Branch pipe repair device and branch pipe renewal method

Abstract

To provide a branch pipe repair device which achieves high working efficiency for repairing a branch pipe.SOLUTION: A branch pipe repair device P includes: a device body 2 having a base part 21 facing an outer surface at the side of a branch pipe D in a fluid pipe W, and an enclosure part 22 which is connected to the base part 21 and encloses at least a part of the outer peripheral surface of the branch pipe D; a seal member S which is disposed between the base part 21 and the fluid pipe W and prevents leakage of fluid to the outside of the device body 2; and a drawing member 31 which is fixed to the device body 2 and the fluid pipe W and draws the device body 2 to the side of the fluid pipe W along the pipe axis direction X of the branch pipe D. The seal member S includes a first seal member and a second seal member each including annular contact parts which contact with the outer surface of the fluid pipe W in a continuous manner, and an annular groove part which is recessed from the contact parts, the first seal member and the second seal member split along the pipe axis direction Y of the fluid pipe W. The contact parts of the first seal member and the contact parts of the second seal member are adhered to each other at the pipe top part WA in the fluid pipe W.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a branch pipe repair device for repairing a branch pipe branched off from a fluid pipe, and a branch pipe renewal method for renewing such a branch pipe. [Background technology]

[0002] Conventionally, fluid pipes have been used to circulate fluids, and some of these fluid pipes have branch pipes to branch off the fluid and circulate it. As a technology for preventing leakage of fluid due to damage to the connection between such a fluid pipe and the branch pipe, for example, there is a technology described in Patent Document 1, the source of which is shown below.

[0003] Patent Document 1 discloses a branch pipe repair device equipped with a branch sealing member that integrates a ceiling wall forming plate having a through hole facing the outer peripheral surface of the flange part of the branch pipe and a peripheral wall forming plate covering the outer peripheral surface of the branch pipe (see the third embodiment). In this branch pipe repair device, after the branch sealing member is welded along the outer peripheral surface of the fluid pipe, the through hole of the ceiling forming plate is welded to the outer peripheral surface of the flange part of the branch pipe, and mortar is filled inside the branch sealing member.

[0004] Patent Document 1 also discloses a branch pipe repair device that includes a split joint body that faces the outer circumferential surface of a fluid pipe, and a branch tubular section that is connected to the split joint body and covers the outer circumferential surface of a branch pipe (see the fourth embodiment). In this branch pipe repair device, after the split joint body and the branch tubular section are connected to the outer circumferential sides of the fluid pipe and the branch pipe, mortar is filled between the outer circumferential surface of the fluid pipe and the split joint body, and between the outer circumferential surface of the branch pipe and the branch tubular section. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-24729 A Summary of the Invention [Problem to be solved by the invention]

[0006] The branch pipe repair device described in Patent Document 1 fills the inside of the branch sealing member or the branch tubular portion with mortar, so if there is fluid inside, it is necessary to drain this fluid to the outside, which reduces work efficiency. Moreover, since the branch pipe is repaired using mortar, the repair of the branch pipe is not completed until the mortar hardens, which requires repair costs and time.

[0007] Therefore, there is a demand for a branch pipe repair device that can repair branch pipes with high work efficiency, and a branch pipe renewal method for renewing branch pipes. [Means for solving the problem]

[0008] A characteristic configuration of a branch pipe repair device according to the present invention is a branch pipe repair device for repairing a branch pipe branched off from a fluid pipe, comprising: an apparatus main body having a base portion facing an outer surface of the fluid pipe on the branch pipe side and an enclosing portion connected to the base and enclosing at least a part of the outer surface of the branch pipe; a seal member disposed between the base and the fluid pipe for preventing leakage of fluid to the outside of the apparatus main body; and a clamping member fixed to the apparatus main body and the fluid pipe for pulling the apparatus main body toward the fluid pipe along the pipe axis direction of the branch pipe, wherein the seal member has an annular abutment portion that is in continuous abutment with the outer surface of the fluid pipe and an annular groove portion that is recessed from the abutment portion, and includes a first seal member and a second seal member that are divided along the pipe axis direction of the fluid pipe, and the abutment portion of the first seal member and the abutment portion of the second seal member are in close contact with each other at a pipe top of the fluid pipe.

[0009] With this characteristic configuration, the first seal member and the second seal member, which are divided along the axial direction of the fluid pipe of the seal member, can be closely attached to the top of the fluid pipe along the axial direction. Therefore, regardless of the outer diameter of the fluid pipe, both the first seal member and the second seal member can be closely attached to the fluid pipe at the top of the fluid pipe. At this time, since the seal member has an annular abutment portion and an annular groove portion that is recessed from the abutment portion, the abutment portion protrudes inside the groove portion, improving the sealing function. In this way, according to this branch pipe repair device, regardless of the outer diameter of the fluid pipe, the first seal member and the second seal member can be easily closely attached to the fluid pipe without using an adhesive such as mortar, so that the work efficiency for repairing the branch pipe can be improved.

[0010] It is also preferable that the device body is divided along the axial direction of the fluid pipe.

[0011] With this configuration, the device body can bring the first seal member and the second seal member into closer contact with each other, and the device body can be easily attached to the branch pipe.

