Sealing structure for fluid pipes and method of installation thereof

Abstract

To provide a sealing structure for a fluid pipe and a method for installing the same that can reliably prevent fluid from entering between the main pipe section and the inner pipe section that constitute the fluid pipe. [Solution] A case body 30, which serves as a connecting member, is attached to the metal pipe 2. The case body 30 consists of a metal pipe 2, which is the main pipe section, and a rehabilitation pipe 4, which is an inner pipe section provided along the inner circumferential surface of the metal pipe 2, and has a communication section 31C that communicates with a hole 4c formed in the rehabilitation pipe 4. A gibolt packing 37, which serves as a sealing member, is disposed between the inner surface 36a of the flange 36 of the case body 30 and the outer circumferential surface 4f of the rehabilitation pipe 4.

Description

Technical Field

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[0001] The present invention relates to a sealing structure of a fluid pipe composed of a main pipe portion and an inner pipe portion provided along the inner peripheral surface of the main pipe portion, and an installation method thereof.

Background Art

[0002] Conventionally, an inner pipe portion is disposed along the inner peripheral surface of a main pipe portion which is an existing fluid pipe, and at a connection portion such as an air valve or a fire hydrant branched in the main pipe portion, a sealing member is disposed around a hole formed in the inner pipe portion, thereby preventing fluid from entering between the peripheral surfaces of the main pipe portion and the inner pipe portion (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, since the sealing member abuts on the inner surface of an existing main pipe portion whose structural strength has decreased or whose shape has changed due to aging deterioration or the like, the sealing function cannot be sufficiently exerted at this abutting portion, and there is a problem that fluid may enter between the peripheral surfaces of such a main pipe portion and the inner pipe portion.

[0005] The present invention has been made paying attention to such problems, and an object thereof is to provide a sealing structure of a fluid pipe capable of surely preventing the intrusion of fluid between a main pipe portion and an inner pipe portion constituting the fluid pipe, and an installation method thereof.

Means for Solving the Problems

[0006] In order to solve the above problems, the sealing structure of the fluid pipe of the present invention is A sealing structure for a fluid tube comprising a main tube and an inner tube provided along the inner circumferential surface of the main tube, A connecting member having a communication portion that communicates with a hole formed in the inner pipe portion is attached to the main pipe portion, and a sealing member is disposed between the inner surface of the connecting member and the outer surface of the inner pipe portion. According to this feature, since the sealing member is positioned between the inner surface of the connecting member supported by the main pipe and the outer surface of the inner pipe provided along the main pipe, the sealing member does not strongly press against the main pipe, allowing the sealing function to be performed stably and sufficiently, and reliably preventing fluid from entering the space between the circumferential surfaces of the main pipe and the inner pipe.

[0007] The connecting member is characterized by being attached to the outer surface of the main pipe portion in the circumferential direction. This feature allows the connecting member to be supported using the entire circumference of the main pipe.

[0008] The aforementioned connecting member is characterized by having a segmented structure. This feature makes it easy to attach connecting components to the main pipe.

[0009] The connecting member is characterized by being installed in the existing connecting section of the main pipe. This feature allows for the construction of a sealed fluid pipe structure using existing connecting sections.

[0010] The sealing member is characterized by being configured in an annular shape so as to surround the hole in the inner tube. This feature allows for minimizing the shape of the sealing component while achieving the desired sealing function.

[0011] The outer surface of the inner tube portion on which the sealing member is disposed is characterized in that it is formed on an outer diameter side of the hole portion of the inner tube portion and on an inner diameter side of the communication portion of the connecting member. This feature allows for easy installation of the sealing member, as it is placed on the outer surface of the inner tube portion that is exposed to the outside.

[0012] The method for installing the sealing structure of a fluid pipe according to the present invention is: A method for installing a sealing structure for a fluid pipe, comprising a main pipe section and an inner pipe section provided along the inner circumferential surface of the main pipe section, The process involves arranging the inner pipe section along the pipeline on the inner circumferential surface of the existing main pipe section, The process of forming a hole in the inner tube portion, A step of attaching a connecting member having a communication portion that communicates with the hole portion of the inner pipe portion to the main pipe portion, The present invention is characterized by comprising at least the step of arranging a sealing member between the inner surface of the connecting member and the outer surface of the inner tube portion. According to this feature, since the sealing member is positioned between the inner surface of the connecting member supported by the main pipe and the outer surface of the inner pipe provided along the main pipe, the sealing member does not strongly press against the main pipe, allowing the sealing function to be performed stably and sufficiently, and reliably preventing fluid from entering the space between the circumferential surfaces of the main pipe and the inner pipe.

[0013] The present invention further comprises the step of drilling a hole in the pipe wall surrounding the existing connecting portion of the main pipe to form a perforated portion that communicates with the hole in the inner pipe. This feature allows for the formation of fluid pipe connections at the same suitable locations as existing connections in the main pipe section.

[0014] The present invention further comprises the step of perforating the straight section of the main pipe in the direction of the pipe axis to form a perforated section that communicates with the hole in the inner pipe. This feature allows for a high degree of freedom in drilling holes at any point in the main pipe section to form a connection point for the fluid pipe.

[0015] The present invention is further characterized by having a step of connecting a drilling means to the communication portion of the connecting member. This feature allows for the creation of holes in the inner tube through the connecting portion of the connecting member.

[0016] The present invention is further characterized by having the step of arranging a straightening jig inside the aforementioned communication section. According to this feature, when arranging the inner pipe part, it is possible to prevent the pipe wall of the inner pipe part from bulging into the communication part on the outer diameter side.

Brief Description of the Drawings

[0017] [Figure 1] It is a partially broken front view showing a state where a repair valve and an air valve are connected to a communication pipe communicating with an existing metal pipe in an embodiment of the present invention. [Figure 2] It is a partially broken front view showing a state where the periphery of a communication pipe communicating with an existing metal pipe is covered by a case body. [Figure 3] It is a partially broken front view showing a state where the periphery of a communication pipe communicating with an existing metal pipe is being drilled by a drilling device. [Figure 4] It is a cross-sectional view showing a state of forming a rehabilitation pipe along the inner peripheral surface of an existing metal pipe. [Figure 5] (a) is a plan view showing a case body, (b) is a cross-sectional view taken along line A-A of (a), and (c) is a bottom view showing the case body. [Figure 6] (a) is a plan view showing a case cover, and (b) is a side view showing the case cover. [Figure 7] (a) is a plan view showing a branch part packing, and (b) is a cross-sectional view taken along line B-B of (a). [Figure 8] It is a partially broken front view showing a sealing structure of a fluid pipe during a hydraulic pressure test as an embodiment of the present invention. [Figure 9] It is a cross-sectional view showing a sealing structure of a fluid pipe during a hydraulic pressure test as an embodiment of the present invention. [Figure 10] It is a partially broken front view showing a state of forming a hole in a rehabilitation pipe. [Figure 11] It is a partially broken front view showing a state where a repair valve and an air valve are hermetically connected to a newly established communication part. [Figure 12] It is a partially broken front view for explaining a sealing structure of a fluid pipe and an installation method thereof as Modification 1 of the present invention. [Figure 13] It is a partially broken front view for explaining a sealing structure of a fluid pipe and an installation method thereof as Modification 2 of the present invention. [Figure 14] (a) is a plan view showing the connecting pipe to be attached to the case body of Modified Example 2, (b) is a cross-sectional view of (a), and (c) is a bottom view. [Figure 15] This is a partially broken front view showing the sealing structure of the fluid pipe during a hydrostatic test in Modification 2. [Figure 16] This is a cross-sectional view showing the sealing structure of the fluid pipe during a hydrostatic test in the modified example 2. [Figure 17] This is a partially broken front view showing the state in which a hole is formed in the rehabilitation pipe of modified example 2. [Figure 18] This is a partially broken front view showing the repair valve and air valve sealed together in the newly installed communication section of Modification 2. [Figure 19] This is a cross-sectional view showing a state in which a connecting pipe is assembled to the upper flange of a fluid pipe, as a third modification of the present invention. [Figure 20] This is a partially broken front view showing the sealing structure of the fluid pipe during a hydrostatic test in Modification 3. [Figure 21] This is a cross-sectional view showing the rehabilitation pipe of modified example 3 with a hole formed in it. [Figure 22] This is a partially cutaway front view showing the newly installed communication section of Modification 3 with the repair valve and air valve connected in a sealed manner. [Modes for carrying out the invention]

