Methods for repairing fluid leaks, and repair tools.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- JFE STEEL CORP
- Filing Date
- 2023-08-07
- Publication Date
- 2026-06-30
Smart Images
Figure 0007882184000001 
Figure 0007882184000002 
Figure 0007882184000003
Abstract
Description
Technical Field
[0001] The present invention relates to a technique for repairing leaks in pipes to be repaired, such as pipes for low-pressure fluids. In the repair of pipe leaks, since there is no valve to stop the flow on the upstream side of the leak portion (also referred to as the primary side), it is necessary to repair the leak without stopping the fluid flow. Further, it is an effective technique when repair using stronger welding is required. Here, in this specification, the low-pressure fluid pipe refers to, for example, a pipe in which the fluid pressure is 2 MPa or less.
Background Art
[0002] Conventional pipe leak repairs have adopted methods such as those described in Patent Document 1. Such a repair method is a method in which a dedicated tool much larger than the pipe diameter is attached to the pipe, and a valve or a branch pipe for stopping the fluid flow is attached without stopping the water flow by an operator with specialized skills.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In the above-described non-stop water method, in order to attach a valve or a branch pipe for stopping the fluid flow, it is necessary to drill a hole in the side surface of the existing pipe. However, this construction usually requires a drilling jig that is several times larger than the pipe diameter, and thus is not suitable for construction in narrow spaces. Further, if only a branch pipe is attached, it can be performed relatively inexpensively. However, the construction method of attaching a valve for stopping the fluid flow tends to be very expensive. Further, since this construction method uses special products, there is a concern about stock shortages. Furthermore, since this construction method requires an operator with specialized skills, it may be difficult to respond promptly to leak repairs in some cases. In pipe repair, welding is generally used as a long-term solution. However, if it is not possible to cut off the fluid flow inside the pipe using the special products mentioned above, there is a risk that the welding repair may become impossible due to fluid ingress into the welded joint.
[0005] This invention was made with the above-mentioned points in mind, and aims to make welding-based repairs easier to perform with a simpler device. [Means for solving the problem]
[0006] To solve the problem, one aspect of the present invention provides a method for repairing a fluid leak in a pipe to be repaired, in which there is no valve to stop the fluid flow upstream of the fluid leakage location in the pipe to be repaired, comprising: an endless annular first ring whose inner diameter is equal to the outer diameter of the pipe to be repaired; an endless annular second ring whose inner diameter is equal to the outer diameter of the pipe to be repaired and whose outer diameter is smaller than the outer diameter of the first ring; and a fitting pipe whose inner diameter is equal to the outer diameter of the second ring and whose outer diameter is less than or equal to the outer diameter of the first ring, wherein the outer surface of the pipe upstream of the leakage location in the pipe to be repaired is provided with the above The method includes the steps of: fixing the first ring and the second ring such that the first ring is positioned upstream of the second ring; cutting the pipe to be repaired at a position downstream of the position where the second ring is attached; and, after the fixing and cutting steps, attaching the fitting pipe by bringing the outer diameter surface of the second ring into contact with the inner diameter surface of the fitting pipe and fixing one axial end of the fitting pipe in contact with the side surface of the first ring, and connecting the downstream side of the pipe to be repaired to the other axial end of the fitting pipe.
