Fluid leakage prevention tool and fluid leakage prevention structure

Abstract

To prevent leakage of a fluid and repair the leakage of the fluid while preventing complication of constitution and cost increase.SOLUTION: The fluid leakage prevention device (1) includes a main body (5) covering an outer periphery of the flange joint portion (4) in a state extending over both the fluid pipes (2), a seal member (7) sealing between the main body (5) and outer surface portions (21) of both the fluid pipes (2), and a pressing portion (83) abutting on and pressing an outer surface portion (31) of the flange portion (3).SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a fluid leakage prevention device and a fluid leakage prevention structure that prevent fluid leakage at flange joints where flange portions of fluid pipes are fastened together using bolt and nut fasteners, and that repair fluid leakage if fluid leakage occurs and stop the fluid leakage. [Background technology]

[0002] At flange joints where flanges of fluid pipes are fastened together, fluid leakage may occur if the gap between the flanges increases due to external forces such as earthquakes or aging, etc. Therefore, in order to reinforce the flange joints, a flange joint reinforcing jig has been proposed that includes a pair of clamping members that clamp both flanges together and a fastening member that pulls both clamping members in the flange joining direction to tighten and fix them (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-141995 Summary of the Invention [Problem to be solved by the invention]

[0004] In the flange joint reinforcing jig described in Patent Document 1, both flanges are clamped by a pair of clamping members, but if the flanges are misaligned in the radial direction of the fluid pipe or if the outer surfaces of the flanges are uneven, the pair of clamping members may not be able to properly clamp both flanges. Therefore, there is still a possibility of fluid leakage, and there is room for improvement.

[0005] Furthermore, fluids may leak not only between the flanges but also through the bolt holes formed in the flanges at the flange joints. This requires measures such as replacing the bolts with ones that have a watertight function, which not only requires a lot of work but also complicates the structure and increases costs.

[0006] In view of this situation, the main object of the present invention is to provide a fluid leakage prevention device and a fluid leakage prevention structure that can prevent fluid leakage and repair fluid leakage while preventing the configuration from becoming complicated and increasing costs. [Means for solving the problem]

[0007] A first characteristic configuration of the present invention is a fluid leakage prevention device that prevents fluid leakage at a flange joint where flange portions of two fluid pipes are fastened and joined together using fasteners of bolts and nuts, a main body that covers the outer periphery of the flange joint portion while spanning both fluid pipes; a seal member for sealing between the main body and outer surfaces of both fluid pipes; a pressing portion that abuts against and presses the outer surface of the flange portion.

[0008] According to this configuration, the presser portion is provided to abut against and press the outer surface of the flange portion, so that the outer surface of the flange portion can be pressed by the presser portion, preventing the gap between the flange portions from becoming too large, thereby preventing fluid from leaking out from between the flange portions.

[0009] Furthermore, since the main body is provided so as to cover the outer periphery of the flange joints, and the gap between the main body and the outer surfaces of both fluid pipes is sealed with a sealing member, the internal space of the main body can be an enclosed space that covers the outer periphery of the flange joints. Therefore, even if fluid leaks between the flanges, it is possible to prevent the fluid from leaking outside the main body. Furthermore, by providing the main body so as to cover the outer periphery of the flange joints, it is possible to flexibly respond to any case, for example, even if the flanges are misaligned in the radial direction of the fluid pipe, if the outer surfaces of the flanges are uneven, or if the outer shapes of the flanges are not perfectly round, and it is possible to prevent the fluid from leaking outside the main body.

[0010] Furthermore, not only when fluid leaks from between the flange portions, but also when fluid leaks from bolt holes formed in the flange portions, it is possible to prevent fluid from leaking outside the main body. Therefore, it is not necessary to take measures such as replacing the bolts with ones that have a watertight function, and it is possible to prevent and repair fluid leakage while reducing the amount of work required and preventing the configuration from becoming more complicated and increasing costs.

