JP2002295724A - Removal method of resin branch pipe - Google Patents

Abstract

(57) [Problem] To provide a method of removing a resin branch pipe which can reduce the risk of damage to a remaining branch pipe in another work after removing the branch pipe. SOLUTION: In a first stage, a cutter 106 housed in an upper part 105a of a service tee 105 is connected to a main pipe 1.
No. 01 is inserted into a tapping hole 101a formed in the side wall. In the second stage, the root of the upper portion 105a of the service tee 105 is cut above the cutter 106, and then the upper portion 105a and the branch portion 105c of the service tee 105 are cut.
And a branch pipe 1 connected thereto via a socket 111
03 is removed. In the third stage, the no-blow gas bag 10 is attached to the upper root 105a 'of the service tee 105, and the temporary plug 11 is attached in the tapping hole 101a after the cutter 106 is removed therein. In the fourth stage, the main closure plug 15 is fused to the tapping hole 101a by using the closure tool 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for removing a resin branch pipe such as a gas pipe. In particular, the present invention relates to a method for removing a resin branch pipe that can reduce the risk of damage to a remaining branch pipe in other work after the branch pipe is removed.

[0002]

2. Description of the Related Art The prior art will be described taking the field of city gas piping as an example. In recent years, resin pipes such as polyethylene pipes have been frequently used for city gas pipes. This is because resin pipes are more resistant to corrosion and earthquakes than conventional plated steel pipes, and are excellent in workability of pipe work. When a branch pipe is connected to an existing pipe in such a resin pipe, an electric fusion joint (electrofusion joint; abbreviated as EF joint) is generally used.

FIG. 6 is a partial sectional side view showing an example of a resin pipe using a Q-type EF joint. FIG. 6 shows a state in which a resin main pipe 101 extending in the front and back directions in the figure and a resin branch pipe 103 extending in the right direction in the figure are connected via an EF joint (service tee) 105. Have been. The service tee 105 is made of a thermoplastic such as polyethylene. The service tee 105 includes a cylindrical upper portion 105a, a saddle-shaped fusion welding portion 105b integrated with a lower end of the upper portion 105a, and a branch portion 105c branched laterally from a side surface of the upper portion 105a.

A built-in tapping tool (cutter) 106 is housed in an upper portion 105a of the service tee 105. This cutter 106 is for opening a tapping hole 101a in the side wall of the main pipe 101 after the service tube 105 is fused to the main pipe 101. Cutter 1
The tapping hole 101a opened in 06 is
It penetrates the side wall and the fusion welding portion 105 b of the service tube 105, and forms a communication hole between the inside of the main pipe 101 and the inside of the branch pipe 103. A heating wire (not shown) is embedded in the fusion welding portion 105b of the service tee 105. An electric current is applied to the heating wire to generate heat, and the fusion welding portion 105b is air-tightly fused to the side surface of the main tube 101. In the branch 105c of the service team 105,
The branch pipe 103 is connected via the socket 107. The socket 107 is connected to the branch 105 of the service
The connection ends of the c and the branch pipe 103 are fixed while sealing.

By the way, in the case of removing such a branch pipe which becomes unnecessary due to removal of a building or the like in such a resin pipe, the existing branch pipe 103 is conventionally removed by the following procedures (1) to (3). Has been removed. 7 to 9 are partial cross-sectional side views showing an outline of a conventional method for removing a resin branch pipe. (1) As shown in FIG. 7, compression is cut off (squeeze off) by sandwiching the middle of the branch pipe 103 with the squeeze bar 110.
At this time, the position 103 where the branch pipe 103 is squeezed off
x is the end of the socket 107 (the right end in the figure) in order to prevent adverse effects of compression on the socket fusion splice.
Must be at least three times the outer diameter D of the branch pipe 103 from the outside. By performing this squeeze-off, the branch pipe 1
The gas flow inside 03 is shut off.