[0018] Embodiments for implementing the fluid tube sealing structure according to the present invention will be described below based on examples. [Examples]

[0019] A sealing structure for a fluid pipe and its installation method according to an embodiment of the present invention will be described with reference to Figures 1 to 11. In the following description, the front side of Figure 1 will be referred to as the front of the main pipe and connecting section, the back side as the rear, the left side as the leftward direction, and the right side as the rightward direction.

[0020] In order to prevent corrosion in existing metal main pipes, repair partial damage to restore the functionality of the pipeline, and improve its service life, rehabilitation pipes are sometimes installed along the inner circumference of the main pipe. Furthermore, in locations where connecting pipes (connecting sections) for branching and connecting air valves, bypass pipes, etc., are provided in the main pipe, holes are formed in the rehabilitation pipe in the portion corresponding to the connecting pipe to connect the rehabilitation pipe and the connecting pipe. However, there is a risk that fluid may enter between the main pipe and the rehabilitation pipe at the connecting section, and that the fluid may spread to the beginning and end of the rehabilitation pipe, potentially causing widespread rust and corrosion.

[0021] The sealing structure for a fluid pipe and its installation method in this embodiment can seal the space between the main pipe and the rehabilitated pipe. It is particularly applicable when the existing connecting pipe (connecting section) is in poor condition due to rust, corrosion, etc., and cannot be used as is after pipe rehabilitation. This sealing structure and installation method are for installing a new connecting pipe in the location where the existing connecting pipe has been removed. In the installation method of the sealing structure for a fluid pipe in this embodiment, the water supply should be cut off (flow cut off) in the section of the existing flow path that includes at least the location where the sealing structure for the fluid pipe is to be installed.

[0022] As shown in Figure 1, the metal pipe 2 extending in the left-right direction constitutes the main pipe section that forms an existing flow path as a water supply pipe. A branch port 2a is formed at a predetermined location in the axial direction of the metal pipe 2, and the lower end of a connecting pipe 3a that extends vertically and branches upward from the metal pipe 2 is connected and fixed in a sealed state by welding around the branch port 2a. The existing connecting section 3 (hereinafter sometimes simply referred to as connecting section 3) is formed as the part including the connection between the metal pipe 2 and the base end of the connecting pipe 3a and the circumferential surface of the connecting pipe 3a.

[0023] An upper flange 3b is formed to protrude outward from the upper end of the connecting pipe 3a, and a repair valve 11 is connected above the connecting pipe 3a in a sealed state by flange connection. Furthermore, an air valve 12 is connected above the repair valve 11 in a sealed state by flange connection for the purpose of discharging air from inside the pipe to the outside or preventing negative pressure inside the pipe.

[0024] [Installation method for sealing structures in fluid pipes] To explain the installation method of the fluid pipe sealing structure, first, as shown in Figure 2, the existing repair valve 11 and air valve 12 are removed from the upper end of the connecting pipe 3a, and the perforation flange cover 13 is connected to the upper flange 3b of the connecting pipe 3a to close the opening at the upper end of the connecting pipe 3a and prevent foreign matter from entering the metal pipe 2.

[0025] Next, the connecting section 3 and the perforation flange cover 13 are surrounded by a steel work case body 60. The work case body 60 mainly consists of a work case main body 61 that is attached to cover the upper part of the metal pipe 2 and the connecting pipe 3a, a work case cover 62 that is attached to cover the lower part of the metal pipe 2, and bolts 63a and nuts 63b as fastening means for fastening the work case main body 61 and the work case cover 62.

[0026] The work case body 61 mainly consists of a semi-cylindrical base portion 61A that covers the outer circumferential surface of the metal pipe 2 on the side of the connecting pipe 3a, and a cylindrical connecting pipe 61B whose lower end is welded to the periphery of the connecting hole 64 formed in the base portion 61A, and which is large enough to surround the connecting portion 3 and the perforation flange cover 13. The connecting portion 61C is formed by the connection portion between the base portion 61A and the base end of the connecting pipe 61B, as well as the circumferential surface of the connecting pipe 61B.

[0027] At both the front and rear ends of the base 61A, protruding seats 61c are provided, each having multiple through-holes (not shown) through which bolts 63a can be inserted, and these seats extend in the direction of the pipe axis of the metal pipe 2. A packing 69 is attached to the periphery of the communication hole 64 on the inner surface of the base 61A. Furthermore, the inner diameter of the communication pipe 61B is larger than the outer diameter of the upper flange 3b of the communication pipe 3a, creating a gap between the communication pipe 61B and the upper flange 3b through which a cutter 72 (see Figure 3), described later, can be inserted.

[0028] The work case cover 62 is mainly composed of a semi-cylindrical base 62A that covers the outer surface of the metal pipe 2 opposite to the connecting pipe 3a. On the front and rear sides of the base 62A, there are protruding seats 62c, each having multiple through holes (not shown) through which bolts 63a can be inserted, which extend in the direction of the pipe axis of the metal pipe 2.

[0029] The work case body 60 is positioned to cover the upper part of the metal pipe 2, the connecting section 3, and the perforation flange cover 13, while the work case cover 62 is positioned to cover the lower part of the metal pipe 2. Bolts 63a attached from below are inserted into the insertion holes (not shown) of the protruding seat 62c of the work case cover 62, and these bolts are inserted into the insertion holes (not shown) of the protruding seat 62c of the work case body 61. Nuts 63b are screwed onto the bolts 63a protruding above the protruding seat 61c to fasten them, thereby surrounding the connecting section 3 and the perforation flange cover 13 with the work case body 60. The work case cover 62 may be made of U-bands or the like.

[0030] Next, as shown in Figure 3, the drilling device 70 is sealed and connected above the connecting pipe 61B. The drilling device 70 mainly consists of a mounting flange cylinder 71 made of a cylindrical member with a closed opening at the upper end, a cutter 72 for cutting the metal pipe 2, and a drive motor (not shown) and a retraction mechanism (not shown) provided above the mounting flange cylinder 71 for rotating the cutter 72 and for advancing and retracting the cutter 72 toward the metal pipe 2.