[0011] A second characteristic feature of the present invention is that the pressing portion exerts a pressing force that presses the outer surface portions of the flange portions in the direction in which the flange portions approach each other by receiving a force acting on the pressing portion.

[0012] According to this configuration, when the pressing portion is subjected to a force acting on it, it exerts a pressing force that presses the outer surface of the flange portion in the direction that brings the flange portions closer together. This pressing force can appropriately restrict the flange portions from moving in the direction that brings the flange portions apart, thereby effectively preventing fluid leakage from between the flange portions.

[0013] A third characteristic configuration of the present invention is a pressing body that is configured separately from the main body and has the pressing portion, the pressing body is disposed inside the main body between the fasteners in the circumferential direction of the flange portion, the main body has a plurality of divided bodies divided in the circumferential direction of the flange portion, and the plurality of divided bodies are configured to be freely assemblable to the flange joint portion by fastening and fixing the divided bodies to each other by fastening tools in an assembly posture in which the divided bodies cover the outer periphery of the flange joint portion, The feature is that the fastener is configured to apply a compressive force to the sealing member by tightening the fastener when assembling the main body to the flange joint portion, and also to freely apply the acting force to the pressing body.

[0014] According to this configuration, when assembling the multiple segments to the flange joints, the segments are fastened together with fasteners, which allows both a compressive force to be applied to the seal member and an acting force to be applied to the pressing body. Therefore, simply fastening the segments together with fasteners allows the seal member to properly seal the internal space of the main body and also generates a pressing force that presses the outer surfaces of the flanges toward each other.

[0015] A fourth characteristic feature of the present invention is that the pressing portions are provided as a pair in a state in which the flange portions of the flange joint portion are sandwiched from both sides.

[0016] According to this configuration, the outer surface of the flange portion can be pressed by sandwiching the flange portions from both sides with a pair of pressing portions, thereby appropriately preventing the gap between the flange portions from becoming too large and effectively preventing fluid leakage from between the flange portions.

[0017] A fifth characteristic configuration of the present invention is a pressing body having the pressing portion, The main body is provided with an operating state switching operation unit that can be freely switched between an operating state in which the pressing body is pressed to apply the acting force and a non-operating state in which the pressing body is not pressed and the acting force is not applied.

[0018] According to this configuration, since the main body is provided with an action state switching operation unit, by switching the action state switching operation unit to the action state, it is possible to directly press the pressing body and apply an action force. Therefore, by simply switching the action state switching operation unit, it is possible to efficiently and easily apply an action force to the pressing body.

[0019] A sixth characteristic configuration of the present invention is a fluid leakage prevention structure that prevents fluid leakage at a flange joint where flange portions of two fluid pipes are fastened and joined together using fasteners of bolts and nuts, a main body that covers the outer periphery of the flange joint portion while spanning both fluid pipes; a seal member for sealing between the main body and outer surfaces of both fluid pipes; a pressing portion that abuts against and presses the outer surface of the flange portion.

[0020] According to this configuration, as with the first characteristic configuration, the presser portion is provided to reinforce the flange joint portion and prevent fluid from leaking between the flange portions. Moreover, the internal space of the main body can be made into an enclosed space that covers the outer periphery of the flange joint portion. Therefore, not only if fluid leaks between the flange portions but also if fluid leaks from the bolt holes formed in the flange portions, it is possible to prevent fluid from leaking to the outside of the main body. This eliminates the need to take measures such as replacing the bolts with ones that have a watertight function. This reduces the amount of work required and prevents the configuration from becoming more complicated and the costs from increasing, while allowing for prevention and repair of fluid leakage. [Brief explanation of the drawings]

