Method for manufacturing fluid pipes, and device for testing fluid pipe leaks.

Abstract

To provide a fluid pipe manufacturing method and a fluid pipe leakage inspection device that have simplified a process to inspect a packing that seals a lining layer.SOLUTION: A fluid pipe manufacturing method includes: forming a lining layer 2 on an inner peripheral surface K1 of a fluid pipe K; arranging a packing 3 that covers the inner peripheral surface K1 of the fluid pipe K located on the outside in a pipe axis direction AD of an end 21 in the pipe axis direction AD of the lining layer 2 and the end of the lining layer 2 from the pipe radial inside RD1; applying an inspection agent generating air bubbles upon passage of gas to predetermined check portions (P1, P2, P3) of a sealed part that is sealed by the packing 3; and pressing a cylindrical portion 50 of an inspection cover 5 against a position surrounding the predetermined check portions (P1, P2, P3) to adjust the pressure inside the inspection cover 5 to negative pressure, and checking the presence or absence of air bubbles of the inspection agent at the predetermined check portions (P1, P2, P3).SELECTED DRAWING: Figure 5A

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a fluid pipe such as a water pipe, and a leak inspection apparatus for a fluid pipe.

Background Art

[0002] It is known to form a lining layer on the inner peripheral surface of a fluid pipe in order to rehabilitate an existing fluid pipe such as a water pipe to manufacture a new fluid pipe (see, for example, Patent Document 1). Patent Document 1 discloses disposing a packing that covers an end portion of the lining layer in the pipe axis direction in order to prevent fluid from entering between the lining layer and the inner peripheral surface of the fluid pipe.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An inspection step is required to inspect whether the sealing function (airtightness) of the packing that prevents fluid from entering between the lining layer and the inner peripheral surface of the fluid pipe is properly exerted.

[0005] The present disclosure provides a method for manufacturing a fluid pipe and a leak inspection apparatus for a fluid pipe, in which the inspection step for the packing that seals the lining layer is simplified.

Means for Solving the Problems

[0006] The method for manufacturing a fluid tube according to the present disclosure includes: forming a lining layer on the inner surface of a fluid tube; arranging a packing that covers the inner surface of the fluid tube located outside the axial end of the lining layer and the end of the lining layer from the inside in the radial direction of the tube; applying an inspection agent that generates bubbles when gas passes through to a predetermined check location in the seal portion sealed by the packing; and pressing a cylindrical portion of an inspection cover against a position surrounding the predetermined check location to create negative pressure inside the inspection cover and confirm the presence or absence of bubbles in the inspection agent at the predetermined check location. [Brief explanation of the drawing]

[0007] [Figure 1] An explanatory side view relating to the process of forming a lining layer on an existing fluid pipe according to this disclosure. [Figure 2] A cross-sectional view relating to the process of placing a packing and a retaining device in the lining layer. [Figure 3] A perspective view of the end of the packing in the axial direction of the pipe, seen from the outside in the axial direction of the pipe and the inside in the radial direction of the pipe. [Figure 4A] A plan view showing the inspection cover. [Figure 4B] Side view showing the inspection cover. [Figure 4C] Cross-sectional view of the A1-A1 region in Figure 4A. [Figure 5A] A cross-sectional view showing an example of the inspection process. [Figure 5B] A cross-sectional view showing an example of the inspection process. [Figure 6] A cross-sectional view showing an example of the inspection process for a modified example. [Modes for carrying out the invention]

[0008] [First Embodiment] The method for manufacturing a fluid pipe according to the first embodiment of this disclosure will be described below with reference to the drawings. As shown in Figure 2, a flexible and airtight lining layer 2 is formed on the inner circumferential surface K1 of an existing fluid pipe K using an adhesive (not shown). As a specific example, as shown in Figure 1, shafts 10 are excavated in the underground fluid pipe K at positions that straddle the area where the lining layer 2 will be formed. The fluid pipe K is cut at each shaft 10, a tube 20 which will become the lining layer 2 is inserted inverted, and the tube 20 is bonded to the inner circumferential surface K1 of the fluid pipe K using an adhesive to form the lining layer 2. As shown in Figure 2, the end 21 of the lining layer 2 in the direction AD is away from the end K2 of the fluid pipe K in the direction AD, and is located inside the direction AD in the direction AD of the fluid pipe K compared to the end K2 of the fluid pipe K in the direction AD.