[0012] It is also preferable that the base includes an arc-shaped portion having an arc surface formed on its bottom surface that conforms to the outer peripheral surface of the fluid pipe, and a pair of bent portions bent from both ends of the arc-shaped portion so as to move away from the fluid pipe, and the clamping member is fixed to the pair of bent portions and is formed of a plurality of band members that conform to the outer peripheral surface of the fluid pipe.

[0013] With this configuration, the band member can bring the device body into closer contact with the fluid pipe, thereby improving the sealing performance of the seal member.

[0014] It is also preferable that the seal member is fitted into a recess formed in a dividing surface of the surrounding portion and an opposing surface of the base portion facing the fluid pipe.

[0015] With this configuration, the seal member is fitted into the recess, so that displacement of the seal member can be prevented.

[0016] In addition, it is preferable that the branch pipe repair device further includes a connecting mechanism that connects the gate valve connected to the branch pipe to the device main body after the pulling member has pulled the device main body toward the fluid pipe, and pulls the branch pipe and the gate valve toward the device main body.

[0017] With this configuration, the branch pipe and the gate valve can be appropriately positioned relative to the fluid pipe.

[0018] In addition, a characteristic configuration of the branch pipe renewal method of the present invention is a branch pipe renewal method for renewing a branch pipe having one end connected to a fluid pipe and the other end connected to a gate valve, comprising: a blocking step of connecting a blocking device having a blocking portion capable of blocking the flow path of the branch pipe to the gate valve, and expanding and blocking the blocking portion inserted through the gate valve in an open state; a gate valve removal step of removing the gate valve from the connecting portion of the branch pipe while leaving the blocking portion in the branch pipe; a connecting step of connecting a short pipe to the connecting portion of the branch pipe; a drawing step of attaching a protective tube covering the outside of the short pipe and the branch pipe in a sealed state around the short pipe and the fluid pipe, and drawing the protective tube toward the fluid pipe along the pipe axial direction of the branch pipe by a drawing member; and a blocking portion removal step of connecting the gate valve to the connecting portion of the short pipe opposite the branch pipe, and then removing the blocking portion through the gate valve in an open state.

[0019] With this characteristic configuration, the branch pipe can be easily replaced. [Brief description of the drawings]

[0020] [Figure 1] 1 is a front view of a piping system before a branch pipe repair device is installed. FIG. [Diagram 2] 1 is a front view showing a state in which the branch pipe repair device is attached to a piping system. FIG. [Diagram 3]1 is a side view showing a state in which the branch pipe repair device is attached to a piping system. FIG. [Figure 4] 4 is a cross-sectional view taken along line IV-IV in FIG. 3. [Diagram 5] FIG. 13 is a diagram showing a divided structure. [Figure 6] FIG. 13 is a diagram showing a state in which a seal member is attached to the divided structure. [Figure 7] 5A and 5B are schematic diagrams illustrating a state in which a seal member is compressed and deformed. [Figure 8] FIG. 1 is an explanatory diagram of a branch pipe renewal method. [Figure 9] FIG. 1 is an explanatory diagram of a branch pipe renewal method. [Figure 10] FIG. 1 is an explanatory diagram of a branch pipe renewal method. [Figure 11] 13 is a modified example of a branch pipe renewal method according to the present invention. [Figure 12] 13 is a modified example of a branch pipe renewal method according to the present invention. [Figure 13] 13 is a modified example of a branch pipe renewal method according to the present invention. [Figure 14] 13 is a modified example of a branch pipe renewal method according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] 1.Branch pipe repair device The branch pipe repair device according to the present invention is used to repair a branch pipe branched off from a fluid pipe. The branch pipe repair device P of this embodiment will be described below. In this embodiment, the branch pipe repair device P that repairs a branch pipe D branched off from a water main pipe W (an example of a fluid pipe) will be described as an example. However, the branch pipe repair device P is not limited to the following embodiment, and various modifications are possible within the scope of the gist of the invention.

[0022] Fig. 1 is a perspective view of a piping system before a branch pipe repair device P (see Fig. 2) is attached. In Fig. 1, the pipe axis direction X of the branch pipe D is described as the up-down direction, and since water (an example of a fluid) flows from the lower side (the side connected to the water main pipe W) of the branch pipe D to the upper side (the side separated from the water main pipe W), the upstream side and downstream side may be expressed along the water flow direction.

[0023] As shown in Fig. 1, a branch pipe D branching off from the main water pipe W is provided on the outer circumferential surface of the upper side of the main water pipe W through which water flows. The connection between the main water pipe W and the branch pipe D is joined by welding or the like. A disk-shaped first flange portion 11 protruding radially outward is formed on the end (downstream side) of the branch pipe D.

[0024] A gate valve H is connected to the branch pipe D downstream in the pipe axis direction X. As shown in Fig. 1, the gate valve H has a case Va, a ball valve body (not shown) housed in the case Va, and an operating part 13 for opening and closing the ball valve body.

[0025] A disk-shaped second flange portion 12 to which a first flange portion 11 of the branch pipe D is attached is formed protruding in the radially outward direction at the lower end of the case Va. A disk-shaped third flange portion 15 to which a connecting pipe such as an air valve or an operation valve is attached is formed protruding in the radially outward direction at the upper end of the case Va.