[0031] The cutter 72 is mainly composed of a hole saw 72a, which is formed in a cylindrical shape having an outer diameter larger than the outer diameter of the upper flange 3b of the connecting pipe 3a and has a cutting blade 72c with a carbide tip facing in the circumferential direction at its lower end, and a center drill 72b which is arranged coaxially with the rotation center of the hole saw 72a, and is rotatably mounted on the lower part of the advancement mechanism (not shown) with the center drill 72b as its center.

[0032] When the cutter 72 housed in the mounting flange cylinder 71 is advanced downward while being rotated by an advancing and retracting mechanism (not shown), first, the hole saw 72a enters between the upper flange 3b of the communication pipe 3a and the communication pipe 61B, and then the center drill 72b pierces the center of the piercing flange cover 13 and enters the interior of the communication pipe 3a. Next, after the cutting edge 72c of the hole saw 72a reaches the upper part of the metal pipe 2, when the cutter 72 continues to descend, the periphery of the branch port 2a of the metal pipe 2 is pierced, and a pierced portion 2b having a diameter dimension L2 (see FIG. 4) larger than the diameter dimension L1 (see FIG. 2) of the branch port 2a (L1 < L2) is formed to penetrate at a position substantially concentric with the branch port 2a.

[0033] When the pierced portion 2b is formed, the piercing flange cover 13 is locked to the locking portion 74 provided on the center drill 72b. Then, when the rotation of the cutter 72 is stopped and the cutter 72 is raised by an advancing and retracting mechanism (not shown), the communication pipe 3a integrated with the piercing flange cover 13 locked to the locking portion 74 in the hole saw 72a and a part of the severed metal pipe 2 are raised together with the cutter 72 and recovered into the mounting flange cylinder 71. After the recovery, the mounting flange cylinder 71 is removed from the communication pipe 61B, and the piercing device 70 is removed.

[0034] Next, as shown in FIG. 4, by attaching the correction jig 20 to the opening at the upper end of the communication pipe 61B, the protrusion of the regeneration pipe 4 described later into the communication pipe 61B is prevented. Specifically, the correction jig 20 includes a cylindrical body 20a inserted into the cylindrical communication pipe 61B, a mounting flange 20b attached to the upper part of the cylindrical body 20a, and a bottom plate 20c that closes the lower end opening. By attaching the mounting flange 20b to the upper flange 61f of the communication pipe 61B, the pierced portion 2b is closed by the bottom plate 20c. The bottom plate 20c of the correction jig 20 is formed as a flat surface or a concave curved surface having substantially the same diameter as the outer peripheral surface of the regeneration pipe 4.

[0035] After attaching the straightening jig 20 to the opening at the upper end of the connecting pipe 61B, the rehabilitated pipe 4 (self-supporting pipe) is formed. Specifically, the rehabilitated pipe 4 is formed by inserting a bag-shaped rehabilitation material impregnated with liquid thermosetting resin into the metal pipe 2 while applying internal pressure and inverting it, with the water supply to the metal pipe 2 cut off. The rehabilitation material is then hardened by heat treatment by supplying a mixture of steam and air to the inside of the rehabilitation material, and is arranged along the pipeline on the inner circumference of the metal pipe 2. Note that the method of forming the rehabilitated pipe 4 is not limited to the method described above, and other methods may be used.

[0036] As shown in Figure 4, the fluid pipe 1 in this embodiment consists of an existing metal pipe 2 as the main pipe section, which is formed in a substantially circular shape in cross-section, and a rehabilitated pipe 4 as the inner pipe section, which is provided along the inner surface of the metal pipe 2 in order to rehabilitate the inner circumference of the existing metal pipe 2, and is a water pipe that extends in a substantially horizontal direction. Between the inner surface of the metal pipe 2 that constitutes this fluid pipe 1 and the outer surface 4f of the rehabilitated pipe 4, it is necessary to prevent the intrusion of fluid in order to prevent rust, corrosion, and water leakage.

[0037] Furthermore, as long as the fluid pipe 1 consists of a main pipe section and an inner pipe section provided on its inner circumference, the materials and uses of both pipe sections are not limited to those of this embodiment. For example, the main pipe section is not limited to a metal pipe 2 made of steel with a roughly circular cross-section as in this embodiment, but may also be made of other metals such as cast iron or ductile cast iron, or synthetic resins such as concrete, polyvinyl chloride, polyethylene, or polyolefin. Also, the inner pipe section is not limited to a rehabilitated pipe 4 made of FRP resin as in this embodiment, but may also be a coating layer made of epoxy resin, mortar, plating, etc. In addition, in this embodiment, the fluid inside the fluid pipe 1 is tap water, but the fluid flowing inside the fluid pipe is not necessarily limited to tap water, but may also be industrial water, agricultural water, sewage, or other liquids other than water, or even gas or a gas-liquid mixture.

[0038] Furthermore, the straightening jig 20 attached to the connecting pipe 61B closes the branch opening 2a of the metal pipe 2, preventing the rehabilitation material from bulging and entering the inside of the connecting pipe 61B when the rehabilitation material is inserted into the metal pipe 2. Therefore, when the rehabilitation pipe 4 is laid along the pipeline on the inner circumference of the existing metal pipe 2, the perforated section 2b is closed. Thus, after laying the rehabilitation pipe 4, it is necessary to form a hole in the pipe wall portion of the rehabilitation pipe 4 that closes the perforated section 2b using the perforation device 50 described later.

[0039] After the rehabilitation pipe 4 has hardened and installation is complete, the straightening jig 20 and the work case body 60 are removed from the metal pipe 2, and as shown in Figures 5 and 6, a case body 30 (see Figure 8), which serves as a connecting member having a connecting portion that communicates with the hole formed in the rehabilitation pipe 4, is attached to the metal pipe 2.

[0040] [Case body] The case body 30 mainly consists of a case body 31 (see Figure 5) that is attached to cover the upper part of the metal pipe 2, a case cover 32 (see Figure 6) that is attached to cover the lower part of the metal pipe 2, and bolts 33a and nuts 33b (see Figure 8) that serve as fastening means for fastening the case body 31 and the case cover 32 together. The work case cover 32 may be made of a U-band or the like.

[0041] As shown in Figures 5(a) to 5(c), the case body 31 mainly consists of a semi-cylindrical base 31A that covers the outer circumferential surface of the perforated portion 2b side of the metal pipe 2, and a connecting pipe 31B which is a cylindrical pipe whose lower end is welded to the periphery of the connecting hole 34 formed in the base 31A. A newly constructed connecting section 31C (hereinafter sometimes simply referred to as connecting section 31C) is formed by the connection part between the base 31A and the base end of the connecting pipe 31B, and the circumferential surface of the connecting pipe 31B.

[0042] Protrusion pieces 31c, 31c through which a bolt 33a can be inserted are formed on the left and right near both front and rear ends on the outer peripheral surface of the base portion 31A. Further, an annular packing seat 36 that forms an annular shape and curves along the inner peripheral surface of the base portion 31A is fixed to the lower end of the communication pipe 31B. The outer diameter dimension L5 (see FIG. 5(c)) of the packing seat 36 in plan view is larger than the outer diameter dimension L3 (see FIG. 8) of the communication pipe 31B and smaller than the diameter dimension L2 (see FIG. 8) of the perforated portion 2b of the metal pipe 2 (L3 < L5 < L2). Incidentally, the protrusion piece 31c may be formed as a protrusion seat that extends in the axial direction of the metal pipe 2, like the protrusion seat 61c of the work case main body 61.

