Repairing method for fluid leakage and repairing tool

Abstract

To facilitate repair using welding by a simpler device.SOLUTION: A repairing method for fluid leakage from a pipe 11 with no valve for stopping a flow of fluid is provided. The method comprises: a first ring 1 whose internal diameter is equal to the external diameter of the pipe 11; a second ring 2 whose internal diameter is equal to the external diameter of the pipe 11, and whose external diameter is smaller than the external diameter of the first ring 1; and a joint pipe 3 whose internal diameter is equal to the external diameter of the second ring 2, and whose external diameter is equal to or smaller than the external diameter of the first ring 1; and comprises: a step of fixing the first ring 1 and the second ring 2 to an outer peripheral surface of the pipe 11 from an upstream side; a step of cutting the pipe 11 at a position downstream of a position at which the second ring 2 is attached; and a joint pipe attachment step S40 of bringing an external diameter surface of the fixed second ring 2 into contact with an internal diameter surface of the joint pipe 3, bringing one end side in the axial direction of the joint pipe 3 into contact with a side surface of the fixed first ring 1, and fixing it.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technology for repairing leaks in piping, such as piping for low pressure fluids. The present invention is an effective technology for repairing leaks in piping when there is no valve to stop the flow of fluid on the upstream side (also referred to as the primary side) of the leak and therefore it is necessary to perform the leak repair without stopping the flow of the fluid, and when repair using stronger welding is required. In this specification, the term "low pressure fluid piping" refers to a piping in which the fluid pressure is, for example, 2 MPa or less. [Background technology]

[0002] Conventionally, repairs to pipe leaks have been carried out using a method such as that described in Patent Document 1. This type of repair method involves attaching a dedicated tool that is significantly larger than the diameter of the pipe to the pipe, and having a worker with specialized skills install a valve or branch pipe to stop the flow of fluid without interrupting the water supply. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-181790 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned non-stop water supply method requires drilling holes in the side of the existing pipe to install valves and branch pipes to stop the flow of fluid. However, this method usually requires a drilling tool several times larger than the diameter of the pipe, making it unsuitable for work in narrow spaces. Also, while simply installing a branch pipe can be done relatively inexpensively, the construction method of installing a valve to stop the flow of fluid can be very expensive. In addition, this construction method requires special parts, so there is a concern that they may be in short supply. Furthermore, this construction method requires workers with specialized skills, so it may be difficult to repair leaks quickly. Pipe repairs are generally performed using welding as a long-term solution, but if the fluid inside the pipe cannot be cut off using special products such as those mentioned above, there is a risk that the fluid may get into the welded area, making the welded repair impossible.

[0005] The present invention has been made in light of the above-mentioned points, and has an object to make it easier to carry out repairs by welding using simpler equipment. [Means for solving the problem]

[0006] In order to solve the problem, one aspect of the present invention is a method for repairing a fluid leak in a pipe to be repaired that does not have a valve for stopping a flow of a fluid upstream of a fluid leakage position in the pipe to be repaired, the method comprising: an endless annular first ring having an inner diameter equal to an outer diameter of the pipe to be repaired; an endless annular second ring having an inner diameter equal to the outer diameter of the pipe to be repaired and an outer diameter smaller than the outer diameter of the first ring; and a joint pipe having an inner diameter equal to the outer diameter of the second ring and an outer diameter equal to or smaller than the outer diameter of the first ring, the method comprising the steps of: providing a joint pipe having an outer peripheral surface of the pipe upstream of the leakage position in the pipe to be repaired with the valve for stopping a flow of the fluid; The method includes the steps of: fixing a first ring and the second ring so that the first ring is positioned upstream of the second ring; cutting the pipe to be repaired at a position downstream of a position at which the second ring is attached; and, after the fixing and cutting steps, an attachment step of a fitting pipe in which the outer diameter surface of the second ring is brought into contact with the inner diameter surface of the fitting pipe and one axial end side of the fitting pipe is brought into contact with a side surface of the first ring and fixed, and the downstream side of the pipe to be repaired is connected to the other axial end side of the fitting pipe.