[0026] The case Va has a first divided portion V1 having a second flange portion 12 at its lower end, and a second divided portion V2 having a third flange portion 15 at its upper end. The first divided portion V1 and the second divided portion V2 are fastened and fixed by bolts and nuts (not shown).

[0027] The first flange portion 11 of the branch pipe D and the second flange portion 12 formed at the lower end of the first divided portion V1 are connected by a plurality of bolts 42a and nuts 42b. The third flange portion 15 formed at the upper end of the second divided portion V2 is also configured so as to be connectable to the flange portion of the above-mentioned connecting pipe by a plurality of bolts and nuts.

[0028] Here, since the connection between the branch pipe D and the water main pipe W is welded, there is a risk that the connection may be damaged and cause a water leak. In addition, there is a risk that a part of the outer circumferential surface of the aged branch pipe D may be damaged and cause a water leak. The branch pipe repair device P is configured to be able to repair the branch pipe D.

[0029] Fig. 2 shows a front view of the branch pipe repair device P attached to a piping system, and Fig. 3 shows a side view of the branch pipe repair device P attached to a piping system. Fig. 4 shows a cross-sectional view taken along line IV-IV in Fig. 3. The front view in Fig. 2 is shown as a half cross-sectional view.

[0030] As shown in FIG. 2 to FIG. 4, the branch pipe repair device P includes a split structure 2 (one example of an "apparatus body") to which a plurality of split members 2a (two in this embodiment) are connected, a seal member S attached to the split structure 2, and a plurality of band members 31 (one example of a "drawing member") (three in this embodiment) that pull the split structure 2 toward the water main pipe W along the pipe axis direction X. The split structure 2 is split so that the joint surfaces of a pair of split members 2a are along the pipe axis direction X. Here, in this embodiment, the pipe axis direction X of the branch pipe D is perpendicular to the pipe axis direction Y of the water main pipe W. Therefore, the split structure 2 is split along the pipe axis direction Y of the water main pipe W. The branch pipe repair device P is configured to press the second flange portion 12 of the first split portion V1 toward the water main pipe W by connecting the split structure 2 and the second flange portion 12 of the first split portion V1 with the connecting mechanism 6.

[0031] The divided structure 2 includes a base 21 that faces the upper side of the outer circumferential surface of the water main pipe W (the outer surface of the branch pipe D side), and an enclosing portion 22 that is connected to the base 21 and encloses at least a part of the outer circumferential surface of the branch pipe D. The surrounding portion 22 surrounds at least a part of the outer circumferential surface of the branch pipe D including the connection portion between the water main pipe W and the branch pipe D.

[0032] The base 21 includes an arc-shaped portion 21a having an arc surface formed on its bottom surface that conforms to the outer circumferential surface of the water main pipe W, and a pair of bent portions 21b bent from both ends of the arc-shaped portion 21a so as to move away from the water main pipe W. The bent portion 21b is formed with a plurality of insertion holes 21b1 (six in this embodiment) into which end bolts 31a formed on both ends of two band members 31 described later are inserted.

[0033] The surrounding portion 22 has a cylindrical portion 22a that extends from the center of the arc-shaped portion 21a along the pipe axis direction X and faces the outer circumferential surface of the branch pipe D, and a pair of fastening portions 22b that extend along the pipe axis direction X from a portion that straddles the arc-shaped portion 21a and the bent portion 21b and protrude radially outward from both side surfaces of the cylindrical portion 22a. As described above, the divided structure 2 in this embodiment is configured by connecting a pair of divided members 2a, so that each of the pair of fastening portions 22b has a plurality of fastening holes 22b1 (two each in this embodiment) into which the fastening bolts 23a are inserted. The two divided members 2a are fastened and fixed by fastening nuts 23b on the fastening bolts 23a inserted into the fastening holes 22b1.

[0034] The surrounding portion 22 has a flange portion 22c extending from the cylindrical portion 22a to the fastening portion 22b along the pipe axis direction Y of the water main pipe W. The flange portion 22c has a connection hole portion 22c1 to which the connection mechanism 6 is connected, as viewed from above.

[0035] The two split members 2a in the split structure 2 are each formed in the same shape and are fastened to each other while being inverted around the pipe axis direction X. The split structure 2 is thus composed of multiple split members 2a, and has a base portion 21 facing the upper side of the outer circumferential surface of the water main pipe W and an enclosing portion 22 that fits along the outer circumferential surface of the branch pipe D, so that the split structure 2 can be attached from the side of the branch pipe D. This makes it easy to attach the split structure 2 to the water main pipe W and the branch pipe D.

[0036] FIG. 5 shows a plan view, an outer view, a front view, an inner view, and a bottom view of the split structure 2. The outer view and the inner view show only one of the split members 2a. As shown in the inner view of FIG. 5, a linear first seal groove 24 is formed on the joint surface of the split member 2a along the pipe axis direction X of the branch pipe D. In addition, an arc-shaped second seal groove 25 is formed on the upper end of the inner surface of the split member 2a that faces the outer circumferential surface of the branch pipe D. Furthermore, as shown in the bottom view of FIG. 5, an arc-shaped third seal groove 26 is formed on the bottom surface of the cylindrical portion 22a of the split structure 2 that faces the upper side of the outer circumferential surface of the water main pipe W.

