JP2000310356A - Pipe line repair method and device using therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent increase in working man-hour and a working period, and also to certainly prevent gas leakage after recovering. SOLUTION: This method repairs a broken part 1A produced in a part of a synthetic resin conduit 1 laid in the ground. In this case, only a part matched to the broken part 1A is excavated. A joint 2 which can enclose the inner and outer parts of the synthetic resin conduit 1 is arranged under condition that the broken part 1A is covered with the joint 2 and the joint 2 is tightly stuck to the peripheral surface of the synthetic resin conduit 1 on an outer side than the periphery of the broken part 1A, and the peripheral surface of the synthetic resin conduit 1 and the joint 2 are fused together by exothermic action generated by carrying electric current to the joint 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing a pipeline and an apparatus used therefor, and more particularly to a method for repairing a synthetic resin pipe such as a polyethylene pipe and an apparatus used therefor.

[0002]

2. Description of the Related Art Conventionally, as a gas pipe laid under a road, a synthetic resin pipe such as polyethylene is sometimes used instead of a cast iron pipe or a steel pipe. This is to allow a certain degree of elongation / bending deformation with respect to an external force generated at the time of a disaster such as an earthquake to make it hard to break. By the way, there is a danger that a part of the polyethylene pipe buried underground is damaged by construction machines and tools, and gas flowing in the polyethylene pipe leaks from the damaged part. Therefore, conventionally, as a repairing method, a method has been proposed in which a tape for closing the periphery of the damaged portion is wound around the peripheral surface of the polyethylene pipe, or a range including the damaged portion in the pipe is cut and removed. The best way to cut and remove a part of a pipeline is to cut off the gas flowing through the pipeline,
Actually, it is not preferable because it causes inconvenience to the user of the gas. At present, it is desired to cut the pipe while the gas is flowing. For this reason, conventionally, the following method has been employed. That is, after forming perforations on both sides of the damaged portion in the direction of gas flow in the direction in which the pipeline is laid, and communicating these perforations with the bypass path,
Airbags (balloons) are inserted on both sides of the gas flow direction near the damaged part, and the airbag is inflated to seal both sides of the damaged part so that the gas flowing in the pipeline flows through the bypass path. A new construction method has been proposed. In this method, after cutting the damaged part sealed by the airbag, a new pipeline is connected via a joint such as Service Q integrated into the outer peripheral surface of the pipeline by electrofusion, and the joint is connected to the joint. After the air is purged from the connection opening, the airbag is removed and the bypass is shut off to resume the gas flow.

[0003]

However, the above method has the following problems. That is, the working time for forming a hole for inserting the airbag into the pipe and forming the bypass passage is lengthened, and the time required for the repair work is lengthened.
In addition, not only the excavation area for exposing the repair target part but also the excavation area for forming the bypass is required, so that the excavation area increases, and the work cost required for excavation and backfilling increases. . In addition, many work procedures such as installation of bypass, gas shut-off, cutting of pipes, and connection of new pipes are required. Then, the recovery time until the gas supply is restarted tends to be delayed.

Further, on both sides of the damaged portion, a joint for a bypass passage and a connection of a new pipe, in which case a branch saddle or the like is used, so that a fusion portion with the pipe is completely adhered. However, gas may leak from the joints and openings provided in the joints, and monitoring of the joints and the like may be required even after restoration, and maintenance costs after repair may be required.

In view of the above problems in the conventional pipeline repairing method of the present invention, it is possible to prevent an increase in the number of working steps and working time and to surely prevent leakage of gas after restoration, and to be used in the method. It is to provide a device.

[0006]

Means for Solving the Problems In order to achieve this object, the invention according to claim 1 is a method for repairing a defective portion occurring in a part of a synthetic resin pipe laid underground. Excavating only the location corresponding to the above-mentioned missing location,
A repair member is disposed in a state of covering the defective portion and being in close contact with the outer peripheral surface of the synthetic resin pipe outside the periphery of the defective portion, and the synthetic resin pipe is generated by heat generated by energizing the repair member. The outer peripheral surface and the repair member are fused.

[0007] The invention according to claim 2 is characterized in that before the repairing member is arranged at the defective portion, a process for covering the defective portion and preventing leakage of fluid from inside the synthetic resin pipe is performed. I have.