[0007] Another aspect of the present invention is a repair device for a fluid leak in a pipe to be repaired that does not have a valve to stop the flow of fluid upstream of the fluid leakage position in the pipe to be repaired, the device comprising: an endless annular first ring having an inner diameter equal to the outer diameter of the pipe to be repaired; an endless annular second ring having an inner diameter equal to the outer diameter of the pipe to be repaired and an outer diameter smaller than the outer diameter of the first ring; and a fitting pipe having an inner diameter equal to the outer diameter of the second ring and an outer diameter equal to or smaller than the outer diameter of the first ring. Effect of the Invention

[0008] According to an aspect of the present invention, a second ring is attached to the pipe to be repaired as a backflow prevention ring. In this way, when welding is performed to attach an end of a fitting pipe to the first ring in order to attach the fitting pipe to the pipe to be repaired, the second ring prevents the fluid flowing through the pipe to be repaired from moving toward the welding position. Therefore, according to this aspect of the present invention, welding repair can be easily performed. Repair materials (repair tools) are relatively easy to obtain, inexpensive, and made from common piping materials, making it possible to repair leaks at low cost without interrupting water supply, regardless of location or the number of workers required. [Brief description of the drawings]

[0009] [Figure 1] 1A to 1C are diagrams illustrating a repair tool according to an embodiment of the present invention in a used state. [Diagram 2] 1A and 1B are diagrams showing a first ring, in which (a) is a plan view and (b) is a view seen from a radial direction. [Diagram 3] 1A and 1B are diagrams showing the second ring, in which (a) is a plan view and (b) is a view seen from the radial direction. [Figure 4] FIG. 2 is a diagram showing a configuration example of a repair process according to an embodiment of the present invention. [Diagram 5] FIG. 1 is a diagram showing an example of a piping configuration and a leak. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] 11A to 11C are diagrams illustrating a ring mounting process. [Figure 9] FIG. 11 is a diagram illustrating a pipe cutting process. [Figure 10] 11 is a diagram illustrating the fitting pipe installation step S40. FIG. [Figure 11] 11A to 11C are diagrams illustrating a valve installation process and a downstream piping installation process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Next, an embodiment based on the present invention will be described with reference to the drawings. In the present embodiment, a low-pressure fluid pipe is exemplified as a pipe to be repaired. The present invention is suitable for low-pressure fluid pipes, but can also be applied to pipes that carry other fluids. (Repair tools) 1, the repair tool of this embodiment includes a first ring 1, a second ring 2, a joint pipe 3, and a closure plate 4. The closure plate 4 is not necessary. The first ring 1, the second ring 2, and the joint pipe 3 are made of a weldable metallic material.

[0011] <First Ring 1> 1 and 2, the first ring 1 is made of an endless annular plate material whose inner diameter D10 is equal to the outer diameter D0 of the pipe 11 to be repaired. As shown in Fig. 2, the first ring 1 is made of two halved semicircular arc-shaped members 1A, and is configured so that it can be attached to the outer circumferential surface of the pipe 11 to be repaired before the pipe cutting process S30.

[0012] <Second Ring 2> 1 to 3, the second ring 2 is made of an endless annular plate material whose inner diameter D11 is equal to the outer diameter D0 of the pipe 11 to be repaired. Furthermore, the second ring 2 is made of an endless annular plate material whose outer diameter D21 is smaller than the outer diameter D20 of the first ring 1. As shown in Fig. 3, the second ring 2 is made of two halved semicircular arc-shaped members 2A, and is configured so that it can be attached to the outer peripheral surface of the pipe 11 to be repaired before the pipe cutting step S30.