[0008] (2) As shown in FIG. 8, the front end (right end side in the figure; opposite side to the main pipe 101) 103 z of the branch pipe 103 is cut with a saw or the like, and then the cut end 103 of the branch pipe 103 is cut
Attach cap 111 to y. At this time, the branch pipe 1
No. 03 cuts at a position (cut end 103y) at least three times the branch pipe outer diameter D from the squeeze-off position 103x.
This is to prevent the adverse effect of the compression from exerting on the socket fusion-bonded portion as in the case of (1). After the cutting operation of the branch pipe 103 is completed, the cut branch pipe 1 is cut.
03's 103 'is removed. (3) As shown in FIG.
The squeeze bar 110, which has squeezed off the 3 ″, is opened.
3 is elastically deformed and returns to the original state. The gas flowing from the main pipe 101 to the branch pipe 103 is blocked by the cap 111, so that the gas does not leak even after the branch pipe 103 is cut.

[0007]

As described above, in the conventional method of removing a branch pipe made of resin, the squeeze-off of the branch pipe 103 is performed at least three times the outer diameter D of the branch pipe from the right end of the socket 107. This must be done at a remote location 103x. Furthermore, the cutting of the branch pipe 103 must be performed at a position 103y that is at least about three times the branch pipe outer diameter D from the squeeze-off position 103x. Therefore, when measured from the root of the main pipe 101, the cutting position 103y is a position at least about 6 times the branch pipe outer diameter D or more.
Therefore, even after the removal work is completed, a part of the branch pipe 103 ″
(Remaining part) remains for a considerably long time (see FIG. 9).

The remaining portion 103 "of the branch pipe 103 is buried again in the ground after the removal operation is completed.
If 03 "remains, there is a risk that a drilling tool or the like may hit the remaining portion 103" when performing other work such as excavation after a period of time after the removal operation. Since the remaining portion 103 ″ of the branch pipe 103 is made of resin, the remaining portion 103 ″ is easily damaged by an excavation tool or the like, and there is a risk that gas leakage or the like may occur from the damaged portion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in consideration of the above-described problem, and is intended to reduce the risk of damage to a remaining branch pipe in another work after removing the branch pipe. The purpose is to provide a removal method.

[0010]

According to a first aspect of the present invention, there is provided a method for removing a resin branch pipe, the method comprising the steps of: removing a resin branch pipe connected to a main pipe via a tube having a built-in tapping tool (cutter); A method of removing a pipe, wherein the cutter is inserted into a tapping hole in a side wall of the original pipe, the chee is cut above the cutter, and a sealing work bag is attached to a cutting part of the chee; In
After removing the cutter from the tapping hole, a temporary plug is attached to the tapping hole, and a resin closing stopper is rotated and applied from the outside of the temporary stopper, and the temporary closing stopper and the end of the tapping hole are connected. The closure plug is fused to the cutting portion of the Qi by frictional heat generated therebetween.

According to the first aspect, the root of the Qi connected to the main pipe can be cut and the entire branch pipe can be removed, so that no branch pipe remains after the removal operation. For this reason, the risk of the remaining piping being damaged in other works after removing the branch pipe can be reduced.

When the cutter is removed from the tapping hole, a sealing work bag (commonly called a no-blow gas bag) surrounding the tapping hole is attached, and the cutter is removed inside the no-blow gas bag. Since the temporary plug is attached, the tapping hole is not exposed to the outside when removing the cutter or attaching the temporary plug.
Therefore, when the cutter is removed or the temporary plug is attached, gas leakage can be prevented, and dust or the like can be prevented from entering the tapping hole.

A method for removing a resin branch pipe according to a second invention is a method for removing a resin branch pipe connected to a main pipe via a resin joint, wherein the resin joint is compressed and shut off (squeeze-off). And cutting off the connection end side (branch pipe side) of the resin joint in the vicinity of the compression breaking position, attaching a temporary plug to the opening of the cut end of the resin joint, and forming a resin plug from the outside of the temporary plug. The present invention is characterized in that the main closure is rotated while being applied thereto, and the final closure is fused to a cut portion of the resin joint by frictional heat generated between the main closure and the opening end.