[0021] [Figure 1] A perspective view showing the flange joint [Figure 2] FIG. 10 is a perspective view showing the installation state of the pressing body with the main body to be assembled to the flange joint removed. [Figure 3] FIG. 10 is a perspective view showing the state in which the divided bodies are temporarily assembled to the flange joint portion. [Figure 4] A perspective view showing the state in which the main body is assembled to the flange joint portion. [Figure 5] FIG. 1 is a perspective view showing a pressing body; [Figure 6] Half cross-sectional view of the flange joint and fluid outflow prevention device with the divided body temporarily assembled to the flange joint [Figure 7] Half cross-sectional view of the flange joint and fluid outflow prevention device with the main body attached to the flange joint [Figure 8] (A) is a perspective view showing the outer side of the divided body, and (B) is a perspective view showing the inner side of the divided body. [Figure 9] FIG. 10 is a half cross-sectional view of a flange joint and a fluid outflow prevention device in a state where the operating state switching operation unit is switched to a non-operating state in the second embodiment. [Figure 10] FIG. 10 is a half cross-sectional view of a flange joint and a fluid outflow prevention device in a state where the operating state switching operation unit is switched to the operating state in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fluid leakage prevention device and a fluid leakage prevention structure according to the present invention will be described with reference to the drawings. As shown in Figure 1, this fluid leakage prevention device and fluid leakage prevention structure are intended to prevent fluid leakage at a flange joint 4 where the flanges 3 of two fluid pipes 2 are fastened together using a fastener C consisting of a connecting bolt B1 and a connecting nut A1, and to perform repairs to stop the fluid leakage if a fluid leak does occur. For example, a cast iron water pipe can be used for the fluid pipe 2, but other fluid pipes can also be used.

[0023] [First embodiment] The fluid leakage prevention device 1 and the fluid leakage prevention structure will be described below while defining directions based on the fluid pipe 2. As shown in Fig. 1, the pipe axial direction of the fluid pipe 2 is designated as X, and is abbreviated as "pipe axial direction X," and the radial direction of the fluid pipe 2 that is perpendicular to the pipe axial direction X of the fluid pipe 2 is designated as Y, and is abbreviated as "radial direction Y." In the radial direction Y, the center side of the fluid pipe 2 is designated as the inner side, and the outer periphery side of the fluid pipe 2 is designated as the outer side.

[0024] As shown in Figures 4 and 7, the fluid leakage prevention device 1 is provided with a main body 5 that covers the outer periphery of the flange joint 4 (see Figure 1) across both fluid pipes 2, and a sealing member 7 that seals between the main body 5 and the outer surface portions 21 of both fluid pipes 2, as shown in Figure 7.

[0025] As shown in Figures 3 and 4, the main body 5 is divided into a plurality of segments 6 in the circumferential direction of the flange portion 3 (fluid pipe 2). As shown in Figure 4, the main body 5 is configured to be freely assembled to the flange joint 4 (see Figure 1) by taking an assembly position in which the segments 6 cover the outer periphery of the flange joint 4, and fastening the segments 6 together by tightening fasteners C, such as headed T-bolts, with assembly bolts B2 and assembly nuts A2. In this embodiment, the segments 6 are formed in half, and two segments 6 are provided, but the number of segments 6 can be changed as appropriate.

[0026] As shown in Figure 8(A), the divided body 6 is provided with a covering portion 61 that is curved in a U-shape to fit around the outer periphery of the flange joint 4 (see Figure 1) and covers the outer periphery of the flange joint 4, and a main body flange portion 62 that is integrally formed at both ends of the covering portion 61 and extends radially outward from the fluid pipe 2.

[0027] As shown in FIGS. 4 and 8A, the covering portion 61 is integrally formed with a first covering portion 63, a second covering portion 64, and a third covering portion 65 aligned in the pipe axial direction X. The first covering portion 63 is disposed toward the center in the pipe axial direction X, and the second covering portion 64 and the third covering portion 65 are disposed on either side of the first covering portion 63, sandwiching the first covering portion 63. The first covering portion 63 is formed to cover the outer peripheries of both flanges 3 at the flange joint portion 4 (see FIG. 1), and the third covering portion 65 is formed to cover the outer surfaces 21 of both fluid pipes 2 at the flange joint portion 4 (see FIG. 1), with the first covering portion 63 having a larger diameter than the third covering portion 65. The second covering portion 64 is formed in an inclined shape that increases in diameter outward in the radial direction Y (toward the first covering portion 63) so as to connect the first covering portion 63 and the third covering portion 65.

