JP2004239319A - Tool and method for blocking conduit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tool and a method for blocking a conduit in which higher blocking performance can be ensured with a single blocking tool of a small in-conduit installation width , the blocking performance is not degraded even by impurities in conduits, unevenness of an inner surface of the conduits, or different diameter conduits, and the safety is ensured by expansive bodies demarcated into a plurality of spaces against any possible breakage. <P>SOLUTION: An expansion body 10 has a plurality of expansion spaces 11 demarcated by a bulkhead 10a. In the expansion spaces 11, all expansion spaces 11 are communicated with each other by a communication hole 12 and a check valve 13. An in-conduit tightly fitting part 14 to be tightly fitted to an inner surface of the conduit is formed in each of the expansion space 11. The in-conduit tightly fitting part 14 is formed so that each thereof is separated and linearly and tightly fitted to the entire circumference of the conduit. A non-tightly fitting part 15 which is not tightly fitted to the inside of the conduit is formed on an outer circumference of the expansion body 10 between the adjacent in-conduit tightly fitting parts 14. A pouring pipe 16 is connected to the expansion space 11 on one end, and an expansion fluid pouring path is formed from one end side to the other end side of the expansion space 11. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an in-conduit shutoff tool and an in-conduit shutoff method using the same.
[0002]
[Prior art]
In order to shut off fluid flowing through a conduit such as a gas conduit, a shutoff device called a gas bag is used. Taking a buried gas conduit as an example, as shown in the figure, in a part replacement work performed on a buried live pipe or a former rearranging work in which unused parts are separated and closed, a shaft A Is excavated, and an operation of blocking the conduit 1 in the shaft A is performed. This operation is performed as a no-blow operation (non-ejection operation), a perforation 1a is formed in the conduit 1, and the gas bag B is inserted into the conduit 1 from the perforation 1a. The gas bag B is composed of a main ball B1 inserted on the upstream side of the perforation 1a and an inverted ball B2 inserted on the downstream side, thereby blocking gas from flowing into the construction section. Further, in order to secure gas supply to the downstream side during the construction period, a bypass take-out portion C is provided upstream of the portion where the gas bag B is provided, and a bypass pipe C1 is provided therefrom to the downstream side of the construction section. Installed towards. In addition, even if such a gas bag B is used, it may be difficult to completely shut off the flow. Therefore, a diffusion tube E whose periphery is sealed with a seal D is provided on a perforation 1a formed in the conduit 1. Disaster prevention measures have been taken to prevent the gas (overgas) coming out of the main ball B1 from being released from the perforations 1a and filling the shaft A serving as a work area (see Patent Document 1 below).
[0003]
[Patent Document 1]
JP 2001-152435 A
[Problems to be solved by the invention]
According to the blockage in the conduit using such a gas bag, two bags (the main ball B1 and the inverted ball B2) are provided around the perforation formed in the conduit, so that the bag installation width L is secured large. There must be. As a result, in the buried gas pipe work, when the installation space of the bypass take-out section C is also taken into consideration, the width of the shaft A is increased, which causes a problem that the construction time or construction cost is increased. On the other hand, if two gas bags are used instead of one, the gas shut-off performance will be reduced and the necessity of taking extra measures in case of gas bag breakage will increase. Problems will arise.
[0005]
Further, various impurities may be accumulated in a conduit such as a gas conduit and the diameter of the conduit itself may be deformed, so that the cross section cut off by the gas bag may not be a perfect circle. When a conventional gas bag is used in such a situation, an unexpected local pressing force acts on the in-pipe contact surface of the gas bag, and the gas bag may be damaged. Furthermore, the gas-in-pipe contact surface of the gas bag may not be able to adhere properly to the uneven cut-off cross section, and the gas cut-off performance may be reduced.
[0006]
Furthermore, in the conventional gas shut-off using a gas bag, a small amount of passing gas was released to the atmosphere via a diffuser tube while taking safety and environmental impact into consideration, but stricter measures against environmental issues and safety have been taken. In order to achieve this, there is a demand for the development of a barrier with higher barrier performance.
[0007]
The present invention has been proposed in order to address such a problem, and in a conduit shutoff device and a conduit shutoff method using the same, while being a single shutoff device having a small installation width in a conduit, Higher blocking performance can be ensured, the blocking performance does not decrease even for impurities in the pipe, irregularities on the inner surface of the pipe, or different-diameter pipes, and safe handling is possible even in the event of damage. The purpose is.