[0007] Another aspect of the present invention provides a fluid leak repair device for a pipe to be repaired in which there is no valve to stop the flow of fluid upstream of the fluid leak location, comprising: a first endless annular ring whose inner diameter is equal to the outer diameter of the pipe to be repaired; a second endless annular ring whose inner diameter is equal to the outer diameter of the pipe to be repaired and whose outer diameter is smaller than the outer diameter of the first ring; and a fitting pipe whose inner diameter is equal to the outer diameter of the second ring and whose outer diameter is less than or equal to the outer diameter of the first ring. [Effects of the Invention]
[0008] According to an aspect of the present invention, a second ring is attached to the piping to be repaired as a backflow prevention ring. This prevents the fluid flowing through the piping to be repaired from moving to the welding position when welding is performed to attach the end of the fitting pipe to the first ring in order to attach the fitting pipe to the piping to be repaired. Therefore, according to an aspect of the present invention, welding repair is made easier. By using readily available, inexpensive, and common piping materials (repair tools), it becomes possible to repair leaks without interrupting the water supply at a low cost, regardless of location or the need for workers with special skills. [Brief explanation of the drawing]
[0009] [Figure 1] This figure illustrates a repair device according to an embodiment of the present invention in a state of use. [Figure 2] This is a diagram of the first ring. (a) is a plan view, and (b) is a view from the radial direction. [Figure 3] This is a diagram of the second ring. (a) is a plan view, and (b) is a view from the radial direction. [Figure 4] This figure shows an example of the configuration of a repair process according to an embodiment of the present invention. [Figure 5] This diagram shows examples of piping configurations and leaks. [Figure 6] This is a diagram illustrating the depressurization process. [Figure 7] This is a diagram illustrating the depressurization process. [Figure 8] This is a diagram illustrating the ring mounting process. [Figure 9] This is a diagram illustrating the pipe cutting process. [Figure 10] This diagram illustrates the installation process S40 for fittings piping. [Figure 11] This diagram illustrates the valve installation process and the downstream piping installation process. [Modes for carrying out the invention]
[0010] Next, embodiments based on the present invention will be described with reference to the drawings. In this embodiment, low-pressure fluid piping is used as an example to describe the piping to be repaired. While the present invention is suitable for low-pressure fluid piping, it can also be applied to piping that carries other fluids. (Repair tools) The repair tool of this embodiment, as shown in Figure 1, comprises a first ring 1, a second ring 2, a fitting pipe 3, and a closing plate 4. The closing plate 4 is optional. The first ring 1, the second ring 2, and the fitting pipe 3 are made of a weldable metal material.
[0011] <Ring 1> As shown in Figures 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 Figure 2, the first ring 1 is made up of two halved semi-circular members 1A, so that it can be attached to the outer surface of the pipe 11 to be repaired before the pipe cutting process S30.
[0012] <The Second Ring 2> As shown in FIGS. 1 to 3, the second ring 2 is made of an endless annular plate material with an inner diameter D11 equal to the outer diameter D0 of the pipe 11 to be repaired. Further, the second ring 2 is made of an endless annular plate material with an outer diameter D21 smaller than the outer diameter D20 of the first ring 1. As shown in FIG. 3, the second ring 2 is composed of two semi-circular arc-shaped members 2A that are halved, 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] <Pipe 3 for joint> As shown in FIG. 1, the pipe 3 for joint is composed of a pipe body with an inner diameter D30 equal to the outer diameter D21 of the second ring 2 and an outer diameter D31 not exceeding the outer diameter D20 of the first ring 1. Thereby, the pipe 3 for joint can be arranged coaxially or substantially coaxially on the outer peripheral side of the pipe 11 to be repaired. Note that the length of the pipe 3 for joint is longer than the length from the cut surface cut in the pipe 11 to be repaired to the attachment position of the first ring 1 in the pipe 11 to be repaired. There is no particular upper limit to the length of the pipe 3 for joint.
[0014] As shown in FIG. 1, a pressure relief valve 7 is connected to the side wall of the pipe 3 for joint. 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 pipe 3 for joint can be guided to a position away from the pipe 3 for joint. When fixing the pipe 3 for joint to the first ring 1, it is advisable to adjust the circumferential position so that the position of the pressure relief valve 7 is at the lowermost position. Further, an outward flange 3A is provided on the other end side in the axial direction (downstream end side) of the pipe 3 for joint. A plurality of bolt holes 3Aa are opened along the circumferential direction of the outward flange 3A.
[0015] <Blocking plate 4> The closing plate 4 is a plate material that closes the opening on the other axial end of the joint pipe 3. The closing plate 4 has an outer circumference that is large enough to face the outward flange 3A, and a through hole 4a is opened on the outer circumference at a position facing the bolt hole 3Aa. As shown in Figure 1, the closing plate 4 is fixed to the outward flange 3A of the joint pipe 3 by bolt fastening using bolts 5 and nuts 6, thereby closing the opening on the other axial end of the joint pipe 3. Furthermore, it is not necessary to close the opening on the other axial end of the joint pipe 3 with the closing plate 4.
[0016] (Methods for repairing fluid leaks in piping) As shown in Figure 4, the fluid leak repair method of this embodiment comprises a depressurization step S10, a ring installation step S20, a pipe cutting step S30, a fitting pipe installation step S40, a valve installation step S50, and a downstream pipe installation step S60. In this example, we will explain using the piping connection shown in Figure 5 as an example. We will also assume that the fluid flowing through the piping is water. However, the present invention is also applicable when the fluid flowing through the piping is a liquid or gas other than water.
