KR20090124804A - Apparatus for testing multiple pipe and method for testing multiple pipe - Google Patents

Abstract

PURPOSE: A multiple pipe inspection device and an inspecting method for multiple pipe are provided to measure the concentration of the tracer gas and to inspect a defect site with a non-destruction method. CONSTITUTION: A multiple pipe inspection device comprises a pair of couplings(21,23), a tracer gas spray unit(30), a vacuum pump(32) and a tracer gas detection unit(34). The couplings are respectively combined in both ends of multiple pipe. The couplings seal a first space(26) and a second space(28). The first space is between the outer wall of an first pipe(12) and the inner wall of a second pipe(14). The second space is divided with an inner area of the first pipe. The tracer gas spray unit sprays the tracer gas to one of the first space and the second space. The vacuum pump inhales the gas remaining in the first space and the second space. The tracer gas detection unit detects the tracer gas from the inhaled gas.

Description

Apparatus for testing multiple pipe and method for testing multiple pipe}

The present invention relates to a multi-pipe inspection device and a multi-pipe inspection method.

Pipeline is used for the transport of various liquids and gases, and it can be divided into single pipe and multi pipe according to the arrangement of pipes. Single pipe means transporting liquid or gas in one pipe, and multi pipe means inserting multiple pipes into the pipe again.

If a defect occurs in such a pipeline, a liquid or gas leaks, which may cause an accident. In particular, in the case of a multi-pipe, when a defect occurs in an inner tube, a problem such as mixing of liquid or gas may occur.

Therefore, it is necessary to inspect these pipelines by non-destructive inspection method in advance. In the case of a single pipe, inspection is performed using magnetic particle inspection, ultrasonic inspection, eddy current inspection, penetration inspection, and leakage inspection.

However, in the case of multiple pipes, the pipes are inserted into several layers, which makes it difficult to inspect the inner and outer pipes.

The present invention provides a multi-pipe inspection apparatus and a multi-pipe inspection method capable of precisely inspecting a defect and a defect portion of an internal and external pipe of a multi-pipe in which pipes are arranged in multiple layers.

According to an aspect of the present invention, an apparatus for inspecting a multi-pipe including a first pipe and a second pipe into which the first pipe is inserted, comprising: a first space between an outer wall of the first pipe and an inner wall of the second pipe; A pair of couplings respectively coupled to both ends of the multi-pipe so that the second spaces partitioned by the inside of the first pipe are sealed to each other, and the tracer gas spraying the tracking gas into any one of the first space and the second space. Provided is a multi-pipe inspection apparatus including a four-part, a vacuum pump for sucking gas present in the other one of the first space and the second space, and a tracking gas detection unit for detecting a tracking gas from the sucked gas.

The pair of couplings may be formed on the first plug and the second plug, which are respectively coupled to both ends of the multi-pipe, and the first connector and the first plug or the first plug or the first plug or the second plug which are in communication with the first space. It is formed on the 2 stopper, it may include a second connector in communication with the second space.

The tracking gas injection unit may be connected to either the first connector or the second connector, and the vacuum pump may be connected to the other of the first connector or the second connector.

The tracking gas injection unit may include an injection nozzle for injecting the tracking gas while moving in the longitudinal direction of the multi-pipe through the first connector or the second connector.

The tracer gas may be an inert gas, which is different from other elements such as helium, nitrogen, neon, argon, krypton, xenon, and radon. It may include all gases that are difficult to cause chemical reactions.

Further, according to another aspect of the present invention, a method for inspecting a multi-pipe including a first pipe and a second pipe into which the first pipe is inserted, the method comprising: a first between an outer wall of the first pipe and an inner wall of the second pipe; Sealing the space, inhaling gas in the first space to maintain the first space in vacuum pressure, injecting a tracer gas into a second space partitioned by the interior of the first pipe and from the sucked gas Provided are a multi-pipe inspection method comprising measuring a concentration of tracer gas.