In the second invention, the connection end side of the resin joint is cut off near the squeezed-off resin joint, and the entire branch pipe is removed. For this reason, the resin joint remains slightly after the removal operation, but its length is shorter than before. The second invention has an advantage that it can be applied to a resin joint (a saddle, a cheese, or the like) without a tapping tool.

In the method for removing a resin branch pipe according to the present invention, it is preferable that the temporary plug has an O-ring for sealing between the temporary plug and the tapping hole. Since the temporary plug and the tapping hole are sealed by the O-ring, it is possible to prevent a blow hole from being generated in the fusion part due to gas pressure when the main closure is fused to the main pipe.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are partial cross-sectional side views showing an outline of a method for removing a resin branch pipe according to a first embodiment of the present invention. In the embodiments described below, a city gas pipe will be described as an example as in the related art.

(1) First stage (cutter moving operation) The resin pipe shown in FIG. 1 has the same configuration as the resin pipe shown in FIG. That is, FIG. 1 shows a state in which the main pipe 101 and the branch pipe 103 are connected via the service tee 105, and the service tee 105
a, a fusion welding portion 105b and a branch portion 105c. In the upper part 105a of the service team 105,
A built-in tapping tool (cutter) 106 is stored. A heating wire (not shown) is embedded in the fusion welding portion 105b of the service tee 105. The connection end of the branch 105c of the service tee 105 and the connection end of the branch pipe 103 are connected to the socket 1
At 07, it is airtightly connected and fixed. As described above, the tapping hole 101a opened by the cutter 106 penetrates the side wall of the main pipe 101 and the fusion welding portion 105b of the service tube 105, and serves as a communication hole between the inside of the main pipe 101 and the inside of the branch pipe 103. .

In the first step of the method for removing a resin branch pipe according to the present invention, first, the periphery of a pipe buried underground is excavated and exposed. Then, as shown in FIG. 1, the cutter 106 housed in the upper portion 105a of the service tee 105 is lowered (inserted) into the tapping hole 101a opened in the side wall of the main pipe 101. The operation of lowering the cutter 106 is performed using a dedicated hexagon wrench fly or the like (not shown).

(2) Second stage (service tee cutting operation) In the second stage, as shown in FIG. 2, the root of the upper portion 105a of the service tee 105 (the upper portion 105a and the fusion welding portion 105b, (Near the boundary of).
This cutting operation is performed manually using a saw or the like (not shown). After the cutting operation is completed, the upper part 105a and the branch part 105c of the service tee 105 and the socket 11
The branch pipe 103 connected via 1 is removed. At this time, the cutter 106 lowered in the first stage remains in the tapping hole 101a and plays a role of a stopper for sealing the hole 101a. After removal of the branch pipe 103, the fusion pipe 105b of the service pipe 105 fused to the main pipe 101 and the service pipe 1 on the upper surface of the fusion pipe 105b.
In this state, only the upper base 105a 'of the part 05 remains.

(3) Third Stage (Cutter Removal / Temporary Plug Attachment Operation) In the third stage, as shown in FIG.
5a '. This no blow gas bag 10
Is a transparent resin bag-like body having two openings 10
A, 10B. Around each of the openings 10A and 10B is a diaphragm port to which rubber or the like is attached, and is freely expandable and contractible. Therefore, the no-blowing gas bag 10 has one opening 1
0A is attached to the upper base 105a 'of the service tee 105, the hand H is inserted through the other opening 10B, and the cutter 106 is removed using a hexagon wrench fry or the like (not shown).

After removing the cutter 106, the temporary plug 11 is mounted in the tapping hole 101a. This temporary plug 11
As shown in FIG. 3 (B), the main body 12 includes a main body 12 made of a disc made of resin such as polyethylene, and an O-ring 13 provided on a side peripheral surface of the main body 12. When the temporary plug 11 is attached, the peripheral surface of the temporary plug 11 on the body 12 side and the tapping hole 1
Oa ring 13 seals between the inner walls of 01a. This third
At the stage, by working using the no-blow gas bag 10, the tapping hole 101a is not exposed to the outside when the cutter 106 is removed or the temporary plug 11 is attached. For this reason, it is possible to prevent a large amount of gas leakage and to prevent dust and the like from entering the tapping hole 101a when the cutter 106 is removed or the temporary plug 11 is attached.