[0017] In the example shown in Figure 5, a branch pipe 11 is connected to the main pipe 10, causing the flow path to branch off. The branch pipe 11 is in a state requiring repair, meaning it has ruptured or fractured, causing the internal fluid to leak to the outside. In Figure 5, reference numeral 11A indicates the leak point 11A (leak location). In other words, in this example, the branch pipe 11 is the pipe 11 that needs repair. As described above, in this example, the pipe 11 to be repaired is a low-pressure fluid pipe that does not have a valve to stop the fluid flow upstream of the leak 11A. It is not relevant whether the main pipe 10 has a shut-off valve (not shown). If the shut-off valve of the main pipe 10 is closed in order to repair the branch pipe, a problem arises in that the supply of fluid to pipes and equipment other than the pipe 11 being repaired will be stopped.
[0018] <Depressurization process S10> First, locate a suitable location upstream of the leak 11A in the pipe 11 to be repaired for the installation of a branch pipe for continuous water supply. Then, as shown in Figure 6, connect the branch pipe 12 for continuous water supply to the located location. The branch pipe 12 for continuous water supply can be made of readily available tubing. By installing the branch pipe 12 for continuous water supply in this way, the flow rate in the pipe 11 to be repaired is reduced, and the fluid pressure at and near the leak 11A is decreased. This process can be carried out, for example, using a Cosmo Borer.
[0019] In this embodiment, after installing the branch pipe 12 for continuous water supply, a baffle plate 13 is inserted into the pipe 11 to be repaired from inside the branch pipe, as shown in Figure 7. This further restricts the flow rate in the pipe 11 to be repaired, thereby lowering the pressure even more. For example, the fluid in the pipe 11 to be repaired, which normally has a low pressure of about 1 to 2 MPa, can be reduced to about 0.3 MPa. The depressurization process S10 may be omitted. However, performing the depressurization process S10 allows for a more reliable reduction of the fluid pressure at the repair location.
[0020] <Ring installation process S20> The ring installation process S20 is performed after the depressurization process S10. The ring installation process S20 is a process of fixing the first ring 1 and the second ring 2 to the outer surface of the pipe upstream of the leak location in the pipe 11 to be repaired, as shown in Figure 8. At this time, as shown in Figure 8, the first ring 1 and the second ring 2 are installed so that the first ring 1 is positioned upstream of the second ring 2. The first ring 1 and the second ring 2 can be installed by welding.
[0021] Here, the first ring 1 and the second ring 2 have a split structure. Therefore, the first ring 1 and the second ring 2 can be attached to the pipe 11 to be repaired before cutting the pipe 11 for repair. This prevents the fluid flowing inside the pipe 11 from interfering with the welding work. At this time, the leak 11A may be temporarily sealed before performing the welding work.
[0022] <Piping cutting process S30> Once the ring installation process S20 is completed, the pipe cutting process S30 is executed. As shown in Figures 8 and 9, the pipe cutting process S30 is a process in which the pipe 11 to be repaired is cut at a position downstream from the position where the second ring 2 is attached. Although the ring installation process S20 may be performed after the pipe cutting process S30, the fluid flowing through the pipe 11 to be repaired is likely to interfere with the welding work.
[0023] <Installation process for fittings and piping S40> The fitting pipe installation process S40 is performed after the ring installation process S20 and the pipe cutting process S30. In the fitting pipe installation process S40, as shown in Figure 10, the fitting pipe 3 is moved axially from the cutting direction of the pipe 11 to be repaired toward the first ring 1. The fitting pipe 3 is then positioned on the outer circumference of the pipe 11 to be repaired. At this time, as shown in Figure 10, the outer diameter surface of the second ring 2 contacts the inner diameter surface of the fitting pipe 3, guiding the fitting pipe 3 coaxially with the pipe 11 to be repaired. At this time, the circumferential position of the fitting pipe 3 is adjusted so that the pressure relief valve 7 faces downwards. Furthermore, the axial end of the fitting pipe 3 is brought into contact with the side surface of the first ring 1. Then, the axial end of the fitting pipe 3 is fixed to the surface of the first ring 1 by welding. Reference numeral 20 indicates a welded joint.