[0037] The seal member S is disposed between the base 21 and the water main pipe W to prevent leakage of fluid to the outside of the split structure 2. Fig. 6 shows the seal member S attached to the first seal groove 24, the second seal groove 25, and the third seal groove 26 of the split member 2a. The seal member S includes a first seal member SA and a second seal member SB. The first seal member SA and the second seal member SB are formed by dividing the seal member S along the pipe axis direction Y of the water main pipe W.

[0038] The seal member S is fitted into recesses formed in the dividing surface of the surrounding portion 22 and the opposing surface of the base portion 21 facing the water main pipe W. The recesses formed in the dividing surface of the surrounding portion 22 correspond to the first seal groove 24 and the second seal groove 25 described above. Moreover, the recesses formed in the opposing surface of the base portion 21 facing the water main pipe W correspond to the third seal groove 26 described above.

[0039] As shown in Fig. 6, a linear first seal portion S1 protruding from the joint surface of the divided member 2a is attached to the first seal groove 24. An arc-shaped second seal portion S2 that is in close contact with the outer circumferential surface of the branch pipe D is attached to the second seal groove 25 by connecting the pair of divided members 2a. An arc-shaped third seal portion S3 that faces the upper side of the outer circumferential surface of the water main pipe W is attached to the third seal groove 26. The first seal portion S1, the second seal portion S2, and the third seal portion S3 of the first seal member SA are integrally formed. The first seal portion S1, the second seal portion S2, and the third seal portion S3 of the second seal member SB are also integrally formed.

[0040] The third seal portion S3 has a pair of abutment portions SCA and a groove portion SCB. As described above, the seal member S is divided into the first seal member SA and the second seal member SB along the pipe axis direction Y of the water main pipe W. Therefore, the first seal member SA and the second seal member SB are each provided with a pair of abutment portions SCA and groove portion SCB. The abutment portion SCA is provided in an annular shape so as to be in continuous abutment with the outer surface of the water main pipe W. That is, the abutment portion SCA is formed in a continuous annular shape without having a cut portion in the circumferential direction in the first seal member SA and the second seal member SB. The groove portion SCB is formed in an annular shape retracting from the abutment portion SCA. Retracting means retracting in a direction away from the outer surface of the water main pipe W (upward). Therefore, the groove portion SCB is formed in the first seal member SA and the second seal member SB so as to recede in a direction away from the outer surface of the water main pipe W (upward) without having any cut portion in the circumferential direction.

[0041] The abutment portion SCA of the first seal member SA and the abutment portion SCA of the second seal member SB are configured to be in close contact with each other at the pipe top WA of the water main pipe W (see also Figs. 2 and 4). The pipe top WA of the water main pipe W corresponds to the uppermost portion of the outer surface of the water main pipe W when the water main pipe W is installed so that the pipe axis direction X of the branch pipe D is along the vertical direction. As a result, the abutment surfaces where the first seal member SA and the second seal member SB come into contact with each other do not come into close contact with each other at a portion located below the pipe top WA along the outer surface of the water main pipe W, so that the first seal member SA and the second seal member SB can be reliably brought into close contact with each other regardless of the outer shape of the branch pipe D. At this time, since the seal member S has an annular abutment portion SCA and an annular groove portion SCB that is recessed from the abutment portion SCA, the abutment portion SCA protrudes into the inside of the groove portion SCB of the groove portion, improving the sealing function. Therefore, it is possible to prevent water leakage between the divided structure 2 and the water main pipe W.

[0042] In this way, because the split structure 2 is fitted with the sealing member S that prevents water from leaking out of the split structure 2, there is no need to fill the inside of the split structure 2 with mortar, and the repair period can be shortened. In addition, the split structure 2 is made compact, and the sealing area on the water main pipe W side is configured as the third sealing portion S3, which is minimized as shown in Fig. 6, so the split structure 2 can be used even if the outer diameter of the water main pipe W side is different. Furthermore, by increasing the volume of the third sealing portion S3, it can be fitted closely to the outer peripheral surface of the water main pipe W having various curvatures, so it can be used for water main pipes W having various curvatures.

[0043] Furthermore, the first seal groove 24 of this embodiment has a predetermined gap E in the radially inward direction before the pair of divided members 2a are connected (see FIG. 6). Also, the third seal groove 26 of this embodiment has a predetermined gap F in the radially inward direction along the circumferential direction relative to the third seal portion S3 before the pair of divided members 2a are connected (see FIG. 6).

[0044] As shown in Fig. 7, by connecting a pair of divided members 2a, the first seal portion S1 protruding from the joint surface of the divided members 2a is compressed and moves (expands) to fill the radially inward gap E against the water pressure. In this way, since the first seal groove 24 has the gap E in the radially inward direction to which the water pressure is applied, the first seal portion S1 is supported by the end face on the radially outward side of the first seal groove 24, and the amount of compressive deformation of the first seal portion S1 is concentrated in the radially inward direction. Therefore, the first seal portion S1 is evenly compressed and deformed, and the first seal portion S1 does not irregularly protrude toward the water main pipe W, preventing the inconvenience of water leakage from between the water main pipe W and the base 21.

