JP2001124284A - Gas pipe end machining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the pipe inside closing work using a gas leakage prevention tool and to machine a pipe end, while surely preventing the gas leakage from the pipe end opening, even when the gas leakage prevention tool cannot prevent the gas leakage completely. SOLUTION: This pipe end machining method is that a pipe end machining device A is inserted from the pipe end opening 1 to the pipe end of a live gas pipe C filled with transportation gas to support it and the pipe end is machined while preventing the gas leakage from the pipe end opening. After the gas leakage prevention tool 41 is installed inside the pipe through a through hole in the pipe wall to close the pipe inside with the pipe end opening closed by a pipe end closing tool 40, the pipe end closing tool is detached, a pipe inside closing tool B is installed inside the pipe through the pipe end opening, and the pipe inside closing tool closes the pipe inside between the gas leakage prevention tool and the pipe end opening, so that the pipe end is machined by the pipe end machining device A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe end processing apparatus for processing a pipe end of a gas pipe in a live pipe state filled with a transport gas. The present invention relates to a gas pipe end processing method for processing the pipe end with the pipe end processing device while supporting the pipe by entering the pipe through an opening and preventing gas leakage from the pipe end opening.

[0002]

2. Description of the Related Art In the above-described gas pipe end processing method, a pipe end is processed by a pipe end processing apparatus which is inserted into a pipe through a pipe end opening and supported at the pipe end, so that the transport gas is, for example, city gas. In the case of such flammable gas, it is necessary to prevent gas leakage from the pipe end opening so that the flammable gas does not leak from the pipe end opening and ignite. A gas leak prevention device such as a gas bag that can be attached to
The simplification of the in-pipe closing operation accompanying the processing of the pipe end is achieved. That is, in a state where the pipe end opening is closed with the pipe end closing device, the gas bag is mounted in the pipe through a through hole formed in the pipe wall of the gas pipe, and the inside of the pipe is closed with the gas bag. By removing the pipe end closing device, the pipe end processing device is inserted into the pipe through the pipe end opening and supported at the pipe end, and while preventing gas leakage from the pipe end opening with the gas bag, the pipe end processing device is removed. The end of the pipe is machined. The gas bag is folded small and mounted in a pipe, and then inflated with a pressurized gas such as pressurized air to close the pipe.

[0003]

In the conventional gas pipe end processing method described above, gas leakage from the pipe end opening is prevented by the gas leakage prevention tool inserted through the through hole in the pipe wall and mounted in the pipe. There is a disadvantage that the reliability of completely preventing gas leakage from the pipe end opening is lacking. In other words, it is necessary to further push in the pipe axis direction the gas leakage prevention tool inserted in the pipe diameter direction from the through hole in the pipe wall and mount the gas leakage prevention tool in the pipe. Difficult, for example, when using a gas bag as a gas leak prevention device,
This is because, when the gas bag is inflated, it is difficult to mount the gas bag in an appropriate posture that allows the gas bag and the inner peripheral surface of the pipe to be tightly adhered over the entire circumference, and gas leakage may not be completely prevented. . SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and it is possible to simplify a pipe closing operation associated with machining of a pipe end using a gas leakage prevention device, and to use a gas leakage prevention device. It is an object of the present invention to process a pipe end while reliably preventing gas leakage from a pipe end opening even when leakage cannot be completely prevented.

[0004]

According to a first aspect of the present invention, there is provided a pipe end processing apparatus for processing a pipe end of a gas pipe in an active pipe state filled with a transport gas. Gas pipe end processing for processing the pipe end with the pipe end processing device while supporting the gas by entering the pipe from the pipe end opening of the pipe end and preventing gas leakage from the pipe end opening. A method for forming a gas leakage preventing device for preventing gas leakage from the tube end opening in a state in which the tube end opening is closed with a tube end closing device on the tube wall of the gas tube. After the pipe is detachably mounted in the pipe through the through-hole and the inside of the pipe is closed with the gas leakage preventing device, the pipe end closing tool is removed, and the pipe closing device is detachably mounted in the pipe through the pipe end opening. By closing the inside of the pipe between the gas leakage prevention tool and the pipe end opening with a pipe closing tool, In terms of processing the tube end with the tube end machining device for supporting the tube end. [Operation] In a state where the pipe end opening is closed with the pipe end closing device, the gas leakage preventing device is detachably mounted in the pipe through an openable and closable through hole formed in the pipe wall of the gas pipe. After closing the inside of the pipe with the pipe end opening, the pipe end closing tool is removed, and the pipe inside closing pipe is detachably mounted in the pipe from the pipe axis direction. The pipe end is machined by a pipe end processing device supported at the pipe end by reliably blocking the gas leak from the pipe end opening. [Effect] After the pipe is closed with the gas leakage prevention device mounted in the pipe through the through hole in the pipe wall, the pipe can be easily mounted in the pipe in an appropriate posture that can secure the close contact with the pipe inner peripheral surface through the pipe end opening. Since the inside of the pipe between the gas leakage prevention tool and the pipe end opening is closed by the pipe insertion tool inserted in the axial direction, simplification of the pipe closing work accompanying the processing of the pipe end using the gas leakage prevention tool is simplified. Even when gas leakage cannot be completely prevented by the gas leakage prevention device, gas leakage from the tube end opening is reliably prevented, and the pipe end is supported by the pipe end processing device. Can process parts.

