluid pipes (such as water pipes) installed outdoors, such as on water pipe bridges, may become weaker due to corrosion, resulting in water leakage. It is therefore necessary to repair and reinforce the corroded parts of the pipes before they succumb to water pressure and lead to water leakage.

[0037] For example, Japanese Patent Application Laid-Open No. 2006-116734 describes a method for repairing pipes in which a reinforcing material and a glass fiber layer are integrally molded to conform to the shape of the pipe before being attached to the pipe, and then the reinforcing material and a glass fiber layer are attached to the pipe.

[0038] Carbon fiber and aramid fiber are considered as reinforcing materials for being lightweight and for strengthening the tube.

[0039] On the other hand, when aramid fibers are wound around a pipe as a reinforcing material and bonded with a waterproof adhesive, the aramid fibers have poor adhesive impregnation, so the adhesive either sags due to gravity or escapes from the aramid fibers before it dries and hardens, resulting in uneven application of the adhesive to the aramid fibers and a decrease in the waterproofing properties of the adhesive.

[0040] A reinforcement structure and a reinforcement method for a fluid pipe that can ensure watertightness in a reinforcement structure using aramid fiber are provided.

[0041] <Fourth embodiment> A reinforcement structure and a reinforcement method for a fluid pipe according to a fourth embodiment of the present disclosure will be described with reference to the drawings. Fig. 12 is a cross-sectional view parallel to the pipe axis direction AD of the fluid pipe K. Fig. 13A is a cross-sectional view perpendicular to the pipe axis direction AD of the fluid pipe K. Fig. 13B is a cross-sectional view parallel to the pipe axis direction AD of the fluid pipe K. Note that although adhesive 4 is present between the sheets and between the fluid pipe and the sheet in the drawings, the adhesive 4 may not be shown in the drawings.

[0042] 12, 13A, and 13B, the reinforcing structure for the fluid pipe K includes a first fiber sheet 1 made of aramid fiber and attached to the outer peripheral side RD1 of the fluid pipe K with an adhesive, and a second fiber sheet 2 that is disposed on the outer peripheral side RD1 of the first fiber sheet 1 and holds the adhesive. No other fiber sheet is disposed on the inner peripheral side RD2 of the first fiber sheet 1. No other fiber sheet is disposed on the outer peripheral side RD1 of the second fiber sheet 2.

[0043] The adhesive 4 is an adhesive for aramid fibers and has water-stopping properties. In this embodiment, an epoxy resin is used, but it is not limited to this. The epoxy resin adhesive for aramid fibers has a tensile strength of 39.2 N / mm2 in a test method conforming to JIS K7208. 2 However, it is not limited to this. The time required for hardening is 12 hours. The bond strength according to the JHS492 test method based on JIS A6909 is 2.0 N / mm 2 However, it is not limited to this.

[0044] The first fiber sheet 1 is a fabric woven from aramid fibers. In this embodiment, a twill or plain weave fabric is used, but is not limited thereto. Aramid fibers have poor adhesive absorption. Twill weave is a fabric woven in such a way that warp threads and weft threads are bundled together, similar to gauze and ramie, to create an appearance similar to that of gauze and ramie. As a result, there are gaps between each bundle, resulting in a woven structure with many gaps overall. Due to the poor adhesive absorption of aramid fibers themselves and the tendency for the adhesive to escape from the gaps, even if the first fiber sheet 1 is attached to the fluid pipe K using adhesive alone, the adhesive will escape before hardening, resulting in uneven adhesive application to the aramid fibers. Plain weave is a fabric in which warp and weft threads are woven alternately. While plain weave has fewer gaps than twill weave, the poor adhesive absorption of aramid fibers causes the adhesive to escape when tension is applied to the first fiber sheet 1.

[0045] The strength of the aramid fiber used in the fourth embodiment is 2060 N / mm 2 However, the present invention is not limited to this. The basis weight of the aramid fiber used in the fourth embodiment is 180 g / m 2 or 650 g / m 2 However, it is not limited to this.

[0046] The second fiber sheet 2 is a plain weave or nonwoven fabric made of a fiber other than aramid fiber. Because the second fiber sheet 2 is not made of aramid fiber, it is impregnated with adhesive and can hold more adhesive than aramid fiber. Examples of combinations of material and weave include plain weave polyester fiber, nonwoven polyester fiber, plain weave glass fiber, nonwoven glass fiber, and nonwoven felt fiber. These can adequately exhibit adhesive holding capacity.