[0043] An annular guide portion 35a made of a steel material having a circular cross-section is fixed to the lower end of the communication pipe 31B by welding. An annular guide portion 35b made of a steel material having a circular cross-section is fixed to the inner surface of the packing seat 36 by welding on the outer diameter side of the guide portion 35a. These guide portions 35a, 35b are separated in the radial direction, and a branch packing 37 (see FIG. 7) as a sealing member can be arranged in an annular groove portion surrounded by the guide portions 35a, 35b.

[0044] As shown in FIGS. 6(a) and 6(b), the case cover 32 is mainly composed of a curved base portion 32A that covers the outer peripheral surface of the metal pipe 2 on the side opposite to the communication pipe 3a. Protrusion pieces 32c, 32c through which a bolt 33a can be inserted are formed on the left and right near both front and rear ends on the outer peripheral surface of the base portion 32A. Incidentally, the protrusion piece 3'2c may be formed as a protrusion seat that extends in the axial direction of the metal pipe 2, like the protrusion seat 62c of the work case cover 62. Further, a plurality (three in this example) of guide rods 38 formed linearly from a steel material having a circular cross-section are fixed to the inner peripheral surface of the base portion 32A by welding. One of the three guide rods 38 is arranged parallel to the pipe axis at a substantially central position in the circumferential direction on the inner surface, and the other two guide rods 38, 38 are arranged in parallel at equal intervals in the circumferential direction. Incidentally, the outer diameter dimensions of the guide portions 35a, 35b and the guide rod 38 are substantially the same.

[0045] The branching packing 37 is made of styrene-butadiene rubber or the like, which has a roughly circular cross-section, and is formed in an annular shape (O-ring shape) as shown in Figure 7. The outer diameter of the branching packing 37 is larger than the outer diameter of the guide parts 35a and 35b in its natural state, so when it is housed in the grooves within the guide parts 35a and 35b, it protrudes inward from the guide parts 35a and 35b (see Figures 8 and 9).

[0046] To attach the case body 30 to the fluid pipe 1, the case body 31 is positioned to cover the perforated portion 2b formed on the upper part of the metal pipe 2, as shown in Figures 8 and 9. More specifically, in the rehabilitated pipe 4, the specific portion 4E (the area shown by the mesh in Figures 8 and 9), which is approximately circular in plan view and whose outer surface 4f is exposed outward through the perforated portion 2b, is composed of a central portion 4a which is approximately circular in plan view and a sealed portion 4b which is approximately annular in plan view and is arranged to surround the central portion 4a.

[0047] When positioning the case body 31 on top of the metal pipe 2, the connecting pipe 31B is positioned above the central part 4a of the specific part 4E so that the pipe axis of the connecting pipe 31B aligns with the center of the perforated part 2b. As a result, the packing seat 36 is positioned above the sealed part 4b of the specific part 4E, and the branch packing 37 contacts the outer circumferential surface 4f of the sealed part 4b in the rehabilitated pipe 4.

[0048] Next, the case cover 32 is positioned to cover the lower part of the metal pipe 2. A bolt 33a, which is attached from below to the insertion hole 32d of the protruding piece 32c of the case cover 32, is inserted through the insertion hole 31d of the protruding piece 31c of the case body 31. A nut 33b is then screwed onto the bolt 33a protruding above the protruding piece 31c to fasten it. As a result, the case body 31 and the case cover 32 move inward, and the branch section packing 37 is tightly pressed against the outer circumferential surface 4f of the sealed portion 4b of the rehabilitated pipe 4 by the inner surface 36a of the packing seat 36.

[0049] As shown in Figure 8, the base 31A of the case body 31 and the base 32A of the case cover 32 cover the area corresponding to the perforation 2b on the outer surface 2f of the metal pipe 2 in a cylindrical shape over the circumferential direction, and the length dimension L4 of the bases 31A and 32A in the axial direction of the pipe is greater than the diameter dimension L2 of the perforation 2b (L4 > L2), thus covering a wide area around the perforation 2b in both the circumferential and axial directions.

[0050] Furthermore, when the case body 31 and the case cover 32 are assembled, a gap S is formed between the outer circumferential surface 2f of the metal pipe 2 and the inner surfaces of the base 31A of the case body 31, the packing seat 36, and the base 32A of the case cover 32. Therefore, when the bolts 33a and nuts 33b are tightened, the inner surfaces of the base 31A of the case body 31, the packing seat 36, and the base 32A of the case cover 32 do not come into contact with the outer circumferential surface 2f of the metal pipe 2 over a wide area. Only the branch packing 37 and the multiple guide rods 38 positioned at the lower part opposite the branch packing 37 in the circumferential direction come into contact with the outer circumferential surface 2f of the metal pipe 2, thereby centering the case body 30 relative to the metal pipe 2.

[0051] In this way, a substantially cylindrical case body 30, which serves as a connecting member having a connecting portion 31C, is attached to the metal pipe 2 in the circumferential direction, and a branch portion packing 37, which serves as a sealing member, is arranged in an endless annular shape surrounding the connecting pipe 31B between the inner surface 36a of the packing seat 36 of the case body 30 and the outer surface 4f of the rehabilitated pipe 4, thereby forming the sealing structure 10 of the fluid pipe 1. The branch portion packing 37, which serves as a sealing member, is in close contact with the outer surface 4f of the rehabilitated pipe 4 without directly contacting the metal pipe 2, which is in poor condition due to rust or corrosion.

[0052] Next, before welding the case body 30 together with the metal pipe 2, the opening at the upper end of the connecting pipe 31B is closed with the sealing cover 22, and the connecting pipe 31B is filled with fluid to perform a hydrostatic test and confirm the sealing performance of the branch section packing 37.

[0053] After confirming the sealing performance of the branch packing 37 by hydrostatic pressure testing, the closure cover 22 is removed to drain the fluid in the connecting pipe 31B, and as shown in Figure 10, side rings 23, 23, which are roughly annular in side view, are placed at both ends in the pipe axis direction of the base 31A of the case body 31 and the base 32A of the case cover 32. Next, both ends of the bases 31A, 32A and the sides of the side rings 23, 23 are fixed by welding, and the inner circumferential surfaces of the side rings 23, 23 and the outer circumferential surface 2f of the metal pipe 2 are fixed by welding, thereby fixing the case body 30 to the metal pipe 2 via the side rings 23, 23.

[0054] Next, the short pipe 56 is connected to the upper flange 31f of the connecting pipe 31B using bolts and nuts 55. Furthermore, the base portion 57 of the drilling device 50 is attached to the short pipe 56 using bolts 54. The drilling device 50 mainly consists of the base portion 57, a rotating shaft 59 that extends vertically and is pivotally rotatably supported on the base portion 57, a cutter 52 fixed to the tip of the rotating shaft 59 for cutting the rehabilitation pipe 4, and a handle 58 provided on the upper part of the rotating shaft 59 for advancing and retracting the cutter 52 relative to the rehabilitation pipe 4 while rotating it with a drive motor (not shown).

[0055] The cutter 52 is formed in a cylindrical shape with an outer diameter smaller than the inner diameter of the connecting pipe 31B and mainly consists of a hole saw 52a with a drilling blade 52c facing circumferentially at its lower end, and a center drill 52b that is arranged coaxially with the rotation center of the hole saw 52a and housed inside, and is mounted so as to be rotatable around the center drill 52b.