[0009] Next, as shown in Figure 2, adhesive is applied to the inner circumferential surface K1 of the fluid pipe K (the portion indicated by range Ar1) located outside the end AD 21 of the lining layer 2 in the axial direction of the pipe, and to the end of the lining layer 2 (the portion indicated by range Ar1). A packing 3 is then placed to cover the inner circumferential surface K1 of the fluid pipe K and the end of the lining layer 2 from the inside RD1 in the radial direction of the pipe. The packing 3 is a strip-shaped rubber member with a length corresponding to the circumference of the fluid pipe K. As shown in Figure 3, the two ends of the packing 3 in the circumferential direction of the pipe are joined together with adhesive to form a joint surface (first joint surface P1). Returning to Figure 2, the packing 3 is bonded to the end of the lining layer 2 and the inner circumferential surface K1 of the fluid pipe K via adhesive. Next, the retainer 4, which has a ring member 40, is placed on the inner diameter RD1 of the packing 3 in the pipe diameter direction, and the ring member 40 of the retainer 4 is expanded in diameter, and the retainer 4 is fixed in a state in which the retainer 4 presses the packing 3 against the outer diameter RD2 in the pipe diameter direction. The expanded state of the ring member 40 of the retainer 4 is maintained by fastening it with fasteners such as bolts (not shown). Since the structure of the retainer 4 is known, a detailed explanation is omitted.

[0010] Next, a step is performed to inspect the airtightness of predetermined check points (P1, P2, P3) in the sealing portion sealed by packing 3. This inspection step includes a coating step and a negative pressure application step.

[0011] In the coating process, a test agent that generates bubbles when gas passes through is applied to predetermined check locations (P1, P2, P3). The predetermined check locations (P1, P2, P3) include the joint surfaces of both ends of the circumferential direction CD of the packing 3 shown in Figure 3 (first joint surface P1), the joint surface between the inner circumferential surface K1 of the fluid pipe K shown in Figures 2 and 3 and the packing 3 (second joint surface P2), and the joint surface between the lining layer 2 and the packing 3 shown in Figure 2 (third joint surface P3). The test agent used in this embodiment is a gas leak test agent manufactured by Taseto Co., Ltd., product name "Leak Check", product number RIC450, but is not limited to this.

[0012] In the negative pressure application process, a leak inspection device equipped with an inspection cover 5, as shown in Figures 4A, 4B, and 4C, is used. The inspection cover 5 has a cylindrical portion 50 that is pressed against a position surrounding predetermined check points (P1, P2, P3). The inspection cover 5 is made of rubber. A negative pressure hose 52 for creating negative pressure inside the inspection cover 5 can be connected to the inspection cover 5. Although not shown, a pressure gauge for measuring the pressure inside the inspection cover 5 may be connected to the inspection cover 5 along with the negative pressure hose 52. A compressible foamed sealant 51 is attached to the annular tip of the cylindrical portion 50. The foamed sealant 51 can be made of various materials as long as it is compressible, can fill in some steps, and has airtightness that can prevent the passage of air. In this embodiment, the foamed sealant 51 is made of EPDM foamed rubber and has a width and thickness of 20 mm. The outer diameter of the annular tip of the cylindrical portion 50 is 170 mm. The product name is "Eptosealer," manufactured by Nitto El Material Co., Ltd., with product number 686X20X20, but it is not limited to this product.

[0013] In this embodiment, the foamed sealant 51 has notches formed that penetrate the inside and outside of the annular tip, and these notches make it easier for the foamed sealant 51 to fill in steps. However, the effect of filling in steps can be achieved even without the notches.

[0014] The cylindrical portion 50 of the inspection cover 5 is pressed against the position surrounding the predetermined check points (P1, P2, P3), and the inside of the inspection cover 5 is pressurized to a predetermined pressure via the negative pressure hose 52. At this time, if the seal of the predetermined check points is incomplete, gas will pass through and bubbles of the inspection agent will be generated at the predetermined check points. Conversely, if the seal of the predetermined check points is complete, gas will not pass through, and no bubbles of the inspection agent will be generated at the predetermined check points. The inspection cover 5 in this embodiment has a transparent window 53 that allows the inside to be seen, so the presence or absence of bubbles can be directly observed by visually inspecting the predetermined check points through the window 53. If there is no window 53, the inspection cover 5 would have to be removed and visually checked to see if bubbles have been generated at the predetermined check points. In this embodiment, the window 53 is a single transparent acrylic plate, and the rubber member of the cylindrical portion 50 is sandwiched between the acrylic plate (53) and a ring member 54 made of metal or the like to form the inspection cover 5.