[0008]
[Means for Solving the Problems]
In order to achieve such an object, the in-conduit blocking device and the in-conduit blocking method according to the present invention have the features according to the following claims.
[0009]
The invention according to claim 1 is an in-conduit blocking device that is inserted from a perforation formed in a conduit and expands in the conduit to block a conductive fluid, wherein the single unit has a plurality of partitioned expansion spaces. The inflatable body is provided with a plurality of in-pipe contact portions formed on each of the inflatable spaces and separated from each other on the outer periphery.
[0010]
According to a second aspect of the present invention, in the conduit blocking device according to the first aspect, the in-pipe contact portion is linearly adhered to the entire inner periphery of the pipe.
[0011]
According to a third aspect of the invention, in the conduit blocking device according to the first or second aspect, a non-adhesive portion that is not in close contact with the inside of the pipe is formed on an outer periphery of the inflatable body between the adjacent close contact sections in the pipe. It is characterized by the following.
[0012]
According to a fourth aspect of the present invention, in the blockage device for a conduit according to any one of the first to third aspects, the expansion space is formed such that a plurality of spaces that can communicate with each other are independently formed. .
[0013]
According to a fifth aspect of the present invention, in the conduit shut-off device according to any one of the first to fourth aspects, the expansion space is communicated with a check valve that communicates at a pressure equal to or higher than a set pressure, and one end of the communicated expansion space. An inflation fluid injecting path is formed from to the other end.
[0014]
According to a sixth aspect of the present invention, in the blockage device for a conduit according to any one of the first to fifth aspects, the inflation space has a separate inflation fluid injection path formed in an independent space.
[0015]
The invention according to claim 7 is a blocking method in a conduit, comprising a step of forming a hole in the conduit, a plurality of partitioned expansion spaces, and a plurality of separated expansion spaces formed for each of the expansion spaces. A step of inserting an inflatable body having an in-tube tight contact portion on the outer periphery from the perforation in a contracted state, and a step of inflating the inflatable body by injecting an inflation fluid from outside the conduit into each of the expansion spaces, It is characterized in that the inside of the conduit is shut off by bringing the in-pipe contact portion into close contact with the inner surface of the conduit upstream of the perforation.
[0016]
According to an eighth aspect of the present invention, in the conduit shut-off method according to the seventh aspect, the expansion space is communicated with a check valve that communicates at a pressure equal to or higher than a set pressure, and is directed from one end to the other end of the communicated expansion space. The inflation fluid is injected along an inflation fluid injection path formed as described above.
[0017]
According to a ninth aspect of the present invention, in the conduit blocking method according to the seventh aspect, the inflation fluid is injected into the inflation space along an inflation fluid injection path individually formed in an independent space. It is characterized by the following.
[0018]
According to a tenth aspect of the present invention, in the method for blocking the inside of the conduit according to any one of the seventh to ninth aspects, at the time of removing the inflatable body, the inflation fluid is discharged from the inflatable space by forced suction to contract the inflatable body. It is characterized by making it.
[0019]
The invention according to each claim having the above-mentioned features has the following operations.
[0020]
First, by using a blocking member made of a single inflatable body, it is possible to reduce the installation width in a pipe, and a plurality of in-pipe adhesion portions formed in a plurality of partitioned expansion spaces are formed on the inner surface of the pipe. , So that multi-stage sealing is possible, and high blocking performance can be secured. In addition, by making the plurality of partitioned expansion spaces independent spaces, even if one expansion space is broken, it is possible to maintain the blockage of the inside of the pipe by the in-pipe tight contact portion formed in the other expansion space. Become.
[0021]
Furthermore, since the in-pipe contact portions formed in the respective expansion spaces are separated from each other, it is possible to seal over the ridges of impurities and the like deposited in the tube at the adjacent in-pipe contact portions, and to seal the inside of the tube. The high blocking performance can be maintained even in a situation where impurities are deposited on the substrate.
[0022]
Secondly, since the in-pipe contact area is linear and closely adhered to the entire circumference of the pipe, the in-pipe in-pipe part adheres to the inner surface shape even with irregularities on the inner surface of the pipe and different-diameter pipes. And a high blocking performance can be obtained even with a blocking cross section that is not a perfect circle. In addition, since the linear contact portion in the pipe is arranged so as to avoid the protuberance in the pipe when the expandable body expands, and the movable impurities and the like are arranged so as to move the impurities during the expansion, so that the inner surface of the pipe can be disposed on the inner surface of the pipe. Adhesion is increased, and the blocking performance can be improved.