[0013] <Fitting pipe 3> 1, the joint pipe 3 is made of a tube having an inner diameter D30 equal to the outer diameter D21 of the second ring 2 and an outer diameter D31 equal to or smaller than the outer diameter D20 of the first ring 1. This allows the joint pipe 3 to be arranged coaxially or approximately coaxially on the outer periphery of the pipe 11 to be repaired. The length of the joint pipe 3 is longer than the length from the cut surface of the pipe 11 to be repaired to the mounting position of the first ring 1 on the pipe 11 to be repaired. There is no particular upper limit to the length of the joint pipe 3.

[0014] As shown in Fig. 1, a pressure relief valve 7 is connected to the side wall of the joint pipe 3. A hose or pipe (not shown) may be connected to the discharge side of the pressure relief valve 7. When a hose or pipe is connected, the fluid discharged from the joint pipe 3 can be guided to a position away from the joint pipe 3. When the joint pipe 3 is fixed to the first ring 1, it is preferable to adjust the circumferential position of the pressure relief valve 7 so that the position of the pressure relief valve 7 is at the lowest position. An outward flange 3A is provided on the other axial end (downstream end) of the joint pipe 3. A plurality of bolt holes 3Aa are opened in the outward flange 3A along the circumferential direction thereof.

[0015] <Occluded plate 4> The closure plate 4 is a plate material that closes the opening on the other axial end side of the joint pipe 3. The closure plate 4 has an outer periphery that is large enough to face the outward flange 3A, and a through hole 4a is opened in the outer periphery at a position facing the bolt hole 3Aa. As shown in FIG. 1, the closure plate 4 is fixed to the outward flange 3A of the joint pipe 3 by bolt fastening using bolts 5 and nuts 6, and closes the opening on the other axial end side of the joint pipe 3. It is not necessary to close the opening on the other axial end side of the joint pipe 3 with the closing plate 4 .

[0016] (How to repair a fluid leak in a pipe) As shown in FIG. 4, the method for repairing a fluid leak in this embodiment includes a depressurization step S10, a ring attachment step S20, a pipe cutting step S30, a joint pipe attachment step S40, a valve attachment step S50, and a downstream pipe attachment step S60. Here, in this example, a pipe connection as shown in Fig. 5 will be taken as an example for explanation. Also, the explanation will be given assuming that the fluid flowing through the pipe is water. The present invention is also applicable to cases where the fluid flowing through the pipe is a liquid or gas other than water.

[0017] In the example of Fig. 5, a branch pipe 11 is connected midway through a main pipe 10, and the flow path branches off. Assume that the branch pipe 11 is in a state that requires repair, that is, the piping 11 is broken or chipped, causing the internal fluid to leak to the outside. In Fig. 5, reference symbol 11A indicates a leaking portion 11A (leakage position). That is, in this example, the branch pipe 11 is the piping 11 to be repaired. As described above, in this example, the pipe 11 to be repaired is a low-pressure fluid pipe that does not have a valve for stopping the flow of fluid located upstream of the leaking part 11A. It does not matter whether the main pipe 10 has a shutoff valve (not shown). If the shutoff valve of the main pipe 10 is closed to repair a branch pipe, a problem occurs in that the supply of fluid to pipes and equipment other than the pipe 11 to be repaired is stopped.

[0018] <Decompression step S10> First, a location is found in the pipe 11 to be repaired, upstream of the leaking part 11A, where a branch pipe for uninterrupted water supply can be attached. Then, as shown in FIG. 6, the branch pipe 12 for uninterrupted water supply is connected to the identified location. The branch pipe 12 for uninterrupted water supply may be made of a pipe that is relatively easy to obtain. In this way, by attaching the branch pipe 12 for uninterrupted water supply, the flow rate in the pipe 11 to be repaired is narrowed, and the fluid pressure at and near the leaking part 11A is reduced. This process is carried out using, for example, a Cosmo Borer.