Injecting the tracer gas may include injecting the tracer gas into an inner wall of the first pipe along the longitudinal direction of the first pipe.

The tracer gas may be an inert gas, which is different from other elements such as helium, nitrogen, neon, argon, krypton, xenon, and radon. It may include all gases that are difficult to cause chemical reactions.

According to yet another aspect of the present invention, there is provided a method for inspecting a multi-pipe including a first pipe and a second pipe into which the first pipe is inserted, the method comprising: between the outer wall of the first pipe and the inner wall of the second pipe; Closing the first space, inhaling the gas in the first space to maintain the first space in a vacuum pressure, injecting the tracer gas to the outside of the second pipe, and measuring the concentration of the tracer gas from the sucked gas Provided is a multi-tubular inspection method comprising the steps of:

Injecting the tracer gas may include injecting the tracer gas to the outer wall of the first pipe along the longitudinal direction of the second pipe.

The tracer gas may be an inert gas, which is different from other elements such as helium, nitrogen, neon, argon, krypton, xenon, and radon. It may include all gases that are difficult to cause chemical reactions.

In addition, according to another aspect of the present invention, a coupling (coupling) used for the multi-pipe inspection comprising a first pipe and a second pipe into which the first pipe is inserted, the outer wall of the first pipe and the second pipe A stopper coupled to an end of the multi-pipe so that the first space between the inner wall of the first wall and the second space partitioned by the inside of the first pipe are sealed to each other, a first connector formed on the stopper and communicating with the first space, A coupling is provided that includes any one of a second connector and a combination thereof formed in the plug and in communication with the second space.

The coupling according to the present invention may further include a pair of valves for opening and closing the first connector and the second connector, respectively.

Non-destructive inspection enables precise inspection of defects and their defects in the inner and outer pipes of multiple pipes with multiple pipe arrangements.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification, and one or more other It is to be understood that the present invention does not exclude the possibility of the presence or the addition of features, numbers, steps, operations, components, parts, or a combination thereof.

Hereinafter, embodiments of a multi-pipe inspection device, a multi-pipe inspection method, and a coupling according to the present invention will be described in detail with reference to the accompanying drawings. In the following description with reference to the accompanying drawings, the same or corresponding components are the same. The reference numerals will be given and overlapping description thereof will be omitted.

1 is a schematic diagram of a multi-tubular inspection device according to a first embodiment of the present invention. 2 is a cross-sectional view of a multi-pipe according to a first embodiment of the present invention. 1 and 2, a first pipe 12, a second pipe 14, a first stopper 18, a second stopper 20, a first connector 22, and a second connector 24. The couplings 21, 23, the first space 26, the second space 28, the tracer gas injection unit 30, the vacuum pump 32, and the tracer gas detection unit 34 are shown.

The multi-pipe inspection apparatus according to the present embodiment is a device for inspecting a multi-pipe including a first pipe 12 and a second pipe 14 into which the first pipe 12 is inserted, and the first pipe 12. Coupled to both ends of the multi-pipe so that the first space 26 and the second space 28 partitioned by the inside of the first pipe 12 between the outer wall of the second pipe 14 and the inner wall of the second pipe 14 are sealed to each other. A pair of couplings 21 and 23, a tracking gas injection unit 30 connected to any one of the first space 26 and the second space 28, and injecting the tracking gas, and the first space ( 26) and the vacuum pump 32 which inhales the gas which exists in the other one of the 2nd space 28, and the tracking gas detection part 34 which detects trace gas from the sucked gas as a component.

The multi-pipe including the first pipe 12 and the second pipe 14 into which the first pipe 12 is inserted includes a second space 28 and a second space partitioned by the interior of the first pipe 12. Liquid or gas are respectively transported through the first space 26 formed by the outer wall of the first pipe 12 and the inner wall of the second pipe 14.