[0028] 8(B), a plurality of protrusions 66 (for example, three) are arranged at intervals in the circumferential direction of the flange portion 3 (fluid pipe 2) on the inner wall portion 63a of the first covered portion 63. The protrusions 66 are formed, for example, in a cylindrical shape protruding inward in the radial direction Y from the inner wall portion 63a.

[0029] As shown in Fig. 8(B), a plurality of bulging portions 67 (for example, three) are arranged at intervals in the circumferential direction of the flange portion 3 (fluid pipe 2) on each inner wall portion 64a of the second covered portion 64. As shown in Fig. 7, the bulging portions 67 have a desired length in the pipe axial direction X and are formed in an inclined shape that bulges inward in the radial direction Y.

[0030] As shown in Figures 7 and 8(B), an attachment recess 68 for attaching the seal member 7 is formed in the inner wall portion 65a of the third covering portion 65 and the back surface portion 62a of the main body flange portion 62. As shown in Figure 8(B), the attachment recess 68 is formed in a continuous recessed shape over the entire curved inner wall portion 65a of the third covering portion 65 and the entire flat back surface portion 62a of the main body flange portion 62. Figures 7 and 8(B) show a state in which the seal member 7 is attached to the attachment recess 68, and the seal member 7 is made of an annular elastic body that is continuous over the entire length of the attachment recess 68.

[0031] As shown in Fig. 8, the main body flange 62 is formed with a plurality of bolt holes 69 for inserting the assembly bolts B2 (see Fig. 4). As shown in Fig. 8(B), the bolt holes 69 are arranged outward of the mounting recesses 68, and as shown in Fig. 4, the assembly bolts B2 and the fasteners C for the assembly nuts A2 are tightened outward of the sealing portion where the seal member 7 seals between the main body 5 and the outer surface 21 of the fluid pipe 2.

[0032] 2 and 5, the fluid leakage prevention device 1 is equipped with a pressing body 8 that is configured separately from the main body 5, in addition to the main body 5 and the sealing member 7. Incidentally, in order to show the installation state of the pressing body 8 in the fluid leakage prevention device 1, FIG. 2 shows a state in which the main body 5 has been removed, leaving only the pressing body 8.

[0033] 5, the pressing body 8 is formed in a symmetrical inverted U-shape having a pair of left and right leg portions 81 and a connecting portion 82 connecting the pair of left and right leg portions 81. Each of the pair of left and right leg portions 81 is formed in a block shape having a predetermined length in the left-right and up-down directions, and the connecting portion 82 is formed in a curved shape by curving a plate-like body so as to fit along the outer peripheries of both flange portions 3.

[0034] As shown in Fig. 2, the pressing bodies 8 are disposed inside the main body 5 between the fasteners C (connecting nuts A1 and connecting bolts B1) in the circumferential direction of the flange portions 3, with a pair of left and right legs 81 sandwiching both flange portions 3 at the flange joint portion 4. As shown in Fig. 2, it is preferable to dispose a plurality of pressing bodies 8, for example, three, but the number of pressing bodies 8 to be disposed can be changed as appropriate.

[0035] 6 and 7, the pressing body 8 has a pressing portion 83 that abuts against and presses the outer surface portion 31 of the flange portion 3. As shown in Fig. 5, the pressing portion 83 is disposed on each of the pair of left and right leg portions 81 on the side (inner side) where the legs 81 approach each other in the left-right direction of the pressing body 8, and is composed of a flat surface portion that has the same width as the plate-like connecting portion 82 and extends in the up-down direction. In this way, the pressing portion 83 presses the outer surface portion 31 of the flange portion 3, and restricts the flange portions 3 from moving in the direction in which the two flange portions 3 move away from each other.