[0045] Returning to FIG. 2-FIG. 4, the band members 31 are fixed to the pair of bent portions 21b and are provided along the outer circumferential surface of the water main pipe W. In this embodiment, the band members 31 each have a pair of end bolts 31a, which are male threads fixed to the insertion holes 21b1 formed in the bent portions 21b of the divided member 2a by nuts 31b at both ends, and a U-shaped portion 31c formed integrally with the end bolts 31a in a U-shape. The end bolts 31a and the U-shaped portion 31c are integrally formed of a metal material such as stainless steel, and the U-shaped portion 31c is covered with an insulating material (resin, etc.). The U-shaped portion 31c does not need to be covered with an insulating material, and the U-shaped portion 31c may be made of a belt or fiber material different from the end bolts 31a, and the U-shaped portion 31c and the end bolts 31a may be connected with hooks or the like.

[0046] The band member 31 is fixed to the split structure 2 and the water main pipe W by tightening the bolts 31a at both ends with nuts 31b at both ends, and draws the bent portion 21b of the split member 2a arranged symmetrically with respect to the pipe axis direction Y of the water main pipe W toward the water main pipe W. As a result, the split structure 2 in which the multiple split members 2a are connected is drawn toward the water main pipe W along the pipe axis direction X of the branch pipe D. As a result, the third seal portion S3 attached to the third seal groove 26 of each split member 2a is compressed so as to be in close contact with the upper side of the outer circumferential surface of the water main pipe W, and moves (swells) to fill the gap F in the radial direction against the water pressure (see FIG. 6). As a result, the third seal portion S3 does not deform irregularly, and water leakage from between the water main pipe W and the base 21 can be prevented. At this time, the band member 31 draws the split structure 2 toward the water main pipe W along the pipe axis direction X of the branch pipe D, so that the attitude of the split structure 2 is stable and the sealing function of the seal member S can be properly maintained.

[0047] 2 to 4, after the band member 31 has pulled the split structure 2 toward the water main pipe W, the connecting mechanism 6 connects the gate valve H connected to the branch pipe D to the split structure 2, and pulls the branch pipe D and the gate valve H toward the split structure 2. In other words, the connecting mechanism 6 connects the split structure 2 and the second flange portion 12 via multiple connecting members 60 (four in this embodiment), and applies a force in a direction that brings the split structure 2 and the second flange portion 12 closer to each other, thereby pressing the second flange portion 12 toward the water main pipe W. The connecting member 60 has a connecting bolt 60A that is inserted through the first flange portion 11 into the second flange portion 12 and the connecting hole portion 22c1 of the flange portion 22c formed in the surrounding portion 22 of the split structure 2, a connecting nut 60B that screws into the connecting bolt 60A from the connecting hole portion 22c1 side, and a connecting nut 60C that screws into the connecting bolt 60A from the second flange portion 12 side.

[0048] By screwing the connecting bolt 60A and the connecting nut 60B and the connecting nut 60C together, the second flange portion 12 approaches the side of the split structure 2 that is pulled and fixed to the side of the water main pipe W, and the second flange portion 12 is pressed against the water main pipe W. As a result, the branch pipe D is pressed against the water main pipe W, and it is possible to prevent the branch pipe D from being broken and coming off the water main pipe W due to water pressure.

[0049] The connecting mechanism 6 further includes a plurality of (four in this embodiment) spacing maintaining members 9 that maintain a constant distance between the second flange portion 12 and the split structure 2. In this embodiment, the plurality of spacing maintaining members 9 are configured with hollow cylindrical members made of an elastic material (such as resin or rubber) that are individually attached to the outer periphery of the male threaded portion of each connecting bolt 60A.

[0050] Next, a method of mounting the branch pipe repair device P will be described with reference to Figures 2 to 4. First, a pair of divided members 2a are arranged from the side of the branch pipe D in contact with the outer circumferential surface of the branch pipe D and the upper side of the outer circumferential surface of the water main pipe W, and the pair of divided members 2a are fastened and fixed by the fastening bolts 23a and fastening nuts 23b. As a result, the joint surfaces of the divided members 2a are sealed by the first seal parts S1, and the inner surfaces of the divided members 2a and the outer circumferential surface of the branch pipe D are sealed by the second seal parts S2. Next, with the U-shaped parts 31c of the three band members 31 aligned along the outer circumferential surface of the water main pipe W, the two end bolts 31a are inserted into the insertion holes 21b1 of the bent parts 21b of the divided members 2a, and the two end nuts 31b are screwed onto the two end bolts 31a and fastened. As a result, the split structure 2 is pulled toward the water main pipe W along the pipe axis direction X of the branch pipe D by the band member 31, and the third seal portion S3 comes into close contact with the upper side of the outer circumferential surface of the water main pipe W. This prevents water from leaking out of the split structure 2.

[0051] Next, each of the multiple connecting bolts 60A is inserted into the connecting hole 22c1 of the flange 22c formed in the surrounding portion 22 of the split structure 2 through the first flange 11 from the second flange 12 side. Then, the connecting bolt 60A is tightened with the connecting nut 60C from the second flange 12 side, and the connecting bolt 60A is tightened with the connecting nut 60B from the connecting hole 22c1 side, and the second flange 12 is pulled toward the split structure 2 side. This presses the water main W side along the pipe axis direction X, preventing the branch pipe D from slipping out. Moreover, the joint surface between the first flange 11 and the second flange 12 of the branch pipe D is also reinforced. In this manner, the branch pipe repair device P is attached.