[0015] The cylindrical portion 50 of the inspection cover 5 is positioned so that it overcomes at least one of the steps (P2) between the inner circumferential surface K1 of the fluid pipe K and the packing 3, and the step (P3) between the lining layer 2 and the packing 3. At this time, the foamed sealant 51 is compressed, filling the gap of the step that the annular tip (foamed sealant 51) is overcoming. Figure 5A shows the inspection of the sealing performance at a predetermined check point (P2) while the foamed sealant 51 fills the step (P2) between the inner circumferential surface K1 of the fluid pipe K and the packing 3. Figure 5B shows the inspection of the airtightness at a predetermined check point (P3) while the foamed sealant 51 fills the step (P3) between the lining layer 2 and the packing 3.

[0016] The joint surface (second joint surface P2) between the inner peripheral surface K1 of the fluid pipe K and the packing 3, and the joint surface (third joint surface P3) between the lining layer 2 and the packing 3 are each predetermined check points that extend one full turn in the pipe circumferential direction CD, and it is not possible to inspect all locations by pressing the inspection cover 5 only once. Therefore, the inspection is repeated while gradually shifting the inspection position in the pipe circumferential direction, and if no bubbles of the inspection agent are confirmed to be generated at all check points, it can be determined that the airtightness provided by the packing 3 is favorable.

[0017] <Modified Example> (A) In the first embodiment, the embodiment having two ring members 40 of the pressing tool 4 that presses the packing 3 has been described, but the number of the ring members 40 of the pressing tool 4 that presses the packing 3 can be appropriately changed as long as it is 1 or more. For example, Fig. 6 shows an embodiment in which there is one ring member 40 of the pressing tool 4 that presses the packing 3. The embodiment in Fig. 6 shows an example of a small-diameter fluid pipe K with a diameter of less than 400 mm. The diameter of the existing fluid pipe K may be 100 mm or more and 1000 mm or less.

[0018] (B) In the first embodiment, since the outer diameter of the cylindrical portion 50 of the inspection cover 5 is about 170 mm, it is preferably used for the inspection of a large-diameter fluid pipe K with a diameter of 400 mm or more. In the case of a fluid pipe K with a smaller diameter, it is preferable to use the leak inspection apparatus of the second embodiment shown in Fig. 6. A bellows structure is formed on the cylindrical portion 50 of the inspection cover 5 shown in Fig. 6. This makes it easy to press the cylindrical portion 50 of the inspection cover 5 against the check point in a desired orientation, and facilitates the inspection process. In Fig. 6, no window 53 is formed in the inspection cover 5. On the other hand, when the window 53 is formed in the inspection cover 5, visual inspection is facilitated by appropriately pressing the cylindrical portion 50 against the predetermined check point with the bellows structure and orienting the window 53 toward the opening side of the fluid pipe K. In the example of Fig. 6, the outer diameter of the cylindrical portion 50 is 40 mm, but is not limited thereto. For example, the outer diameter of the cylindrical portion 50 may be 60 mm. The number of stages of the bellows structure can be changed as appropriate.

[0019] (C) In the above-described embodiment, the fluid pipe K is a water pipe, but is not limited thereto.

[0020] (D) In the above-described embodiment, the annular distal end portion of the cylindrical portion 50 of the inspection cover 5 is a flat surface, but the present invention is not limited thereto. For example, the annular distal end portion of the cylindrical portion 50 may be curved in an arc shape along the inner peripheral surface K1 of the fluid pipe K. Further, a step may be provided on the annular distal end portion of the cylindrical portion 50 in accordance with the step at the predetermined check location.

[0021] (E) In the above-described embodiment, of the predetermined check locations (P2, P3) extending in the pipe circumferential direction of the fluid pipe K, a part of the space in the pipe circumferential direction is partitioned by the inspection cover 5 to be under negative pressure, and the airtightness of the predetermined check locations is inspected, but the present invention is not limited thereto. Although the inspection cover 5 is required for each pipe diameter, a ring-shaped inspection cover 5 that simultaneously surrounds the entire pipe circumferential direction of the predetermined check locations (P2, P3) extending in the pipe circumferential direction of the fluid pipe K to create a negative pressure may be adopted.