Although FIG. 1 illustrates a multi-pipe consisting of two pipes, the inspection apparatus of the present embodiment may be used in a multi-pipe consisting of a plurality of first pipes 12 and second pipes 14. For example, the present invention also applies to a multi-pipe consisting of a first pipe 12, a second pipe 14 into which the first pipe 12 is inserted, and a third pipe (not shown) into which the second pipe 14 is inserted. can do. In this case, the outer wall of the second pipe 14 and the inner wall of the third pipe form another first space.

The multi-pipe inspection apparatus according to the present embodiment may be applied to all kinds of pipes regardless of the material of the pipes.

Hereinafter, a multi-pipe inspection apparatus that can be applied to a multi-pipe consisting of the first pipe 12 and the second pipe 14 into which the first pipe 12 is inserted will be described.

Briefly describing a method for inspecting a defect of an inner tube (first pipe 12 in the present embodiment) of a multi-pipe using the multi-pipe inspection apparatus according to the present invention, the outer wall of the first pipe 12 and the second In order to maintain the first space 26 formed by the inner wall of the pipe 14 in a constant vacuum pressure state, while being continuously sucked gas in the first space 26, it is partitioned by the interior of the first pipe 12 The tracking gas is injected into the second space 28. If there is a crack in the first pipe 12 such as a crack that may occur, the trace gas may be cracked due to the pressure difference between the first space 26 and the second space 28. Through the leak to the first space 26, to maintain the vacuum pressure is to check the defect of the first pipe 12 by measuring the concentration of the tracer gas from the sucked gas.

Alternatively, the second space 28 is maintained at a constant vacuum pressure, and the tracking gas is injected into the first space 26 formed by the outer wall of the first pipe 12 and the inner wall of the second pipe 14. And it is also possible to check the defect of the first pipe 12 by measuring the concentration of the tracer gas from the gas sucked in the second space (28).

The pair of couplings 21, 23 are respectively coupled to both ends of the multi-pipe to form a first space 26 and a first pipe between the outer wall of the first pipe 12 and the inner wall of the second pipe 14. The second space 28 partitioned by the inside of 12) is sealed to each other.

The pair of couplings 21 and 23 according to the present embodiment includes a first stopper 18 and a second stopper 20 and a first stopper 18 or a second stopper respectively coupled to both ends of the multi-pipe. And formed in the first connector 22 and the first plug 18 or the second plug 20 in communication with the first space 26 and in communication with the second space 28. It consists of two connectors 24.

The first plug 18 and the second plug 20 are respectively coupled to both ends of the multi-pipe to form the second space 28, the outer wall of the first pipe 12, and the inner wall of the second pipe 14. Each of the first spaces 26 is sealed so as not to be connected to each other airflow.

The first connector 22 and the second connector 24 may be formed in the first plug 18 or the second plug 20. That is, the first connector 22 and the second connector 24 are formed together in the first plug 18 or the first connector 22 is formed in the first plug 18 and the second plug 20 It is also possible to form the second connector 24. In this case, the first connector 22 communicates with the first space 26, and the second connector 24 communicates with the second space 28.

In the present embodiment, the first connector 22 is formed in the first plug 18, and the second connector 24 is formed in the second plug 20. That is, the first connector 22 is formed in the first stopper 18 to communicate with the first space 26, and the second connector 24 is formed in the second stopper 20 to form the second space 28. Communicating with

The tracer gas may be injected through the first connector 22, the gas in the first space 26 may be sucked, the tracer gas may be injected through the second connector 24, or present in the second space 28. You can inhale the gas.

The first connector 22 and the second connector 24 may be equipped with a valve (not shown) for opening and closing the first connector 22 and the second connector 24, respectively.

The tracking gas injection unit 30 may be connected to any one of the first connector 22 or the second connector 24 to inject and inject the tracking gas. In this embodiment, the tracking gas injection unit 30 is connected to the second connector 24.

On the other hand, the tracking gas injection unit 30 may include a spray nozzle for injecting the tracking gas while moving in the longitudinal direction of the multi-pipe through the first connector 22 or the second connector (24).