[0047] To ensure weather resistance, the second fiber sheet 2, which is disposed on the outer periphery side RD1 of the first fiber sheet 1, is preferably a plain weave fabric of polyester fiber with an ultraviolet absorber kneaded in. The plain weave fabric of polyester fiber has high weather resistance, and furthermore, the ultraviolet absorber prevents ultraviolet rays from coming into contact with the adhesive before it hardens.

[0048] The wrapping length of the first fiber sheet 1 and the second fiber sheet 2 in the circumferential direction CD may be less than one circumference of the fluid pipe in the circumferential direction CD, or may be one circumference of the fluid pipe in the circumferential direction CD. As shown in FIG. 2, the wrapping length of the first fiber sheet 1 and the second fiber sheet 2 in the circumferential direction CD may be one circumference or more of the fluid pipe in the circumferential direction CD. To ensure strength, the first fiber sheet 1 made of aramid fiber is preferably attached so that the first end 1a and the second end 1b in the circumferential direction CD overlap. The second end 1b is located on the opposite side of the first end 1a in the circumferential direction CD. The overlap amount L1 in the circumferential direction CD is preferably at least 100 mm or more. It may also be 200 mm or more.

[0049] When multiple first fiber sheets 1 are arranged along the tube axis direction AD, the ends of the first fiber sheets may or may not overlap. To ensure strength, as shown in FIG. 14, two first fiber sheets 1 adjacent in the tube axis direction AD are preferably attached so that the third end 1c in the tube axis direction AD of one first fiber sheet 1 overlaps the fourth end 1d in the tube axis direction AD of the other first fiber sheet 1. The fourth end 1d is located on the opposite side of the third end 1c in the tube axis direction AD. The overlap amount L2 along the tube axis direction AD is preferably at least 100 mm or more. It may also be 200 mm or more.

[0050] <Method of reinforcing fluid pipe K> FIG. 14 shows a flow chart of a method for reinforcing a fluid pipe K according to a fourth embodiment. As shown in FIG. 14, the reinforcing method first performs a scraping step ST1. Examples of the scraping step ST1 include type 2 scraping, type 3 scraping, or the application of a coating-type surface adjustment reducer and type 4 scraping. Type 2 scraping is a process that uses a power tool such as a disc sander to remove the old paint film and rust, exposing the metal surface (steel surface, etc.) of the fluid pipe. Type 3 scraping is a process that leaves the active film and removes any remaining rust, cracks, and blisters. Type 4 scraping is a process that removes powder and dirt.

[0051] Next, a degreasing step ST2 is performed. The degreasing step ST2 is a treatment for removing oil, and acetone, for example, is used.

[0052] Next, the primer application step ST3 is carried out. This step is carried out on the entire surface to be bonded with adhesive. For example, an epoxy resin primer is applied to the pipe with a roller. A two-component base agent (epoxy resin) and a curing agent (modified polyamidoamine) are mixed in a 2:1 ratio. The viscosity of the mixture at 20°C should be 60 mPa·s, and it should harden to the touch at 20°C within one hour.

[0053] Next, the unevenness adjustment step ST4 is performed as needed. This step can be omitted. The unevenness adjustment step ST4 is a process of applying putty to recesses or steps in the fluid pipe K. Examples of the putty that can be applied include underwater waterproof paint, rapid hardening paste, and metal repair material.

[0054] Next, a sheet attachment step ST5 is performed. The sheet attachment step ST5 is a step of attaching at least the first fiber sheet 1 and the second fiber sheet 2 to the fluid pipe K using an adhesive 4. In the embodiment shown in FIGS. 12, 13A, and 13B, first, the first fiber sheet 1 is attached to the fluid pipe K with an adhesive, and then the second fiber sheet 2 is attached to the outer circumferential side RD1 of the first fiber sheet 1 with an adhesive. The first fiber sheet 1 and the second fiber sheet 2 are attached to the fluid pipe K one by one separately.

[0055] Next, a finish coating step ST6 is performed. The finish coating step ST6 is a treatment for applying a urethane-based or fluorine-based paint to the outer circumferential side RD1 of the first fiber sheet 1 and the second fiber sheet 2 attached to the fluid pipe K.