[0005] The characteristic configuration of the invention according to claim 2 is that the in-pipe obturator is expanded and deformed in the radial direction of the gas pipe to close the pipe and a closed state in which the inner diameter of the gas pipe is reduced and deformed in the radial direction. A non-blocking state that can be taken in and out is provided by providing a closing member that can be switched from the outside of the tube end opening. [Operation] When an in-pipe obturator is mounted in the pipe through the pipe end opening to close the pipe, the closing member switched to the non-blocking state is inserted into a position between the gas leakage prevention tool and the pipe end opening. When the closing member is switched to the closed state by an operation from the outside of the tube end opening, and the in-tube closing device closing the inside of the tube is taken out of the tube through the tube end opening, the operation is performed from outside the tube end opening. Then, the closing member is switched to the non-closed state and taken out of the tube. [Effect] The pipe closing device can be easily attached to and detached from the pipe through the pipe end opening.

A feature of the invention according to claim 3 is that the in-pipe obturator is connected to the pipe end processing device and mounted in the pipe. [Function] Since the in-pipe obturator mounted in the pipe and the pipe end processing device supported at the pipe end are connected, the in-pipe obturator is installed in the pipe when removing the pipe end processing device from the pipe end. It can be easily checked whether or not it remains as it is. [Effect] When removing the pipe end processing device from the pipe end, there is no risk of forgetting to take out the pipe closing device attached to the pipe, and when the pipe is connected to the pipe end, gas does not flow properly. The situation can be prevented.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show a pipe end processing apparatus A used in a gas pipe end processing method according to the present invention, and an in-pipe obturator B assembled to the pipe end processing apparatus A. A city gas (an example of flammable gas) which is an example of a transport gas (a gas transported through a gas pipe) is flowing therethrough, and a synthetic resin gas pipe in an activated state filled with the city gas ( In the present embodiment, the outer peripheral surface of the pipe end is cut while supporting the pipe end of the polyethylene resin gas pipe C) at the pipe end to prevent gas leakage from the pipe end opening 1 at the pipe end. A fusion-bonded portion is formed to thermally fuse the pipe joint. The pipe end processing apparatus A includes a pipe end opening 1
A processing tool 3 for processing the pipe end in an active tube state is supported on a support 2 which is inserted into the pipe and attached to the pipe end so as to be capable of processing, and the pipe closing device B is assembled to the support 2. Thus, it is integrally connected to the support 2 so as to be freely inserted into the gas pipe C.

The support 2 has a cylindrical shaft member 6 in which a large-diameter male screw portion 4 and a small-diameter male screw portion 5 are formed so as to be reversely screwed to each other. A ring member 7, a second ring member 8 screwed to the small-diameter male screw portion 5, and four plate-shaped contact members 9 arranged at equal intervals in the circumferential direction of the gas pipe C; For each contact member 9, the contact member 9 is connected to the first ring member 7 and the second
A pantograph-type link mechanism 11 that is connected to the ring member 8 and supports the contact member 9 so as to be able to move back and forth in the pipe diameter direction.
And a grip portion 12 having a larger diameter than the large-diameter male screw portion 4 for manually rotating the cylindrical shaft member 6. The contact member 9 is formed in a curved shape along the pipe circumferential direction, and has a gas pipe C in a state where the contact member 9 is in contact with the inner peripheral surface of the gas pipe C at one end. A flange 13 is formed in contact with the end face of the base member to regulate the amount of entry in the tube axis direction.