[0036] As shown in Fig. 7, the pressing portion 83 is configured to be able to exert a pressing force (for example, pressing force F3) that presses the outer surface portions 31 of the flange portions 3 in a direction that brings the flange portions 3 closer together by receiving an acting force (for example, acting force F2) from the main body 5. To this end, as shown in Figs. 5 and 7, on each of the pair of left and right leg portions 81, an acting force receiving portion 84 that receives the acting force from the main body 5 is disposed on the side (outer side) where the legs 81 are separated from each other in the left-right direction of the pressing body 8. The acting force receiving portion 84 is configured with an inclined surface portion that is positioned more outward as it approaches the lower side.

[0037] As shown in Fig. 5, the top portion of the connecting portion 82 of the pressing body 8 is provided with a fitting hole 86 that fits onto the protrusion 66 (see Fig. 8(B)) of the main body 5. As shown in Fig. 6, the pressing body 8 can be attached to the inner wall portion of the divided body 6 by fitting the fitting hole 86 of the pressing body 8 onto the protrusion 66 of the divided body 6.

[0038] When the pressing body 8 is attached to the inner wall portion of the divided body 6, each of the pair of left and right leg portions 81 of the pressing body 8 is provided with a guide portion 85 that guides the bulging portion 67 (see FIG. 8(B)) of the divided body 6 to a position facing the acting force receiving portion 84, as shown in FIG. 5. The guide portions 85 are disposed on both sides of the acting force receiving portion 84 and are formed in an inclined shape that corresponds to the acting force receiving portion 84, protruding upward beyond the acting force receiving portion 84.

[0039] Below, as shown in Figure 7, the configuration will be explained, including the assembly method of the fluid leakage prevention device 1, whereby the pressing body 8 receives an acting force (e.g., acting force F2) from the main body 5, and the pressing portion 83 exerts a pressing force (e.g., pressing force F3) that presses the outer surface portion 31 of the flange portion 3 in the direction in which the flange portions 3 approach each other.

[0040] As shown in FIG. 1 , at the flange joint 4, the flanges 3 of both fluid pipes 2 are fastened together using fasteners C, which are connecting bolts B1 and connecting nuts A1. The method of assembling the fluid leakage prevention device 1 first involves a presser body mounting step in which a presser body 8 is mounted on the inner wall of the divided body 6. In this presser body mounting step, the fitting hole 86 (see FIG. 5 ) of the presser body 8 is fitted into the protrusion 66 (see FIG. 8(B)) formed on the inner wall of the divided body 6, thereby mounting the presser body 8 on the inner wall of the divided body 6. At this time, the pair of guide portions 85 (see FIG. 5 ) of the presser body 8 can guide the bulge 67 (see FIG. 8(B)) formed on the inner wall of the divided body 6 to a clamping position, thereby simplifying the mounting operation of the presser body 8 to the divided body 6.

[0041] Incidentally, in this embodiment, three pressing bodies 8 are attached to one divided body 6, so that protrusions 66 and bulges 67 corresponding to the number of pressing bodies 8 are formed on the inner wall portion of the divided body 6.

[0042] Next, as shown in Fig. 3, a temporary assembly process is performed in which the multiple segments 6 are temporarily assembled in an assembly position that covers the outer periphery of the flange joint 4. By performing the temporary assembly process, the segments 6 cover the outer sides and both lateral sides of both flanges 3 at the flange joint 4, as well as the outer sides of the outer surface portions 21 of both fluid pipes 2 adjacent to both flanges 3, as shown in Fig. 6.

[0043] Next, as shown in Fig. 4, an assembly bolt B2 is inserted into each of the bolt holes 69 (see Fig. 3) formed in the main body flange portion 62 and tightened into the assembly nut A2, thereby performing an assembly process in which the divided bodies 6 are tightened and fixed together, and the main body 5 is assembled to the flange joint portion 4. In this assembly process, as shown in Fig. 7, by tightening the assembly bolt B2 and the assembly nut A2 with the tightening tool C, a compressive force (for example, compressive force F1) is applied to the sealing member 7, and an acting force (for example, acting force F2) can be freely applied to the pressing body 8.