[0056] <Modification of the Fourth Embodiment> (2-1) In the embodiment shown in FIGS. 12 , 13A, and 13B, the first fiber sheet 1 and the second fiber sheet 2 are attached separately, but the sheet attachment method is not limited thereto. For example, as shown in FIGS. 15A and 15B, the first fiber sheet 1 and the second fiber sheet 2 are bonded together with an adhesive 4 to prepare a sheet unit 5, and the sheet unit 5 is then wrapped around the fluid pipe K via the adhesive 4. This facilitates installation. The sheet unit 5 has a first end 51 and a second end 52 in the pipe circumferential direction CD, and the second end 52 is opposite the first end 51 in the pipe circumferential direction CD. The ends of the sheet units 5 in the pipe circumferential direction CD may or may not overlap. To ensure strength, it is preferable to overlap the ends of the sheet units 5 in the pipe circumferential direction CD. In this case, when the sheet unit 5 is wound around the fluid pipe K, the first end 51 is overlapped with the second end 52, and as a result, the first end 51 of the first fiber sheet 1, the first end 51 of the second fiber sheet 2, the second end 52 of the first fiber sheet 1, and the second end 52 of the second fiber sheet 2 are stacked in this order from the inner circumferential side RD2 of the pipe toward the outer circumferential side RD1 of the pipe.

[0057] When multiple sheet units 5 are arranged along the tube axis direction AD, the ends of the sheet units 5 may or may not overlap. To ensure strength, as shown in FIG. 15B , two sheet units 5 adjacent to each other in the tube axis direction AD are preferably attached so that the third end 53 in the tube axis direction AD of one sheet unit 5 overlaps the fourth end 54 in the tube axis direction AD of the other sheet unit 5. The fourth end 54 is located on the opposite side of the third end 53 in the tube axis direction AD. In this case, when the sheet units 5 are wound around the fluid pipe K, the third end 53 overlaps the fourth end 54. As a result, the third end 53 of the first fiber sheet 1, the third end 53 of the second fiber sheet 2, the fourth end 54 of the first fiber sheet 1, and the fourth end 54 of the second fiber sheet 2 are stacked in this order from the inner peripheral side RD2 of the pipe toward the outer peripheral side RD1 of the pipe.

[0058] (2-2) As an attachment method other than the methods shown in FIGS. 12 , 13A , 13B , 15A , and 15B , the method shown in FIGS. 16A and 16B is an example. As shown in FIGS. 16A and 16B , a sheet unit 5 is prepared in which portions of the first fiber sheet 1 and the second fiber sheet 2 are previously bonded together with an adhesive 4, and the sheet unit 5 is then wrapped around the fluid pipe K via the adhesive 4. At a first end 51 in the circumferential direction CD of the sheet unit 5, the first fiber sheet 1 and the second fiber sheet 2 are not bonded with the adhesive 4 and are separable. At a second end 52 in the circumferential direction CD of the sheet unit 5, the first fiber sheet 1 and the second fiber sheet 2 are bonded with the adhesive 4 and fixed. When the sheet unit 5 is wrapped around the fluid pipe K, the first fiber sheet 1 and the second fiber sheet 2 at the first end 51 are spaced apart, and the second end 52 is sandwiched between the spaced first fiber sheet 1 and the second fiber sheet 2. This strengthens the bond.

[0059] 16B , when multiple sheet units 5 are arranged along the tube axis direction AD, it is preferable to overlap the ends of the sheet units 5. In this case, of two sheet units 5 adjacent in the tube axis direction AD, the first fiber sheet 1 and the second fiber sheet 2 at the third end 53 in the tube axis direction AD of one sheet unit 5 are spaced apart, and the spaced first fiber sheet 1 and second fiber sheet 2 sandwich the fourth end 54 in the tube axis direction AD of the other sheet unit 5. This makes it possible to strengthen the adhesion.

[0060] Fifth Embodiment A reinforcement structure and a reinforcement method for a fluid pipe according to a fifth embodiment of the present disclosure will be described with reference to Fig. 17. Fig. 17 is a cross-sectional view of a fluid pipe K parallel to the pipe axis direction AD. As shown in Fig. 17, the reinforcement structure for a fluid pipe according to the fifth embodiment includes a first fiber sheet 1 made of aramid fiber and attached to an outer peripheral side RD1 of the fluid pipe K via an adhesive; a second fiber sheet 2 disposed on the outer peripheral side RD1 of the first fiber sheet 1 and holding the adhesive; and a third fiber sheet 3 disposed on the outer peripheral side RD1 of the second fiber sheet 2. No other fiber sheet is disposed on the inner peripheral side RD2 of the first fiber sheet 1. No other fiber sheet is disposed on the outer peripheral side RD1 of the third fiber sheet 3.

