JP2012172753A - Branch channel blocking method of fluid piping system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a worker to sensuously know that a drilling work has completed with sure, even if parts of inner peripheral surface of a main pipe and that of a branch pipe part are flush with each other, and to surely block a channel by smoothly delivering a blocking means of a blocking device into the branch pipe part.SOLUTION: A main pipe 1 which is continued from a branch 2 of small diameter in such condition as parts of inner peripheral surfaces are flush each other, is continued to a working pipe part 4 under such condition as to face a base end opening 2b of the branch 2 each other. A drilling tool A1 of a drilling device A which is connected to the working pipe part 4 through a working opening/closing valve 6 is used to form an insert opening on the main pipe 1. After that, a blocking means B1 of a blocking device B connected to the working opening/closing valve 6 is fed to a channel blocking position in the branch 2, for blocking the channel. Here, a set feeding axial core X of the drilling tool A1 is decentered toward such side as comes away from a flush connection point 2a of the inner peripheral surface of the branch 2, relative to a branch axial core X1 of the branch 2. A set feeding axial core of the blocking means B1 is set to a position matching with the branch axial core X1.

Description

  The present invention is a fluid in which a branch pipe portion having a smaller diameter is connected to a main pipe through which a fluid such as clean water or gas flows, with a part of the inner peripheral surface being flush or substantially flush. The present invention relates to a branch flow path blocking method for blocking a flow path of the branch pipe section while maintaining a fluid flow in a main pipe in a piping system.

  As a method for shutting off the branch flow path of the fluid piping system, the applicant of the present application, for example, has no on-off valve on the branch pipe side, or even if the on-off valve exists, the applicant remains in an open state and cannot operate. Under this condition, even when removing the piping equipment of the branch piping system connected to the branch pipe section, a construction method that can reliably shut off the flow path of the branch pipe section was first developed.

As shown in the following Patent Document 1, the branch flow path blocking method of this fluid piping system is as follows:
A branch pipe portion having a smaller diameter than the main pipe through which the fluid flows is connected to the main pipe with a part of the inner peripheral surface being flush or substantially flush with the main pipe, and branches off from the proximal end opening of the branch pipe portion A working pipe part connecting step for connecting a working pipe part having the same diameter as the branch pipe part in a concentric state with the branch pipe part on the pipe wall of the main pipe facing each other in the axial direction;
A drilling device is connected to the working on-off valve connected to the working pipe portion in a state where the setting feed shaft core of the drilling tool is coincident with the branch shaft core of the branch pipe portion, and the punching tool of this drilling device is used for the work. An on-off valve, an insertion port forming step for forming an insertion port on the tube wall of the main pipe facing the base end opening of the branch pipe portion in the branch axis direction by feeding through the work pipe portion;
A piercing device removing step of pulling out the piercing tool of the piercing device downstream from the work on-off valve, and removing the piercing device in a state in which the work on-off valve is closed;
A closing device provided with a closing means capable of switching between a diameter-expanded state and a diameter-reduced state capable of shutting off a flow path of the branch pipe portion in the working on-off valve, and a setting feed shaft core of the closing means is a branch pipe portion. A closing device connecting step for connecting in a state matching the branch axis;
The closing means of the closing device is sent to the flow path closing position in the branch pipe section through the insertion opening of the work opening / closing valve, the working pipe section, and the main pipe wall in the reduced diameter state, and the closing means is switched to the expanded diameter state. A flow path blocking step for blocking the flow path of the branch pipe section;
have.
In Patent Document 1, after the flow path blocking step, a step of replacing an air valve, which is an example of a fluid device connected to the branch pipe portion, with a new air valve, and a blocking means of the blocking device are provided. A closing device removing step of drawing out the closing device with the work opening / closing valve being pulled out and being closed with the work opening / closing valve closed.

Japanese Patent Laying-Open No. 2008-170008 (FIGS. 20 to 23)

  In the branch flow path blocking method of the conventional fluid piping system, in the insertion port forming step, the feed amount of the drilling tool of the drilling device is calculated and set based on the construction conditions, but the thickness tolerance of the main pipe, In order to prevent the drilling operation from being terminated in the middle due to installation errors of the work pipe, installation tolerances of the work on / off valve or drilling device, etc., the water flowing out from the main pipe into the work pipe At the same time, the operator sensuously captures a sudden change in the feeding resistance when the drilling is completed, and determines whether or not the drilling operation is completed.

  However, in a state in which a part of the inner peripheral surface of the main pipe and the inner peripheral surface of the branch pipe portion are flush or substantially flush, even after the insertion port is formed in the pipe wall of the main pipe, There is a possibility that the drilling action part will continue to slidably contact with the series of locations on the inner peripheral surface of the main pipe.In this case, it becomes difficult for the operator to sensuously capture the sudden change in the feeding resistance when drilling is completed. If the drilling tool is continuously fed, there is a disadvantage in that it causes damage to the surface continuous portions on the inner peripheral surface of the main pipe and the inner peripheral surface of the branch pipe portion.

  The present invention has been made in view of the above-described actual situation, and the main problem is that a part of the inner peripheral surface of the main pipe and the inner peripheral surface of the branch pipe portion are in a flush or substantially flush state. Even if there is, the operator can surely capture the completion of the drilling operation, and the blocking means of the closing device can be smoothly fed into the branch pipe portion to reliably block the flow path. It is in the point which provides the branch flow path interruption | blocking method of the fluid piping system which can be performed.