[0044] By tightening the fasteners C in the assembly process, the segment 6 and the outer surfaces 21 of both fluid pipes 2 are moved from a state in which they are separated as shown in FIG. 6 during the temporary assembly process to a state in which the segment 6 approaches the outer surfaces 21 of both fluid pipes 2 as shown in FIG. 7, and a compressive force (e.g., compressive force F1) can be applied to the seal member 7. This allows the seal member 7 to be compressed and the gap between the segment 6 and the outer surfaces 21 of both fluid pipes 2 to be appropriately sealed, making the internal space of the segment 6 an enclosed space that covers the outer periphery of the flange joint 4. Therefore, even if fluid leaks from between the flanges 3 or from bolt holes formed in the flanges 3, leakage of fluid to the outside of the main body 5 can be prevented.

[0045] As shown in Fig. 7, tightening with the tightening tool C not only applies a compressive force (e.g., compressive force F1) to the seal member 7, but also applies an acting force (e.g., acting force F2) from the segment 6 to the pressing body 8. Tightening with the tightening tool C moves the segment 6 toward the outer surface portions 21 of both fluid pipes 2, so that the bulging portion 67 exerts an acting force (e.g., acting force F2) pressing the acting force receiving portions 84 when the bulging portion 67 comes into contact with the acting force receiving portions 84 of the pair of left and right leg portions 81 of the pressing body 8. At this time, since the bulging portion 67 and the acting force receiving portions 84 are formed into opposing inclined surfaces, an acting force is applied from the bulging portion 67 to the acting force receiving portions 84 when the bulging portion 67 and the acting force receiving portions 84 are in surface contact with each other, and this acting force becomes an acting force in an oblique direction (e.g., acting force F2).

[0046] This diagonal acting force (e.g., acting force F2) causes, for example, the pressing body 8 to bend and deform with the top or the like as a fulcrum so that the pair of left and right leg portions 81 approach each other, or the diagonal acting force (e.g., acting force F2) generates an acting force having a component in the direction of bringing the flange portions 3 closer together. As a result, with the planar pressing portion 83 in surface contact with the planar outer surface portions 31 of both flange portions 3, a pressing force (e.g., pressing force F3) is exerted from the pressing portion 83 on the outer surface portions 31 of both flange portions 3, pressing the flange portions 3 in the direction of bringing them closer together. A pair of pressing portions 83 is provided so as to sandwich both flange portions 3 from both sides, and therefore both flange portions 3 are firmly sandwiched together, thereby suitably reinforcing the flange joint portion 4.

[0047] Regarding the assembly method of the fluid leakage prevention device 1, the assembly method of the fluid leakage prevention device 1 can be applied not only to prevent fluid leakage when the flange portions 3 of both fluid pipes 2 are fastened together using the fasteners C of the connecting bolt B1 and connecting nut A1 to form the flange joint 4, but also to repair the fluid leakage when fluid leakage has already occurred after the flange joint 4 has been formed.

[0048] Second Embodiment The second embodiment is a modification of the first embodiment in terms of the configuration in which the pressing portion 83 exerts a pressing force that presses the outer surface portions 31 of the flange portions 3 in the direction in which the flange portions 3 approach each other, as shown in Fig. 7. Below, the configuration in which the pressing portion 102 exerts a pressing force that presses the outer surface portions 31 of the flange portions 3 in the direction in which the flange portions 3 approach each other will be mainly described with reference to Figs. 9 and 10. The other configurations are the same as those in the first embodiment, and therefore the same reference numerals will be used and the description will be omitted.