[0061] The first fiber sheet 1 of the fifth embodiment is a fiber sheet woven with aramid fibers, as in the fourth embodiment, and is made of, but not limited to, a twill weave or a plain weave.

[0062] The second fiber sheet 2 is a plain weave fabric of glass fiber, a nonwoven fabric of glass fiber, or a nonwoven fabric of polyester fiber. The second fiber sheet 2 does not contain an ultraviolet absorber.

[0063] The third fiber sheet 3 is provided to ensure weather resistance. The third fiber sheet 3 is a plain weave polyester fiber fabric with an ultraviolet absorber kneaded into it. The plain weave polyester fiber fabric has high weather resistance, and the ultraviolet absorber prevents ultraviolet rays from coming into contact with the adhesive before it hardens. The third fiber sheet 3 makes it possible to suppress deterioration due to ultraviolet rays.

[0064] The method of attaching the first fiber sheet 1, the second fiber sheet 2, and the third fiber sheet 3 may be to attach each sheet individually, as described in the fourth embodiment, or to attach two or more sheets together with an adhesive to form a sheet unit, which is then attached to the fluid pipe K, as shown in modified example (2-1) or (2-2) of the fourth embodiment.

[0065] Sixth Embodiment A reinforcement structure and reinforcement method for a fluid pipe according to a sixth embodiment of the present disclosure will be described with reference to Fig. 18. Fig. 18 is a cross-sectional view of a fluid pipe K parallel to the pipe axis direction AD. As shown in Fig. 18, the reinforcement structure for a fluid pipe K according to the sixth embodiment includes a first fiber sheet 1 made of aramid fiber attached to an outer peripheral side RD1 of the fluid pipe K via an adhesive, and a second fiber sheet 2 disposed on an inner peripheral side RD2 of the first fiber sheet 1. No other fiber sheet is disposed on the outer peripheral side RD1 of the first fiber sheet 1.

[0066] The first fiber sheet 1 of the sixth embodiment is a fiber sheet woven with aramid fibers, as in the fourth embodiment, and is made of, but not limited to, a twill weave or a plain weave.

[0067] The second fiber sheet 2 is a plain weave fabric of glass fiber, a nonwoven fabric of glass fiber, or a nonwoven fabric of polyester fiber. The second fiber sheet 2 of the adhesive does not contain an ultraviolet absorber.

[0068] According to the sixth embodiment, the non-aramid fiber second fiber sheet 2 is close to the fluid pipe K, which makes it possible to increase the adhesive strength to the fluid pipe K. In particular, if the second fiber sheet 2 is a nonwoven fabric, it easily conforms to the surface of the fluid pipe and adheres to it.

[0069] The method of attaching the first fiber sheet 1 and the second fiber sheet 2 may be to attach each sheet individually, as described in the fourth embodiment, or, as shown in modified example (2-1) or (2-2) of the fourth embodiment, to combine the two sheets with adhesive to form a sheet unit, which is then attached to the fluid pipe K.

[0070] <Modifications of the Fourth to Sixth Embodiments> (2-3) As shown in Fig. 19, a fluid pipe K and an axial rib structure R1 extending in the pipe axis direction AD may be integrally formed. In this case, a sheet unit 5 including at least a first fiber sheet 1 and a second fiber sheet 2 may be attached to both the axial rib structure R1 and the fluid pipe K via an adhesive. In Fig. 19, the sheet unit 5 is indicated by diagonal lines. Specifically, the sheet unit 5 is disposed from the axial rib structure R1 to the outer peripheral surface of the fluid pipe K, then around the outer peripheral surface of the fluid pipe K until it reaches the axial rib structure R1.

[0071] (2-4) As shown in Figure 20, there is a case where a fluid pipe K, an axial rib structure R1 extending in the pipe axis direction AD, and a circumferential rib structure R2 extending in the pipe circumferential direction CD are integrally formed. In this case, a first sheet unit 5' may be provided that is bonded from the axial rib structure R1 to the outer surface of the fluid pipe K, and a second sheet unit 5'' may be provided that is bonded from the circumferential rib structure R2 to the outer surface of the fluid pipe K. In Figure 20, the first sheet unit 5' and the second sheet unit 5'' are indicated by diagonal lines.

[0072] (2-5) In FIG. 20, both the axial rib structure R1 and the circumferential rib structure R2 are integrally formed with the fluid pipe K, but if only the circumferential rib structure R2 is integrally formed with the fluid pipe K, only the second seat unit 5'' may be provided.

