Pipe isolating method and pipe isolating apparatus

Abstract

To provide a pipe isolation method and a pipe isolation device capable of blocking and isolating a pipe through which combustible gas flows.SOLUTION: The pipe isolation method according to the first embodiment includes a jig installing step of installing a jig 1 (pipe isolation device) on a pipe P to be isolated, a boring step of boring the pipe P using the jig 1 to form a through-hole, a scavenging step of supplying inert gas into the pipe P from a through-hole H via the jig 1 to scavenge the inside of the pipe P, and a blocking step of inserting a blockage S into the pipe P from the through-hole H via the jig 1 to block the pipe P.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pipe isolation method and a pipe isolation device, and more particularly to a pipe isolation method and a pipe isolation device for blocking and isolating a pipe through which a flammable gas flows. [Background technology]

[0002] In a pipe through which harmful substances such as radioactive substances flow, it has been proposed to block and isolate the pipe to prevent leakage of the harmful substances from the pipe when the pipe is cut (see Patent Document 1).

[0003] For example, Patent Document 1 discloses that, prior to cutting the pipe, a filling material is filled into the inside of the pipe using a specified pipe blocking device to block the pipe, in order to prevent leakage of radioactive materials (harmful substances) inside the pipe when the pipe is disconnected from the reactor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-116831 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when cutting pipes through which flammable gases such as hydrogen, methane, and propane flow, there is a risk that the flammable gases may ignite during cutting.

[0006] Therefore, even if filler material is filled into the middle of the piping as in the invention described in Patent Document 1, there is a possibility that the flammable gas may ignite if it remains at the cut point.

[0007] Furthermore, even if the pipe is cut at the part filled with filler, there is a possibility that flammable gas may be trapped inside the filler, and the possibility of the flammable gas igniting cannot be ruled out.

[0008] Furthermore, in pipes through which both harmful substances such as radioactive materials and flammable gases flow, if the flammable gas ignites when the pipe is cut and an explosion occurs, this could lead to the leakage of harmful substances.

[0009] The present invention has been made in view of the above problems, and an object of the present invention is to provide a pipe isolation method and a pipe isolation device that can block and isolate a pipe through which a flammable gas flows. [Means for solving the problem]

[0010] According to the present invention, there is provided a piping isolation method comprising: a jig installation step of installing a predetermined jig on a piping to be isolated; a drilling step of drilling the piping using the jig to form a through hole; a scavenging step of supplying an inert gas from the through hole into the piping via the jig to scavenge the inside of the piping; and a blocking step of inserting an obstruction object into the piping from the through hole via the jig to block the piping.

[0011] The piping isolation method may include a measuring step of measuring the concentration of the flammable gas with a gas concentration meter placed on the jig after the scavenging step and before the closing step, and the scavenging step and the measuring step may be repeated until the concentration of the flammable gas falls below a predetermined reference value.

[0012] The obstruction may be a filler, an inflatable bag or a plug.

[0013] The plugging step may include temporarily plugging with a mortar plug and then fully plugging with grout.

[0014] The blocking step may include a step of blocking the pipe with a first blocking object that can be positioned within the pipe, and then filling one side of the first blocking object with a filler material up to a position where the pipe is to be cut.

[0015] Further, according to the present invention, there is provided a piping isolation method comprising: a first jig installation step of installing a predetermined first jig on a piping to be isolated; a first drilling step of drilling the piping with a drilling machine arranged on the first jig to form a first through hole; a first scavenging step of supplying an inert gas from the first through hole into the piping via the first jig to scavenge the inside of the piping; a first closing step of inserting a first obstructing object into the piping from the first through hole via the first jig to block the piping; a second jig installation step of installing a predetermined second jig on the piping at a position different from the first jig; a second drilling step of drilling the piping with a drilling machine arranged on the second jig to form a second through hole; a second scavenging step of supplying an inert gas from the second through hole into the piping via the second jig to scavenge the inside of the piping;

[0016] The second jig may be disposed at a position where the second obstructing object can come into close contact with the first obstructing object.

[0017] The pipe isolation method may include a cutting step in which the second obstruction is a filler material and the pipe is cut at a position where the second obstruction is filled.

[0018] The first obstruction may be located upstream of a first cut in the piping, and the second obstruction may be located downstream of a second cut in the piping.

[0019] The piping isolation method may include an airtightness confirmation step of confirming airtightness of the piping between the first obstruction and the second obstruction.

[0020] The pipe isolation method may include a pipe removal process in which the first jig is placed on a vertical portion of the pipe extending vertically from a building floor, and the pipe cut after the first jig installation process to the second blocking process is removed; a third jig installation process in which a third jig is installed above the first jig, the third jig being configured to be able to block the first cut portion of the pipe and to be able to insert a third blocking object; a first blocking object removal process in which the third jig blocks the first cut portion and removes the first blocking object; a third blocking object insertion process in which the first cut portion is unblocked and the third blocking object is inserted to a position below the building floor; a grout filling process in which grout is filled above the third blocking object; a jig removal process in which the first jig and the third jig are removed; and a finishing process in which the pipe is cut at the height of the building floor and the building floor is chipped.

[0021] Furthermore, according to the present invention, there is provided a piping isolation device comprising a main body portion arranged along a piping to be isolated, and a fixing portion for fixing the main body portion to the piping, wherein the main body portion comprises: a hollow portion having an opening that opens to the surface of the piping; a drilling machine arranged in the hollow portion; a purge gas supply portion that communicates with the hollow portion and is capable of supplying an inert gas into the piping through a through-hole formed in the piping by the drilling machine; and an obstruction insertion portion that inserts an obstruction into the piping through the hollow portion and the through-hole.

[0022] The fixing portion may include a pair of arms fixed to the main body portion, a claw portion disposed at the tip of the arm portion and rotatable from an open position where the piping can be inserted to a closed position where the piping can be straddled and fixed to the main body portion, and a switch portion interposed between the arm portion and the claw portion and contacting the piping to rotate the claw portion from the open position to the closed position.

[0023] The switch unit may include a lever arranged on the arm unit so as to be rotatable in conjunction with the claw unit, and a spring member that holds the claw unit in the open position before the lever contacts the piping and urges the claw unit to rotate to the closed position when the lever contacts the piping.

[0024] The main body may include a gas concentration meter that measures the concentration of the flammable gas in the piping through the through hole and the hollow portion.

[0025] The obstruction may be a filler, an inflatable bag, a plug, or a combination thereof.

[0026] The blocking material may be a mortar plug and grout that fills the gap, and the mortar plug may include a piping system that exhausts trapped gas to the outside.

[0027] The piping system may include a pipe arranged to penetrate the mortar plug, a buffer material arranged at the tip of the pipe, and a quick connection arranged at the rear end of the pipe, and the portion of the pipe between the mortar plug and the buffer material may be composed of perforated piping.