[0052] 2. Branch pipe renewal method Next, a branch pipe renewal method will be described with reference to Figures 8 to 10. The branch pipe renewal method described below is capable of renewing a branch pipe D with one end connected to a water main pipe W and the other end connected to a gate valve H. This branch pipe renewal method makes it possible to renew a branch pipe D that has a leak at the connection point with the water main pipe W while maintaining the flow of fluid in the water main pipe W. Note that a gate valve H is fastened and fixed to the downstream side of the branch pipe D by a bolt 42a and a nut 42b.

[0053] 8, a blocking device 70 is connected to the gate valve H. The blocking device 70 includes a connecting flange portion 71, a cylindrical support 72, a blocking portion 73, and an operating tool 74 for operating the blocking portion 73.

[0054] The connecting flange portion 71 is provided at the lower end of the blocking device 70, and is fastened and fixed to the third flange portion 15 of the gate valve H by bolts 75a and nuts 75b. The support pillar 72 is provided so as to extend from the connecting flange portion 71 along the pipe axis direction X of the branch pipe D. The blocking portion 73 is provided inside the support pillar 72, and configured so as to be able to block the flow path of the branch pipe D. The operating tool 74 is configured so as to be able to enter the blocking portion 73 into the branch pipe D via the gate valve H along the pipe axis direction X.

[0055] Next, the gate valve H is opened, and the blocking portion 73 is inserted into the branch pipe D using an operating tool 74 through the open gate valve H. The blocking portion 73 is then expanded in diameter and blocked (see #02 in FIG. 8). The process of connecting the blocking device 70 to such a gate valve H and blocking the flow path in the branch pipe D with the blocking portion 73 is referred to as the blocking step in the branch pipe renewal method.

[0056] After the flow path in the branch pipe D is blocked by the blocking portion 73, the support 72 and the gate valve H are removed from the connection portion of the branch pipe D while leaving the blocking portion 73 in the branch pipe D. In this embodiment, the connection portion of the branch pipe D is the first flange portion 11 of the branch pipe D. The state in which the gate valve H has been removed in this manner is shown in #02 of FIG. 8. The process of removing the gate valve H in this manner is referred to as the gate valve removal step in the branch pipe renewal method.

[0057] Next, as shown in #03 in Fig. 8, a short pipe 81 is connected to the connecting portion of the branch pipe D. The short pipe 81 is formed in a cylindrical shape so that its inside extends linearly, and has a flange portion 81A at its lower end that can be connected to the first flange portion 11, and a flange portion 81B at its upper end that can be connected to a new gate valve H described below. With the blocking device 70 inserted inside the cylindrical interior, the short pipe 81 is connected (fastened and fixed) to the first flange portion 11 of the branch pipe D via the flange portion 81A with bolts 86a and nuts 86b. The process of connecting such a short pipe 81 is referred to as a connecting step in the branch pipe renewal method.

[0058] In this state, the protective pipe 82 is attached as shown in #04 of FIG. 9. The protective pipe 82 is attached so as to cover the outside of the short pipe 81 and the branch pipe D. The protective pipe 82 includes a cylindrical portion 82A, an arc-shaped portion 82B, and a bent portion 82C. The cylindrical portion 82A is formed of a cylindrical body with an inner diameter corresponding to the outer diameter of the flange portion 81A of the short pipe 81. The arc-shaped portion 82B is connected to the lower end of the cylindrical portion 82A and is configured to fit along the surface of the water main pipe W. The bent portion 82C is bent from both ends of the arc-shaped portion 82B so as to be spaced apart from the water main pipe W. The protective pipe 82 is attached in a sealed state across the short pipe 81 and the water main pipe W.

[0059] Furthermore, the protective pipe 82 attached in a sealed state is pulled toward the water main pipe W along the pipe axis direction X of the branch pipe D by the band member 31. The process of attaching such a protective pipe 82 and pulling it toward the water main pipe W is called a pulling step in the branch pipe renewal method.

[0060] Next, mortar is filled between the protective pipe 82 and the branch pipe D (#05 in FIG. 9). This makes it possible to reinforce the connection between the branch pipe D and the water main pipe W. This process of filling with mortar is called a filling step in the branch pipe renewal method. It is not necessary to fill the space between the protective pipe 82 and the branch pipe D with mortar.

[0061] Next, as shown in #06 in FIG. 9, a gate valve H is connected to the connecting portion of the short pipe 81 on the opposite side to the branch pipe D. The connecting portion of the short pipe 81 on the opposite side to the branch pipe D is the flange portion 81B of the short pipe 81. The gate valve H is a new one that is different from the gate valve H that was originally installed. Note that the gate valve H may be the gate valve H that was originally installed.

[0062] Thereafter, a blocking device 70 is connected to the upper part of the gate valve H, and the blocking portion 73 is removed through the gate valve H that is in an open state, and the gate valve H is closed. Such a process of removing the blocking portion 73 is called a blocking portion removal step in the branch pipe renewal method.