[0073] As described above, although not particularly limited, as in the fourth to sixth embodiments, the reinforcing structure of the fluid pipe K may include a first fiber sheet 1 woven from aramid fiber and attached to the outer peripheral side RD1 of the fluid pipe K via an adhesive 4, and a second fiber sheet 2 that is a plain weave or nonwoven fabric of fibers other than aramid fiber and that is arranged on the outer peripheral side RD1 or the inner peripheral side RD2 of the first fiber sheet 1 and holds the adhesive 4.

[0074] Aramid fibers have poor adhesive impregnation, so the adhesive either drips due to gravity or escapes from the aramid fibers, resulting in uneven application of the adhesive to the aramid fibers and a decrease in the water-stopping ability of the adhesive. In contrast, according to the above configuration, not only the first fiber sheet 1 made of aramid fibers but also the second fiber sheet 2 made of a plain weave or nonwoven fabric of fibers other than aramid fibers is wrapped around the aramid fibers to hold the adhesive 4, so it is possible to avoid a decrease in water-stopping ability due to uneven application of the adhesive 4.

[0075] Although not particularly limited, as shown in the fourth or fifth embodiment, the second fiber sheet 2 may be disposed on the outer circumferential side RD1 of the first fiber sheet 1. This allows the strong aramid fibers to be placed closer to the fluid pipe K, thereby enhancing the reinforcing effect.

[0076] Although not particularly limited, the second fiber sheet 2 may be a plain weave polyester fabric, a nonwoven polyester fabric, a plain weave glass fiber fabric, or a nonwoven glass fiber fabric, as shown in the fourth or fifth embodiment, which allows the adhesive 4 to be held in a suitable state.

[0077] Although not particularly limited, as shown in the fourth embodiment, the second fiber sheet 2 may be a plain weave fabric of polyester fibers with an ultraviolet absorber kneaded in. This makes it possible to suppress deterioration due to ultraviolet rays, and the plain weave fabric of polyester fibers can improve weather resistance.

[0078] Although not particularly limited, as shown in the fifth embodiment, the second fiber sheet 2 may be a polyester fiber nonwoven fabric, a glass fiber plain weave fabric, or a glass fiber nonwoven fabric, and a third fiber sheet 3 may be disposed on the outer circumferential side RD1 of the second fiber sheet 2, and the third fiber sheet 3 may be a polyester fiber plain weave fabric having an ultraviolet absorber kneaded in. This makes it possible to suppress deterioration due to ultraviolet rays, and the polyester fiber plain weave fabric can improve weather resistance.

[0079] Although not particularly limited, as shown in the sixth embodiment, the second fiber sheet 2 is disposed on the inner peripheral side RD2 of the first fiber sheet 1, and the second fiber sheet 2 may be a plain weave glass fiber fabric, a nonwoven glass fiber fabric, or a nonwoven polyester fiber fabric. This positioning of the non-aramid fiber second fiber sheet 2 closer to the fluid pipe K increases the adhesive strength to the fluid pipe K. In particular, if the second fiber sheet 2 is a nonwoven fabric, it easily conforms to the irregularities on the surface of the fluid pipe K and adheres tightly to it.

[0080] Although not particularly limited, the first fiber sheet 1 may be attached so that its ends in the pipe circumferential direction CD overlap each other, as shown in the fourth to sixth embodiments. This allows the aramid fibers to overlap, thereby improving the reinforcing effect of the fluid pipe K.

[0081] Although not particularly limited, as in the fourth to sixth embodiments, a reinforcing method for a fluid pipe (K) may include the steps of: arranging a first fiber sheet (1) on an outer peripheral side (RD1) of the fluid pipe (K) via an adhesive (4); and arranging a second fiber sheet (2) on either the outer peripheral side (RD1) or the inner peripheral side (RD2) of the first fiber sheet (1) via an adhesive (4), wherein the first fiber sheet (1) is woven from aramid fiber, and the second fiber sheet (2) is a plain weave or nonwoven fabric of a fiber other than aramid fiber and holds the adhesive. In this way, not only the first fiber sheet (1) made of aramid fiber but also the second fiber sheet (2) made of a plain weave or nonwoven fabric of a fiber other than aramid fiber are wound around the first fiber sheet (1) to hold the adhesive (4), thereby making it possible to avoid a decrease in watertightness due to unevenness of the adhesive (4).