[0019] In this embodiment, after the branch pipe 12 for uninterrupted water supply is installed, a baffle plate 13 is inserted into the pipe 11 to be repaired from inside the branch pipe, as shown in Fig. 7. This further restricts the flow rate in the pipe 11 to be repaired, thereby further reducing the pressure. For example, in the pipe 11 to be repaired, the low pressure fluid, which is normally about 1 to 2 MPa, can be reduced to about 0.3 MPa. This depressurization step S10 may be omitted. However, by performing the depressurization step S10, the pressure of the fluid at the repair position can be more reliably suppressed.

[0020] <Ring attachment process S20> The ring attachment step S20 is performed after the depressurization step S10. The ring attachment step S20 is a step of fixing the first ring 1 and the second ring 2 to the outer circumferential surface of the pipe 11 to be repaired on the upstream side of the leak position, as shown in Fig. 8. At this time, the first ring 1 and the second ring 2 are attached so that the first ring 1 is disposed upstream of the second ring 2, as shown in Fig. 8. The first ring 1 and the second ring 2 may be attached by welding.

[0021] Here, the first ring 1 and the second ring 2 have a half-split structure. Therefore, the first ring 1 and the second ring 2 can be attached to the pipe 11 to be repaired before the pipe 11 to be repaired is cut for repair. This prevents the fluid flowing through the pipe 11 to be repaired from interfering with the welding work. At this time, the leaking portion 11A may be temporarily blocked before the welding work is performed.

[0022] <Piping cutting process S30> After the ring attachment step S20 is completed, the pipe cutting step S30 is performed. The pipe cutting step S30 is a step of cutting the pipe 11 to be repaired at a position downstream of the position where the second ring 2 is attached, as shown in Figs. Although the ring attachment step S20 may be performed after the pipe cutting step S30, the welding work is likely to be hindered by the fluid flowing inside the pipe 11 to be repaired.

[0023] <Fitting process for fitting pipes S40> The fitting pipe attachment step S40 is performed after the ring attachment step S20 and the pipe cutting step S30. In the fitting pipe attachment step S40, as shown in Fig. 10, the fitting pipe 3 is moved in the axial direction from the cutting direction of the pipe 11 to be repaired toward the first ring 1. Then, the fitting pipe 3 is placed on the outer periphery of the pipe 11 to be repaired. At this time, as shown in Fig. 10, the outer diameter surface of the second ring 2 comes into contact with the inner diameter surface of the fitting pipe 3, and the fitting pipe 3 is guided coaxially with the pipe 11 to be repaired. At this time, the circumferential position of the joint pipe 3 is adjusted so that the pressure relief valve 7 faces downward. Furthermore, one axial end of the joint pipe 3 is brought into contact with the side surface of the first ring 1. After that, one axial end of the joint pipe 3 is fixed to the surface of the first ring 1 by welding. The reference numeral 20 denotes a welded portion.

[0024] During this welding, fluid flows from the pipe 11 to be repaired into the fitting pipe 3, and as shown in Fig. 10, the fluid flows into a gap formed between the outer diameter surface of the pipe 11 to be repaired and the inner diameter surface of the fitting pipe 3. However, the second ring 2, which is in contact (sliding contact) with the inner diameter surface of the fitting pipe 3, prevents the fluid from flowing into the welded portion between the axial end of the fitting pipe 3 and the first ring 1. As a result, the welding can be performed more reliably.

[0025] Furthermore, in this embodiment, by opening the pressure relief valve 7, the fluid that has flowed into the joint pipe 3 is discharged downward, reducing the pressure in the joint pipe 3 and preventing the fluid from flowing into the welded portion. Note that by connecting a hose or pipe to the pressure relief valve 7, it is also possible to promote the discharge of the fluid outside the repair portion. Here, in this embodiment, an example has been described in which a blocking plate 4 is attached to the joint piping 3 to prevent fluid from being discharged from the other end side of the joint piping 3, and fluid is discharged from the pressure relief valve 7.