In the multi-pipe inspection apparatus according to the present embodiment, in order to roughly determine whether a defect exists in the first pipe 12, a tracer gas is injected and injected into the second space 28, and in the first space 26. It is also possible to determine the presence of a defect by measuring the concentration of the tracer gas from the inhaled gas, and it is also possible to find the defective portion of the pipe by injecting the tracer gas while moving the injection nozzle in the longitudinal direction of the multi-pipe.

That is, when the tracer gas is injected while moving the injection nozzle in the longitudinal direction of the first pipe 12, the tracer gas immediately cracks when a defect such as a crack exists in a predetermined portion of the first pipe 12. The defect site of the first pipe 12 can be directly inspected because the concentration of the tracer gas is increased by moving to the first space 26.

The vacuum pump 32 is connected to the other of the first connector 22 or the second connector 24 to suck the gas. When the tracking gas injection unit 30 is connected to the second connector 24, the vacuum pump 32 is connected to the first connector 22, and the tracking gas injection unit 30 is connected to the first connector 22. In this case, the vacuum pump 32 is connected to the second connector 24.

In this embodiment, the tracking gas injection unit 30 is connected to the second connector 24, and the vacuum pump 32 is connected to the first connector 22.

The vacuum pump 32 sucks gas in the first space 26 or the second space 28 to maintain the first space 26 or the second space 28 at a constant vacuum pressure.

In the present embodiment, a case in which the vacuum pump 32 sucks gas in the first space 26 and maintains the first space 26 at a constant vacuum pressure state.

The tracking gas detection unit 34 detects the concentration of the tracking gas from the sucked gas. The tracking gas detector 34 may be connected to the vacuum pump 32 to measure the concentration of the tracking gas from the gas sucked into the vacuum pump 32.

As the tracer gas, an inert gas which is difficult to cause a chemical reaction with other elements may be used. Inert gases such as helium, neon, argon, krypton, xenon, and radon, which are difficult to chemically react with other elements, are used for precise concentration measurement of tracer gas. In this embodiment, helium, which is harmless to the human body, was used as the tracer gas. Accordingly, the tracking gas detector 34 includes a helium detector.

3 is a flow chart of a multi-tubular inspection method according to a second embodiment of the present invention, Figure 4 is a state diagram for explaining the multi-tubular inspection method according to a second embodiment of the present invention. Referring to FIG. 4, a first pipe 12, a second pipe 14, a first space 26, a second space 28, and a defective portion 36 are illustrated.

The method for inspecting a multi-pipe according to the present embodiment is a method for inspecting a multi-pipe including a first pipe 12 and a second pipe 14 into which the first pipe 12 is inserted. Sealing the first space (26) between the outer wall of the (12) and the inner wall of the second pipe (14), sucking the gas in the first space (26) to maintain the first space (26) under vacuum pressure. Injecting the tracer gas into the second space 28 partitioned by the interior of the first pipe, and measuring the concentration of the tracer gas from the sucked gas. It is possible to precisely inspect the defects of the inner and outer pipes of the arranged multi-pipes and their defects 36.

Referring to FIG. 4, a method of inspecting a defect of an inner tube of a multi-pipe including a first pipe 12 and a second pipe 14 into which the first pipe 12 is inserted will be described. The first space 26 between the outer wall of the first pipe 12 and the inner wall of the second pipe 14 is sealed (S100). In order to maintain the first space 26 at a constant vacuum pressure, the first space 26 is first sealed from the outside. The above-described coupling can be used so that the first space 26 and the second space 28 partitioned by the inside of the first pipe are not connected to each other in an air flow.

Next, the gas in the sealed first space 26 is sucked to maintain the first space 26 in a vacuum pressure state (S200). If the crack 36 is present in the second pipe 14 while the first space 26 is maintained at a constant vacuum pressure, the pressure difference between the first space 26 and the second space 28 is increased. As a result, the gas existing in the second space 28 moves to the first space 26. A vacuum pump communicating with the first space 26 may be used to suck gas in the first space 26.