[0063] Next, as shown in #07 of Fig. 10, the blocking device 70 is removed. Such a process of removing the blocking device 70 is called a blocking device removing step in the branch pipe renewal method.

[0064] Furthermore, as shown in #08 of Fig. 10, a flange retaining cover 83 is provided to cover the flange portion 81B. The process of providing such a flange retaining cover 83 is called a cover mounting step in the branch pipe renewal method. In this manner, the branch pipe D can be renewed.

[0065] 11 to 14 show modified examples of the renewal of the branch pipe D by the branch pipe renewal method. In the example of FIG. 11, the protective pipe 82 is pulled toward the water main pipe W along the pipe axis direction X of the branch pipe D by the band member 31, but the short pipe 81 is not connected to the first flange portion 11. In this example, a flange portion 82d is integrally formed at the downstream end of the protective pipe 82. A water stop flange 85 is provided on this flange portion 82d, and a gate valve H is connected to this water stop flange 85. A seal member 85d is provided on the upstream end face of the water stop flange 85 to prevent water leakage between the second flange portion 12 and the gate valve H. The second flange portion 12 of the gate valve H is fastened and fixed to the flange portion 82d of the protective pipe 82 by the bolt 84 via the water stop flange 85. In this way, in this example, the branch pipe D is renewed by covering the branch pipe D with the protective pipe 82.

[0066] Also, as shown in FIG. 12, it is possible to renew the gasket without providing the water-stop flange 85 in the example shown in FIG. 11. In this case, as shown in FIG. 12, the second flange portion 12 of the gate valve H is fastened and fixed by a bolt 84 to a flange portion 82d formed integrally with the downstream end of the protective pipe 82. In this way, even if the water-stop flange 85 is not provided, the branch pipe D can be renewed by covering the branch pipe D with the protective pipe 82. In this example, a gap G is provided between the upstream end face of the flange portion 82d of the protective pipe 82 and the downstream end face of the first flange portion 11 of the branch pipe D. This gap G can be used as an adjustment margin when the gasket is compressed by tightening the both end bolts 31a with the both end nuts 31b when the protective pipe 82 is pulled to the water main pipe W by the band member 31.

[0067] 13, the protective pipe 82 can be configured without being fastened to the gate valve H by the bolts 84. In this case, the protective pipe 82 may have a convex portion 82e protruding in the circumferential direction on the outer peripheral surface instead of the flange portion 82d. A short pipe 81 with a gate valve H connected and fixed on the downstream side is placed on the first flange portion 11, and a seal member 81d is provided between the inner peripheral surface of the protective pipe 82 and the outer peripheral surface of the short pipe 81. Furthermore, a flange holding cover 83 having an annular groove portion 83a in which the convex portion 82e can move along the pipe axis direction X is provided. The flange holding cover 83 is divided into two along the pipe axis direction X, and the two flange holding covers 83 are fastened and fixed by bolts 83c and nuts 83d with their holes 83b aligned with each other. The downstream radial protrusion 83e of the flange retaining cover 83 is provided so as to abut from the downstream side against a predetermined axial surface 81f whose position in the pipe axis direction X coincides with the downstream end face of the protective pipe 82 in the short pipe 81. The upstream radial protrusion 83f of the flange retaining cover 83 is provided so as to be able to abut when the branch pipe D breaks from the water main pipe W due to corrosion or the like and the protrusion 82e moves along the pipe axis direction X. At this time, by setting the length L1 of the axial surface 81f and the seal member 81d along the pipe axis direction X to be longer than the length L2 between the downstream surface of the protrusion 82e and the upstream surface of the radial protrusion 83f in a state in which the downstream end face of the protective pipe 82 in the short pipe 81 coincides with the position in the pipe axis direction X, the seal member 81d can prevent water leakage between the protective pipe 82 and the short pipe 81 even when the protrusion 82e moves along the pipe axis direction X within the groove portion 83a. In addition, the length L2 can be used as an adjustment margin for tightening the both end bolts 31a with the both end nuts 31b when the band member 31 is used to pull the protective pipe 82 to the water main pipe W.

[0068] Furthermore, as shown in Fig. 14, it is also possible to replace the short pipe 81 in the example of Fig. 13 with a water stop flange 85, and fasten the gate valve H to the first flange portion 11 with a bolt 89a and a nut 89b with the water stop flange 85 interposed therebetween. In this case, as shown in Fig. 14, it is preferable to provide a water stop washer 89c between the bolt 89a and the first flange portion 11, and a water stop ring 89d between the first flange portion 11 and the water stop flange 85. In this case, by configuring in the same manner as in Fig. 13, the gap L3 between the downstream surface of the convex portion 82e and the upstream surface of the radial convex portion 83f can be used as an adjustment margin for tightening the both end bolts 31a with the both end nuts 31b when the band member 31 draws the protective pipe 82 to the water main pipe W.

[0069] 3. Other embodiments Other embodiments of the branch pipe repair device P will be described below.

[0070] In the above embodiment, the water main pipe W is taken as an example of a fluid pipe, but the fluid pipe does not have to be a water main pipe W as long as the fluid pipe is a pipe through which the fluid flows.