[0049] In the first embodiment, as shown in Figures 4 and 7, a pressing body 8 having a pressing portion 83 is provided, and by tightening the assembly bolt B2 and the assembly nut A2 with the fastener C, an acting force (e.g., acting force F2) is applied to the pressing body 8, and the pressing portion 83 exerts a pressing force (e.g., pressing force F3) that presses the outer surface portion 31 of the flange portion 3 in the direction in which the flange portions 3 approach each other.

[0050] In contrast, in the second embodiment, as shown in Figures 9 and 10, a pressing body 101 having a pressing portion 102 is provided, and the main body 5 (divided body 6) is provided with an action state switching operation unit 104 that can be freely switched between an action state (see Figure 10) in which the pressing body 101 is pressed to apply an action force, and a non-action state (see Figure 9) in which the pressing body 101 is not pressed and no action force is applied.

[0051] 9 and 10, a pair of pressing bodies 101 are provided, sandwiching both flange portions 3. A recessed storage portion 105 capable of storing the pressing body 101 is formed in the divided body 6, and the pressing body 101 is supported so as to be movable in the tube axial direction X relative to the storage portion 105. The pressing body 101 is formed in a block shape having a planar pressing portion 102 facing the outer surface portion 31 of the flange portion 3, and a planar acting force receiving portion 103 disposed on the opposite side of the pressing portion 102.

[0052] 9 and 10, the action state switching operation part 104 is composed of a push bolt that can be screwed into a bolt hole 106 formed in the divided body 6. An O-ring 107 is disposed at the tip of the action state switching operation part 104 to prevent fluid from leaking to the outside through the storage part 105 and the bolt hole 106.

[0053] 9, the distal end surface of the action state switching operation unit 104 is merely in contact with the action force receiving portion 103 of the pressing body 101 or is separated from the action force receiving portion 103, and the action state is switched to a non-acting state in which the action state is not applied to the pressing body 101 and no action force is applied. In the non-acting state of FIG. 9, by rotating the action state switching operation unit 104, the action state switching operation unit 104 is threadedly advanced as shown in FIG. 10, and the distal end surface of the action state switching operation unit 104 presses the action force receiving portion 103 of the pressing body 101, thereby switching to an acting state in which an action force (e.g., action force F4) is applied to the pressing body 101. By applying the action force (e.g., action force F4) to the pressing body 101, the holding portion 102 of the pressing body 101 exerts a pressing force (e.g., pressing force F4) that presses the outer surface portion 31 of the flange portion 3 toward the flange portions 3 approaching each other.

[0054] In the second embodiment, as shown in Fig. 4, the operating state switching unit 104 can be switched between the inactive state and the active state separately from the tightening operation of the assembly bolt B2 and the assembly nut A2 by the tightening tool C. Therefore, for example, after the main body 5 is assembled to the flange joint 4, the operating state switching unit 104 can be operated to switch from the inactive state (see Fig. 9) to the active state (see Fig. 10), causing the pressing portion 102 of the pressing body 101 to exert a pressing force (e.g., pressing force F4) that presses the outer surface portions 31 of the flange portions 3 toward each other, thereby reinforcing the flange joint 4.

[0055] Incidentally, in the second embodiment, the shape of the covering portion 61 in the dividing body 6 is different from that in the first embodiment, but similar to the first embodiment, it is configured to be curved in a U-shape to fit along the outer periphery of the flange joint 4 (see Figure 1) and cover the outer periphery of the flange joint 4, so a description of the covering portion 61 in the second embodiment will be omitted.

[0056] [Another embodiment] Other embodiments of the present invention will be described below. Note that the configurations of the embodiments described below are not limited to being applied independently, but can also be applied in combination with the configurations of other embodiments.

[0057] (1) In the above embodiment, a pair of pressing portions 83, 102 are provided to sandwich both flange portions 3. In the first embodiment, for example, in FIG. 5, by cutting the connecting portion 82 midway, it is possible to provide the pressing portion 83 on only one side of both flange portions 3. In the second embodiment, in FIG. 8, by providing a pressing body 101 on only one side of both flange portions 3, it is possible to provide the pressing portion 102 on only one side of both flange portions 3.