[0023]
Thirdly, since a non-adhesive portion that is not tightly adhered to the inside of the pipe is formed between the adjacent tight contact portions in the pipe on the outer periphery of the expansion body, a raised portion such as an impurity layer deposited in the tube is allowed to escape to the non-adhesive portion. Can be. Thereby, a local pressing force does not act on the inflatable body, and damage to the inflatable body can be prevented. In addition, since it is possible to prevent the in-tube contact portion from adhering to the impurities, it is possible to enhance the adhesion of the in-tube contact portion.
[0024]
Fourth, since the expansion space is formed as a plurality of units independently of several communicable spaces, for example, even if one unit of space is damaged, other independent spaces are sound. And the shut-off performance can be maintained by the in-pipe contact portion formed in the space. And since it can be formed by several spaces which can be connected, an expansion fluid can be inject | poured into these spaces continuously and favorable workability can be obtained.
[0025]
Fifth, the expansion space is communicated with a check valve that communicates at a set pressure or higher, and an expansion fluid injection path is formed from one end to the other end of the communicated expansion space. The inflation fluid can be injected into the plurality of inflation spaces, and the inflation body can be quickly inflated to obtain the shut-off state.
[0026]
Sixth, since an individual inflation fluid injection path can be formed in an independent space, the inflation body can be inflated smoothly by injecting the inflation fluid along the individual inflation fluid injection path. Can be. Further, the inflation body can be more smoothly expanded by connecting the individual expansion fluid injection paths and branching from one injection path.
[0027]
Seventh, according to the in-pipe shut-off method using the shut-off device having the above-described features, the installation width of the inflatable body inserted into the conduit can be reduced, so that the work area of the shut-off work can be narrowed. In particular, in the blocking work of underground buried conduits, the width of the shaft to be formed can be reduced, so that the construction time and construction cost can be reduced. In addition, since a blocking tool having high blocking performance is used, generation of passing gas can be suppressed, and emission of passing gas to the atmosphere can be eliminated. Therefore, it is possible to provide a good method in terms of environment and safety.
[0028]
Eighth, there is an in-pipe shut-off method having such a characteristic. When the expansion body is removed, the expansion fluid can be discharged from the expansion space by forced suction and the expansion body can be contracted. The blocking device can be removed.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view (partial cross-sectional view) showing a configuration of an in-pipe shutoff device according to an embodiment of the present invention. This in-pipe shut-off device includes a single inflatable body 10 inserted into a pipe from a perforation 1a formed in the conduit 1, and the inflatable body 10 expands in the pipe as shown in FIG. To block the conducting fluid. The expansion body 10 is provided upstream of the perforation 1a, and blocks the flow of the conductive fluid from the expansion body 10 to the downstream side.
[0030]
When the material of the inflatable body 10 is applied to a gas conduit that conducts a combustible gas, a material that is not damaged by heat at the time of gas ignition is required, and the base fabric is covered with a flame-retardant or non-flammable paint. Alternatively, a flame retardant is applied to the base material itself.
[0031]
Further, the expansion body 10 has a plurality of expansion spaces 11 defined by partition walls 10a. Each of the expansion spaces 11 may be a completely independent space, or may be one in which some of the plurality of expansion spaces 11 communicate with each other. In the embodiment shown in FIG. 1, the expansion space 11 adjacent to the communication hole 12 provided in the partition wall 10 a and the check valve 13 can communicate with each other.
[0032]
In each of the expansion spaces 11, an in-pipe contact portion 14 that is in close contact with the inner surface of the conduit is formed. The in-pipe contact portions 14 are formed so as to be separated from each other and adhere to the entire inside of the pipe in a linear manner. Therefore, in the inflatable body 10, the in-pipe contact portion 14 partially adheres to the inner surface of the conduit, and a non-contact portion 15 that is not in-pipe contact is formed on the outer periphery of the inflatable body 10 between the adjacent in-pipe intimate portions 14. ing.
[0033]
In this embodiment, the injection pipe 16 is connected to one end of the plurality of expansion spaces 11, and the check valve 13 moves the fluid only in the direction from the expansion space 11 at one end to the expansion space 11 at the other end. Is possible, and the expansion space 11 in front is opened when the pressure is equal to or higher than the set pressure.
[0034]
Therefore, when the contracted inflatable body 10 is inserted into the conduit 1 through the perforation 1a and the inflation fluid is injected from outside the tube through the infusion tube 16, the one end of the inflation space 11 where the infusion tube 16 is connected is connected to the other end. As a result, an inflation fluid injection path is formed. The inflation fluid is inflated sequentially from one end of the inflation space 11, and when one of the inflation spaces 11 reaches a set pressure, the check valve 13 is opened and the adjacent inflation space 11 is in a communicating state. And the inflation fluid is injected there.