[0024] During this welding process, fluid flows from the pipe 11 to be repaired into the fitting pipe 3, and as shown in Figure 10, this fluid flows into the 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) with the inner diameter surface of the fitting pipe 3, prevents the fluid from flowing to the welding point 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 piping 3 is discharged downwards, reducing the pressure inside the joint piping 3 and further preventing the fluid from flowing into the welding area. Additionally, by connecting a hose or pipe to the pressure relief valve 7, it is possible to facilitate the discharge of fluid outside the repair area. In this embodiment, an example was described in which a blocking plate 4 is attached to the fitting pipe 3 to prevent fluid discharge from the other end of the fitting pipe 3, and fluid is discharged from the pressure relief valve 7.
[0026] Instead of omitting the pressure relief valve 7, the installation of the blocking plate 4 may also be omitted. Even in this case, the pressure inside the fitting piping 3 can be reduced. However, when fluid is discharged from the pressure relief valve 7, the fluid discharge location is limited to one place, making it easier to handle the discharged fluid. Alternatively, instead of pre-attaching the closing plate 4 to the fitting pipe 3, the shut-off valve 15 may be attached to the fitting pipe 3 (see Figure 11). In this case, the valve installation process S50 will be performed in advance. However, in this case, handling the fitting pipe 3 may be time-consuming, especially when working in confined spaces.
[0027] <Valve installation process S50, downstream piping installation process S60> After the installation process S40 for the fitting piping is completed, the closing plate 4 is removed and a shut-off valve 15 is installed in its place, as shown in Figure 11. The shut-off valve 15 is a gate valve or a ball valve, etc. Furthermore, a downstream pipe 16 is installed downstream of the shut-off valve 15. In this case, the downstream pipe 16 may be directly attached to the outward flange 3A of the fitting pipe 3. Furthermore, after the repairs are completed, remove the baffle plate 13 and close the branch pipe 12 for continuous water supply. Also, close the pressure relief valve 7.
[0028] (Functions and other effects) In this embodiment, when a fitting pipe 3 is welded to a first ring 1 attached to the pipe 11 to be repaired, the second ring 2 acts as a backflow prevention ring towards the first ring 1. This prevents water from entering the welded area. In other words, it makes welding repairs easier with a simple configuration. Furthermore, readily available, inexpensive, and common piping materials can be used for the repair equipment. Moreover, the entire process can be performed anywhere, and by any worker with welding skills. Thus, it becomes possible to repair leaks at low cost without interrupting the water flow, without requiring workers with special skills. This embodiment allows for inexpensive and location-independent leak repair without completely stopping the fluid flow in the target pipe 11. Furthermore, by installing a branch pipe to release the fluid before repair work, the fluid pressure at the repaired section can be further reduced.
[0029] (others) This disclosure may also take the following form: (1) A method for repairing a fluid leak in a pipe to be repaired, in which there is no valve to stop the flow of fluid upstream of the location of the fluid leak in the pipe to be repaired, A first ring with an endless ring whose inner diameter is equal to the outer diameter of the pipe to be repaired, A second ring having an endless annular shape, the inner diameter of which is equal to the outer diameter of the pipe to be repaired and the outer diameter of which is smaller than the outer diameter of the first ring, The fitting includes a pipe whose inner diameter is equal to the outer diameter of the second ring and whose outer diameter is less than or equal to the outer diameter of the first ring, The process involves fixing the first ring and the second ring to the outer surface of the pipe upstream of the leak location in the pipe to be repaired, such that the first ring is positioned upstream of the second ring. The process involves cutting the pipe to be repaired at a position downstream from the location where the second ring is to be installed, After the above fixing step and the above cutting step, the fitting pipe installation step involves bringing the outer diameter surface of the second ring into contact with the inner diameter surface of the fitting pipe, and fixing the axial end of the fitting pipe in contact with the side surface of the first ring, Equipped with, The downstream side of the pipe to be repaired is connected to the other axial end of the above-mentioned joint piping. Methods for repairing fluid leaks.
[0030] (2) The piping subject to repair as described above is piping for low-pressure fluids. (3) In the piping to be repaired, a branch pipe for forcibly restricting the flow rate is installed upstream of the first ring and its mounting position, and then the cutting process is performed. (4) An outward-facing flange with mounting bolt holes is provided on the other axial end of the above-mentioned joint piping, During the above installation process, a closing plate is attached to the outward-facing flange to close the opening on the other axial end side of the joint piping. (5) The piping for the above-mentioned joint is equipped with a pressure relief valve.