[0022] (F) In the above-described embodiment, the lining layer 2 is formed of the tube 20 made of a composite material such as polyester fiber, glass fiber, and resin, and the construction method is such that the tube 20 is inverted and inserted into the fluid pipe K by compressed air. However, the lining layer 2 is not limited to this as long as it can cover the inner peripheral surface K1 of the fluid pipe K. For example, a construction method may be used in which a bag serving as the lining layer is drawn into the fluid pipe by water pressure or air pressure. Alternatively, a construction method may be used in which a new pipe having a slightly smaller diameter than the inside of the fluid pipe K is inserted, and the new pipe is used as the lining layer.

[0023] (G) In the above-described embodiment, the joint surface (first joint surface P1) between both end portions of the packing 3 in the pipe circumferential direction CD is fixed by means such as an adhesive, but the present invention is not limited thereto. Although both end portions of the packing 3 in the pipe circumferential direction CD are brought into contact and aligned with each other, the joint surface may be in a state where the both end portions are not fixed to each other by adhesion or the like.

[0024] (H) In the above embodiment, the packing 3 is made into a ring shape by joining both ends of the ribbon-shaped packing 3, but it is not limited to this. A link-shaped packing having a diameter that matches the fluid pipe K and the lining layer 2 may also be used. In this case, since the packing does not have the first joint surface, the predetermined check points will be the second joint surface P2 and the third joint surface P3.

[0025] [1] As described above, although not particularly limited, a method for manufacturing a fluid tube may include: forming a lining layer 2 on the inner circumferential surface K1 of the fluid tube K; arranging a packing 3 to cover the inner circumferential surface K1 of the fluid tube K located outside the axial AD of the lining layer 2 beyond the axial AD end 21 of the lining layer 2, and the end of the lining layer 2 from the inner radial side RD1; applying an inspection agent that generates bubbles when gas passes through to predetermined check locations (P1, P2, P3) in the seal portion sealed by the packing 3; and pressing the cylindrical portion 50 of the inspection cover 5 against a position surrounding the predetermined check locations (P1, P2, P3) to create negative pressure inside the inspection cover 5 and confirming the presence or absence of bubbles in the inspection agent at the predetermined check locations (P1, P2, P3). In this way, the sealing defects of the packing 3 can be inspected by applying the inspection agent, pressing the inspection cover 5 against it, and creating negative pressure inside the inspection cover 5 to check for foaming of the inspection agent, thus simplifying the inspection process.

[0026] [2] In the method for manufacturing a fluid pipe described in [1] above, the predetermined check points may be the joint surface between the inner circumferential surface K1 of the fluid pipe K and the packing 3 (second joint surface P2), and the joint surface between the lining layer 2 and the packing 3 (third joint surface P3).

[0027] [3] In the method for manufacturing a fluid pipe described in [2] above, the packing 3 is joined at both ends of the circumferential CD of the pipe, and the predetermined check location may further include the joint surface (first joint surface P1) between the two ends of the circumferential CD of the packing 3.

[0028] [4] In the method for manufacturing a fluid pipe described in any of [1] to [3] above, the annular tip of the cylindrical portion 50 of the inspection cover 5 may be fitted with a compressible foamed sealing material 51. Since the foamed sealant 51 fills the gaps in the steps, inspection can be easily performed even if there are steps in the sealing portion of the fluid pipe K provided by the packing 3.

[0029] [5] In the method for manufacturing a fluid pipe described in [4] above, an annular tip portion may be positioned to overcome at least one of the steps (P2) between the inner circumferential surface K1 of the fluid pipe K and the packing 3, and the step (P3) between the lining layer 2 and the packing 3, and the foamed sealing material 51 may be compressed to fill the gap of at least one of the steps. Since the foamed sealing material 51 fills the gap in at least one of the steps, inspection can be easily performed even if there is a step in the sealing portion of the fluid pipe K provided by the packing 3.

[0030] [6] In the method for manufacturing a fluid pipe described in any of [1] to [5] above, the cylindrical portion 50 of the inspection cover 5 may have a bellows structure. The cylindrical portion 50 of the inspection cover 5 can be easily pressed against the designated check points (P1, P2, P3) in the desired orientation, making the inspection process easier.

[0031] [7] In the method for manufacturing a fluid pipe described in any of the above [1] to [6], the inspection cover 5 may have a transparent window 53 that allows the inside to be seen. Since the foaming process can be visually observed while negative pressure is applied, confirmation becomes easier.