[0056] Next, by rotating the handle 58, the cutter 52 is moved downward via the rotating shaft 59 pivotally supported on the base 57, thereby drilling a hole 4c (see Figure 11) in the pipe wall of the rehabilitation pipe 4, which will serve as a branching port. The diameter L6 of the hole 4c is smaller than the diameter L2 of the drilled portion 2b (L6 <L2)。

[0057] Then, as shown in Figure 11, after removing the short pipe 56 and the drilling device 50 from the connecting pipe 31B, the pipeline is restored by sealing the newly installed repair valve 11N above the connecting pipe 31B and sealing the newly installed air valve 12N above the newly installed repair valve 11N.

[0058] [Effects / Effects] As described above, the sealing structure 10 of the fluid pipe 1 as an embodiment of the present invention consists of a metal pipe 2 which is the main pipe section and a rehabilitated pipe 4 which is the inner pipe section provided along the inner circumferential surface of the metal pipe 2. A case body 30 as a connecting member having a communication section 31C that communicates with a hole 4c formed in the rehabilitated pipe 4 is attached to the metal pipe 2, and a branch section packing 37 as a sealing member is disposed between the inner surface 36a of the packing seat 36 of the case body 30 and the outer circumferential surface 4f of the rehabilitated pipe 4.

[0059] According to this, the branching packing 37 is disposed between the inner surface 36a of the packing seat 36 of the case body 30 supported by the metal pipe 2 and the outer surface 4f of the rehabilitation pipe 4 provided along the metal pipe 2. As a result, the branching packing 37 does not strongly press against the metal pipe 2, and the sealing function can be stably and sufficiently performed, and the intrusion of fluid into the space between the inner surface of the metal pipe 2 and the outer surface 4f of the rehabilitation pipe 4 can be reliably prevented.

[0060] Furthermore, since the bases 31A and 32A of the case body 30 are attached to the outer surface 2f of the metal pipe 2 in the circumferential direction, the case body 30 can be supported using the entire circumference of the metal pipe 2. In addition, since the base 31A of the case body 30 is formed to extend around the perforation 2b not only in the circumferential direction but also in the direction of the pipe axis, the load required to bring the branch packing 37 into close contact with the metal pipe 2 can be distributed over a wide area, thereby reducing the load on the metal pipe 2.

[0061] Furthermore, the case body 30 has a segmented structure consisting of a case body 31 and a case cover 32 that can be separated in the outer diameter direction, making it easy to attach to the metal pipe 2. Also, by tightening the case body 30, the base portions 31A and 32A are reduced in diameter, allowing the branching packing 37 to be stably and tightly in contact with the fluid pipe 1 in the inner diameter direction.

[0062] Furthermore, since the branch packing 37 is configured in an annular shape to surround the hole 4c of the rehabilitation pipe 4, the shape of the branch packing 37 can be minimized to achieve the desired sealing function.

[0063] Furthermore, the outer circumferential surface 4f of the sealed portion 4b of the rehabilitation pipe 4, where the branch packing 37 is installed, is formed on the outer diameter side of the hole 4c of the rehabilitation pipe 4 and on the inner diameter side of the communication portion 31C of the case body 30. As a result, the branch packing 37 is installed on the outer circumferential surface 4f of the sealed portion 4b of the rehabilitation pipe 4 that is exposed to the outside, making it easy to install the branch packing 37.

[0064] Furthermore, the case body 30 is fixed to the metal pipe 2 by welding via the side ring 23, thereby stably supporting the communication portion 31C with respect to the metal pipe 2. Additionally, the case body 30 is fixed to the metal pipe 2 by bolts 33a and nuts 33b as fastening means, thereby stably supporting the communication portion 31C with respect to the metal pipe 2.

[0065] Furthermore, the method for installing the sealing structure 10 for a fluid pipe 1 of the present invention is a method for installing the sealing structure 10 for a fluid pipe 1 consisting of a metal pipe 2 which is the main pipe section and a rehabilitated pipe 4 which is an inner pipe section provided along the inner circumferential surface of the metal pipe 2, and comprises at least the steps of: arranging the rehabilitated pipe 4 along the pipeline on the inner circumferential surface of the existing metal pipe 2; forming a hole 4c in the rehabilitated pipe 4; attaching a case body 30 as a connecting member having a communication portion 31C that communicates with the hole 4c of the rehabilitated pipe 4 to the metal pipe 2; and arranging a branch section packing 37 as a sealing member between the inner surface 36a of the packing seat 36 of the case body 30 and the outer circumferential surface 4f of the rehabilitated pipe 4.

[0066] According to this, the branching packing 37 is disposed between the inner surface 36a of the packing seat 36 of the case body 30 supported by the metal pipe 2 and the outer surface 4f of the rehabilitation pipe 4 provided along the metal pipe 2. As a result, the branching packing 37 does not strongly press against the metal pipe 2, and the sealing function can be stably and sufficiently performed, and the intrusion of fluid into the space between the inner surface of the metal pipe 2 and the outer surface 4f of the rehabilitation pipe 4 can be reliably prevented.

[0067] Furthermore, by further including the step of drilling a hole in the pipe wall surrounding the existing connecting section 3 of the metal pipe 2 to form a perforated section 2b that communicates with the hole 4c of the rehabilitated pipe 4, a new connecting section 31C can be formed at a suitable location in the same pipeline as the existing connecting section 3.

[0068] Furthermore, by adding a step of connecting a drilling device 50, which serves as a drilling means, to the communication portion 31C of the case body 30, a hole 4c can be drilled in the rehabilitation pipe 4 through the communication portion 31C of the case body 30.

[0069] Furthermore, by including a step of placing the straightening jig 20 inside the connecting portion 61C of the work case body 60, it is possible to prevent the pipe wall of the rehabilitation pipe 4 from bulging into the connecting portion 31C on the outer diameter side when the rehabilitation pipe 4 is installed.

[0070] Although embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and any changes or additions that do not depart from the gist of the present invention are also included. In the following modifications, parts and configurations similar to those in the above embodiments will be denoted by the same reference numerals, and detailed explanations will be omitted.

[0071] [Example 1] In the above embodiment, when the condition of the connecting section 3, including the existing connecting pipe 3a, is poor due to rust, corrosion, etc., and it cannot be used as is after pipe rehabilitation, the sealing structure and installation method for removing the existing connecting pipe 3a in the metal pipe 2 and installing a new connecting section 31C in that location have been described. However, for example, the sealing structure and installation method for a fluid pipe as Modification 1 of the present invention shown in Figure 12 may also be applied.

[0072] Specifically, as shown in Figure 12, the fluid pipe sealing structure and installation method as Modification 1 of the present invention is applicable when forming a perforation 102b in the straight section of the metal pipe 2, separate from the existing connecting pipe 3a, and installing a new connecting section 31C (see Figures 10 and 11) that communicates with the perforation 102b. The steps after forming the perforation 102b are substantially the same as those in Figures 4 to 11 of the above embodiment, so a detailed explanation is omitted.

[0073] This modified example 1 of the fluid pipe sealing structure and installation method provides the same functions and effects as the embodiment described above. Furthermore, by further including the step of perforating the pipe wall of the straight section in the axial direction of the metal pipe 2 to form a perforated portion 102b that communicates with the hole 4c of the rehabilitated pipe 4 (see Figures 10 and 11), it is possible to perforate at any location in the metal pipe 2 with a high degree of freedom to form the communication portion 31C of the fluid pipe 1.