[0028] The main body may be configured to be detachably attached to the tip of an arm of a remote-controlled robot. [Effects of the Invention]

[0029] According to the above-described pipe isolation method and pipe isolation device of the present invention, flammable gas can be removed and blocked before the pipe to be isolated is blocked, and ignition of the flammable gas can be prevented when the pipe is cut. Furthermore, according to the present invention, even if the pipe to be isolated contains hazardous substances such as radioactive materials, leakage of the hazardous substances can be prevented. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is an explanatory diagram showing a pipe isolation method according to a first embodiment. [Figure 2] 1A and 1B are perspective views showing the configuration of a pipe isolation device according to one embodiment, in which FIG. 1A shows a state before pipes are fixed, and FIG. 1B shows a state after pipes are fixed. [Figure 3]2(b) is a cross-sectional view of the pipe isolation device shown in FIG. 2(b), where (a) shows the state before drilling the pipe, and (b) shows the state after drilling the pipe. [Figure 4] 1A to 1C are explanatory diagrams showing the operation of the switch unit, where (a) shows the initial state, (b) shows the intermediate state, and (c) shows the completed state. [Figure 5] 5A to 5C are explanatory views showing a piping isolation method according to a second embodiment, in which (a) shows a first jig installation step, (b) shows a first drilling step, and (c) shows a retraction step. [Figure 6] 5A to 5C are explanatory views showing a pipe isolation method according to a second embodiment, in which (a) shows a first scavenging step, (b) shows a first closing step, and (c) shows a second jig installation step. [Figure 7] 5A to 5C are explanatory views showing a pipe isolation method according to a second embodiment, in which (a) shows a second drilling step, (b) shows a second blocking step, and (c) shows a cutting step. [Figure 8] 10A to 10C are explanatory views showing a pipe isolation method according to a third embodiment, in which (a) shows a jig installation step, (b) shows a drilling step, and (c) shows a retraction step. [Figure 9] 10A to 10C are explanatory views showing a pipe isolation method according to a third embodiment, in which (a) shows a scavenging process, (b) shows a blocking process (insertion state), and (c) shows a blocking process (blocked state). [Figure 10] 10A and 10B are explanatory views showing a pipe isolation method according to a third embodiment, in which FIG. 10A shows a filling step and FIG. [Figure 11] FIG. 10 is an explanatory diagram showing a modified example of the pipe isolating method according to the third embodiment. [Figure 12] 10A and 10B are explanatory views showing a pipe isolation method according to a fourth embodiment, in which FIG. 10A shows an initial state and FIG. 10B shows a first jig installation step. [Figure 13] 10A and 10B are explanatory views showing a pipe isolation method according to a fourth embodiment, in which FIG. 10A shows a first drilling step and FIG. 10B shows a first scavenging step. [Figure 14] 10A and 10B are explanatory views showing a pipe isolation method according to a fourth embodiment, in which FIG. 10A shows a replacement step and FIG. 10B shows a first closing step. [Figure 15]10A and 10B are explanatory views showing a pipe isolation method according to a fourth embodiment, in which FIG. 10A shows a closed state and FIG. 10B shows an airtightness confirmation step. [Figure 16] 10A and 10B are explanatory views showing a pipe isolation method according to a fourth embodiment, in which FIG. 10A shows a cutting step and FIG. [Figure 17] 10A and 10B are explanatory views showing a pipe isolation method according to a fifth embodiment, in which FIG. 10A shows a replacement step and FIG. 10B shows a first closing step. [Figure 18] 10A and 10B are explanatory views showing a pipe isolating method according to a fifth embodiment, in which FIG. 10A shows a second closing step, and FIG. 10B shows an airtightness checking step. [Figure 19] 10A and 10B are explanatory views showing a pipe isolating method according to a fifth embodiment, in which FIG. 10A shows a pipe removing step, and FIG. 10B shows a third jig installing step. [Figure 20] 10A and 10B are explanatory views showing a pipe isolation method according to a fifth embodiment, in which FIG. 10A shows a first obstruction removal step, and FIG. 10B shows a mortar plug insertion step. [Figure 21] 10A and 10B are explanatory views showing a piping isolation method according to a fifth embodiment, in which FIG. 10A shows an insertion jig removal step, and FIG. 10B shows a grout filling preparation step. [Figure 22] 10A and 10B are explanatory views showing a pipe isolation method according to a fifth embodiment, in which FIG. 10A shows a grout filling step and FIG. 10B shows a jig removal step. [Figure 23] 10A and 10B are explanatory views showing a pipe isolation method according to a fifth embodiment, in which FIG. 10A shows a finishing step and FIG. 10B shows a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, embodiments of the present invention will be described with reference to Figures 1 to 23. Here, Figure 1 is an explanatory diagram showing a piping isolation method according to a first embodiment. In this specification, the term "upstream side" means a side closer to a source of flammable gas, and the term "downstream side" means a side farther from the source of flammable gas.

[0032] As shown in Figure 1, the pipe isolation method of the first embodiment includes a jig installation process in which a jig 1 (pipe isolation device) is installed on the pipe P to be isolated, a drilling process in which the jig 1 is used to drill a hole in the pipe P to form a through hole H, a scavenging process in which an inert gas is supplied from the through hole H into the pipe P via the jig 1 to scavenge the inside of the pipe P, and a blocking process in which an obstruction object S is inserted into the pipe P from the through hole H via the jig 1 to block the pipe P.

[0033] The jig installation process is, for example, a process of installing a pipe isolation device (jig 1) equipped with a drilling machine, a scavenging mechanism, a blocking mechanism, etc., on the pipe P to be isolated. The configuration of the jig 1 (pipe isolation device) will be described later. The pipe P may be a horizontal pipe arranged in a horizontal direction, or a vertical pipe arranged in a vertical direction. Furthermore, the pipe P may be a U-shaped pipe, a U-shaped trap, or a pipe of a similar shape.

[0034] The drilling step is a step of forming a through hole H by inserting a drilling machine (for example, a drill drill) of the jig 1 into the inside of the pipe P from the side surface and then pulling it out.

[0035] The scavenging process is a process in which the scavenging mechanism (purge gas supply unit 23) of the jig 1 supplies an inert gas (such as nitrogen) into the pipe P through the through-hole H to purge the inside of the pipe P. In pipes through which flammable gases such as hydrogen, methane, and propane flow, if flammable gas remains in the pipe, there is a risk that the flammable gas will ignite when the pipe is cut. Therefore, it is necessary to take measures to prevent flammable gas from remaining or accumulating at least around the cut part of the pipe P.