[0032] [8] Although not particularly limited, the fluid pipe leak testing device may include an inspection cover 5 having a cylindrical portion 50 that is pressed against a position surrounding predetermined check points (P1, P2, P3) in the sealing portion of the fluid pipe K sealed by the packing 3, and the inspection cover 5 may be connected to a negative pressure hose 52 for creating negative pressure inside the inspection cover 5, and a compressible foamed sealing material 51 may be attached to the annular tip of the cylindrical portion 50 of the inspection cover 5. Since the foamed sealant 51 fills in the gaps and creates an airtight seal, negative pressure can be applied to the designated check points (P1, P2, P3), making it easy to inspect the airtightness of the packing 3.

[0033] [9] In the fluid pipe leak testing device described in [8] above, the cylindrical portion 50 of the inspection cover 5 may have a bellows structure. The cylindrical portion 50 of the inspection cover 5 can be easily pressed against the designated check points (P1, P2, P3) in the desired orientation, making the inspection process easier.

[0034]

[10] In the fluid pipe leak testing device described in [8] or [9] above, the inspection cover 5 may have a transparent window 53 that allows the inside to be seen. Since the foaming process can be visually observed while negative pressure is applied, confirmation becomes easier.

[0035] Although embodiments of this disclosure have been described above with reference to the drawings, it should be understood that the specific configurations are not limited to these embodiments. The scope of this disclosure is indicated not only by the description of the embodiments above but also by the claims, and further includes all modifications within the meaning and scope equivalent to the claims.

[0036] The structures adopted in each of the above embodiments can be adopted in any other embodiment. The specific configuration of each part is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of this disclosure. [Explanation of Symbols]

[0037] K…Fluid pipe K1…Inner peripheral surface 2…Lining layer 3… Gasket 5…Inspection cover 50...Tubular part 51… Foamed sealant AD…Pipe axis direction RD1…Inner side in pipe radial direction RD2…Outside in pipe radial direction P1…First joint surface (designated check point) P2...Second bonding surface (designated check point) P3...Third joint surface (designated check point)

Claims

1. Forming a lining layer on the inner surface of the fluid tube, A packing is provided to cover the inner circumferential surface of the fluid pipe located outside the axial end of the lining layer in the axial direction, and the end of the lining layer, from the inside in the radial direction of the pipe. The inspection agent, which generates bubbles when gas passes through, is applied to a predetermined check point in the sealing portion sealed by the packing, A method for manufacturing a fluid tube, comprising pressing the cylindrical portion of an inspection cover against a position surrounding the predetermined check location to create negative pressure inside the inspection cover, and confirming the presence or absence of air bubbles in the inspection agent at the predetermined check location.

2. The method according to claim 1, wherein the predetermined check locations are the joint surface between the inner circumferential surface of the fluid pipe and the packing, and the joint surface between the lining layer and the packing.

3. The packing is joined at both ends in the circumferential direction of the pipe. The method according to claim 2, wherein the predetermined check location further includes the joint surfaces of the two ends of the packing in the circumferential direction of the pipe.

4. The method according to any one of claims 1 to 3, wherein a compressible foam sealing material is attached to the annular tip of the cylindrical portion of the inspection cover.

5. The method according to claim 4, wherein the annular tip is positioned to overcome at least one of the steps between the inner circumferential surface of the fluid tube and the packing, and the steps between the lining layer and the packing, and the foamed sealing material is compressed to fill the gap of the steps.

6. The method according to claim 1, wherein the cylindrical portion of the inspection cover has a bellows structure.

7. The method according to claim 1, wherein the inspection cover has a transparent window that allows the interior to be viewed.

8. A fluid pipe leak inspection device used in the method for manufacturing a fluid pipe according to claim 1, The inspection cover comprises a cylindrical portion made of a rubber member that is pressed against a position surrounding a predetermined check point in the sealing portion of the fluid pipe that is sealed by a packing, and a metal ring member and a transparent plate that sandwich the annular base end of the cylindrical portion, The inspection cover is capable of connecting a negative pressure hose to create negative pressure inside the inspection cover. A compressible foam sealing material is attached to the annular tip of the cylindrical portion of the inspection cover. The inspection cover is a fluid pipe leak inspection device having a transparent window that allows the interior to be seen, formed by the hollow portion of the metal ring member and the transparent plate.

9. The apparatus according to claim 8, wherein the cylindrical portion of the inspection cover has a bellows structure.

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