(4) Fourth Step (Fuser Closing Operation) In the fourth step, as shown in FIG. 4, the closing tool 15 is fused to the tapping hole 101a using the closing tool 20.
First, the configuration of the main stopper 15 will be described. As shown in FIG. 4, the main stopper 15 is made of a resin such as polyethylene, and has a disc-shaped straight portion 16 and the straight portion 1.
It has a tapered portion 17 having a tapered shape at the tip of 6. The main stopper 15 is rotatably and removably attached to the rod 21 of the closing tool 20.

Next, the configuration of the closing tool 20 will be described. The closure tool 20 has a rod 21 to which the closure plug 15 is rotatably attached. The rod 21 is driven to rotate by a motor 23 stored in a casing 25. A handle 29 for manually gripping the closing tool 20 is provided on an outer surface of the casing 25 that stores the motor 23. A bearing 27 is interposed between the lower end of the casing 25 and the rod 21. The rod 21 is connected to the motor 2
3 and is synchronously rotated with this rotating shaft. In this example, the motor 23 is 120
An air motor capable of rotating at 0 to 1300 rpm can be used.

The straight portion 16 of the closure plug 15 is engaged with the rod 21 so as to rotate synchronously. This engagement method,
A simple method such as a method in which the protrusion of the rod 21 is engaged with a groove cut in the end surface of the cylindrical portion 11 is acceptable. In addition, a chuck type and a screw type can also be used.

In order to fuse the main closure plug 15 to the tapping hole 101a on the side wall of the main pipe 101 by using such a closure tool 20, the following procedure is performed. First, the main stopper 15 is attached to the rod 21 of the closing tool 20. Next, the closing tool 20 is lifted by grasping the handle 29, and the motor 23 is rotated. Then, as shown in FIG. 4, the main closure plug 15 that rotates together with the rod 21 of the closure tool 20 approaches the tapping hole 101 a of the main pipe 101, and closes the tapping hole 101 a from above the temporary plug 11 so as to close the tapping hole 101 a. Taper part 1
Hit 7.

When the high-speed rotating main stopper 15 comes into contact with the upper edge of the tapping hole 101a, frictional heat is generated therebetween. Further, when the rod 21 continues to rotate, the amount of heat generated increases, and when the temperature rises to near the melting point of the polyethylene which is the material of the main stopper 15 and the main pipe 101, the main stopper 1
5 and the tapping hole 101a of the main pipe 101 start melting.

When the rod 21 is further rotated with the upper end edge of the tapping hole 101a being melted, the melting portion of the main stopper 15 and the main pipe 101 is widened, and the two are mixed and integrated. At this time, the rotational torque of the motor 23 increases, and when the torque reaches a certain level, the motor 2
Stop rotation of 3. In this state, the main stopper 15 and the main pipe 10
When the contact portion with the base tube 1 is left to cool down, as shown in FIG.
a is fused and fixed so as to cover a. Thereafter, the rod 21 is removed from the main stopper 15 and the operation is completed.

The temporary plug 11 attached to the tapping hole 101a in the third stage is connected to the O-ring 13 and the tapping hole 1a.
By the action of the frictional force between the stoppers 01a, the stoppers 15 remain in the tapping holes 101a below the main stopper 15. During the operation of the fourth stage, the tapping hole 101 is
Since the inner wall a is sealed, it is possible to prevent blow holes from being generated in the fused portion due to gas pressure.

As described above, according to the method for removing the resin pipe of the first embodiment, the service tee 10 above the main pipe 101 is removed.
Since the root of No. 5 can be cut and the cut service tree 105 and the branch pipe 103 can be removed at a time, a part of the branch pipe 103 does not remain after the removal operation. For this reason, the risk of remaining pipes being damaged in other works after removing the branch pipe 103 can be reduced.