[0036] The blocking process is a process in which a filler is injected into the pipe P through the through-hole H using the filler injection mechanism (blocking material insertion unit 24) of the jig 1, and the solidification of the filler blocks the pipe P. Note that although the case where a filler is used as the blockage S is described here, the blockage S is not limited to this. Furthermore, when the pipe P is a vertical pipe, it is preferable that the pipe P has a portion for receiving the filler, such as a U-trap, or that the diameter of the pipe P is thin enough to prevent the filler from falling due to the viscosity of the filler.

[0037] The pipe isolation method according to this embodiment includes a scavenging process as a pretreatment for the closing process. If the pipe P is closed without the pretreatment for the scavenging process, flammable gas may remain inside or be mixed in the filler, and there is a risk that the flammable gas may ignite when the pipe P is cut.

[0038] As in this embodiment, by performing pre-treatment for the scavenging step, it is possible to remove flammable gas remaining or stagnating in the pipe P, and in the subsequent closing step, the flammable gas will not be mixed into the filler material or remain in the pipe P. Therefore, by cutting the pipe P at the portion where the pipe P is closed with the filler material, it is possible to prevent the flammable gas from igniting.

[0039] Next, the pipe isolation device (jig 1) will be described with reference to Figures 2 to 4. Here, Figure 2 is a perspective view showing the configuration of a pipe isolation device according to one embodiment, where (a) shows the state before the pipe is fixed, and (b) shows the state after the pipe is fixed. Figure 3 is a cross-sectional view of the pipe isolation device shown in Figure 2(b), where (a) shows the state before drilling a hole in the pipe, and (b) shows the state after drilling a hole in the pipe. Figure 4 is an explanatory diagram showing the operation of the switch unit, where (a) shows the initial state, (b) shows an intermediate state, and (c) shows the completed state.

[0040] 2 and 3, the pipe isolation device (jig 1) includes a main body 2 arranged along the pipe P to be isolated, and a fixing part 3 that fixes the main body 2 to the pipe P. The main body 2 includes a hollow part 21 having an opening that opens to the surface of the pipe P, a drilling machine 22 arranged in the hollow part 21, a purge gas supply part 23 that communicates with the hollow part 21 and can supply an inert gas into the pipe P through a through hole H formed in the pipe P by the drilling machine 22, and an obstructing object insertion part 24 that inserts an obstructing object S into the pipe P through the hollow part 21 and the through hole H. Note that the case where the obstructing object S is a filler will be described here.

[0041] The main body 2 has a groove 25 at its upper part that can fit tightly against the surface of the pipe P. A packing 25a is disposed on the surface of the groove 25. The groove 25 and the packing 25a have openings formed therein that communicate with the cavity 21.

[0042] The main body 2 has a gripper gripping unit 26 arranged at its bottom, which is configured to be attachable to and detachable from the tip of the arm of a remote-controlled robot. The gripper gripping unit 26 is arranged, for example, on a side surface facing the main body 2. The gripper gripping unit 26 is configured to be able to be grasped by a gripper arranged at the tip of the arm of the remote-controlled robot. The configuration of the gripper gripping unit 26 is not limited to the configuration shown in the figure, and can be changed as appropriate to match the shape of the gripper of the remote-controlled robot.

[0043] The main body 2 is provided with a bottom plate 27 that seals the cavity 21. The bottom plate 27 is arranged on the main body 2 via a sealing member such as an O-ring, and is fixed to the main body 2 with fasteners such as bolts. An opening is formed in the center of the bottom plate 27, through which the drilling machine 22 can be inserted. A sealing member such as an O-ring is arranged in the opening.

[0044] The hollow portion 21 is an approximately cylindrical space formed inside the main body portion 2, and is provided with an opening 21a through which the drilling drill 22a of the drilling machine 22 can be inserted, and an opening 21b through which the shaft of the drilling machine 22 can be placed.

[0045] The drilling machine 22 includes, for example, a drilling drill 22a to be inserted into the piping P, a shaft 22b that supports the drilling drill 22a, and a linear bushing 22c that is arranged on the outer periphery of the shaft 22b. Note that the configuration of the drilling machine 22 is not limited to the configuration shown in the figure.

[0046] The linear bushing 22c includes an outer cylinder 22d fixed to the hollow portion 21 and an inner cylinder 22e fixed to the shaft 22b, and the inner cylinder 22e is arranged so as to be able to move back and forth linearly relative to the outer cylinder 22d. The outer cylinder 22d is formed, for example, by a part of the main body 2. Note that the configuration of the linear bushing 22c is not limited to the configuration shown in the figure.

[0047] Between the shaft 22b and the inner cylinder 22e, members such as an oil seal 22f and a bearing 22g are disposed as needed. The inner cylinder 22e is a part that slides along the hollow portion 21, and an O-ring 22h is disposed between the main body portion 2 and the inner cylinder 22e. In addition, an O-ring 22i is disposed between the outer cylinder 22d and the bottom plate 27. Backup rings may be disposed around the O-rings 22h and 22i.

[0048] The purge gas supply unit 23 includes, for example, an opening 23a communicating with the cavity 21 and a purge gas inlet 23b disposed in the opening 23a. A tube for supplying an inert gas is connected to the purge gas inlet 23b.

[0049] The obstruction object insertion section 24 includes, for example, an opening 24a that communicates with the hollow section 21 and a filler material injection port 24b that is disposed in the opening 24a. A tube for supplying a filler material is connected to the filler material injection port 24b.

[0050] The purge gas inlet 23b and the filler material inlet 24b may be formed at staggered positions so that their flow paths are not in the same straight line. For example, the filler material inlet 24b is disposed closer to the pipe P than the purge gas inlet 23b. Also, a check valve may be disposed in each system of the purge gas inlet 23b and the filler material inlet 24b.

[0051] The fixing part 3 includes, for example, a pair of arms 31 fixed to the main body 2, claws 32 arranged at the tips of the arms 31 and rotatable from an open position where the pipe P can be inserted to a closed position where the arms 31 can be fixed to the main body 2 across the pipe P, and a switch 33 interposed between the arms 31 and the claws 32 and coming into contact with the pipe P to rotate the claws 32 from the open position to the closed position. Note that the configuration of the fixing part 3 is not limited to the configuration shown in the figure.

[0052] The arm portion 31 includes, for example, a base 31a fixed to the main body portion 2 by a fastener such as a bolt, and a pair of arms 31b extending obliquely above the pipe P from the base 31a.

[0053] The claw portion 32 is, for example, a block body rotatably arranged between a pair of arms 31b, and has a groove 32a on the inside that can come into close contact with the surface of the pipe P. A packing 32b is arranged on the surface of the groove 32a. A bracket 32c is arranged at the tip of the claw portion 32. When the claw portion 32 is rotated to the closed position, a bracket 28 fixed to the main body 2 is arranged at a position facing the bracket 32c. The bracket 32c and the bracket 28 are fixed by a fastener such as a bolt.