[0035]
On the other hand, a discharge pipe 17 is connected to each expansion space 11, and the connection portion of the discharge pipe 17 is closed at the set pressure of the expansion space 11, but is opened by forced suction through the discharge pipe 17. A discharge valve portion 17a is provided. Thereby, when removing the expansion body 10 from the inside of the conduit 1, the fluid in the expansion space 11 is discharged by forced suction through the discharge pipe 17, and the expansion space 11 is contracted.
[0036]
In the in-pipe blocking device of such an embodiment, the in-pipe installation width L1 can be reduced because the inflatable body 10 is used alone. In addition, since the plurality of in-pipe contact portions 14 formed in the plurality of partitioned expansion spaces 11 are in close contact with the inner surface of the tube, multi-stage sealing is possible, and high blocking performance can be obtained.
[0037]
Further, since the plurality of partitioned expansion spaces 11 are independent spaces after expansion, even if one expansion space 11 is damaged, the other expansion space 11 can maintain a healthy state, and is not damaged. The in-pipe contact portion 14 formed in the expansion space 11 can keep the inside of the pipe blocked.
[0038]
Further, since the in-pipe contact portions 14 formed in the respective expansion spaces 11 are separated from each other, the adjacent in-pipe contact portions 14 can seal over the ridges of impurities and the like deposited in the tubes. Thus, high blocking performance can be maintained even in a situation where impurities are deposited in the tube.
[0039]
In addition, since the in-pipe contact portion 14 is linear and is in close contact with the entire periphery of the tube in a linear manner, the in-pipe contact portion can be adhered to irregularities on the inner surface of the tube and even to a different-diameter tube by following the inner surface shape. Can be. Therefore, high breaking performance can be obtained even with a breaking cross section that is not a perfect circle.
[0040]
Further, the linear in-pipe contact portion 14 is arranged so as to avoid the in-tube protruding portion when the inflatable body 10 is inflated, and is arranged so as to move the impurities with respect to movable impurities and the like when inflated. Adhesion to the substrate is increased, and the blocking performance can be improved.
[0041]
In addition, since the non-adhesive portion 15 that is not in close contact with the inside of the tube is formed between the adjacent in-tube contact portions 14 on the outer periphery of the expansion body 10, the raised portion such as an impurity layer deposited in the tube escapes to the non-adhesive portion 15. be able to. Thereby, the local compressive force does not act on the expansion body 10, and the damage of the expansion body 10 can be prevented. Since the non-contact portion 15 can prevent the in-tube contact portion 14 from adhering to impurities, it is possible to enhance the adhesion of the in-tube contact portion 14.
[0042]
FIG. 2 is an explanatory view (partial sectional view) showing another embodiment of the in-pipe blocking device. The same parts as those in the above-described embodiment are denoted by the same reference numerals, and duplicate description will be omitted. The in-pipe shut-off device of this embodiment includes an inflation body 20 provided with a discharge pipe 17 having an inflation space 11, an in-pipe contact portion 14, a non-adhesion portion 15, and a discharge valve portion 17a similar to the above-described embodiment. The expansion body 20 is independently partitioned by a partition wall 20a, and an injection pipe 26 is connected to each expansion space 11 via a check valve 26a.
[0043]
According to this, it has the same operation as the above-described embodiment, but at the time of inflation fluid injection, an individual inflation fluid injection path is formed in the independent expansion space 11, and the check valve portion 26a is provided from the injection pipe 26 to each space. The inflation fluid is to be injected via. Therefore, it is possible to inflate the plurality of expansion spaces 11 at the same time, and it is possible to immediately shut off the inside of the conduit 1 after inserting the inflatable body 10 into the conduit 1.
[0044]
FIG. 3 is an explanatory view (partial sectional view) showing another embodiment of the in-pipe blocking device. The same parts as those in the above-described embodiment are denoted by the same reference numerals, and duplicate description will be omitted. The in-pipe shut-off device of this embodiment includes an inflatable body 30 having expansion spaces 11A and 11B, an in-tube intimate contact portion 14, and a non-intimate contact portion 15 similar to those in the above-described embodiment. The expansion body 30 is independently partitioned by a partition 30a, the odd-numbered expansion space 11A from the left is connected to the communication pipe 36 through the opening 36a, and the even-numbered expansion space 11B from the left is connected to the opening 37a. It is communicated by the communication pipe 37 through the intermediary.