Next, the tracking gas is injected into the second space 28 partitioned by the inside of the first pipe 12 (S300). The present embodiment is for determining whether there is a defect in the first pipe 12 and injects the tracking gas at one end of the first pipe 12 so that the tracking gas is filled in the second space 28. When the tracer gas is filled in the second space 28 and the defect portion 36 such as the crack exists in the first pipe 12, the gas containing the tracer gas moves to the first space 26 through the crack. When the concentration of the tracer gas is increased by measuring the concentration of the tracer gas from the sucked gas to maintain the first space 26 at a constant vacuum pressure, it is determined that the first pipe 12 is defective. In order to measure the concentration of the tracer gas, a tracer gas detector connected to the vacuum pump and detecting the tracer gas from the sucked gas may be used.

On the other hand, the inside of the first pipe 28 is maintained at a constant vacuum pressure and the tracer gas is injected into the first space 26 to measure the concentration of the tracer gas from the gas sucked in the first pipe 12 and the first It is also possible to check for defects in the pipe 12.

5 is a state diagram used for explaining the multi-pipe inspection method according to a third embodiment of the present invention. Referring to FIG. 5, a first pipe 12, a second pipe 14, a first space 26, a second space 28, and a defective portion 36 are illustrated.

The method for inspecting the multi-pipe according to the present embodiment is for inspecting the position of the defect portion 36 of the first pipe 12, and the outer wall of the first pipe 12 and the inner wall of the second pipe 14. Sealing the first space 26 therebetween, sucking gas in the first space 26 to maintain the first space 26 in a vacuum pressure state, along the longitudinal direction of the first pipe 12. The defect portion 36 of the first pipe 12 may be inspected including spraying a tracer gas on an inner wall of the first pipe 12 and measuring a concentration of the tracer gas from the sucked gas.

In the following description of the present embodiment, components different from those of the second embodiment will be described. Unlike the second embodiment, the present embodiment injects tracer gas into the inner wall of the first pipe 12 along the longitudinal direction of the first pipe 12. That is, the first space 26 is sealed, the gas in the first space 26 is sucked to maintain the first space 26 at a constant vacuum pressure state, and then the first pipe ( A tracer gas is injected into the inner wall of the first pipe 12 along the longitudinal direction of 12), and the concentration of the tracer gas is measured from the sucked gas to inspect the position of the defective portion 36.

When the injection nozzle 38 moves along the longitudinal direction of the first pipe 12 and slowly injects the tracer gas, if a defect part 36 such as a crack is present in a predetermined portion of the first pipe 12, it is immediate. As a result, the tracer gas is moved to the first space 26 through the defect portion 36 such as a crack, and the concentration of the tracer gas from the sucked gas is maintained to maintain a constant vacuum pressure of the first space 26. Measure That is, the concentration of the tracer gas is measured while injecting the tracer gas along the longitudinal direction of the first pipe 12, and when the concentration of the tracer gas increases rapidly, it is determined that the defective portion 36 exists at the injection position. .

6 is a state diagram used for explaining the multi-pipe inspection method according to a fourth embodiment of the present invention. Referring to FIG. 6, a first pipe 12, a second pipe 14, a first space 26, a second space 28, and a defective portion 36 are illustrated.

The method for inspecting the multi-pipe according to the present embodiment is for inspecting the position of the defect portion 36 of the second pipe 14, and the outer wall of the first pipe 12 and the inner wall of the second pipe 14. Sealing the first space 26 therebetween, sucking gas in the first space 26 to maintain the first space 26 in a vacuum pressure state, along the longitudinal direction of the second pipe 14. The defect portion 36 of the second pipe 14 may be inspected, including spraying a tracer gas on the outer wall of the second pipe 14 and measuring a concentration of the tracer gas from the sucked gas.