[0054] The switch unit 33 includes, for example, a lever 33a arranged on the arm unit 31 so as to be rotatable in conjunction with the claw 32, and a spring member 33b which holds the claw 32 in the open position before the lever 33a comes into contact with the pipe P and biases the claw 32 to rotate to the closed position when the lever 33a comes into contact with the pipe P. The posture of the claw 32 in the open position is maintained by components such as a ball button and a ball plunger.

[0055] As shown in FIG. 4(a), the fixing part 3 is brought closer to the pipe P and the lever 33a is brought into contact with the pipe P. As shown in FIG. 4(b), the fixing part 3 is brought even closer to the pipe P and the lever 33a is pushed down. When the position of the lever 33a passes the turning point, as shown in FIG. 4(c), the biasing force of the spring member 33b causes the lever 33a to rotate in a direction away from the pipe P. Through this series of operations, the claw part 32 rotates to the closed position across the pipe P and is finally fixed.

[0056] The switch unit 33 is not limited to the configuration shown in the figure, as long as it has a mechanism that detects the approach of the fixed unit 3 and the pipe P and rotates the claw unit 32. Furthermore, since there may be obstacles or other pipes around the pipe P to be isolated, the claw unit 32 and the switch unit 33 have a shape and configuration that allows them to be inserted from gaps around the pipe P (for example, gaps below, above, diagonally below, or diagonally above).

[0057] Next, a piping isolation method according to a second embodiment will be described with reference to FIGS. 5 to 7. Here, FIG. 5 is an explanatory diagram showing the piping isolation method according to the second embodiment, where (a) shows the first jig installation step, (b) shows the first drilling step, and (c) shows the evacuation step. FIG. 6 is an explanatory diagram showing the piping isolation method according to the second embodiment, where (a) shows the first scavenging step, (b) shows the first closing step, and (c) shows the second jig installation step. FIG. 7 is an explanatory diagram showing the piping isolation method according to the second embodiment, where (a) shows the second drilling step, (b) shows the second closing step, and (c) shows the cutting step.

[0058] The piping isolation method according to the second embodiment is a method of isolating a piping P using two piping isolation devices (a first jig 11 and a second jig 12). The configurations of the first jig 11 and the second jig 12 are the same as those of the above-described piping isolation device (jig 1). Note that the configurations of the first jig 11 and the second jig 12 are illustrated in a simplified form.

[0059] FIG. 5(a) shows the first jig installation step of installing a first jig 11 on a pipe P to be isolated. The illustrated pipe P is a horizontal pipe arranged in a horizontal direction. The outer diameter of the pipe P is, for example, approximately several tens to several hundreds of mm. The pipe P may be one of a group of pipes arranged at regular intervals. Although not shown, a purge gas supply unit 23 or the like may be used to check whether the main body 2 of the first jig 11 is in tight contact with the pipe P to ensure airtightness.

[0060] 5(b) shows a first drilling step in which the piping P is drilled with the drilling machine 22 arranged in the first jig 11 to form a first through hole H1. Here, the drawing shows a state in which the drill drill of the drilling machine 22 is inserted into the piping P under predetermined drilling conditions.

[0061] 5(c) shows a retraction step in which, after the first through hole H1 has been formed, the drilling machine 22 is retracted to open the first through hole H1. By retracting the drilling drill of the drilling machine 22, the first through hole H1 can be communicated with the hollow portion 21 of the first jig 11. Although not shown, by using a drilling drill with an oil hole or the like, the first through hole H1 can also be communicated with the hollow portion 21 of the first jig 11 without retracting the drilling drill.

[0062] 6(a) shows a first scavenging step in which an inert gas is supplied into the pipe P from the first through-hole H1 via the first jig 11 to purge the inside of the pipe P. An inert gas such as nitrogen is supplied from the purge gas supply unit 23 into the pipe P via the cavity 21 and the first through-hole H1. This process purges (scavenges) the ambient gas around the first through-hole H1, and removes flammable gas from the portion where the obstruction object is inserted. Although not shown, a gas concentration meter may be disposed in the first jig 11 to measure the concentration of flammable gas.

[0063] FIG. 6(b) shows a first closing step in which a first closing object S1 is inserted into the pipe P through the first through-hole H1 via the first jig 11 to close the pipe P. Here, the case where the first closing object S1 is a filler is illustrated. Specifically, the filler is supplied from the closing object insertion portion 24 into the pipe P via the hollow portion 21 and the first through-hole H1. The amount of filler to be supplied is determined by calculating in advance the volume of the portion of the pipe P that is to be filled, and supplying an amount of filler equal to or greater than that volume into the pipe P.

[0064] 6(c) shows a second jig installation step in which a second jig 12 is installed at a position different from the first jig 11 on the pipe P. The second jig 12 is preferably installed after the first obstruction material S1 has solidified, but may be installed at the same time as the installation of the first jig 11. In addition, the second jig 12 is installed at a certain distance from the first jig 11 so that it does not overlap with the first obstruction material S1 filled in the pipe P when forming the through hole.

[0065] 7(a) shows a second drilling step in which the piping P is drilled with a drilling machine 22 disposed on a second jig 12 to form a second through hole H2. Here, the state in which the drilling machine 22 is retracted after the second through hole H2 is formed is shown. The second through hole H2 is formed using the second jig 12 in the same procedure as for the first jig 11. Although not shown, as with the first jig 11, after the second through hole H2 is formed, a second scavenging step is performed in which an inert gas is supplied from the second through hole H2 into the piping P using the purge gas supply unit 23 of the second jig 12 to purge the inside of the piping P.

[0066] 7(b) shows a second blocking step in which a second blocking object S2 is inserted into the pipe P from the second through-hole H2 via the second jig 12 to block the pipe P. Here, the example illustrates a case in which the second blocking object S2 is a filler. As illustrated, the second blocking object S2 is filled so as to be in close contact with the first blocking object S1. That is, the second jig 12 is placed in a position where the second blocking object S2 can be in close contact with the first blocking object S1.

[0067] FIG. 7(c) shows a cutting step in which the pipe P is cut at a position where the pipe P has been filled with a filler. The filler, which is the second obstruction S2, is supplied into the pipe P so that it fills up to a position beyond the cutting portion C. After the second obstruction S2 has solidified, the pipe is cut at the cutting portion C. In this way, by blocking the pipe P in multiple stages with multiple obstructions, the pipe P can be blocked more reliably.

[0068] For example, by arranging the first jig 11 on the upstream side of the pipe P and the second jig 12 on the downstream side of the pipe P, even if there is a source of flammable gas on the upstream side of the pipe P, the pipe P can be blocked with the first blocking object S1 to block the flammable gas, and then the scavenged pipe P can be blocked with the second blocking object S2, thereby more reliably eliminating the flammable gas. In addition, it is possible to more reliably isolate the flammable gas source present on the upstream side of the pipe P.