Then, by operating the grip portion 12, the cylinder shaft member 6 is rotated in one rotation direction, and the first ring member 7 and the second ring member 7 are rotated.
By moving the ring member 8 in a direction approaching each other, each contact member 9 is moved outward in the tube radial direction, and is supported by each contact member 9 contacting the inner peripheral surface of the gas pipe C. The tool 2 is locked and fixed to the inner peripheral surface of the gas pipe C so as to protrude in the pipe diameter direction, and from this state, the cylindrical shaft member 6 is rotated in the opposite direction, so that the first ring member 7 and the second ring member 8 Are moved in a direction away from each other, whereby each contact member 9 is moved inward in the radial direction of the tube, and the fixing of the support 2 to the inner peripheral surface of the gas pipe C is released. .

The processing tool 3 includes a scraper blade 14 for cutting the outer peripheral surface of the gas pipe C, an L-shaped holding arm 15 for holding the scraper blade 14 at a tip end thereof in a side view,
A screw member 16 that rotatably supports the base of the holding arm 15 around the tube axis so that the scraper blade 14 moves around while contacting the outer peripheral surface of the gas pipe C; Female thread portion 17 formed on the inner peripheral portion of cylindrical shaft member 6
And the scraper blade 14 is fed in the tube axis direction as the scraper blade 14 moves around. The holding arm 15 is detachably fixed to one end side of the screw shaft member 16 with a washer 18 and a nut 19. The scraper blade 14 is attached to a scraper blade supporting portion 20 provided at the tip end of the holding arm 15. It is supported in a state where it is urged by a spring 21 toward the outer peripheral surface of the gas pipe C. At the end of the screw member 16, an engaging portion 24 with which the rotating shaft member 23 of the electric drill 22 is provided is provided, and the rotation of the screw member 16 by the electric drill 22 causes the scraper blade 1 to rotate.
While rotating the screw shaft 4 in the cutting direction, the screw shaft member 16 is screwed and moved to the inner side of the gas pipe C along the female screw portion 17 of the cylindrical shaft member 6 so that the scraper blade 14 is fed in the tube axis direction to a desired range. The outer peripheral surface of the gas pipe C can be cut.

The in-pipe closing member B is inserted into the gas pipe C from the pipe end opening 1 to the back side of the supporting member 2 and closes the gas pipe C. The closing member 25 is operable to switch between a closed state in which the inside of the pipe is closed by expanding and closing the closing member 25 in the radial direction of the gas pipe and a non-blocking state in which the closing member 25 is reduced in diameter in the radial direction of the gas pipe so as to be able to be taken in and out of the pipe. An operation tool 26 is provided.

As shown in FIG. 4, the operating tool 26 includes first and second metal disc members 27 and 28 sandwiching the closing member 25 from both sides in the axial direction of the tube, and a back side of the gas pipe C. A pulling tool 29 for pulling the second disc member 28 into the first disc member 27 side and compressing and deforming the closing member 25; and the pulling tools 29 are provided at four locations at equal intervals in the pipe circumferential direction. It is. The pulling tool 29 hermetically welds and fixes the head on one end side of the shaft member 30, which penetrates between the closing member 25 and the two disk members 27 and 28, to the second disk member 28. One end of the cylindrical member 31 for maintaining the interval into which the projecting portion from the first disk member 27 is inserted is fixed to the first disk member 27 by welding, and the other end of the shaft member 30 is connected to the end of the cylindrical member 31. And the contact plate 33 is brought into contact with one end side of each tubular member 31, and the pulling bolt 34 inserted through the contact plate 33 and inserted into the tubular member 31 is attached to the shaft member 3.
The second disk member 28 is drawn toward the first disk member 27 by screwing into the female screw hole 35 formed at zero.

Then, in a state where the pipe closing member B is mounted integrally with the support member 2 in the gas pipe C, the pulling bolts 34 are screwed into the female screw holes 35 of the shaft member 30 substantially uniformly, so that the gas pipe radial direction is reduced. A closed state in which the outer peripheral portion of the closing member 25 whose diameter has been expanded and deformed is brought into close contact with the inner peripheral surface of the gas pipe C over the entire circumference to close the inside of the pipe, and each pulling bolt screwed into the female screw hole 35 of the shaft member 30. By loosening the tube 34, the tube is radially deformed in the gas tube radial direction and is brought into and out of the gas tube C in a non-blocking state.