In the following description of the present embodiment, components different from those of the second embodiment will be described. Unlike the second embodiment, the present embodiment injects tracer gas to the outer wall of the second pipe 14 along the longitudinal direction of the second pipe 14. That is, the first space 26 is sealed, while the first space 26 is maintained at a constant vacuum pressure while inhaling gas in the first space 26, the first space 26 is formed along the longitudinal direction of the second pipe 14. 2, the tracer gas is injected to the outer wall of the pipe 14, and the concentration of the tracer gas is measured from the sucked gas to inspect the position of the defective portion 36.

When the tracer gas is slowly sprayed on the outer wall of the second pipe 14 while moving along the longitudinal direction of the second pipe 14, a defective part 36 such as a crack is present at a predetermined portion of the second pipe 14. In this case, the tracer gas immediately moves to the first space 26 through the crack, and the concentration of the tracer gas is measured from the gas sucked to maintain the constant vacuum pressure of the first space 26. That is, the concentration of the tracer gas is measured while injecting the tracer gas along the longitudinal direction of the second pipe 14, and it is determined that the defective portion 36 exists at the injection position where the tracer gas concentration rapidly increases.

Through the above-described second, third and fourth embodiments, defects of the inner tube and the outer tube of the multi-pipe can be inspected.

 In the second embodiment, the third embodiment, and the fourth embodiment, the inspection method for the multi-pipe consisting of two pipes (the first pipe 12 and the second pipe 14) is described. 12) and the second pipe 14 can be inspected according to the above-described method for the multi-pipe consisting of a plurality. For example, the present invention also applies to a multi-pipe consisting of a first pipe 12, a second pipe 14 into which the first pipe 12 is inserted, and a third pipe (not shown) into which the second pipe 14 is inserted. can do. In this case, the outer wall of the second pipe 14 and the inner wall of the third pipe form another first space.

As the tracer gas, an inert gas which is difficult to cause a chemical reaction with other elements may be used. Inert gases such as helium, neon, argon, krypton, xenon, and radon, which are difficult to chemically react with other elements, are used for precise concentration measurement of tracer gas. In this embodiment, helium, which is harmless to the human body, was used as the tracer gas. Accordingly, the tracer gas detector includes a helium detector.

Since other components are as described above, a description thereof will be omitted.

7 is a cross-sectional view of a coupling according to a fifth embodiment of the present invention. Referring to FIG. 7, a first pipe 12, a second pipe 14, a stopper 20, a first connector 22, a second connector 24 and a valve 25 are shown.

The coupling of the present embodiment can be used to seal the first space 26 of the multi-pipe and the interior 28 of the pipe to apply the multi-pipe inspection method described above.

Coupling of the present embodiment is a coupling used for a multi-pipe inspection comprising a first pipe 12 and a second pipe 14 into which the first pipe 12 is inserted. The first space 26 between the outer wall of the first pipe 12 and the inner wall of the second pipe 14 and the second space 28 partitioned by the inside of the first pipe 12 are sealed to each other. A stopper 20 coupled to the end, a first connector 22 formed in the stopper 20 and communicating with the first space 26, a stopper 20 formed in the stopper 20 and communicating with the second space 28. Two connectors 24 and any combination thereof. That is, only the first connector 22 communicating with the first space 26 may be formed in the stopper 20, and only the second connector 22 communicating with the second space may be formed in the stopper 20. In addition, the plug 20 may be formed with the first connector 22 communicated with the first space 26 and the second connector 24 communicated with the second hole. In the present embodiment, the coupling 20 has a coupling form in which the first connector 22 and the second connector 24 are formed together.

The tracer gas injection unit is connected to the second connector 24 which communicates with the second space 28 among the pair of connectors 22 and 24 of the plug 20 coupled to one end of the multi-pipe to inject the tracer gas. The first space 26 by connecting a vacuum pump to the first connector 22 in communication with the first space 26 of the pair of connectors 22 and 24 of the plug 20 connected to the other end of the multi-pipe. Can inhale gas. In this case, the connector that is not connected to the tracer gas injection unit and the vacuum pump may be closed.