[0069] Also, although not shown, if the first jig 11 is placed downstream of the piping P and the second jig 12 is placed upstream of the piping P, after the piping P is cut at the cutting portion C, the downstream side of the piping P can be removed, and the first jig 11 and the second jig 12 can also be removed together.

[0070] Next, a piping isolation method according to a third embodiment will be described with reference to FIGS. 8 to 11. FIG. 8 is an explanatory diagram showing the piping isolation method according to the third embodiment, where (a) shows the jig installation step, (b) shows the drilling step, and (c) shows the retraction step. FIG. 9 is an explanatory diagram showing the piping isolation method according to the third embodiment, where (a) shows the scavenging step, (b) shows the blocking step (insertion state), and (c) shows the blocking step (blocked state). FIG. 10 is an explanatory diagram showing the piping isolation method according to the third embodiment, where (a) shows the filling step and (b) shows the cutting step. FIG. 11 is an explanatory diagram showing a modified example of the piping isolation method according to the third embodiment.

[0071] The pipe isolation method according to the third embodiment involves blocking a pipe P with a first blocking object S1 that can be positioned within the pipe P, and then filling one side of the first blocking object S1 with a filler material S4 up to a position where the pipe P is cut. The jig 13 (pipe isolation device) used in this embodiment is configured to be able to supply both the first blocking object S1 and the filler material S4.

[0072] FIG. 8(a) shows the jig installation process for installing a jig 13 on a pipe P to be isolated. The illustrated pipe P is a horizontal pipe arranged in a horizontal direction. The illustrated jig 13 uses an inflatable bag as a first obstruction S1. The jig 13 includes a first obstruction supply section 24c and a filler supply section 24d as an obstruction insertion section 24. A tube is connected to the rear end of the inflatable bag to supply gas to the inside.

[0073] 8(b) shows a drilling process in which the drilling machine 22 arranged on the jig 13 drills the pipe P to form a through hole H. Here, the drawing shows a state in which the drill drill of the drilling machine 22 is inserted into the pipe P under predetermined drilling conditions.

[0074] 8(c) shows a retraction step in which, after the through hole H has been formed, the drilling machine 22 is retracted to open the through hole H. By retracting the drilling drill of the drilling machine 22, the through hole H can be made to communicate with the hollow portion 21 of the jig 13.

[0075] 9(a) shows a scavenging process in which an inert gas is supplied into the pipe P from the through-hole H via the jig 13 to purge the inside of the pipe P. An inert gas such as nitrogen is supplied from the purge gas supply unit 23 into the pipe P via the cavity 21 and the through-hole H.

[0076] FIG. 9(b) shows an obstruction object insertion step in which a first obstruction object S1 is inserted into the pipe P through the through-hole H. The obstruction object insertion step is part of the obstruction step. The inflatable bag, which is the first obstruction object S1, is in a deflated state with a size and shape that allows it to pass through the through-hole H. The inflatable bag is contained in the first obstruction object supply unit 24c until the scavenging step is completed, and after the scavenging step is completed, it is pushed out of the first obstruction object supply unit 24c and inserted into the pipe P. At this time, the inflatable bag may be inserted upstream of the through-hole H of the pipe P.

[0077] 9(c) shows a process of inflating an inflatable bag (first obstructing object S1) to block the pipe P. The obstructing object expanding process is part of the blocking process.

[0078] FIG. 10(a) shows the filling process in which a filler material is injected into the pipe P to fill it. The filling process is also part of the blocking process. By filling the filler material (second blocking object S2) downstream of the first blocking object S1, gaps through which flammable gas can enter can be eliminated. The filler material is filled from the first blocking object S1 to a position beyond the position where the pipe P is cut (cut portion C).

[0079] 10(b) shows the cutting process for cutting the pipe P. The position (cutting portion C) for cutting the pipe P is set at the position where the filler material is filled in the pipe P. By replacing the atmospheric gas in the pipe P with the filler material, it is possible to reduce the possibility of ignition of flammable gas during cutting.

[0080] FIG. 11 is an explanatory diagram showing a modified example of the pipe isolation method according to the third embodiment. This modified example is applied to the case where the pipe P is a vertical pipe arranged in a vertical direction. The first obstruction S1 is inserted and inflated at a position below the through-hole H. By using an obstruction that can be positioned within the pipe P, such as an inflatable bag, a portion of the pipe P can be obstructed, and a filler material (second obstruction S2) can be filled above it. Although not shown, this modified example can also be applied to an inclined pipe having a slope that makes it impossible to obstruct the pipe P with a filler material.

[0081] Next, a piping isolation method according to a fourth embodiment will be described with reference to FIGS. 12 to 16. FIG. 12 is an explanatory diagram showing the piping isolation method according to the fourth embodiment, where (a) shows the initial state and (b) shows the first jig installation step. FIG. 13 is an explanatory diagram showing the piping isolation method according to the fourth embodiment, where (a) shows the first drilling step and (b) shows the first purging step. FIG. 14 is an explanatory diagram showing the piping isolation method according to the fourth embodiment, where (a) shows the replacement step and (b) shows the first closing step. FIG. 15 is an explanatory diagram showing the piping isolation method according to the fourth embodiment, where (a) shows the closing completed state and (b) shows the airtightness confirmation step. FIG. 16 is an explanatory diagram showing the piping isolation method according to the fourth embodiment, where (a) shows the cutting step and (b) shows the sealing step.

[0082] 12(a) shows the initial state (installation environment) of the piping P to be isolated. For example, the piping P has a horizontal section P1 extending horizontally along the building floor F, a vertical section P2 extending vertically upward through the building floor F, and a horizontal section P3 extending horizontally so as to penetrate the building wall W. The upstream side of the piping P is the horizontal section P1 side, and the downstream side of the piping P is the horizontal section P3 side. Also, it is assumed that obstructions I, such as equipment and partition members, are installed on the building floor F around the vertical section P2.

[0083] 12(b) shows a first jig installation step in which the first jig 11 is installed on the vertical portion P2 of the pipe P. When the first jig is to be placed near the building floor F, any interfering objects I that may become obstacles are removed in advance. In addition, the surface of the pipe P in the area where the first jig 11 is to be installed may be cleaned to remove any deposits.

[0084] 13(a) shows a first drilling step in which a first through hole H1 is formed by drilling the piping P with a drilling machine 22 arranged on a first jig 11. Here, the drawing shows a state in which the drill drill of the drilling machine 22 is inserted into the piping P under predetermined drilling conditions.

[0085] 13(b) shows a first scavenging step in which an inert gas is supplied into the piping P from the first through hole H1 via the first jig 11 to purge the inside of the piping P. After the first through hole H1 is formed in the first drilling step, the drilling machine 22 is retracted to connect the first through hole H1 to the cavity 21. The purge gas supply unit 23 is connected to a purge gas supply device 23c arranged on the building floor F, for example, and a gas concentration meter 23d that measures the concentration of flammable gas is arranged in the middle thereof.

