JP2007155358A - Leak location inspection structure for buried gas pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a leakage point inspection structure for a buried gas pipe capable of inspecting and specifying a gas leak point in the buried gas pipe at low cost without damaging the gas pipe and the stopper.
SOLUTION: An in-pipe pressure inspection gauge for inspecting the pressure in the gas pipe by sealing one of the ports of the buried gas pipe is provided, and an insertion tool and a stopper with a stopper pressure tube are inserted into the buried gas pipe for inspection. The insertion jig is sucked and pulled from the other mouth part of the section, the stopper pressurizing tube is connected to the stopper bulging means, and the airtight inspection stopper is defined as a sealed section, and the position of the stopper is the other mouth. It is characterized by inspecting the presence or absence of gas leakage by expanding the sealed section while moving in a stepwise direction.
[Selection] Figure 1

Description

  The present invention relates to a buried gas pipe leakage point inspection structure capable of inspecting and specifying a gas leakage point in a buried gas pipe at low cost and without damaging the gas pipe or stopper.

When leaks occur in the buried gas pipe, it is common to specify the leak location by inspecting with a gas detector at the surface part, but the surface part is concrete or flat plate, When planting, etc., or when other buried objects such as water pipes and drain pipes are close to the gas pipe and a cavity is formed, gas cannot be detected on the surface part directly above the leaked part, There are cases where local excavation cannot identify and repair leaks. In addition, when the groundwater level is high, gas leakage does not occur, and there may be cases where supply failure occurs due to water filling into the gas pipe. In this case, in order to investigate the inside of the pipe instead of the leaked part and identify the watering point, water sampling and a camera inspection inside the pipe are carried out, but there is a bend that the camera head cannot pass, In some cases, it cannot be confirmed because there is no water, and the water location cannot be determined due to corrosion inside the pipe.
Therefore, for the detection of a gas leak location, conventionally, for example, a house-side cock is closed and a device main body is inserted into the gas pipe from the other side as in the gas leak location detection method and apparatus of Japanese Patent Application Laid-Open No. 2003-121294. While changing the extraction head having the guide for insertion and the stopper (gas bag) through the connecting cylinder, the leaked portion is detected by narrowing the sealed section while moving through the buried gas pipe.
Further, there is known a leak plug seal inspection structure for existing piping system disclosed in Japanese Patent Laid-Open No. 9-288033 and a leak locator (trade name, sold by Tokyo Gas Co., Ltd.) as a buried pipe leakage position inspection device based on this.
As shown in FIG. 6, this device 30 is inserted while rotating the stopper 31 and the tube 32 from the meter standing pipe side of the buried gas pipe in the live pipe state to prevent the airtight unit 33 and the raw gas leakage (water-sealed pipe). Inspect by
The stopper 31 is inflated and sealed with water pressure. An airtight inspection is performed while moving the stopper 31, and a leak point is specified based on the presence or absence of a pressure change.
However, since the application length of the device 30 is as short as 10 m6, it is not possible to deal with the case of a 10 m10 bend or a property whose length exceeds 10 m. Moreover, since there are many equipments such as an airtight unit and a water seal tube, it becomes expensive.
Furthermore, in these devices, since one cock is closed and the stopper is moved in the gas pipe, there is protection against the stopper, but there is a possibility that damage due to burrs during pressurization may occur, and scale removal cannot be performed. Therefore, there is a possibility that the sealing performance of the stopper may be hindered.
JP 2003-121294 A Japanese Patent Laid-Open No. 9-288033

The present invention has been devised to solve the above-mentioned problems, and the main problem is that one of the sealed sections to be inspected is closed and a deburring tool and a scale remover are attached to the liner connecting the pig and the stopper. The insertion tool with which the tool is connected is moved in the gas pipe, and the stopper provided on the insertion tool is used to close the other side of the sealed section, so that the leaking part can be inspected and identified at a low price without damaging the stopper or the gas pipe. To provide a structure.
Another object of the present invention is to provide a structure in which one is closed with an airtightness inspection stopper, the other is closed with a stopper of an insertion jig and sealed, and a leakage point is inspected and identified while moving the insertion jig stopper. There is.

In order to solve the above-mentioned problem, in the invention of the leakage point specifying device for the buried gas pipe according to claim 1,
Sealing means for sealing one mouth of the inspection section of the buried gas pipe;
An in-pipe pressure inspection gauge that is provided on the one mouth side and inspects the pressure in the gas pipe;
An insertion jig inserted into the buried gas pipe, and a stopper with a stopper pressure tube detachably connected to the insertion jig,
The insertion jig is sucked and pulled from the other mouth of the inspection section, the stopper pressurizing tube is detached from the insertion jig and connected to the stopper bulging means, and the stopper is bulged between the airtight inspection stopper. , And the stopper is moved stepwise toward the other mouth portion to widen the sealed section, and the presence or absence of gas leakage is inspected by the in-pipe pressure inspection gauge.
In the invention of claim 2,
The insertion jig is characterized in that a deburring tool and / or a scale removing tool are connected to a pig via a linear member such as a wire.
In the invention of claim 3,
An airtight inspection stopper provided at one of the mouths of the inspection section of the buried gas pipe to close one of the mouths of the buried gas pipe; an in-pipe pressure inspection pump connected to the airtight inspection stopper; It consists of a pressure inspection gauge.
According to a fourth aspect of the present invention, the stopper is composed of a substantially spherical bag and a substantially funnel-shaped protective rubber that is fitted on the base end side when the bag is inflated.