Next, a second embodiment of the present invention will be described. FIG. 10A is a partial cross-sectional side view showing an example of a resin pipe using a resin saddle, and FIG.
It is an X-ray arrow view (front view) of 0 (A). In FIG.
The main pipe 101 made of resin (in FIG.
0 (B) in the left-right direction) and the branch pipe 103 made of resin (the right direction in FIG. 10A and the upward direction in FIG. 10B) are connected via the saddle 120. ing. The saddle 120 is made of a thermoplastic such as polyethylene. This saddle 120 has a cylindrical upper part 1.
20a, and a saddle-shaped fusion welding portion 120b integrated with the lower end of the upper portion 120a.

A branch pipe 103 is connected to an upper portion 120 a of the saddle 120 via a socket 121. The socket 121 is provided between the upper part 120a of the saddle 120 and the branch pipe 1.
03 and are fixed while sealing the ends thereof. A heating wire (not shown) is embedded in the fusion welding portion 120b of the saddle 120. An electric current is applied to the heating wire to generate heat, and the fusion welding portion 120b is hermetically fused to the side surface of the main pipe 101. Main pipe 1
A through-hole 101a is formed in the welded portion 120b between the side wall 01 and the saddle 120, and the through-hole 101a is a communication hole between the inside of the main pipe 101 and the inside of the branch pipe 103.

Next, a method of removing a branch pipe according to a second embodiment of the present invention will be described with reference to FIGS. 11 to 15 are partial cross-sectional side views showing an outline of a method for removing a resin branch pipe according to a second embodiment of the present invention. (1) First stage (squeeze-off work) In the first stage of the second embodiment, first, the periphery of a pipe buried underground is excavated and exposed. Then, as shown in FIG. 11, the upper portion 120a of the saddle 120 is sandwiched by the squeeze bar 110 to cut off the compression (squeeze off). By performing this squeeze-off, the gas flow flowing from the inside of the main pipe 101 to the inside of the branch pipe 103 becomes
Is shut off at the upper part 120a.

In the first stage of this example, the branch pipe 103 does not squeeze off, and the upper part 12 of the saddle 120 is not squeezed.
The point of squeezing off 0a is significantly different from the conventional case. The distance L between the squeeze-off position and the base of the upper part 120a
Although 1 is short, since the saddle 120 itself is strong, the saddle 120 is not damaged even if sandwiched between the squeeze bars 110.
On the other hand, the distance L between the squeeze-off position and the end of the upper portion 120a is L
2 is also short and the socket 121 may be damaged,
Since the socket 121 is later removed together with the branch pipe 103, there is no inconvenience even if the socket 121 is damaged.

(2) Second Stage (Saddle Cutting Operation) In the second stage, as shown in FIG. 12, the upper portion 120a of the saddle 120 is moved along the edge of the socket 121 on the branch pipe 103 side from the squeeze-off position. Disconnect. This cutting operation is performed manually using a saw or the like (not shown). After the cutting operation is completed, the socket 121 and the branch pipe 103
To remove. After removing the branch pipe 103, the main pipe 101 and
A fusion welding portion 120b of the saddle 120 fused thereto and the saddle 120 squeezed off by the squeeze bar 110.
The upper part 120a remains. Since the upper portion 120a of the saddle 120 remains, the remaining portion is larger than that of the first embodiment, but it is shorter than the conventional method.

(3) Third Stage (Temporary Plug Attachment Operation) In the third stage, as shown in FIG. 13, the temporary plug 11 is attached to the opening 120c at the cut end of the upper portion 120a of the saddle 120. This temporary plug 11 has the same configuration as that of FIG. 3B described above, and includes a main body 12 and an O-ring 13.
When the temporary plug 11 is attached, the O-ring 13 seals between the peripheral surface of the temporary plug 11 on the body 12 side and the inner wall of the upper portion 120 a of the saddle 120.