[0026] Instead of omitting the pressure relief valve 7, the attachment of the closure plate 4 may be omitted. Even in this case, it is possible to reduce the pressure inside the joint pipe 3. However, when discharging the fluid from the pressure relief valve 7, the position where the fluid is discharged is limited to one location, making it easier to handle the discharged fluid. Also, instead of attaching the closure plate 4 to the joint pipe 3 in advance, the shutoff valve 15 may be attached to the joint pipe 3 (see FIG. 11). In this case, the valve attachment step S50 is executed in advance. However, in this case, when working in a narrow space, it may be time-consuming to handle the joint pipe 3.

[0027] <Valve installation process S50, downstream piping installation process S60> After the joint pipe installation step S40 is completed, the closure plate 4 is removed and a shutoff valve 15 is installed instead, as shown in Fig. 11. The shutoff valve 15 is a gate valve, a ball valve, or the like. In addition, downstream piping 16 is attached downstream of the shutoff valve 15 . Here, the downstream pipe 16 may be directly attached to the outward flange 3A of the joint pipe 3. After the repair work is completed, the baffle plate 13 is removed to close the branch pipe 12 for uninterrupted water supply. The pressure relief valve 7 is also closed.

[0028] (Actions and others) In this embodiment, when the joint pipe 3 is attached by welding to the first ring 1 attached to the pipe 11 to be repaired, the second ring 2 acts as a backflow prevention ring toward the first ring 1 side. This makes it possible to prevent intrusion into the welded portion. In other words, the simple configuration makes it easy to perform welding repair. Furthermore, the repair tools can be made of relatively easy-to-obtain, inexpensive, and general piping materials. Furthermore, the series of operations can be performed anywhere, and by any worker with welding skills. In this way, it is possible to repair leaks at low cost without interrupting water supply, without being limited to workers with special skills. This embodiment is intended to repair leaks at low cost, anywhere, and without completely stopping the flow of fluid in the piping 11 to be repaired. In addition, by installing a branch pipe to release the fluid prior to repair work, the fluid pressure in the area to be repaired can be further reduced.

[0029] (others) The present disclosure may also have the following configuration. (1) A method for repairing a fluid leak in a pipe to be repaired that does not have a valve for stopping the flow of the fluid upstream of the fluid leak position in the pipe to be repaired, comprising the steps of: An endless annular first ring having an inner diameter equal to an outer diameter of the pipe to be repaired; an endless annular second ring having an inner diameter equal to the outer diameter of the pipe to be repaired and an outer diameter smaller than the outer diameter of the first ring; a joint pipe having an inner diameter equal to the outer diameter of the second ring and an outer diameter equal to or smaller than the outer diameter of the first ring; fixing the first ring and the second ring to an outer circumferential surface of a pipe upstream of the leak location in the pipe to be repaired such that the first ring is disposed upstream of the second ring; cutting the pipe to be repaired at a position downstream of a position where the second ring is attached; a fitting step of contacting an outer diameter surface of the second ring with an inner diameter surface of the joint pipe and contacting one axial end side of the joint pipe with a side surface of the first ring and fixing the joint pipe after the fixing step and the cutting step; Equipped with The downstream side of the pipe to be repaired is connected to the other axial end side of the joint pipe. How to repair a fluid leak.

[0030] (2) The piping to be repaired is a piping for low-pressure fluid. (3) A branch pipe for forcibly throttling the flow rate is attached to the pipe to be repaired upstream of the first ring and its attachment position, and then the cutting step is performed. (4) An outward flange having bolt holes for mounting is provided on the other axial end of the joint pipe, During the mounting step, a blocking plate that blocks the opening on the other axial end side of the joint pipe is mounted to the outward flange. (5) The above-mentioned joint piping is provided with a pressure relief valve.