[0086] Purge gas supply device 23c is configured to be able to supply an inert gas such as nitrogen to cavity 21 and to suck the atmospheric gas from cavity 21. When the atmospheric gas from cavity 21 is sucked, gas concentration meter 23d measures the concentration of the flammable gas. The supply of the inert gas and the sucking of the atmospheric gas are repeated until the concentration of the flammable gas falls below a predetermined reference value.

[0087] That is, the piping isolation method according to this embodiment includes a measurement step of measuring the concentration of flammable gas using a gas concentration meter 23d placed in the first jig 11 after the scavenging step and before the blocking step, and the scavenging step and the measurement step are repeated until the concentration of flammable gas falls below a predetermined reference value.

[0088] 14(a) shows the replacement process of replacing the drilling machine 22 with the first obturator insertion device 4. A valve 29 capable of closing the cavity 21 is arranged in the main body 2 of the first jig 11. After the cavity 21 is closed by the valve 29, the drilling machine 22 is pulled out from the main body 2, and the first obturator insertion device 4 is attached to the main body 2.

[0089] The first obstruction insertion device 4, for example, has a casing 41 that houses an inflatable bag, which is the first obstruction S1, and is configured to be able to insert the casing 41 into the piping P, then send the inflatable bag out of the casing 41 into the piping P, and supply inflation gas to the inflatable bag inserted into the piping P.

[0090] 14(b) shows a first blocking step in which an inflatable bag (first blocking object S1) inserted into the pipe P is inflated to block the pipe P. After the first blocking object insertion device 4 is installed in the replacement step, the valve 29 is opened and the tip of the casing 41 is inserted into the first through-hole H1, and the inflatable bag is inserted into the pipe P from the casing 41. Thereafter, inflation gas is supplied to the inflatable bag to inflate it and block the pipe P.

[0091] 15(a) shows a state in which, after the first closing step, a second jig is installed downstream of the pipe P in the same manner as the first jig 11, and the pipe P is closed with a second blocking object S2 (inflatable bag). The procedure for closing the pipe P using the second jig is the same as the procedure for closing the pipe P using the first jig 11, and therefore a detailed description thereof will be omitted here.

[0092] In the pipe isolation method according to the fourth embodiment, the first obstruction S1 and the second obstruction S2 are placed at positions separated from each other so as to block both ends of the portion of the pipe P that is to be removed. Although the second jig is not shown in the figures, the second jig may be left in place, or may be removed when the second obstruction S2 is inserted upstream of the through-hole.

[0093] 15(b) shows an airtightness confirmation process for confirming the airtightness of the portion isolated by the first obstructing object S1 and the second obstructing object S2. The airtightness is confirmed, for example, by connecting a compressor 5 to the purge gas supply unit 23 of the first jig 11 and measuring the internal pressure of the isolated portion of the pipe P. If the airtightness is insufficient, another obstructing object (airbag, filler, grout, etc.) may be added.

[0094] FIG. 16(a) shows a cutting process for cutting a pipe P isolated by a first obstruction S1 and a second obstruction S2. The first cutting portion C1 is set downstream of the first obstruction S1, and the second cutting portion C2 is set upstream of the second obstruction S2. In other words, the first obstruction S1 is disposed upstream of the first cutting portion C1 of the pipe P, and the second obstruction S2 is disposed downstream of the second cutting portion C2 of the pipe P. In the cutting process, the first jig 11 and the second jig are removed in advance. The first cutting portion C1 may be set, for example, to match the building floor F.

[0095] 16(b) shows a sealing step for sealing the first cut portion C1 and the second cut portion C2 of the pipe P. The first cut portion C1 and the second cut portion C2 are sealed with a cover member L such as a hex plug. By sealing the cut portions with such a cover member L, it is possible to prevent the leakage of harmful substances or flammable gases from the cut portions even if, for example, the inflatable bag is deflated or damaged.

[0096] Next, a pipe isolation method according to a fifth embodiment will be described with reference to FIGS. 17 to 23. FIG. 17 is an explanatory diagram showing the pipe isolation method according to the fifth embodiment, where (a) shows the replacement step and (b) shows the first blocking step. FIG. 18 is an explanatory diagram showing the pipe isolation method according to the fifth embodiment, where (a) shows the second blocking step and (b) shows the airtightness confirmation step. FIG. 19 is an explanatory diagram showing the pipe isolation method according to the fifth embodiment, where (a) shows the pipe removal step and (b) shows the third jig installation step. FIG. 20 is an explanatory diagram showing the pipe isolation method according to the fifth embodiment, where (a) shows the first blockage removal step and (b) shows the mortar plug insertion step. FIG. 21 is an explanatory diagram showing the pipe isolation method according to the fifth embodiment, where (a) shows the insertion jig removal step and (b) shows the grout filling preparation step. Fig. 22 is an explanatory diagram showing a piping isolation method according to a fifth embodiment, where (a) shows a grout filling step and (b) shows a jig removal step. Fig. 23 is an explanatory diagram showing a piping isolation method according to the fifth embodiment, where (a) shows a finishing step and (b) shows a modified example.

[0097] The pipe isolation method according to the fifth embodiment is performed in a pipe installation environment similar to that of the fourth embodiment, except that the obstruction object S is replaced with a plug and the first cut portion C1 is sealed with a mortar plug and grout. The first jig 11 and the second jig 12 have a valve 29 capable of sealing the cavity 21, and are configured to be interchangeable between the drilling machine 22 and the plug insertion machine 6. The plugs (first obstruction object S1 and second obstruction object S2) arranged at the tip of the plug insertion machine 6 have a shape capable of obstructing the pipe P, and the drilling machine 22 is configured to be capable of forming a through hole through which the first obstruction object S1 or the second obstruction object S2 can be inserted.

[0098] 17(a) shows the replacement process of replacing the drilling machine 22 of the first jig 11 with the plug insertion machine 6. The process of installing the first jig 11 on the pipe P and forming the first through hole H1 in the pipe P is the same as in the other embodiments described above, and therefore a detailed description thereof will be omitted here. In this embodiment, after the first through hole H1 is formed, the cavity 21 is closed with the valve 29, and the drilling machine 22 is replaced with the plug insertion machine 6.

[0099] 17(b) shows a first blocking step in which a first blocking object S1 (plug) is inserted into the pipe P to block the pipe P. After the replacement step, the valve 29 is opened, and the plug insertion machine 6 inserts the first blocking object S1 (plug) into the pipe P. Note that the first blocking object S1 (plug) is a temporary plug that temporarily blocks the pipe P, as it will be pulled out in a step described later.

[0100] 18(a) shows a second blocking step in which the pipe P is blocked by the second jig 12. The configuration of the second jig 12 is the same as that of the first jig, and the processing from the installation step to the drilling step is the same as that of the first jig 11. The pipe P is blocked by a second blocking object S2 (plug).