(4) Fourth stage (Squeeze-off release operation
In the fourth stage, first, the squeeze bar 110 that has squeezed off the upper portion 120a of the saddle 120 is opened. When the squeeze-off is released, as shown in FIG. 14, the upper portion 120a made of resin is elastically deformed and returns to the original state. The gas flowing from the main pipe 101 to the upper part 120a side is the temporary plug 1
1, the gas does not leak from the opening 120c.

Next, the main stopper 15 is fused to the tapping hole 101a using the closing tool 20. Here, the main stopper 15 has the same configuration as that of FIG. 4 described above, and includes a straight portion 16 and a tapered portion 17. Further, the closing tool 20 has the same configuration as that of FIG.
It includes a rod 21, a motor 23, a casing 25, a bearing 27, and a handle 29. Using the closing tool 21, the main stopper 15 is fused to the opening 120c of the saddle 120 in the same operation procedure as in the first embodiment described above. After the fusion work is completed, the main stopper 15 and the upper part 12 of the saddle 120 are closed.
When the contact portion with the contact hole 0a is left to cool, as shown in FIG.
And it is fixed so as to close it. The temporary plug 11 attached to the opening 120c in the third stage remains in the upper portion 120a of the saddle 120 below the main stopper 15 due to the frictional force between the O-ring 13 and the opening 120c. .

In the second embodiment, the description has been given of the case where the main pipe 101 and the branch pipe 103 are connected by using the resin saddle 120 as a joint. For example, as shown in FIG. When joints are used, the second
The branch pipe can be removed in exactly the same procedure as in the embodiment.

FIG. 16A is a partially sectional side view showing an example of a resin piping using a resin cheese.
(B) is an X-ray arrow view of FIG. 16 (A). The cheese 140 shown in FIG. 16 is made of a thermoplastic plastic such as polyethylene. This cheese 140 has a cylindrical upper part 14.
0a and a cylindrical outer fitting portion 140b integrated with the lower end of the upper portion 140a. The cheese 140 is fused in a state where the outer fitting portion 140b is externally fitted to the outer peripheral portion of the main tube 101. In this case, in the upper portion 140a of the cheese 140, the position indicated by the dashed line in the figure is squeezed off, and
40a is cut and the branch pipe 103 is removed.

Further, in the case where the service tee shown in FIG. 17A or the horizontal take-out service tee shown in FIG. 17B is used for the joint, the branch pipe is removed in exactly the same procedure as in the second embodiment. It can be carried out. FIG. 17 (A) is a plan view showing an example of a resin pipe using a resin service tee, and FIG. 17 (B) is a plan view showing an example of a resin pipe using a resin horizontal take-out service tee. is there.

The service tee 105 shown in FIG. 17A is the same as the one described in the first embodiment.
It has a fusion welding portion 105b and a branch portion 105c. In the first embodiment, the root of the upper portion 105a is cut. However, the position of the branch portion 105c of the service tee 105 shown by the dashed line in the drawing is squeezed off in accordance with the procedure of the second embodiment, and (The edge of the socket 121)
And the branch pipe 103 can be removed.

The horizontal take-out service chee 10 shown in FIG.
The configuration of No. 5 is also the same as that described above, but in this horizontal take-out service tee 105, the fusion welding portion 105b is fused to the side of the main pipe 101. When the horizontal take-out service tee 105 is used, an L-shaped socket 145 is used for a connection portion with the branch pipe 103. Also in this case, the position of the branch 105c of the service tee 105 shown by the dashed line in the figure is squeezed off in accordance with the procedure of the second embodiment, and the branch is made at the position shown by the two-dot chain line (the edge of the socket 121). Cutting the part 105c,
The branch pipe 103 is removed.

As described above, in the method of removing the resin branch pipe according to the second embodiment, a part of the resin joint remains after the removal operation, but the length thereof is shorter than in the conventional case. In the second embodiment,
There is an advantage that it can be applied to a wide variety of joints such as saddles, cheeses, service tees, and sideways service tees. The material, shape, hardness, size, and the like of the stopper shown in the above embodiment can be selected according to the specifications of the resin pipe.