An annular position in which the small-diameter male screw portion 5 of the cylindrical shaft member 6 can be freely inserted and a through hole 36 having a diameter smaller than the outer diameter of the second ring member 8 is formed between the intermediate positions of the cylindrical members 31. They are fixed to each other by a disk 37. Also, the closing member 2
5 and the center of the two disk members 27 and 28, a cylindrical member 38 is inserted so as to protrude deeper into the gas pipe C.
Of the gas pipe C is cut by the scraper blade 14 while the projecting end side of the cylindrical member 38 is airtightly closed by the closing plate 39 while the base side peripheral portion of the gasket C is air-tightly fixed to the first disk member 27. The screw member 16 which is screwed to the back of the gas pipe C
Into the inside of the cylindrical member 38.

As shown in FIG. 6, the contact plate 33 has a through hole 32 through which the grip portion 12 of the cylindrical shaft member 6 can be inserted and whose diameter is smaller than the outer diameter of the first ring member 7. Through hole 3
2 is provided with a groove 56 through which a screw member 16 can be inserted from the radial direction.
4 has a large-diameter hole 57 through which the head can be freely inserted, and a pulling bolt 3
A darma hole 59 having a small diameter hole portion 58 into which the shaft portion 4 can enter in the radial direction is provided corresponding to each cylindrical member 31. Then, with the contact plate 33 removed and each pulling bolt 34 loosely screwed into the shaft member 30, the link members 10 of the link mechanism 11 adjacent to each other in the circumferential direction of the gas pipe C are set.
After assembling the in-pipe obturator B and the support 2 so that the respective tubular members 31 enter between them, a finger is applied to the notch 60 formed at two peripheral portions of the contact plate 33, and the contact is made. The holding plate 33 is held, the screw member 16 is inserted into the through hole 32 through the groove 56, and the head of the drawing bolt 34 is inserted into the large diameter portion 57 of each of the daruma holes 59. Is turned in the circumferential direction to draw the shaft portion of the bolt 34 into the small-diameter portion 58 of each dharma hole 59, and the contact plate 33
The pipe closing device B is assembled to the pipe end processing apparatus A by loosely screwing the pulling bolts 34 in a state where the pipe is brought into contact with the end of each cylindrical member 31. Therefore, the contact plate 33 can be attached and detached while each pulling bolt 34 is screwed into the shaft member 30, and the in-pipe obturator B can be assembled to the pipe end processing apparatus A or removed from the pipe end processing apparatus A. Therefore, there is no possibility that the pulling bolt 34 is lost. Further, the first ring member 7 and the second ring member 8
Since it is incorporated between the contact plate 33 and the annular disk 37,
The range of movement of the ring members 7 and 8 in the direction of relative separation is regulated by contact with the contact plate 33 and the annular disk 37.

Next, in order to connect a new gas pipe to the existing buried gas pipe C, the pipe of the existing gas pipe C is connected by the pipe end processing apparatus A while preventing gas leakage from the pipe end opening 1. A gas pipe end processing method for forming a fused portion with a synthetic resin pipe joint by cutting the outer peripheral surface of the end in a live pipe state will be described.
The gas pipe C has the pipe end opening 1 covered with a cap 40 serving as a pipe end closing tool fused to the end thereof. In this state, as shown in FIG. A gas bag 41 serving as a gas leakage preventing device for preventing gas leakage is detachably mounted in a pipe through a through hole 42 formed in a pipe wall of the gas pipe C, and the gas bag 41 closes the gas pipe C.

That is, fresh tissue of polyethylene is exposed by grinding the outer peripheral surface of the gas pipe C at a position deviated from the cap 40 by a predetermined length with a scraper or the like, and polyethylene (an example of a synthetic resin) is formed on the outer peripheral surface. ) Is temporarily fixed with a clamp tool or the like, and the saddle joint 4 is fixed.
A pair of terminals protruding from the saddle portion 44 with the saddle portion 44 (the saddle portion 44 having an inner surface shape matching the curvature of the outer peripheral surface of the gas pipe C) pressed against the gas pipe C. An electric current is passed between the gas supply tubes 45 and the saddle portion 44 and the gas pipe C are air-tightly fused and united by Joule heat generated in a heating element (not shown) embedded in the saddle portion 44 (FIG. 7
(See (a)). A plug 47 is detachably attached to the working branch pipe 46 of the saddle joint 43 so that the through hole 42 formed in the pipe wall of the gas pipe C can be opened and closed.

Next, the branch pipe 4 of the heat-fused saddle joint 43
6, a shutter device 49 having a shutter slid by an operation rod 48 is fixed, a casing 50 is fixed to the shutter device 49 by bolts, and a punch 51 is airtightly attached to an upper opening of the casing 50. After fixing, the hole saw 52 of the piercing tool 51 is inserted into the branch pipe 46 through the casing 50 to form the through hole 42 in the upper pipe wall of the gas pipe C (see FIG. 7B).