[0101] 18(b) shows an airtightness confirmation process for confirming the airtightness of the portion isolated by the first obstructing object S1 and the second obstructing object S2. The airtightness confirmation is performed, for example, by connecting a compressor 5 to the piping P between the first obstructing object S1 and the second obstructing object S2 and measuring the internal pressure of the isolated portion of the piping P.

[0102] 19(a) shows the piping removal process for cutting and removing the isolated piping P. The first cutting section C1 is set downstream (above) of the first obstruction S1, and the second cutting section C2 is set upstream of the second obstruction S2. The first cutting section C1 is set at a position higher than the building floor F.

[0103] 19(b) shows a third jig installation step of installing a third jig 7 for blocking the first cut portion C1 with a third blocking object S3. The third blocking object S3 is, for example, a mortar plug S31 and grout S32. The mortar plug S31 has an outer diameter smaller than the inner diameter of the pipe P so that it can be inserted into the pipe P from the first cut portion C1, and is therefore a component that temporarily blocks the pipe P.

[0104] The third jig 7 includes a main body 71 having a cylindrical space and positioned above the first cutting portion C1, and a valve 72 positioned at the bottom end of the main body 71 and capable of closing the first cutting portion C1. After the third jig 7 is placed at the top end of the first cutting portion C1, the valve 72 is closed to seal off the first cutting portion C1. A mortar plug S31 is positioned above the valve 72.

[0105] 20(a) shows a first obstruction removal step for removing the first obstruction S1 from the pipe P. In this embodiment, the first obstruction S1 needs to be removed in order to insert the mortar plug S31 deep into the pipe P. Specifically, the first obstruction S1 is pulled out by the first jig 11, and the cavity 21 is closed by the valve 29.

[0106] 20(b) shows a mortar plug insertion step in which a mortar plug S31 is inserted into the pipe P using a third jig 7. Specifically, the valve 72 is opened and the mortar plug S31 is pushed into the pipe P by an insertion jig 73.

[0107] 21(a) shows an insertion jig removal step in which the mortar plug S31 is inserted to a predetermined position and then the insertion jig 73 is removed. After the insertion jig 73 is removed, the valve 72 is closed.

[0108] 21(b) shows a grout filling preparation process in which preparations are made to fill the pipe P with grout S32. Specifically, a grout filling nozzle 74 is installed in the main body 71 of the third jig 7. Although not shown, the grout filling nozzle 74 is connected to a grout supply device.

[0109] FIG. 22(a) shows a grout filling step for filling the pipe P with grout S32. Specifically, the valve 72 is opened, and the grout S32 is allowed to flow above the mortar plug S31 to fill and backfill the pipe P. The grout S32 is filled, for example, to a height equal to or higher than the building floor F. Because there is a small gap between the mortar plug S31 and the pipe P, backfilling with the grout S32 can reliably close the first cut portion C1 of the pipe P. Note that the grout S32 may be filled to a height lower than the building floor F.

[0110] FIG. 22(b) shows a jig removal process for removing the jigs (first jig 11, second jig 12, and third jig 7) that were installed in the piping P. At this time, the first obstruction S1 is also removed together with the removal of the first jig 11. In addition, the second jig 12 is removed while leaving the second obstruction S2 in the piping P. Note that the second jig 12 may be removed or left in place as needed.

[0111] FIG. 23(a) shows a finishing process in which the pipe P is cut at the height of the building floor F and the building floor F is scraped off. In this embodiment, the first cut portion C1 of the pipe P is set at a position higher than the building floor F. Therefore, if the pipe P is left as is, other work may be affected. Therefore, by cutting the pipe P at the height of the building floor F and scraping it off, obstructions on the building floor F can be removed and unevenness on the building floor F can be eliminated. In the finishing process, the upstream portion of the second obstruction S2 remaining at the second cut portion C2 may also be cut and removed. Note that the finishing process can be omitted as necessary, or if the grout has not been filled up to the floor surface, only the cut surface of the pipe P may be scraped off.

[0112] As described above, the pipe isolation method according to the fifth embodiment includes a pipe removal process in which the first jig 11 is placed on the vertical portion P2 of the pipe P extending vertically from the building floor surface F, and the pipe cut after the first jig installation process to the second blocking process is removed; a third jig installation process in which the third jig 7 is installed, which is configured to be able to block the first cut portion C1 of the pipe P located downstream of the first jig 11 and to be able to insert a third blocking object (mortar plug S31); and a third jig installation process in which the third jig 7 is installed to block the first cut portion C1 and to insert the first blocking object S1. the first obstruction removal process, which removes the first obstruction from the first cutting portion C1; the third obstruction insertion process, which releases the blockage at the first cutting portion C1 and inserts a third obstruction (mortar plug S31) to a position below the building floor F; the grout filling process, which fills the third obstruction (grout S32) above the third obstruction (mortar plug S31) until it exceeds the height of the building floor F; the jig removal process, which removes the first jig 11 and the third jig 7; and the finishing process, which cuts the piping P at the height of the building floor F and grinds the building floor F.

[0113] In this embodiment, temporary closing is performed with the mortar plug S31 and then permanent closing is performed with grout S32, so that a piping system that can communicate via the mortar plug S31 can be arranged in the horizontal portion P1 of the pipe P. For example, as shown in the modified example of FIG. 23(b), the mortar plug S31 is a plug manufactured by hardening mortar, so that a piping system including a quick connection 81, a valve 82, a pipe 83, etc. can be installed during manufacturing.

[0114] For example, the piping system includes a pipe 83 disposed through a mortar plug S31, a buffer material 84 disposed at the tip (upstream or lower end) of the pipe 83, a quick connection 81 disposed at the rear end (downstream or upper end) of the pipe 83, and a valve 82 capable of opening and closing the quick connection 81. The section of the pipe 83 between the mortar plug S31 and the buffer material 84 is constructed of perforated piping. The upper opening of the quick connection 81 is closed by a plug 85 such as a hex plug. When such a piping system is installed, for example, if flammable gas accumulates in the horizontal section P1 of the pipe P, the gas can be vented to the outside from the horizontal section P1 of the pipe P via the quick connection 81.

[0115] According to the pipe isolation methods of the first to fifth embodiments described above, it is possible to remove and block the flammable gas before blocking the piping P to be isolated, thereby preventing the flammable gas from igniting when the piping P is cut. Furthermore, according to these embodiments, even if the piping P to be isolated is a piping containing hazardous substances such as radioactive materials, it is possible to prevent leakage of hazardous substances.

[0116] The piping isolation methods according to the first to fifth embodiments described above may be performed using a remote-controlled robot. In addition, in areas where workers are allowed to enter, some of the steps may be performed by workers.

[0117] The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention.