The effects of the present invention are as follows.
(1) Since it can be configured by combining existing equipment, the structure can be light and inexpensive, easy to purchase, and easy to spread.
(2) When moving the stopper in the buried gas pipe, the deburring and scale removal in the buried gas pipe is performed in advance with the deburring tool and / or scale removing tool, so the stopper is damaged by the burr and hinders the sealing performance. And the inner wall of the gas pipe is not easily damaged.
(3) Repair costs can be reduced by reducing the range of excavation (concrete destruction, etc.).
(4) Temporary piping for securing temporary supply can be removed at an early stage by local repair or partial replacement of piping locations with low possibility of replacement.

  Hereinafter, a preferred embodiment of a leakage gas pipe inspection structure according to the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view of a leakage point inspection structure for a buried gas pipe.
The buried gas pipe 1 to be inspected is a leaking gas pipe, and the pipe has two end portions in order to identify the leaking portion.

[Airtight inspection stopper]
An airtight inspection stopper 5 is inserted into the mouth portion 2 serving as one end portion, and the airtight inspection stopper 5 passes through the airtight inspection stopper 5 in order to inspect the pressure in the sealed section to be inspected. An in-pipe pressure inspection pressurizing pump 6 comprising a pump for pressurizing the sealed section and an in-pipe pressure inspection gauge 7 for measuring the pressure value in the tube are connected.
The position of the airtightness inspection stopper 5 is fixed and is not moved in the gas pipe 1.

[Insertion jig]
Further, before inserting the airtightness inspection stopper 5 from the one mouth portion 2, a member connecting the insertion jig 10 and the stopper 20 shown in FIG. 2 is inserted into the gas pipe 1 in advance.
As shown in FIG. 2, the insertion jig 10 has a configuration in which a burr removing tool 13 and a scale removing tool 14 are connected to each other via a wire 12 shown as an example of a flexible linear body on the pig 11. .
Here, the insertion jig 10 is not limited to the above embodiment, and in the present invention, a configuration in which the deburring tool 13 is connected to the pig 11 via the wire 12, or the scale holder 14 is connected to the pig 11 via the wire 12. A connected configuration may be used (not shown).

[Stopper]
As shown in FIGS. 2 and 3, the stopper 20 is composed of a rubber bag 21 such as a spherical shape or a star shape, and is connected to a pressure tube 23 so that air is pressurized by the pressure tube 23. It has become.
The rubber bag 21 is protected by covering a part of the stopper 21 with a protective rubber 22 fitted with a funnel-like (substantially conical) rubber that gradually becomes narrower in the traveling direction of the bag.

  In the present embodiment, the pressurizing tube 23 is set to 10 m and can cope with 10 m10 bending, but the length is an example and can be appropriately determined according to the inspection section. .

  In the case of the illustrated example, the distal end of the pressurizing tube 23 is detachably coupled to the coupling tool 4a provided on the scale holder 14 of the insertion jig 10, but this detachable configuration is not limited to the illustrated example. The pressurization tube 23 should just be connected with the insertion jig | tool 10 using the well-known structure which can be attached or detached.

[Insertion jig]
The insertion jig 10 has a configuration in which a pig 11 is connected to the tip end of a wire 12 and a deburring tool 13 and a scale removing tool 14 are connected in series at a distance from each other.
In the case of the present embodiment, the wire 12 has a length of 20 m as an example.

[Pig]
In this embodiment, the pig 11 is made of a small wooden ball, a sponge ball, etc., and can move in the gas pipe, and is pulled by suction from the other mouth 3. In particular, the material and shape are not limited to the illustrated examples.

[Deburring tool]
As shown in FIG. 4, the deburring tool 13 is a member for deburring in the gas pipe. In this embodiment, the deburring tool 13 has a structure in which wires are bundled. There is no particular limitation as long as it is possible.

[Scale remover]
The scale removing tool 14 is a member for removing the scale in the gas pipe, and in this embodiment, two elastic rubber balls are used.
The scale holder 14 is usually larger than the diameter of the gas pipe, but when it shrinks in the pipe, it passes through while rubbing against the inner wall surface of the gas pipe to remove the scale.
In the present invention, the scale removing tool is not limited to the above-described embodiment, and any other scale may be used as long as it removes other scales and thereby prevents the sealing performance of the stopper 20 from being hindered.