Next, the hole saw 52 is returned into the casing 50 together with the section of the through hole 42, and the shutter device 49 is removed.
And the gas bag insertion tube 53 is hermetically fixed in place of the piercing tool 51. Then, the branch pipe 46 is opened by the shutter device 49 and the guide portion 5 of the gas bag insertion pipe 53 is opened.
4 is inserted into the gas pipe C from the through hole 42 through the branch pipe 46, and the gas bag 41 folded small is inserted into the gas pipe C, and pressurized air supplied from the air supply source is supplied to the gas bag operation pipe 55. 8 into the gas bag 41 and inflate the gas bag 41 to close the gas pipe C (FIG. 8).
(C)).

Next, the end of the gas pipe C is cut off, the cap 40 closing the pipe end opening 1 is removed, and the pipe end processing apparatus A incorporating the in-pipe obturator B is connected to the pipe end of the gas pipe C. The outer peripheral surface of the pipe end is cut in a live pipe state while gas leakage from the pipe end opening 1 at the pipe end is prevented by the gas bag 41 and the in-pipe obturator B (FIG. 8). (D)). That is, as shown in FIG. 1, the in-pipe obturator B assembled to the pipe end processing device A through the pipe end opening 1 is mounted together with the support 2 in the gas pipe C, and the first ring member 7 and the second By rotating the cylindrical shaft member 6 with the grip portion 12 so that the ring member 8 moves in the direction approaching each other, each contact member 9 is moved outward in the tube radial direction, as shown in FIG. As described above, in a state where the flange 13 is in contact with the end face of the gas pipe C, the support member 2 is connected to the gas pipe C by the respective contact members 9 which are in contact with the inner peripheral surface of the gas pipe C so as to project in the pipe radial direction. C is fixed to the inner peripheral surface.

Next, as shown in FIG. 3 and FIG. 4, with the contact plate 33 in contact with the first ring member 7, the pulling bolts 34 are substantially equally inserted into the female screw holes 35 of the shaft member 30. By screwing the gas into the gas pipe C, the closing member 25 is expanded and deformed in the gas pipe radial direction to switch to a closed state in which the inside of the pipe is closed, and the inside of the gas pipe C between the gas bag 41 and the pipe end opening 1 is closed.
Even when gas leakage cannot be completely prevented by the gas bag 41, the screw shaft member 16 is rotated by the electric drill 22 and the scraper blade 14 is rotated while the gas leakage from the tube end opening 1 is reliably prevented by the in-tube obturator B. By rotating the gas pipe C in the cutting direction while feeding it in the pipe axis direction, the outer peripheral surface of a predetermined range of the gas pipe C is cut to form a fused portion for fusing the synthetic resin pipe joint.

Next, the cylinder shaft member 6 is rotated in the opposite direction by the grip portion 12 so that the first ring member 7 and the second ring member 8 are moved in a direction in which they are separated from each other. Is moved inward in the pipe diameter direction, and the gas pipe C of the support 2 is moved.
Release the lock on the inner peripheral surface of the.

At this time, the first ring member 7 is
Therefore, even if the cylindrical shaft member 6 is rotated in the opposite direction, the first ring member 7 cannot move, and as a result, the second ring member 8 moves to the closing member 25 side. At the same time, the cylindrical shaft member 6 also moves to the closing member 25 side, and the cylindrical shaft member 6 hits the disk member 27. If the cylindrical shaft member 6 is further rotated, the pipe closing member B may be damaged. When the cylindrical member 6 comes into contact with the disk member 27, the second ring member 8 comes into contact with the annular disk 37, so that the cylindrical member 6 cannot be rotated in the opposite direction.
There is no risk of damaging the in-pipe obturator B.

If it is necessary to perform the work after forming the fusion portion while closing the gas pipe C with the pipe closing tool B, loosen each pulling bolt 34 and once remove the closing member 25. After switching to the closed state, the contact plate 33 and the support tool 2 are removed from the gas pipe C together with the processing tool 3, and then the contact plate 33 is again applied to the end of each cylindrical member 31, and each pulling bolt 34 is pivoted. It is screwed into the member 20 to switch the closing member 25 to the closed state. Further, when it is not necessary to close the gas pipe C with the working pipe closing tool B in the work after forming the fused portion, each pulling bolt 34 is loosened to switch the closing member 25 to the non-blocking state. The pipe end processing device A with the in-pipe obturator B attached is removed from the gas pipe C.