[0058] (2) In the first embodiment described above, the pressing body 8 is attached to the inner wall portion of the divided body 6 by fitting the fitting hole portion 86 of the pressing body 8 into the protrusion portion 66 of the divided body 6. However, the pressing body 8 can also be attached to the inner wall portion of the divided body 6 using fasteners such as bolts and nuts, and the configuration for attaching the pressing body 8 to the inner wall portion of the divided body 6 can be changed as appropriate.

[0059] (3) In the second embodiment, the pressing body 101 is supported by the main body 5 (divided body 6), but the way in which the pressing body 101 is supported can be changed as appropriate.

[0060] (4) In the above embodiment, the pressing portions 83, 102 exert a pressing force that presses the outer surface portions 31 of the flange portions 3 in the direction in which the flange portions 3 move closer to each other by receiving a force acting on them, but the pressing portions do not have to exert a pressing force that presses the outer surface portions 31 of the flange portions 3 in the direction in which the flange portions 3 move closer to each other. The pressing portions may, for example, simply abut against and press the outer surface portions 31 of the flange portions 3, or may be such that the pressing portions abut against and press the outer surface portions 31 of the flange portions 3 when the flange portions 3 move in the direction in which the flange portions 3 move apart. [Explanation of symbols]

[0061] 1 Fluid leakage prevention device 2 Fluid tube 3 Flange 4 Flange joint 5 Main unit 6 split body 7 Sealing material 8 Pressing body 21 Outer surface of fluid pipe 31 Outer surface of flange 101 pressing body 102 Presser foot 104 Action state switching operation unit A1 Connecting nut (nut) A2 Assembly nut (nut) B1 Connecting bolt (bolt) B2 Assembly bolt (bolt) C Fastener

Claims

1. A fluid leakage prevention device that prevents fluid leakage at a flange joint where flange portions of two fluid pipes are fastened and joined together using bolt and nut fasteners, a main body that covers the outer periphery of the flange joint portion while spanning both fluid pipes; a seal member for sealing between the main body and outer surfaces of both fluid pipes; and a pressing portion that abuts against and presses the outer surface of the flange portion.

2. The fluid leakage prevention device according to claim 1, wherein the pressing portion exerts a pressing force that presses the outer surfaces of the flange portions in the direction in which the flange portions approach each other by receiving a force acting on the pressing portion.

3. a pressing body configured separately from the main body and having the pressing portion; the pressing body is disposed inside the main body between the fasteners in the circumferential direction of the flange portion, the main body has a plurality of divided bodies divided in the circumferential direction of the flange portion, and the plurality of divided bodies are configured to be freely assemblable to the flange joint portion by fastening and fixing the divided bodies to each other by fastening tools in an assembly posture in which the divided bodies cover the outer periphery of the flange joint portion, 3. The fluid leakage prevention device according to claim 2, wherein the fastener is configured to apply a compressive force to the sealing member and to freely apply the force to the pressing body by tightening the fastener when assembling the main body to the flange joint portion.

4. The fluid leakage prevention device according to any one of claims 1 to 3, wherein a pair of the pressing portions are provided so as to sandwich the flange portions of the flange joint portion from both sides.

5. A pressing body having the pressing portion is provided, 3. The fluid leakage prevention device according to claim 2, wherein the main body is provided with an action state switching operation unit that can be freely switched between an action state in which the pressing body is pressed to apply the action force and a non-action state in which the pressing body is not pressed and the action force is not applied.

6. A fluid leakage prevention structure that prevents fluid leakage at a flange joint where flange portions of two fluid pipes are fastened and joined together using fasteners of bolts and nuts, a main body that covers the outer periphery of the flange joint portion while spanning both fluid pipes; a seal member for sealing between the main body and outer surfaces of both fluid pipes; a pressing portion that abuts against and presses the outer surface of the flange portion.

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