[0031] (6) A repair tool for a fluid leak in a pipe to be repaired that does not have a valve to stop the flow of the fluid upstream of the fluid leak location, An endless annular first ring having an inner diameter equal to an outer diameter of the pipe to be repaired; an endless annular second ring having an inner diameter equal to the outer diameter of the pipe to be repaired and an outer diameter smaller than the outer diameter of the first ring; a joint pipe having an inner diameter equal to an outer diameter of the second ring and an outer diameter equal to or smaller than an outer diameter of the first ring; A device for repairing fluid leaks. (7) The above-mentioned joint pipe is provided with an outward flange on the other axial end side, the outward flange having a bolt hole for mounting, Furthermore, a closing plate is provided which is bolted to the outward flange to close the opening on the other axial end side of the joint pipe. (8) The above-mentioned joint pipe is provided with a pressure relief valve. [Explanation of symbols]

[0032] 1. The First Ring 2. The Second Ring 3. Pipe Fittings 3A Outward flange 4 Occlusion plate 7 Pressure relief valve 11 Pipes to be repaired 11A Leak (Leak Location) 12 Branch piping for continuous water supply 13 Baffle Plate 15 Shut-off valve 16 Downstream piping S10 Decompression process S20 Ring installation process (fixing process) S30 Pipe cutting process (cutting process) S40 Fitting pipe installation process S50 valve installation process S60 Downstream piping installation process

Claims

1. A method for repairing a fluid leak in a pipe to be repaired that does not have a valve for stopping a flow of the fluid upstream of a fluid leakage position in the pipe to be repaired, comprising the steps of: An endless annular first ring having an inner diameter equal to an outer diameter of the pipe to be repaired; an endless annular second ring having an inner diameter equal to the outer diameter of the pipe to be repaired and an outer diameter smaller than the outer diameter of the first ring; a joint pipe having an inner diameter equal to the outer diameter of the second ring and an outer diameter equal to or smaller than the outer diameter of the first ring; a step of fixing the first ring and the second ring to an outer circumferential surface of a pipe upstream of the leak position in the pipe to be repaired such that the first ring is disposed upstream of the second ring; cutting the pipe to be repaired at a position downstream of a position where the second ring is attached; a fitting step of contacting an outer diameter surface of the second ring with an inner diameter surface of the joint pipe and contacting one axial end side of the joint pipe with a side surface of the first ring and fixing the joint pipe after the fixing step and the cutting step; Equipped with The downstream side of the pipe to be repaired is connected to the other axial end side of the joint pipe. How to repair a fluid leak.

2. The piping to be repaired is a low-pressure fluid piping.

2. A method for repairing a fluid leak as claimed in claim 1.

3. a branch pipe for forcibly throttling the flow rate is attached to the pipe to be repaired upstream of the first ring and its attachment position, and then the cutting step is performed.

2. A method for repairing a fluid leak as claimed in claim 1.

4. An outward flange having bolt holes for mounting is provided on the other axial end side of the joint pipe, During the mounting step, a blocking plate is attached to the outward flange to block an opening on the other axial end side of the joint pipe. A method for repairing a fluid leak according to any one of claims 1 to 3.

5. The joint pipe is provided with a pressure relief valve. A method for repairing a fluid leak according to any one of claims 1 to 3.

6. The joint pipe is provided with a pressure relief valve.

5. A method for repairing a fluid leak according to claim 4.

7. A repair tool for a fluid leak in a pipe to be repaired that does not have a valve for stopping the flow of the fluid upstream of the fluid leak position, An endless annular first ring having an inner diameter equal to an outer diameter of the pipe to be repaired; an endless annular second ring having an inner diameter equal to the outer diameter of the pipe to be repaired and an outer diameter smaller than the outer diameter of the first ring; a joint pipe having an inner diameter equal to an outer diameter of the second ring and an outer diameter equal to or smaller than an outer diameter of the first ring; A device for repairing fluid leaks.

8. The joint pipe has an outward flange on the other axial end side, the outward flange having bolt holes for mounting, Further, a blocking plate is provided which is bolted to the outward flange to block an opening on the other axial end side of the joint pipe.

8. A tool for repairing a fluid leak as claimed in claim 7.

9. The joint pipe is provided with a pressure relief valve.

9. A tool for repairing a fluid leak according to claim 7 or 8.

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