[0074] [Differentiation 2] In the above embodiment and modification 1, before forming the rehabilitated pipe 4, the work case body 60 attached to the metal pipe 2 when forming the perforations 2b and 102b in the existing metal pipe 2 is removed, and a new connecting section 31C is constructed by replacing it with a case body 30 (connecting member) separate from the work case body 60, which has the connecting section 31C already formed, on the metal pipe 2. However, the present invention is not limited to this, and as will be explained below, the case body 160 attached to the metal pipe 2 when forming the perforation 112b in the existing metal pipe 2 may also be used as a connecting member to construct the new connecting section 161C.

[0075] The following describes a fluid pipe sealing structure and installation method as a modified example 2 of the present invention, based on Figures 13 to 17. Note that parts and components similar to those in the above embodiment and modified example 1 are denoted by the same reference numerals, and their descriptions are omitted; the differences will be the main focus of the explanation.

[0076] As shown in Figure 13, the sealing structure and installation method of the fluid pipe 1 as a modified example 2 involves forming a perforation 112b in the straight section of the pipe wall of the metal pipe 2, separate from the existing connecting pipe 3a, and installing a connecting section 161C that communicates with the perforation 112b. Specifically, the case body 160 used when forming the perforation 112b mainly consists of a case body 161 that is attached to cover the upper part of the metal pipe 2, a case cover 162 that is attached to cover the lower part of the metal pipe 2, and bolts 163a and nuts 163b as fastening means for fastening the case body 161 and the case cover 162.

[0077] The case body 161 mainly consists of a semi-cylindrical base 161A that covers the upper part of the outer circumferential surface 2f of the metal pipe 2, and a cylindrical connecting pipe 161B whose lower end is welded to the periphery of a connecting hole (not shown) formed in the base 161A. The connecting section 161C is formed by the connection part between the base 161A and the base end of the connecting pipe 161B, as well as the circumferential surface of the connecting pipe 161B. An upper flange 161f protruding in the outer diameter direction is provided at the upper end of the connecting pipe 161B. Through holes (not shown) through which bolts 163a can be inserted are formed at both the front and rear ends of the base 161A, with protruding seats 161c facing the axial direction of the metal pipe 2.

[0078] The case cover 162 is mainly composed of a semi-cylindrical base 162A that covers the lower outer surface of the metal pipe 2. On the front and rear sides of the base 162A, through holes (not shown) through which bolts 163a can be inserted are formed, and protruding seats 162c are formed in the direction of the pipe axis of the metal pipe 2.

[0079] Then, the case body 161 is positioned to cover the upper part of the metal pipe 2, and the case cover 162 is positioned to cover the lower part of the metal pipe 2. Bolts 163a attached from below are inserted into each of the through holes (not shown) of the protruding seat 162c of the case cover 162, and nuts 163b are screwed onto the bolts 163a protruding above the protruding seat 161c to fasten them, thereby sealing the perforated portion 112b in the metal pipe 2 and its surrounding area with the case body 160.

[0080] Next, the perforation device 70 is sealed and connected above the connecting pipe 161B to form a perforation 112b in the wall of the metal pipe 2. After that, a rehabilitated pipe 4 is formed inside the metal pipe 2 to constitute the fluid pipe 1. The configuration of the perforation device 70, the perforation process, and the process of forming the rehabilitated pipe 4 are the same as in the above embodiment, so a detailed explanation is omitted.

[0081] Next, without removing the connecting pipe 161B and case cover 162 of the case body 161, the connecting pipe 170a, which is integrated with the case body 160 and constitutes a connecting member, is installed inside the connecting pipe 161B, as shown in Figures 15 and 16.

[0082] As shown in Figures 14(a) to 14(c), the connecting pipe 170a is formed in a cylindrical shape with an outer diameter that allows it to be inserted into the connecting pipe 161B of the case body 161, and an upper flange 170f protruding in the outer diameter direction is provided at its upper end. Multiple bolt holes 172 (four in this example) are formed in the circumferential direction on the upper flange 170f, through which bolts of bolts and nuts 171 for attaching the closing cover 122 (see Figure 15) can be inserted. In addition, multiple screw holes 174 (four in this example) are formed in the circumferential direction on the outer diameter side of the bolt holes 172 on the lower surface, through which stud bolts 173 for connecting to the upper flange 161f of the case body 161 can be screwed in.

[0083] Furthermore, a groove 177 capable of accommodating an annular packing 176 (see Figure 15) is formed in an annular shape around the opening on the upper surface of the upper flange 170f. In addition, a groove 178 with a substantially curved cross-sectional shape capable of accommodating an annular packing 179 (see Figure 15) is formed circumferentially on the inner surface of the connecting pipe 170a (the end face facing the inner diameter side of the fluid pipe 1). The groove 178 is curved to open downward and outward at the outer peripheral edge of the lower end of the connecting pipe 170a, and a wall 170b is formed on the inner diameter side of the groove 178 to prevent the packing 179 from bulging inward.

[0084] To assemble the connecting pipe 170a to the connecting pipe 161B, as shown in Figures 15 and 16, a stud bolt 173 is inserted through a plurality of insertion holes 161g formed in the upper flange 161f of the connecting pipe 161B, and nuts 173a, 173a are screwed onto the top and bottom of the stud bolt 173 to hold it in place. Next, with the packing 179 fitted into the groove 178 at the lower end of the connecting pipe 170a, it is inserted into the case body 160 fixed to the metal pipe 2 through the opening at the top end of the connecting pipe 161B.

[0085] Next, the nuts 173a, 173a are loosened and the stud bolt 173 is screwed into the threaded hole 174 of the connecting pipe 170a, connecting the connecting pipe 161B of the case body 160 fixed to the metal pipe 2 with the connecting pipe 170a. Then, the positions of the upper and lower nuts 173a, 173a relative to the stud bolt 173 are adjusted, and the connecting pipe 170a is brought closer to the fluid pipe 1 side relative to the connecting pipe 161B, so that the groove portion 178 of the connecting pipe 170a presses the packing 179 against the outer surface 4f of the rehabilitated pipe 4. Once the pressing position is determined, the nuts 173a, 173a are tightened to fix it, and the newly created connecting portion 170 is formed by the connecting pipe 170a.

[0086] In this way, a substantially cylindrical case body 160, which serves as a connecting member having connecting portions 161C and 170, is attached to the metal pipe 2 in the circumferential direction, and a packing 179, which serves as a sealing member, is arranged in an endless annular shape between a groove 178 formed on the inner surface of the connecting pipe 170a integrated with the case body 160 and the outer circumferential surface 4f of the rehabilitated pipe 4, thereby forming the sealing structure 110 of the fluid pipe 1. The packing 179, as a sealing member, abuts against the inner end surface of the perforated portion 112b of the metal pipe 2, thereby restricting the outward bulging of the perforated portion 112b and making a tight, close contact with the outer circumferential surface 4f of the rehabilitated pipe 4. Here, as described above, the inner end surface of the perforated portion 112b of the metal pipe 2 is a surface newly formed by the perforation by the cutter 72, so there is no rust or other contaminants attached, and the bulging of the packing 179 can be appropriately restricted. Furthermore, the packing 179 does not necessarily have to be configured to abut the inner end surface of the perforated portion 112b of the connecting pipe 2. For example, walls may be formed on both the inner and outer diameter sides of the groove 178 on the inner surface of the connecting pipe 170a to prevent the packing 179 from bulging outwards toward the inner and outer diameters.