[0044]

As is clear from the above description, according to the present invention, the risk of damage to the remaining branch pipe in other works after the removal of the branch pipe can be reduced.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view showing a first step (cutter moving operation) of a method for removing a resin branch pipe according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional side view showing a second stage (service tee cutting operation) of the method of removing the resin branch pipe.

FIG. 3 is a partial cross-sectional side view showing a third step (cutter removal / temporary plug attaching operation) of the method of removing the resin branch pipe.

FIG. 4 is a partial cross-sectional side view showing a fourth step (main closure plug fusion work) of the method of removing the resin branch pipe.

FIG. 5 is a partial cross-sectional side view showing a pipe state after the completion of the method of removing the resin branch pipe.

FIG. 6 is a partially sectional side view showing an example of a resin pipe using a Qi-type EF joint.

FIG. 7 is a partial cross-sectional side view showing an outline of a conventional method for removing a resin branch pipe.

FIG. 8 is a partial cross-sectional side view showing an outline of a conventional method for removing a resin branch pipe.

FIG. 9 is a partial cross-sectional side view showing an outline of a conventional method for removing a resin branch pipe.

10A is a partial cross-sectional side view showing an example of a resin pipe using a resin saddle, and FIG.
FIG. 11 is a view (front view) taken along the X-ray arrow in FIG.

FIG. 11 is a partial cross-sectional side view showing a first step (squeeze-off operation) of a method for removing a resin branch pipe according to a second embodiment of the present invention.

FIG. 12 is a partially sectional side view showing a second step (saddle cutting operation) of the method of removing the resin branch pipe.

FIG. 13 is a partial cross-sectional side view showing a third step (temporary plug attaching operation) of the method of removing the resin branch pipe.

FIG. 14 is a partial cross-sectional side view showing a fourth step (squeeze-off release operation / main closure plug fusion operation) of the method of removing the resin branch pipe.

FIG. 15 is a partial cross-sectional side view showing a pipe state after the method of removing the resin branch pipe is completed.

FIG. 16 (A) is a partial cross-sectional side view showing an example of resin piping using resin cheese, and FIG. 16 (B)
FIG. 17 is an X-ray arrow view of FIG.

17 (A) is a plan view showing an example of a resin pipe using a resin service tee, and FIG. 17 (B) is an example of a resin pipe using a resin horizontal take-out service tee. FIG.

[Explanation of symbols]

10 No blow gas bag 10A,
10B Opening 11 Temporary plug 12 Main body 13 O
Ring 15 Closing stopper 16 Straight part 17 Tapered part 20 Closing tool 21 Rod 23 Motor 25 Casing 27 Bearing 29 Handle 101 Main pipe 101a
Tapping hole 103 Branch pipe 105 Service tee 105a Upper part 105a
´ Upper root 105b Welded part 105c
Branch 106 Built-in tapping tool (cutter) 107, 121, 145 Socket 120 Saddle 120a Upper part 120b
Fusion welding part 140 Cheese 140a Upper part 140b
Outer fitting

Claims (2)

[Claims] 1. A method for removing a resin branch pipe connected to a main pipe via a tee having a built-in tapping tool (cutter), wherein the cutter is inserted into a tapping hole in a side wall of the main pipe. Cutting the chee on the upper side of the cutter, attaching a sealing work bag to the cutting part of the chee, removing the cutter from the tapping hole in the bag, and attaching a temporary plug to the tapping hole, Rotating and applying a resin-made main stopper from the outside of the temporary stopper, and fusing the final stopper to the cutting portion of the Qi by frictional heat generated between the final stopper and the end of the tapping hole. A method for removing a resin branch pipe. 2. A method for removing a resin branch pipe connected to a main pipe via a resin joint, wherein the resin joint is compression-shut off (squeezed off), and the resin is closed near the compression-shut position. The connection end side (branch pipe side) of the joint made of resin is cut, a temporary plug is attached to the opening of the cut end of the resin joint, and a resin closing stopper is rotated from outside of the temporary plug and applied. A method for removing a resin branch pipe, characterized in that the main stopper is fused to a cut portion of the resin joint by frictional heat generated between the main stopper and the opening end.