Meanwhile, the tracer gas injection unit is connected to the second connector 24 which is in communication with the second space 28 of the connector, among the pair of connectors 22 and 24 of the plug 20 connected to one end of the multi-pipe. And spray a vacuum pump to the other one of the first connector 22 to suck the gas in the first space (26). In this case, the pair of connectors formed on the plugs connected to the other ends of the multi-pipes can be closed.

At the ends of the first connector 22 and the second connector 24, a pair of valves 25 may be provided to open and close the connector, respectively. The valve 25 can be used to open or close the connector.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention as set forth in the claims below It will be appreciated that modifications and variations can be made.

1 is a schematic diagram of a multi-tubular inspection device according to a first embodiment of the present invention.

2 is a cross-sectional view of a multi-pipe according to a first embodiment of the present invention.

3 is a flow chart of a multi-tubular inspection method according to a second embodiment of the present invention.

Figure 4 is a state diagram used for explaining the multi-tubular inspection method according to a second embodiment of the present invention.

5 is a state diagram used for explaining the multi-tubular inspection method according to a third embodiment of the present invention.

6 is a state diagram used for explaining the multi-pipe inspection method according to a fourth embodiment of the present invention.

7 is a sectional view of a coupling according to a fifth embodiment of the present invention;

<Explanation of symbols for the main parts of the drawings>

12: first pipe 14: second pipe

18, 20: stopper 22, 24: connector

26: first space 30: trace gas injection unit

32: vacuum pump 34: trace gas detection unit

Claims (11)

An apparatus for inspecting a multi-pipe comprising a first pipe and a second pipe into which the first pipe is inserted, A pair of couplings respectively coupled to both ends of the multi-pipe such that the first space between the outer wall of the first pipe and the inner wall of the second pipe and the second space partitioned by the inside of the first pipe are sealed to each other. and; A tracking gas injection unit for injecting a tracking gas into any one of the first space and the second space; A vacuum pump for sucking gas existing in the other of the first space and the second space; And And a tracking gas detector for detecting the tracking gas from the sucked gas. The method of claim 1, The pair of couplings, First and second stoppers respectively coupled to both ends of the multi-pipe; A first connector formed in the first stopper or the second stopper and communicating with the first space; And And a second connector formed in the first stopper or the second stopper and communicating with the second space. The method of claim 2, The tracking gas injection unit is connected to any one of the first connector or the second connector, The vacuum pump is a multi-pipe inspection apparatus, characterized in that connected to the other of the first connector or the second connector. The method of claim 2, The tracking gas injection unit, And a spray nozzle which moves in the longitudinal direction of the multi-pipe through the first connector or the second connector and injects the tracer gas. The method of claim 1, The tracer gas is an inert gas including helium, nitrogen, neon, argon, krypton, xenon and radon. A method for inspecting a multi-pipe comprising a first pipe and a second pipe into which the first pipe is inserted, Sealing a first space between an outer wall of the first pipe and an inner wall of the second pipe; Sucking the gas in the first space and maintaining the first space in a vacuum pressure state; Spraying a tracer gas into a second space partitioned by an interior of the first pipe; And And measuring the concentration of tracer gas from the aspirated gas. The method of claim 6, Spraying the tracer gas; And injecting the tracer gas into an inner wall of the first pipe along a longitudinal direction of the first pipe. The method of claim 6, The tracer gas is an inert gas comprising helium, nitrogen, neon, argon, krypton, xenon and radon. A method for inspecting a multi-pipe comprising a first pipe and a second pipe into which the first pipe is inserted, Sealing a first space between an outer wall of the first pipe and an inner wall of the second pipe; Sucking the gas in the first space and maintaining the first space in a vacuum pressure state; Spraying a tracking gas on an outer wall of the second pipe; And And measuring the concentration of tracer gas from the aspirated gas. The method of claim 9, Spraying the tracer gas; And spraying the trace gas on the outer wall of the second pipe along the longitudinal direction of the second pipe. The method of claim 9, The tracer gas is an inert gas comprising helium, nitrogen, neon, argon, krypton, xenon and radon.

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