[0031] (6) A device for repairing a fluid leak in a pipe to be repaired, in which there is no valve to stop the flow of fluid upstream of the location of the fluid leak, A first ring with an endless ring whose inner diameter is equal to the outer diameter of the pipe to be repaired, A second ring having an endless annular shape, the inner diameter of which is equal to the outer diameter of the pipe to be repaired and the outer diameter of which is smaller than the outer diameter of the first ring, A fitting pipe whose inner diameter is equal to the outer diameter of the second ring and whose outer diameter is less than or equal to the outer diameter of the first ring, A device for repairing fluid leaks, equipped with [specific features / features]. (7) The above-mentioned joint piping is provided with an outward-facing flange on the other axial end side, with mounting bolt holes open therein. Furthermore, it is equipped with a closing plate that can be bolted to the outward flange to close the opening on the other axial end side of the joint piping. (8) A pressure relief valve is provided in the above-mentioned fitting piping. [Explanation of Symbols]
[0032] 1. The First Ring 2. The Second Ring 3. Piping for fittings 3A Outward Flange 4 Occlusion plate 7. Pressure relief valve 11. Piping to be repaired 11A Leakage point (leak location) 12 Branch piping for continuous water supply 13 Obstacle board 15 Shut-off valve 16 Downstream Piping S10 Depressurization process S20 Ring installation process (fixing process) S30 Pipe cutting process (the process of cutting) S40 Installation process for fittings and piping S50 Valve Installation Process S60 Downstream piping installation process
Claims
1. A method for repairing a fluid leak in a pipe to be repaired, in which there is no valve to stop the fluid flow upstream of the location of the fluid leak in the pipe to be repaired, A first ring with an endless ring shape whose inner diameter is equal to the outer diameter of the pipe to be repaired, A second ring with an endless ring shape, the inner diameter being equal to the outer diameter of the pipe to be repaired and the outer diameter being smaller than the outer diameter of the first ring, The fitting includes a pipe whose inner diameter is equal to the outer diameter of the second ring and whose outer diameter is less than or equal to the outer diameter of the first ring, The process involves fixing the first ring and the second ring to the outer surface of the pipe upstream of the leak location in the pipe to be repaired, such that the first ring is positioned upstream of the second ring. The process involves cutting the pipe to be repaired at a position downstream from the location where the second ring is to be installed, After the above fixing step and the above cutting step, the fitting pipe installation step involves bringing the outer diameter surface of the second ring into contact with the inner diameter surface of the fitting pipe, and fixing the axial end of the fitting pipe in contact with the side surface of the first ring, Equipped with, The downstream side of the pipe to be repaired is connected to the other axial end of the above-mentioned joint piping. The first ring and the second ring described above are each composed of two semi-circular members that have been cut in half. Methods for repairing fluid leaks.
2. The piping subject to repair as described above is piping for low-pressure fluids. A method for repairing fluid leakage as described in claim 1.
3. In the piping to be repaired, a branch pipe for forcibly restricting the flow rate is installed upstream of the first ring and its mounting position, and then the cutting process is performed. A method for repairing fluid leakage as described in claim 1.
4. An outward-facing flange with mounting bolt holes is provided on the other axial end of the above-mentioned joint piping. During the above installation process, a closing plate is attached to the outward-facing flange to close the opening on the other axial end side of the joint piping. A method for repairing a fluid leak as described in any one of claims 1 to 3.
5. The above-mentioned fitting piping is equipped with a pressure relief valve. A method for repairing a fluid leak as described in any one of claims 1 to 3.
6. The above-mentioned fitting piping is equipped with a pressure relief valve. A method for repairing fluid leakage as described in claim 4.
7. A fluid leak repair device used in the fluid leak repair method described in Claim 1, A first ring with an endless ring shape whose inner diameter is equal to the outer diameter of the pipe to be repaired, A second ring with an endless ring shape, the inner diameter being equal to the outer diameter of the pipe to be repaired and the outer diameter being smaller than the outer diameter of the first ring, A fitting pipe whose inner diameter is equal to the outer diameter of the second ring and whose outer diameter is less than or equal to the outer diameter of the first ring, A device for repairing fluid leaks, equipped with [specific features / features].
8. The above-mentioned pipe for the joint is provided with an outward-facing flange on the other axial end, with mounting bolt holes open. Furthermore, it is equipped with a closing plate that can be bolted to the outward flange to close the opening on the other axial end side of the joint piping. A device for repairing fluid leaks as described in claim 7.
9. A pressure relief valve is provided in the above-mentioned fitting piping. A device for repairing fluid leaks as described in claim 7 or claim 8.