[0082] Although not particularly limited, as in the fourth to sixth embodiments, the reinforcing method for the fluid pipe K may include a step of wrapping the sheet unit 5, in which at least a portion of the first fiber sheet 1 and the second fiber sheet 2 are previously bonded and integrated, around the fluid pipe K via the adhesive 4. This makes it possible to facilitate the installation work.

[0083] Although not particularly limited, as in the fourth to sixth embodiments, the sheet unit 5 has a first end 51 and a second end 52 in the pipe circumferential direction CD, the first fiber sheet 1 and the second fiber sheet 2 are not bonded to each other at the first end 51 and are separable, and the first fiber sheet 1 and the second fiber sheet 2 are bonded and fixed to each other at the second end 52, and the method may include a step of separating the first fiber sheet 1 and the second fiber sheet 2 at the first end 51 and sandwiching the second end 52 between the separated first fiber sheet 1 and the second fiber sheet 2. This makes it possible to strengthen the bond.

[0084] Although the embodiments of the present disclosure have been described above with reference to the drawings, the specific configurations should not be considered to be limited to these embodiments. The scope of the present disclosure is defined not only by the description of the above embodiments but also by the claims, and further includes all modifications within the meaning and scope of the claims.

[0085] The structures employed in the above-described embodiments can be employed in any other embodiment. The specific configurations of the components are not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure. [Explanation of symbols]

[0086] 101...Sealing material 102...Drain plug 103…External tube 104,204…Fixing fixture 106...Reinforcement sheet 107...Putty 120…Discharge path 140...Magnet part 141... Clamp K...Water pipe (fluid pipe) K1…Leak hole

Claims

1. a step of pressing a drain plug against the fluid pipe in a state where the drain plug covers the leak hole through an annular sealing material surrounding the leak hole of the fluid pipe, and fixing the drain plug to the fluid pipe with an adhesive while discharging fluid leaking from the leak hole from the drain plug; and fixing or temporarily fixing the drain plug to the fluid pipe with a non-adhesive fastener before fixing the drain plug to the fluid pipe with the adhesive, The method for repairing a fluid pipe, wherein the fixing device includes a magnet portion that is attached to the fluid pipe, and a pressing device that can press the drain plug against the fluid pipe using the magnet portion as a foothold.

2. A method for repairing a fluid pipe, comprising pressing a drain plug against the water pipe while covering the leak hole through an annular sealing material that surrounds the leak hole, discharging fluid leaking from the leak hole through the drain plug, and fixing the drain plug to the water pipe with a fiber sheet and adhesive that covers at least a portion of the outer surface of the water pipe.

3. a drain plug is pressed against the fluid pipe in a state where the leak hole is covered via an annular sealing material surrounding the leak hole of the fluid pipe, and the drain plug is fixed to the fluid pipe with a reinforcing sheet and adhesive that cover at least a portion of the outer peripheral surface of the fluid pipe while discharging fluid leaking from the leak hole from the drain plug; Before fixing the drain plug with the adhesive, the drain plug is fixed or temporarily fixed to the fluid pipe with a non-adhesive fixing device; The method for repairing a fluid pipe, wherein the fixing device includes a magnet portion that is attached to the fluid pipe, and a pressing device that can press the drain plug against the fluid pipe using the magnet portion as a foothold.

4. An annular sealing material surrounding a leak hole formed on the outer circumferential surface of a water pipe; a drain plug fixed to the water pipe with the sealing material interposed therebetween in a state where the drain plug covers only a portion of the outer circumferential surface of the water pipe including the leakage hole; an adhesive disposed between the drain plug and the water pipe on the outside of the annular sealing material and fixing the drain plug to the water pipe; A water pipe repair structure in which the drain plug has a discharge path for discharging fluid leaking from the leak hole to the outside, an external pipe can be connected to the discharge path, and the discharge path is configured to be closable.

5. an annular sealing material surrounding a leakage hole formed on an outer peripheral surface of the fluid pipe; The sealing material is interposed in a state where it covers only a part of the outer circumferential surface of the fluid pipe including the leakage hole. a drain plug fixed to the fluid pipe; a fixing portion that fixes the drain plug to the fluid pipe, the drain plug has a discharge path for discharging fluid leaking from the leakage hole to the outside, An external pipe can be connected to the discharge path, and the discharge path is configured to be closable, the fixing portion includes a reinforcing sheet and an adhesive; The reinforcing sheet covers at least a part of the outer circumferential surface of the fluid pipe and the drain plug. and the drain plug is adhesively fixed to the outer peripheral surface of the fluid pipe and the drain plug by the adhesive.

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