[0118] This disclosure can contribute, for example, to Goal 7 of the United Nations-led Sustainable Development Goals (SDGs), "Ensure access to affordable, reliable, sustainable and modern energy for all" and Goal 13, "Take urgent action to combat climate change and its impacts." [Explanation of symbols]

[0119] 1,13 Jig (pipe isolation device) 2 Main body 3 Fixed part 4. First Obturator Insertion Device 5. Compressor 6 Plug Insertion Machine 7 Third jig 11 First jig 12 Second jig 21 Cavity 21a,21b opening 22 Drilling machine 22a Drill 22b shaft 22c Linear Bush 22d outer barrel 22e inner cylinder 22f oil seal 22g bearing 22h, 22i O-ring 23 Purge gas supply unit 23a opening 23b Purge gas inlet 23c Purge gas supply device 23d Gas concentration meter 24 Obstruction insertion part 24a opening 24b Filler injection port 24c First obstruction supply section 24d Filler supply section 25 groove 25a Gasket 26 Gripper gripping part 27 Bottom plate 28 Bracket 29 Valve 31 Arm section 31a Pedestal 31b Arm 32 Claw 32a groove 32b Gasket 32c bracket 33 Switch section 33a Lever 33b Spring member 41 Casing 71 Main body 72 Valve 73 Insertion jig 74 Grout filling nozzle 81 Quick Connection 82 Valve 83 Piping 84 Cushioning material 85 plug P piping S Obstruction S1 first obstruction S2 Second obstruction S3 Third obstruction S31 Mortar Plug S32 Grout S4 Filler

Claims

1. a jig installation process of installing a predetermined jig on the piping to be isolated; a drilling step of drilling the pipe using the jig to form a through hole; a scavenging step of scavenging the inside of the pipe by supplying an inert gas into the pipe from the through hole via the jig; a blocking step of inserting a blocking object into the pipe from the through hole via the jig to block the pipe; A method for isolating piping, comprising:

2. 2. The piping isolation method according to claim 1, further comprising a measuring step of measuring a concentration of the flammable gas with a gas concentration meter disposed on the jig after the scavenging step and before the closing step, wherein the scavenging step and the measuring step are repeated until the concentration of the flammable gas decreases below a predetermined reference value.

3. The piping isolation method according to claim 1 , wherein the obstruction is a filler material, an inflatable bag, or a plug.

4. The piping isolation method according to claim 1 , wherein the plugging step includes temporarily plugging the pipe with a mortar plug and then permanently plugging the pipe with grout.

5. 2. The pipe isolation method according to claim 1, wherein the blocking step includes the step of blocking the pipe with a first blockage positionable within the pipe, and then filling one side of the first blockage with a filler material up to a position where the pipe is to be cut.

6. a first jig installation step of installing a predetermined first jig on the piping to be isolated; a first drilling step of drilling the pipe with a drilling machine disposed in the first jig to form a first through hole; a first scavenging step of scavenging the inside of the piping by supplying an inert gas into the piping from the first through hole via the first jig; a first closing step of inserting a first closing object into the pipe from the first through hole via the first jig to close the pipe; a second jig installation step of installing a predetermined second jig at a position different from the first jig on the piping; a second drilling step of drilling the pipe with a drilling machine disposed in the second jig to form a second through hole; a second scavenging step of scavenging the inside of the piping by supplying an inert gas into the piping from the second through hole via the second jig; a second blocking step of inserting a second blocking object into the pipe from the second through hole via the second jig to block the pipe; A method for isolating piping, comprising:

7. The piping isolation method according to claim 6 , wherein the second jig is disposed at a position where the second obstruction can come into close contact with the first obstruction.

8. The piping isolation method according to claim 6, wherein the second obstruction is a filler material, and the method further comprises a cutting step of cutting the piping at a position where the second obstruction is filled.

9. 7. The method of claim 6, wherein the first obstruction is located upstream of a first cut in the pipe and the second obstruction is located downstream of a second cut in the pipe.

10. The piping isolation method according to claim 6, further comprising an airtightness confirmation step of confirming airtightness of the piping between the first obstruction and the second obstruction.

11. 10. The piping isolation method according to claim 9, further comprising: a piping removal step in which the first jig is disposed on a vertical portion of the piping extending vertically from a building floor, and the piping cut after the first jig installation step to the second closing step is removed; a third jig installation step in which a third jig is installed that is capable of closing the first cut portion of the piping located above the first jig and into which a third closing object can be inserted; a first closing object removal step in which the third jig closes the first cut portion and removes the first closing object; a third closing object insertion step in which the first cut portion is opened and the third closing object is inserted to a position below the building floor; a grout filling step in which grout is filled above the third closing object; a jig removal step in which the first jig and the third jig are removed; and a finishing step in which the piping is cut at the height of the building floor and the building floor is chipped.

12. A piping isolation device comprising: a main body portion disposed along a piping to be isolated; and a fixing portion that fixes the main body portion to the piping, The main body includes a hollow portion having an opening that opens to the surface of the piping, a drilling machine disposed in the hollow portion, a purge gas supply unit that communicates with the hollow portion and is capable of supplying an inert gas into the piping through a through-hole formed in the piping by the drilling machine, and an obstruction insertion unit that inserts an obstruction into the piping through the hollow portion and the through-hole. A piping isolation device characterized by:

13. 13. The pipe isolation device according to claim 12, wherein the fixing portion comprises: a pair of arm portions fixed to the main body portion; claw portions disposed at tips of the arm portions and rotatable from an open position where the piping can be inserted to a closed position where the arm portions can be fixed to the main body portion across the piping; and a switch portion interposed between the arm portions and the claw portions and configured to come into contact with the piping to rotate the claw portions from the open position to the closed position.

14. 14. The pipe isolation device according to claim 13, wherein the switch unit includes: a lever disposed on the arm unit so as to be rotatable in conjunction with the claw; and a spring member that holds the claw at the open position before the lever comes into contact with the pipe and biases the claw to rotate to the closed position when the lever comes into contact with the pipe.

15. The pipe isolation device according to claim 12 , wherein the main body includes a gas concentration meter that measures the concentration of the flammable gas in the pipe through the through hole and the hollow portion.

16. 13. The piping isolation device of claim 12, wherein the obstruction is a filler material, an inflatable bag, or a plug.

17. 13. The piping isolation device of claim 12, wherein the obstruction is a mortar plug and grout filling the gap, and the mortar plug includes a piping system for venting trapped gas to the outside.

18. 13. The pipe isolation device according to claim 12, wherein the piping system includes a pipe disposed to penetrate the mortar plug, a buffer material disposed at a front end of the pipe, and a quick connection disposed at a rear end of the pipe, and the portion of the pipe between the mortar plug and the buffer material is constituted by perforated piping.

19. The pipe isolation device according to claim 12, wherein the main body is configured to be detachable from the tip of an arm of a remote-controlled robot.

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