[0045]
This embodiment has basically the same operation as the above-described embodiment, but simplifies the configuration by eliminating the need for a check valve portion and a discharge valve portion. In other words, at the time of inflation of the inflation fluid, the inflation fluid is injected through each of the communication pipes 36 and 37, the inflation fluid is injected from the communication pipe 36 into the odd-numbered expansion space 11A, and the even-numbered expansion space from the communication pipe 37. The expansion fluid is injected into the expansion space 11B. When the inside of the pipe is shut off, the communication pipes 36 and 37 are both closed, and when the inflatable body is removed, the communication pipes 36 and 37 are both opened to simultaneously discharge the expansion fluid.
[0046]
According to this, when one of the odd-numbered expansion spaces 11A is damaged, the other expansion spaces 11A communicating therewith are also affected and contracted, but the even-numbered expansion spaces 11B communicate with them. Therefore, a healthy state can be maintained, and the in-pipe contact portion 14 in the even-numbered expansion space 11B can maintain the cutoff in the pipe.
[0047]
FIG. 4 is an explanatory view showing another embodiment of the in-pipe blocking device (FIG. 4 (a) is a partial cross-sectional view, and FIG. 4 (b) is a view showing a state when the inflatable body is contracted). The same parts as those in the above-described embodiment are denoted by the same reference numerals, and duplicate description will be omitted. The in-pipe shutoff device of this embodiment includes an inflatable body 40 having an inflation space 11, an in-tube intimate contact portion 14, and a non-intimate contact portion 15 similar to the above-described embodiments. In this embodiment, a through tube 41 is provided which penetrates a partition wall 40a defining each of the expansion spaces 11 in an airtight manner. An injection / discharge tube 42 is connected to a base end of the through tube 41. Further, the through pipe 41 is provided with a check valve portion and a discharge valve portion similar to those of the embodiment shown in FIG. 2 for each of the expansion spaces 11.
[0048]
According to this embodiment, when the inflation fluid is injected at the set pressure from the infusion / discharge pipe 42, the inflation fluid is simultaneously injected into each of the expansion spaces 11 via the check valves, and the inflation of the inflation body 40 can be performed quickly. . When the inside of the pipe is shut off, the respective expansion spaces 11 are expanded independently, similarly to the embodiment shown in FIG. 2, so that one breakage does not affect the other expansion spaces 11. Further, when the expansion body 40 is removed, the discharge valve portion is opened by forcibly sucking the gas through the injection / discharge pipe 42, and each expansion space 11 can be contracted.
[0049]
FIG. 4B shows a state in which the expansion body 40 is contracted in this embodiment. The inflatable body 40 can be folded in an umbrella shape along the through tube 41, and the inflatable body 40 can be stored with a small diameter around the through tube 41.
[0050]
FIG. 5 is an explanatory diagram illustrating an in-pipe shut-off method using the in-pipe shut-off device of the embodiment shown in FIG. First, as shown in FIG. 5 (a), a saddle S1 for piercing is attached to the conduit 1 in a live tube state, and a no-blow bag N is attached so as to cover an opening of the saddle S1 for piercing. Then, a perforation 1a is formed in the conduit 1 by using a perforating machine S2 previously arranged in the no-blow bag N.
[0051]
Next, as shown in FIG. 5 (b), the perforator S2 is removed, and a blocking device provided with the inflated body 40, the through tube 41, and the injection / discharge tube 42 in the contracted state is perforated through the no-blow bag N. 1a into the conduit 1.
[0052]
Then, as shown in FIG. 5 (c), the inflation body 40 is guided to the upstream side of the perforation 1a in the conduit 1, and the inflation fluid is injected from outside the conduit 1 through the injection / discharge pipe 42 drawn out of the perforation 1a. To expand the expansion body 40. As a result, the in-pipe contact portion 14 of the expansion body 40 is brought into close contact with the inner surface of the conduit 1, and the flow of the conducting fluid in the conduit 1 is cut off. Further, when the necessary work is completed and the blocking device is removed from the conduit 1, forced suction is performed through the injection / discharge pipe 42 to discharge the expansion fluid in the expansion body 40 and to contract the expansion fluid 40. And pull it out of the perforation 1a.