[0008] The invention described in claim 3 is claim 1 or 2.
An apparatus used in the pipeline repair method according to the above, further comprising a shape that can be in close contact with the outer peripheral surface of the synthetic resin pipe outside the periphery of the defective portion, and the synthetic resin pipe is provided on a surface facing the defective portion. The repair member has a concave portion having a depth in a direction away from the outer peripheral surface of the repair member, and a heat generating means connected to the inside of the repair member.

According to a fourth aspect of the present invention, the repair member includes:
A saddle or split sleeve structure having no opening is provided.

[0010]

According to the first and second aspects of the present invention, a repairing member is provided for the defective portion, which is in close contact with the outer peripheral surface of the synthetic resin pipe outside the peripheral edge of the defective portion. Since a repair member covering the defective portion is arranged to prevent gas leakage from the defective portion, only a portion corresponding to the defective portion is targeted as a ground excavation portion. For this reason, it is not necessary to enlarge the excavation site.

According to the third and fourth aspects of the present invention, a recess having a depth in a direction away from the outer peripheral surface is provided at a position facing the outer peripheral surface of the synthetic resin pipe at a position outside the peripheral edge of the defective portion. Since the formed repair member is used and the repair member is not provided with an opening, even if a protrusion such as a burr is present on the periphery of the defective portion, the repair member does not float up due to the protrusion. It can be in close contact with the outer peripheral surface of the tube, and further, since there is no opening, the defective portion can be reliably closed.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a view for explaining a mounted state of a joint used for describing a repair method according to an embodiment of the present invention. In FIG. 1, a synthetic resin pipe is used in the present embodiment. In FIG. 1, the joint 2 is disposed at a defective portion of the polyethylene pipe 1, that is, at a location 1A having a hole in FIG. In arranging the joint 2, the ground is excavated in correspondence with the previously detected defect site 1A, and the polyethylene pipe 1 is exposed. The joint 2 does not have a branch opening like a commonly known branch saddle, and has a shape capable of covering a defective portion by being seated on the outer peripheral surface of the polyethylene pipe 1.

On the other hand, inside the joint 2, there is provided a seating surface 2A which can be in close contact with the outer peripheral surface of the polyethylene pipe 1 outside the peripheral edge of the defective portion 1A, and inside the seating surface 2A,
A recess 2B is provided. The concave portion 2B is located at the defective portion 1A.
Has a depth in a direction away from the outer peripheral surface of the polyethylene pipe 1 so as not to contact the peripheral edge of the defective portion 1A. A seating surface 2 </ b> A that can be in close contact with the outer peripheral surface of the polyethylene pipe 1 is provided inside the joint 2 having such a configuration.
A heater wire 3 serving as a heating means is passed through the inside, and a terminal portion of the heater wire 3 is exposed to the outside to form a terminal portion 3A.

By using the joint 2 configured as described above, the repair procedure according to the present embodiment performs the following procedure. (1) Excavate only the location corresponding to the missing location to expose the missing location 1A. (2) Before arranging the joint 2 corresponding to the missing portion 1A,
A process for preventing gas from leaking from the inside of the polyethylene pipe 1 is performed. In this process, the peripheral surface of the polyethylene pipe 1 where the defective portion is located is cleaned using a rag or a cleaning liquid, or after the cutting with the scraper is performed as described above, as shown in FIG. 4 is used to cover the entire peripheral surface where the defective portion 1A is located (FIG.
(See (A) and (B)), and remove the tape 4 'at a portion other than the defective portion (see FIG. 3 (C)). As a result, only the defective portion 1A is covered with the tape 4, and the peripheral surface other than the defective portion is exposed to be a contact surface with the joint 2. As shown in FIG. 4, covering of the defective portion 1A with such a tape is as follows.
It is also possible to attach the adhesive tape 5 having the size of the defective portion 1A around the defective portion.