[Stopper press-fitting pump / stopper pressure check gauge]
Further, a stopper press-fitting pump 25 for connecting the pressurizing tube 23 of the stopper 20 to bulge the stopper and a branch to the press-fitting pump 25 are provided at the mouth 3 which is the other end of the buried gas pipe. And a stopper pressure check gauge 24 for checking the pressure of the stopper 20 is prepared.

In the insertion jig 10, the pig 11 is sucked from the other mouth 3 and pulled out of the gas pipe, and the movement of the pig 11 pulls the deburring tool 13 and the scale holder 14 through the wire 12. Then, deburring and scaling in the gas pipe are performed.
Further, since the distal end of the pressure tube 23 is connected to the insertion jig 10, the insertion jig 10 is taken out from the other mouth 3 and removed from the pressure tube 23, and the distal end of the pressure tube 23 is connected to the stopper pressure. Connected to a stopper press-fitting pump 25 with a confirmation gauge 24 (see FIG. 1).

  Then, the stopper 20 is inflated at a position slightly away from the airtightness inspection stopper 5 to seal the inside of the gas pipe, and whether or not there is a gas leak in the sealed section is connected to the airtightness inspection stopper 5. Inspect by pressure change with gauge 7.

When there is no change in pressure, the stopper 20 is moved in the direction of the other mouth 3 by a certain interval to extend the sealing interval, and the same inspection is performed.
In this way, when a decrease in pressure is detected by extending the sealed section in a stepwise manner, it can be seen that there is a gas leak point between the section immediately inspected and the sealed section currently being inspected.

FIG. 5 is a schematic diagram of a leakage point inspection structure for an embedded gas pipe according to the second embodiment.
In this second embodiment, instead of the airtightness inspection stopper 5 inserted into the mouth portion 2 which is one end portion of the first embodiment, the cock 4 of the mouth portion 2 'of the standing pipe provided in the pipe is tightened and shut off. It consists of a configuration.

An in-pipe pressure inspection gauge 7 ′ for inspecting the pressure in the gas pipe 1 is connected to the opening 4.
In the second embodiment, one of the mouth portions 4 is closed by the cock 4 of the gas stopper to become one of the sealed sections, and the other is closed by the stopper 20, and the gas pressure in the sealed section is measured by the in-pipe pressure inspection gauge 7 ′. taking measurement.

Then, while moving the stopper 20 stepwise in the direction of the other mouth 3, the inspection area can be extended to identify the gas leak location.
Since other configurations are the same as those of the above-described embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.
In addition, it goes without saying that various design changes can be made without departing from the scope of the present invention.

It is a schematic explanatory drawing explaining the time of the test | inspection of Example 1 of the leak location inspection structure of a buried gas pipe. It is a side view of the state which connected the insertion jig and the stopper. It is the elements on larger scale which show a stopper, (a) is a case where it moves without expanding, (b) is a case where it expands and inspects. It is a side view which shows an example of a deburring tool. It is a schematic explanatory drawing explaining the time of the test | inspection of Example 2 of the leak location inspection structure of a buried gas pipe. It is a schematic diagram explaining a conventional structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Buried gas pipe 2 Port part 3 Port part 5 Airtightness inspection stopper 6 In-pipe pressure test | inspection pressurization pump 7 In-pipe pressure test | inspection gauge 10 Insertion jig 11 Pig 12 Line body 13 Deburring tool 14 Scale holder 20 Stopper 21 Rubber bag 22 Protective rubber 23 Pressurizing tube 24 Stopper pressure check gauge 25 Stopper press-fitting pump

Claims (4)

Sealing means for sealing one mouth of the inspection section of the buried gas pipe;
An in-pipe pressure inspection gauge that is provided on the one mouth side and inspects the pressure in the gas pipe;
An insertion jig inserted into the buried gas pipe, and a stopper with a stopper pressure tube detachably connected to the insertion jig,
The insertion jig is sucked and pulled from the other mouth of the inspection section, the stopper pressurizing tube is detached from the insertion jig and connected to the stopper bulging means, and the stopper is bulged between the airtight inspection stopper. The embedded gas pipe is characterized by inspecting the presence or absence of gas leakage with the in-pipe pressure test gauge while expanding the sealed section by moving the stopper in a stepwise manner toward the other mouth portion. Leak location inspection structure.   2. The leakage point inspection structure for an embedded gas pipe according to claim 1, wherein the insertion jig connects the deburring tool and / or the scale removing tool to the pig via a linear member such as a wire.   An airtight inspection stopper provided at one of the mouths of the inspection section of the buried gas pipe to seal one mouth side of the buried gas pipe, a pipe pressure inspection pressurizing pump connected to the airtight inspection stopper, and a sealing means The leakage gas point inspection structure for an embedded gas pipe according to claim 1 or 2, characterized by comprising an in-pipe pressure inspection gauge. 4. The stopper according to claim 1, wherein the stopper includes a substantially spherical bag and a substantially funnel-shaped protective rubber that is externally fitted to a base end side of the bag when the bag is inflated. 5. Leaving point inspection structure for buried gas pipes.

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