[0053]
According to such an in-pipe interruption method, the in-pipe installation width L1 of the inflatable body 40 inserted into the conduit 1 can be reduced, and the construction range of the interception work can be narrowed. In particular, in the blocking work of an underground buried conduit, the width of the shaft to be formed can be reduced, so that the construction time and the construction cost can be reduced. In addition, since a blocking member having a high blocking performance that has a plurality of in-pipe contact portions 14 and is sealed in multiple stages is used, generation of a passing gas from the upstream side to the downstream side via the expansion body 40 can be suppressed. it can. As a result, it is possible to eliminate the emission of the passing gas into the atmosphere, so that it is possible to provide a good method in terms of environment and safety. Furthermore, at the time of removal of the expansion body, the expansion fluid is discharged by forced suction to contract the expansion body 40, so that the blocking device can be quickly removed after construction.
[0054]
【The invention's effect】
Since the present invention is configured as described above, in the conduit shutoff device and the conduit shutoff method using the same, it is possible to secure higher shutoff performance even though it is a single shutoff device having a small installation width in the conduit. In addition, the blocking performance is not reduced even for impurities in the tube, irregularities on the inner surface of the tube, and tubes of different diameters. Moreover, even in the unlikely event of breakage, a safe response is possible by the inflatable body partitioned into a plurality.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram (partial cross-sectional view) illustrating a configuration of an in-pipe blocking device according to an embodiment of the present invention.
FIG. 2 is an explanatory view (partial cross-sectional view) showing another embodiment of the in-pipe blocking device.
FIG. 3 is an explanatory view (partial sectional view) showing another embodiment of the in-pipe blocking device.
FIG. 4 is an explanatory view showing another embodiment of the in-pipe shut-off device (FIG. 4 (a) is a partial cross-sectional view, and FIG. 4 (b) is a view showing a state when the inflatable body is contracted).
FIG. 5 is an explanatory diagram illustrating an in-pipe blocking method using the in-pipe blocking tool of the embodiment.
FIG. 6 is an explanatory diagram of a conventional technique.
[Explanation of symbols]
Reference Signs List 1 conduit 1a perforation 10, 20, 30, 40 inflatable body 10a, 20a, 30a, 40a partition 11, 11A, 11B inflatable space 12 continuous pain hole 13 check valve 14 in-tube tight-fitting part 15 non-tight-fitting part 16, 26 injection pipe 17 Discharge pipes 36, 37 Communication pipe 41 Through pipe 42 Injection discharge pipe

Claims (10)

An in-conduit obturator that is inserted from a perforation formed in a conduit and expands in the conduit to block a conductive fluid, comprising a single inflatable body having a plurality of partitioned expansion spaces, wherein the inflatable body is An in-conduit shielding device, characterized in that a plurality of in-pipe contact portions formed for each of the expansion spaces and separated from each other are provided on the outer periphery. The in-conduit shielding device according to claim 1, wherein the in-pipe contact portion is linearly adhered to the entire periphery of the tube. The non-contact part which is not closely_contact | adhered in a pipe | tube is formed in the outer periphery of the said expansion body between the said close contact parts in a pipe | tube, The conduit | blocking tool in a conduit of Claim 1 or 2 characterized by the above-mentioned. 4. The in-conduit shielding device according to claim 1, wherein a plurality of communicating spaces are independently formed in the expansion space. The expansion space is communicated with a check valve that communicates at a set pressure or higher, and an expansion fluid injection path is formed from one end of the communication expansion space to the other end. The conduit blocking device according to any one of the above. The in-conduit blocking device according to any one of claims 1 to 5, wherein the inflation space has an independent inflation fluid injection path formed in an independent space. A step of forming a perforation in the conduit, and the above-mentioned perforation in a contracted state of an inflatable body having a plurality of partitioned expansion spaces, and having a plurality of closely adhered portions in a tube formed for each of the expansion spaces and separated from each other on an outer periphery thereof; And a step of injecting an inflation fluid from the outside of the conduit into each of the inflation spaces to expand the inflatable body, and bringing the in-pipe contact portion into close contact with the inner surface of the conduit upstream of the perforation. A method for shutting off the inside of the conduit by cutting. The expansion space is communicated with a check valve that communicates at a set pressure or higher, and the expansion fluid is injected along an expansion fluid injection path formed from one end of the communication expansion space to the other end. The method according to claim 7, wherein the inside of the conduit is cut off. The method according to claim 7, wherein the inflation fluid is injected into the inflation space along an inflation fluid injection path individually formed in an independent space. The method according to any one of claims 7 to 9, wherein, when removing the expansion body, the expansion fluid is discharged from the expansion space by forced suction to contract the expansion body.

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