[0071] In the above embodiment, the split structure 2 is described as being split along the pipe axis direction Y of the water main pipe W, but the split structure 2 may also be split along a direction intersecting the pipe axis direction Y of the water main pipe W.

[0072] In the above embodiment, the base 21 includes the arc-shaped portion 21a having an arc surface formed on the bottom surface thereof that conforms to the outer circumferential surface of the water main pipe W, and a pair of bent portions 21b bent from both ends of the arc-shaped portion 21a so as to move away from the water main pipe W, and the band member 31 is fixed to the pair of bent portions 21b and formed to conform to the outer circumferential surface of the water main pipe W. However, it is also possible to fix the band member 31 to a portion of the split structure 2 other than the pair of bent portions 21b. It is also possible to configure the split structure 2 to be pulled toward the water main pipe W without using the band member 31.

[0073] In the above embodiment, the seal member S is described as being fitted into the recesses (first seal groove 24, second seal groove 25, third seal groove 26) formed on the dividing surface of the surrounding portion 22 and the opposing surface of the base portion 21 that faces the water main pipe W. However, it is also possible to configure the divided structure 2 without providing any recesses. In this case, the seal member S can be configured to be sandwiched by the divided structures 2.

[0074] In the above embodiment, the branch pipe repair device P has been described as including the connecting mechanism 6 that connects the gate valve H connected to the branch pipe D to the split structure 2 after the band member 31 has pulled the split structure 2 toward the water main pipe W, and pulls the branch pipe D and the gate valve H toward the split structure 2. However, the branch pipe repair device P can also be configured without including the connecting mechanism 6. [Industrial Applicability]

[0075] INDUSTRIAL APPLICABILITY The present invention can be used in a branch pipe repair device that repairs a branch pipe branched off from a fluid pipe, and in a branch pipe renewal method that renews such a branch pipe. [Explanation of symbols]

[0076] 2: Split structure (device body) 6:Connection mechanism 21: Base 21a: Arc-shaped part 21b: Bent part 22: Encirclement 24: First seal groove (recess) 25: Second seal groove (recess) 26: 3rd seal groove (recess) 31: Band member, pulling member 70: Occlusion device 73: Occlusion 81: Short tube 82: Protection tube D: Branch pipe H: Gate valve P: Branch pipe repair device S: Sealing material SA: First seal member SB: Second seal member SCA: Contact area SCB:Groove X: Tube axis direction Y: Tube axis direction W: Water main (fluid pipe) WA: Tube top

Claims

1. A branch pipe repair device for repairing a branch pipe branched off from a fluid pipe, comprising: an apparatus main body including a base portion facing an outer surface of the branch pipe side of the fluid pipe, and an enclosing portion connected to the base portion and enclosing at least a part of an outer circumferential surface of the branch pipe; a seal member disposed between the base and the fluid pipe to prevent leakage of fluid to the outside of the device body; a clamping member that is fixed to the device body and the fluid pipe and that draws the device body toward the fluid pipe along a pipe axis of the branch pipe, the seal member has an annular abutment portion that is in continuous contact with the outer surface of the fluid pipe, and an annular groove portion that is recessed from the abutment portion, and includes a first seal member and a second seal member that are divided along a pipe axis direction of the fluid pipe, A branch pipe repair device, wherein the abutment portion of the first seal member and the abutment portion of the second seal member are in close contact with each other at the pipe top of the fluid pipe.

2. The branch pipe repair device according to claim 1 , wherein the device body is divided along an axial direction of the fluid pipe.

3. the base portion includes an arc-shaped portion having a bottom surface formed with an arc surface that conforms to an outer circumferential surface of the fluid pipe, and a pair of bent portions bent from both ends of the arc-shaped portion so as to be spaced apart from the fluid pipe, 3. The branch pipe repair device according to claim 1, wherein the clamping member is formed of a plurality of band members fixed to the pair of bent portions and extending along an outer circumferential surface of the fluid pipe.

4. 3. The branch pipe repair device according to claim 2, wherein the seal member is fitted into recesses formed on a dividing surface of the surrounding portion and an opposing surface of the base portion facing the fluid pipe.

5. A branch pipe repair device as described in claim 1 or 2, further comprising a connecting mechanism that connects a gate valve connected to the branch pipe to the device main body after the clamping member has drawn the device main body toward the fluid pipe, and draws the branch pipe and the gate valve toward the device main body.

6. A branch pipe renewal method for renewing a branch pipe having one end connected to a fluid pipe and the other end connected to a gate valve, comprising the steps of: a closing step of connecting a closing device having a closing part capable of closing a flow path of the branch pipe to the gate valve and expanding and closing the closing part inserted through the gate valve in an open state; a gate valve removing step of removing the gate valve from the connection portion of the branch pipe while leaving the obstruction portion in the branch pipe; a connecting step of connecting a short pipe to the connecting portion of the branch pipe; a clamping step of attaching a protective tube covering an outside of the short tube and the branch tube in a sealed state around the short tube and the fluid tube, and drawing the protective tube toward the fluid tube along a tube axis direction of the branch tube by a clamping member; an obstruction portion removing step of connecting the gate valve to a connecting portion of the short pipe opposite to the branch pipe, and then removing the obstruction portion through the gate valve in an open state; A branch pipe renewal method comprising:

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