(3) When the gas leakage from the defective portion 1A is immediately prevented by the above-described processing, the joint 2 is mounted on the outer peripheral surface of the polyethylene pipe 1 in correspondence with the defective portion 1A. The joint 2 uses a saddle or a split sleeve, and is positioned with the concave portion 2B provided inside thereof facing the defective portion 1A, and is in the state shown in FIG. When the terminal portion 3A of the heater wire 3 is connected to a power source (not shown) and energization is started, the heater wire 3 generates heat, and when the temperature of the seating surface 2A of the joint 2 rises, heat is transmitted to the polyethylene pipe 1 side. The surfaces in contact with each other are fused together. Since the concave portion 2B provided inside the joint 2 faces the defective portion 1A, the joint 2 does not come into contact with a protrusion such as a burr existing on the periphery of the defective portion 1A. For this reason, since the so-called seating surface 2A does not rise from the outer peripheral surface of the polyethylene pipe 1 without being pushed up by the protrusion, the adhesion between the seating surface 2A and the outer peripheral surface of the polyethylene pipe 1 is maintained well. Is done. Thereby, the heat transfer from the seating surface 2A to the polyethylene pipe 1 is also maintained well, so that the heat loss until the fusion is small and the fusion time does not become long.

According to the above embodiment, the joint 2 is
Unlike conventional joints of this type, since there is no opening such as a branch opening, it is possible to reduce the number of locations where gas may leak. Because it can cover 1A,
Installation on the polyethylene pipe 1 can be performed with a simple operation. In addition, since there is no opening, the structure can be simplified, which is advantageous in terms of cost.

[0017]

According to the first and second aspects of the present invention,
Only a repair member that is in close contact with the outer peripheral surface of the synthetic resin pipe outside the periphery of the defective portion with respect to the defective portion is provided. Since the leakage of gas from the ground can be cut off, only the portion corresponding to the defective portion is targeted as the excavated portion on the ground. Therefore, it is not necessary to increase the size of the excavation site, and the operation time and operation cost can be reduced.

According to the third and fourth aspects of the present invention, the outer peripheral surface of the synthetic resin pipe is in close contact with the outer peripheral surface of the defective portion, and the position facing the defective portion has a depth away from the outer peripheral surface. Using a repair member with a recess formed, furthermore, the repair member is not provided with an opening, so even if there is a protrusion such as a burr on the periphery of the defective part, the repair member does not float up by the protrusion. It can be in close contact with the outer peripheral surface of the synthetic resin pipe, and further, since there is no opening, the defective portion can be reliably closed. This eliminates the need for inspection work after repairing the defective part, thereby reducing maintenance costs.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining one process of a repair method according to an embodiment of the present invention.

FIG. 2 is a sectional view taken in the direction of an arrow (2) in FIG.

FIG. 3 is a diagram for explaining an example of a pretreatment work applied to the repair method according to the embodiment of the present invention.

FIG. 4 is a view for explaining another example of the pretreatment work applied to the repair method according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polyethylene pipe which is one of synthetic resin pipes 1A Defective part 2 Joint 2A Seating surface 2B Depression 3 Heater wire 3A Terminal part 4 Repair tape 5 Strong adhesion tape

Claims (4)

[Claims] Claims: 1. A method for repairing a defective portion occurring in a part of a synthetic resin pipe laid in the ground, wherein only a portion corresponding to the defective portion is excavated, and the defective portion is excavated. A repairing member is disposed in a state of covering and being in close contact with the outer peripheral surface of the synthetic resin pipe outside the peripheral edge of the defective portion, and the outer peripheral surface of the synthetic resin pipe and the outer peripheral surface of the synthetic resin pipe are generated by heat generated by energizing the repair member. A pipeline repairing method characterized by fusing a repair member. 2. The method according to claim 1, wherein before the repairing member is arranged at the defective portion, a process of covering the defective portion and preventing leakage of fluid from inside the synthetic resin pipe is performed. Pipeline repair method. 3. The apparatus used in the pipe line repair method according to claim 1 or 2, further comprising a shape which can be in close contact with an outer peripheral surface of the synthetic resin pipe outside a peripheral edge of the defective portion, wherein the defective portion is provided. A repairing member in which a concave portion having a depth in a direction away from the outer peripheral surface of the synthetic resin pipe is formed on a surface facing the repairing member, and a heat generating means which is connected to the inside of the repairing member. Characteristic pipe repair equipment. 4. The pipeline repair device according to claim 3, wherein the repair member has a saddle or split sleeve structure having no opening.