[0087] Next, the connecting pipe 170a is filled with fluid, the opening at the upper end of the connecting pipe 170a is closed with the closure cover 122, and a hydrostatic pressure test is performed to confirm the sealing performance of the packing 179. If there are no problems with the sealing performance of the packing 179 in the hydrostatic pressure test, the closure cover 122 is removed and the fluid in the connecting pipe 170a is discharged. Then, as shown in Figure 17, the drilling device 50 is connected in a sealed manner above the connecting pipe 170a, and a hole 104c, which will serve as a branching port, is drilled in the pipe wall of the rehabilitation pipe 4.

[0088] Then, as shown in Figure 18, after removing the drilling device 50 from the connecting pipe 170a, the pipeline is restored by connecting the newly installed repair valve 11N in a sealed manner above the connecting pipe 170a, and connecting the newly installed air valve 12N in a sealed manner above the newly installed repair valve 11N.

[0089] Thus, in the fluid pipe 1 sealing structure 110 as the modified example 2, the packing 179 as a sealing member is disposed between the groove 178 formed on the inner surface of the connecting pipe 170a, which is integrated with the case body 160 supported by the metal pipe 2, and the outer surface 4f of the rehabilitation pipe 4 provided along the metal pipe 2. As a result, the packing 179 does not strongly press against the metal pipe 2, and the sealing function can be stably and sufficiently performed, and the intrusion of fluid between the inner surface of the metal pipe 2 and the outer surface 4f of the rehabilitation pipe 4 can be reliably prevented.

[0090] Furthermore, since the connecting pipe 161B guides the connecting pipe 170a toward the inner diameter of the fluid pipe 1, the packing 179 can be stably pressed toward the inner diameter of the fluid pipe 1.

[0091] Furthermore, in this modified example 2 (see Figure 18), as a countermeasure against rainwater entering from the outside (external water leakage), a water-stopping structure (not shown) using a packing groove may be provided on the outer surface of the connecting pipe 170a (the spigot joint with the connecting section 161B by the case body 161), or a cover member (not shown) that covers the entire outer surface of the upper flange 161f and the upper flange 170f of the connecting pipe 170a may be wrapped around it. Alternatively, a spacer member (not shown) may be sealed and sandwiched between the upper surface of the upper flange 161f and the lower surface of the upper flange 170f.

[0092] [Difference 3] In the above embodiments and modifications 1 and 2, the newly formed connecting portions 31C and 161C were described as being constructed by attaching case bodies 30 and 160, each having a case body 31 and 161 with connecting portions 31C and 161C pre-formed on the metal pipe 2, to the metal pipe 2. However, the present invention is not limited to this, and the new connecting portion may be constructed using an existing connecting portion 3.

[0093] The following describes a fluid pipe sealing structure and installation method as a third modification of the present invention, based on Figures 19 to 22. Note that parts and components similar to those in the above embodiment and modifications 1 and 2 are denoted by the same reference numerals, and their descriptions are omitted; the differences will be the main focus of the explanation.

[0094] As shown in Figure 19, the sealing structure and installation method of the fluid pipe 1 in this modified example 3 involves integrally attaching a connecting pipe 270a, which is a connecting member having a connecting portion 270 (see Figure 21) that communicates with a hole 204c (see Figure 21) formed in the rehabilitated pipe 4 (described later), to the inside of the existing connecting pipe 3a in the metal pipe 2.

[0095] As shown in Figure 20, the connecting pipe 270a is formed in a cylindrical shape with an outer diameter that allows it to be inserted into the connecting pipe 3a, and an upper flange 270f protruding in the outer diameter direction is provided at its upper end. The upper flange 270f has multiple bolt holes (not shown) formed in the circumferential direction (four in this example) through which bolts of bolts and nuts 271 for attaching the closing cover 222 can be inserted, and on the outer diameter side of the bolt holes (not shown) on the lower surface, multiple screw holes 274 are formed in the circumferential direction (four in this example) into which stud bolts 273 for connecting to the upper flange 3b of the connecting pipe 3a can be screwed. In addition, a groove portion 277 capable of accommodating an annular packing 276 is formed in an annular shape around the opening on the upper surface of the upper flange 270f.

[0096] A thick-walled cylindrical portion 275 is attached to the inner surface of the connecting pipe 270a (the end face facing the inner diameter side of the fluid pipe 1), with a groove portion 278 formed circumferentially that can accommodate an annular packing 279, allowing for the selection of an appropriate packing diameter. The groove portion 278 is curved to open downward and outward at the outer peripheral edge of the lower end of the connecting pipe 270a, and a wall portion is formed on the inner diameter side of the groove portion 278 to prevent the packing 279 from bulging inward.

[0097] To assemble the connecting pipe 270a to the existing connecting pipe 3a, which is part of the main pipe section, as shown in Figures 20 and 21, stud bolts 273 are inserted through multiple insertion holes 261g formed in the upper flange 3b of the connecting pipe 3a, and nuts 273a, 273a are screwed onto the top and bottom of the stud bolts 273 to hold them in place. Next, with the packing 279 fitted into the groove 278 at the lower end of the connecting pipe 270a, the metal pipe 2 is inserted into the opening at the upper end of the connecting pipe 3a.

[0098] Next, the nuts 273a, 273a are loosened and the stud bolt 273 is screwed into the threaded hole 274 of the connecting pipe 270a, connecting the connecting pipe 3a of the metal pipe 2 to the connecting pipe 270a. Then, the positions of the upper and lower nuts 273a, 273a relative to the stud bolt 273 are adjusted, and the connecting pipe 270a is brought closer to the fluid pipe 1 side relative to the connecting pipe 3a, so that the groove portion 278 of the connecting pipe 270a presses the packing 279 against the outer surface 4f of the rehabilitated pipe 4. Once the pressing position is determined, the nuts 273a, 273a are tightened to fix it in place, thereby forming the newly created connecting section 270 with the connecting pipe 270a.

[0099] Thus, a substantially cylindrical connecting pipe 270a, which serves as a connecting member having connecting portions 161C and 270, is attached to a connecting pipe 3a, which is part of the metal pipe 2. A packing 279, which serves as a sealing member, is arranged in an endless annular shape between a groove 278 formed on the inner surface of the connecting pipe 270a and the outer circumferential surface 4f of the rehabilitated pipe 4, thereby forming a sealing structure 210 for the fluid pipe 1. The packing 279, as a sealing member, contacts the inner end surface of the perforated portion 2b of the metal pipe 2, thereby restricting the outward bulging of the perforated portion 2b and creating a tight seal with the outer circumferential surface 4f of the rehabilitated pipe 4.

[0100] Next, the connecting pipe 270a is filled with fluid, the opening at the upper end of the connecting pipe 270a is closed with a closure cover 222, and a hydrostatic pressure test is performed to confirm the sealing performance of the packing 279. After confirming the sealing performance of the packing 279 with the hydrostatic pressure test, the closure cover 222 is removed to discharge the fluid from the connecting pipe 270a, and as shown in Figure 21, the drilling device 50 is connected in a sealed manner above the connecting pipe 270a to drill a hole 204c in the pipe wall of the rehabilitation pipe 4, which will serve as a branch hole.