[Other Embodiments] In the gas pipe end processing method according to the present invention, a rubber disc-shaped closing member and a disc-shaped closing member are compressed in the pipe axis direction as a gas leakage preventing tool mounted in the pipe through a through hole in the pipe wall. The operation can be switched between a closed state where the inside of the pipe is closed by expanding and deforming the gas pipe in the radial direction, and a non-closed state where the compression of the disc-shaped closing member is released and the pipe can be inserted into and removed from the pipe through the through hole in the pipe wall. A gas leak preventing device provided with a simple operating tool may be used. 2. The gas pipe end processing method according to the present invention may be implemented by detachably mounting a gas bag as an in-pipe obturator into the pipe from the pipe end opening from which the pipe end obturator has been removed. 3. The gas pipe end processing method according to the present invention may be used when a male end or a female thread is machined in a live tube state at the end of a pipe by a pipe end supporting device supported at the end of the pipe. 4. The gas pipe end processing method according to the present invention may be used when processing the pipe end of a metal gas pipe in an active pipe state. 5. The gas pipe end processing method according to the present invention may be implemented by connecting the pipe obturator to a pipe end processing apparatus with a wire or the like. 6. In the gas pipe end processing method according to the present invention, the pipe end processing device is inserted into the pipe through the pipe end opening, and then the pipe end processing device is inserted into the pipe separately from the pipe end opening. It may be supported by a part. 7. The gas pipe end processing method according to the present invention, as a pipe end processing device, so that the pipe wall of the pipe end becomes a guide for movement,
A pipe end processing device which is supported on the pipe end so as to straddle the inner peripheral surface side and the outer peripheral surface side of the pipe end, and is configured to process the pipe end while moving along the pipe wall. Using the pipe end processing device, the pipe end processing device is inserted into the pipe through the pipe end opening and supported at the pipe end to prevent gas leakage from the pipe end opening, while processing the pipe end with the pipe end processing device. May be. 8. The gas pipe end processing method according to the present invention may be used, for example, when processing a pipe end of a gas pipe in an active pipe state filled with a transport gas such as an oxygen gas, a nitrogen gas, or a harmful gas. .

[Brief description of the drawings]

FIG. 1 is a partially sectional side view showing a pipe end processing apparatus and a gas pipe end processing method.

FIG. 2 is a partial cross-sectional side view showing a pipe end processing apparatus and a gas pipe end processing method.

FIG. 3 is a partial cross-sectional side view showing a pipe end processing apparatus and a gas pipe end processing method.

FIG. 4 is a partial cross-sectional side view showing a pipe end processing apparatus and a gas pipe end processing method.

FIG. 5 is a partial sectional front view showing a pipe end processing apparatus and a gas pipe end processing method.

FIG. 6 is a plan view of a main part.

FIG. 7 is an explanatory view of a method of processing an end portion of a gas pipe.

FIG. 8 is an explanatory view of a method of processing an end portion of a gas pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe end opening 25 Closing member 40 Pipe end closing tool 41 Gas leak preventing tool 42 Through hole A Pipe end processing device B Inside pipe closing tool C Gas pipe

Claims (3)

[Claims] 1. A pipe end processing device for processing a pipe end of a gas pipe in an active pipe state filled with a transport gas,
A gas pipe end processing method of processing the pipe end with the pipe end processing device while supporting the gas by entering the pipe from the pipe end opening of the pipe end and preventing gas leakage from the pipe end opening. And a gas leakage preventing member for preventing gas leakage from the tube end opening in a state where the tube end opening is closed with a tube end closing member, in the pipe wall of the gas pipe, which can be opened and closed freely. After the inside of the pipe is closed by the gas leakage prevention device, the pipe end closing tool is removed, and the pipe closing device is detachably mounted in the pipe through the pipe end opening. A gas pipe end processing method for closing a pipe between the gas leakage prevention tool and the pipe end opening, and processing the pipe end with the pipe end processing device supported on the pipe end. 2. A closed state in which the pipe closing device is expanded and deformed in the gas pipe radial direction to close the inside of the pipe, and a non-blocking state in which the pipe closing means is reduced in diameter in the gas pipe radial direction and freely inserted into and out of the pipe.
The gas pipe end processing method according to claim 1, further comprising a closing member that can be switched from outside the pipe end opening. 3. The gas pipe end processing method according to claim 1, wherein the pipe end closing device is connected to the pipe end processing device and mounted inside the pipe.