[0101] Then, as shown in Figure 22, after removing the drilling device 50 from the connecting pipe 270a, the pipeline is restored by connecting the newly installed repair valve 11N in a sealed manner above the connecting pipe 270a, and connecting the newly installed air valve 12N in a sealed manner above the newly installed repair valve 11N.

[0102] Thus, in the fluid pipe 1 sealing structure 210 as the modified example 3, the packing 279 as a sealing member is disposed between the groove 278 formed on the inner surface of the connecting pipe 270a installed in the existing connecting section 3 which constitutes a part of the metal pipe 2, and the outer surface 4f of the rehabilitation pipe 4 provided along the metal pipe 2. As a result, the packing 279 does not strongly press against the metal pipe 2, and the sealing function can be stably and sufficiently performed, and the intrusion of fluid between the inner surface of the metal pipe 2 and the outer surface 4f of the rehabilitation pipe 4 can be reliably prevented.

[0103] Furthermore, by installing the connecting pipe 270a, which serves as a connecting member, in the existing connecting section 3 that branches off from the metal pipe 2, the sealing structure 210 of the fluid pipe 1 can be constructed using the existing connecting section 3. In addition, since the connecting pipe 3a guides the connecting pipe 270a toward the inner diameter of the fluid pipe 1, the packing 279 can be stably pressed toward the inner diameter of the fluid pipe 1.

[0104] Furthermore, in Modification 3 (see Figure 20), as a measure against rainwater entering from the outside (external water leakage), a water-stopping structure (not shown) using packing grooves may be provided on the outer surface of the thick-walled cylindrical portion 275, or a cover member (not shown) may be wrapped around the entire outer surface of the upper flange 3b of the connecting pipe 3a and the upper flange 270f of the connecting pipe 270a. Alternatively, a spacer member (not shown) may be sealed and sandwiched between the upper surface of the upper flange 3b and the lower surface of the upper flange 270f.

[0105] Furthermore, in Modification 2 and Modification 3, as a common measure against rainwater and other water intrusion from the outside (external water leakage), after installation is complete, a cover member (not shown) or the like can be placed over the entire branch section in a sealed manner to prevent water intrusion.

[0106] [Other variations] In the above embodiments and modified examples 1 and 2, as an example of a connecting member having a communication portion that communicates with a hole formed in the inner tube portion, a case body 30, 160 (split T-shaped tube) having cylindrical base portions 31A, 32A, 161A, 162A that are attached to cover the metal tube 2, which is the main tube portion, in the circumferential direction was illustrated. However, the present invention is not limited thereto, and the metal tube 2 does not necessarily have to be configured to cover the metal tube 2 in the circumferential direction.

[0107] Furthermore, in the above embodiments and modifications 1 to 3, the connecting member having a communication portion that communicates with a hole formed in the inner pipe portion was exemplified as a member for connecting an air valve, a repair valve, etc., but the present invention is not limited thereto, and may also be a member for connecting a branch pipe that branches off from a fluid pipe.

[0108] Furthermore, in the above embodiments and modifications 1 to 3, when constructing the sealing structure of the fluid pipe of the present invention, the existing repair valve 11 and air valve 12 are temporarily removed from the connecting pipe 3a, the sealing structure is constructed, and then replaced with newly installed repair valve 11N and air valve 12N. However, the present invention is not limited to this, and the removed existing repair valve 11 and air valve 12 may be reinstalled, or separate connecting members may be attached to the repair valve 11 and air valve 12 and the newly installed repair valve 11N and air valve 12N. [Explanation of Symbols]

[0109] 1 Fluid tube 2. Metal pipe (main pipe section) 2a Branch Outlet 2b Perforation 2f Outer surface (outer surface of the main pipe) 3 Communication section 3a Communication pipe 4 Rehabilitation pipe (inner pipe part) 4E Specific part 4b Sealed part 4f Outer surface (outer surface of the inner tube) 10,110,210 Sealed structure 11,11N Repair valve 12,12N air valve 20 Orthodontic fixtures 23 Side Rings 30 Case body (connecting component) 31 Case body 31A base 31B Communication pipe 31C Communication part 32 Case Covers 32A base 36 Packing Seat 36a Inner surface (inner surface of connecting member) 37 Branching section packing (sealing component) 50,70 drilling equipment 60 work case body 102b Perforation 104c Hole 112b Perforation 160 Case body (connecting component) 161 Case body 161A base 161B Communication pipe 161C Communication part 162 Case Cover 162A base 170 Communication section 170a Communication pipe 178 Recessed groove (inner surface of connecting member) 179 Gasket (sealing component) 204c Hole 270 Communication section 270a Connecting pipe (connecting member) 275 Thick wall tube part 278 Recessed groove (inner surface of connecting member) 279 Gasket (sealing component)

Claims

1. A sealing structure for a fluid tube comprising a main tube and an inner tube provided along the inner circumferential surface of the main tube, A sealing structure for a fluid pipe, characterized in that a connecting member having a communication portion that communicates with a hole formed in the inner pipe portion is attached to the main pipe portion, and a sealing member is disposed between the inner surface of the connecting member and the outer surface of the inner pipe portion.

2. The sealing structure for a fluid pipe according to claim 1, characterized in that the connecting member is attached to the outer surface of the main pipe portion in the circumferential direction.

3. The sealing structure for a fluid pipe according to claim 2, characterized in that the connecting member has a segmented structure.

4. The sealing structure for a fluid pipe according to claim 1, characterized in that the connecting member is installed in an existing communication section of the main pipe.

5. The sealing structure for a fluid pipe according to claim 1, characterized in that the sealing member is configured in an annular shape so as to surround the hole in the inner pipe portion.

6. The sealing structure for a fluid pipe according to claim 5, characterized in that the outer surface of the inner pipe portion on which the sealing member is disposed is formed on an outer diameter side of the hole portion of the inner pipe portion and on an inner diameter side of the communication portion of the connecting member.

7. A method for installing a sealing structure for a fluid pipe, comprising a main pipe section and an inner pipe section provided along the inner circumferential surface of the main pipe section, The process involves arranging the inner pipe section along the pipeline on the inner circumferential surface of the existing main pipe section, The process of forming a hole in the inner tube portion, A step of attaching a connecting member having a communication portion that communicates with the hole portion of the inner pipe portion to the main pipe portion, A method for installing a sealing structure for a fluid pipe, characterized by comprising at least the step of arranging a sealing member between the inner surface of the connecting member and the outer surface of the inner pipe portion.

8. The method for installing a sealing structure for a fluid pipe according to claim 7, further comprising the step of drilling a hole in the pipe wall surrounding an existing connecting portion of the main pipe to form a perforated portion that communicates with the hole in the inner pipe.

9. The method for installing a sealing structure for a fluid pipe according to claim 7, further comprising the step of perforating the pipe wall of the straight section in the axial direction of the main pipe section to form a perforated section that communicates with the hole in the inner pipe section.

10. The method for installing a sealing structure for a fluid pipe according to claim 7, further comprising the step of connecting a drilling means to the communication portion of the connecting member.

11. The method for installing a sealing structure for a fluid pipe according to claim 7, further comprising the step of arranging a straightening jig inside the communication portion.

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