According to a first characteristic configuration of the present invention, a branch pipe portion having a smaller diameter than a main pipe through which a fluid flows is connected in a state where a part of an inner peripheral surface is flush or substantially flush. A work tube portion connecting step for continuously connecting the work tube portion to the outer peripheral surface of the tube wall in a state opposite to the proximal end opening of the branch tube portion in the branch axis direction;
A piercing device is connected to the working on-off valve connected to the working pipe portion, and a piercing tool of the piercing device is fed through the working on-off valve and the working pipe portion, so that a base end opening of the branch pipe portion is provided. An insertion port forming step of forming an insertion port in the opposite main pipe wall;
A piercing device removing step of pulling out the piercing tool of the piercing device downstream from the work on-off valve, and removing the piercing device in a state in which the work on-off valve is closed;
A closing device connecting step for connecting a closing device having a closing means capable of switching between a diameter-expanded state and a diameter-reduced state capable of blocking the flow path of the branch pipe portion to the on-off valve;
With the closing means of the closing device reduced in diameter, it is sent to the flow path closing position in the branch pipe section through the insertion opening formed in the work opening / closing valve, working pipe section, and main pipe wall, and the closing means is expanded in diameter. A channel blocking step for switching to a state and blocking the channel;
A branch flow path blocking method for a fluid piping system comprising:
In the insertion port forming step,
The setting feed shaft core of the piercing tool of the piercing device is branched at an eccentric margin within the dimension of the gap formed between the outer periphery of the closing means in the reduced diameter state and the inner peripheral surface of the working tube portion. It is eccentric with respect to the branch axis of the pipe part on the side away from the surface series location of the inner peripheral surface of the branch pipe part,
In the closing device connecting step,
The setting feed shaft core of the closing means of the closing device is set to a position that matches or substantially matches the branch shaft core of the branch pipe portion.

  According to the above configuration, in the insertion port forming step, when the punching device of the punching device passes through the main pipe wall opposite to the proximal end opening of the branch pipe portion, the setting feed shaft core of the punching device is The drilling tool is inserted into the main pipe from the continuous surface of the inner peripheral surface of the main pipe by the amount that is eccentric to the side away from the continuous surface of the inner peripheral surface of the branch pipe with respect to the branch axis of the branch pipe. It will be spaced apart to the tube axis side.

  For this reason, the drilling action part of the drilling tool is not fed in sliding contact with the surface of the inner peripheral surface of the main pipe, so that the operator completes the drilling operation using the rapid change in the feeding resistance of the drilling tool. You can clearly capture what you have done.

  In addition, the center of the insertion port formed in the pipe wall of the main pipe is eccentric by the amount of the eccentricity of the punching tool with respect to the branching axis of the branching pipe part. This is the eccentricity within the dimension of the gap formed between the outer periphery of the closing means in the radial state and the inner peripheral surface of the working tube, and the setting feed shaft core of the closing means of the closing device branches. Since it is set at a position that matches or substantially matches the branch axis of the pipe part, the closing means of the closing device in the reduced diameter state is formed on the work on / off valve, work pipe part, and main pipe wall Through the insertion port, it can be reliably and smoothly fed into the flow path blocking position in the branch pipe section.

  Therefore, even when a part of the inner peripheral surface of the main pipe and the inner peripheral surface of the branch pipe portion are flush or substantially flush, the setting feed shaft core of the drilling tool and the setting feed shaft core of the closing means are the above-mentioned. As a result of rational improvements that are simply devised, the operator clearly captures the completion of the drilling operation and ensures the drilling operation. It can be smoothly fed into the section and the flow path can be reliably blocked.

According to a second characteristic configuration of the present invention, in the work tube portion connecting step, the work tube portion is configured so that the axial center of the work tube portion is set with respect to the branch axis of the branch tube portion. In the state where it is decentered to the side away from the surface series installation location of the inner peripheral surface of the branch pipe part at the eccentric allowance, it is connected to the outer peripheral surface of the main pipe wall,
Further, in the insertion port forming step, a piercing work case that can accommodate a piercing tool of a piercing device is detachably attached to the work on-off valve, and a downstream connection portion of the piercing work case is attached to the work opening / closing valve. The connecting portion of the drilling device is detachably fixedly connected in a state in which the setting feed shaft core of the drilling tool matches or substantially matches the shaft core of the working tube portion.

  According to the above configuration, when the setting feed shaft core of the drilling tool is eccentric, the working pipe portion is eccentrically provided on the outer peripheral surface of the tube wall of the main pipe by the eccentric margin of the drilling tool. Therefore, for example, the working pipe portion is connected to the outer peripheral surface of the pipe wall of the main pipe in a concentric state with the branch axis of the branch pipe portion, and the work on-off valve or the punching device is perforated with respect to the work pipe portion. Compared to the case where the work case is eccentrically connected by the eccentric margin of the drilling tool, the connection structure between the work pipe and the work on-off valve or the connection structure between the work on-off valve and the drilling work case In addition, it is possible to use a normal connection structure that connects in a concentric state as it is, and it is possible to reduce the construction cost and facilitate the construction.

  According to a third characteristic configuration of the present invention, in the closing device connecting step, a closing work case capable of storing closing means of the closing device is attached to and detached from the work opening / closing valve in a concentric state with the working pipe portion. A bearing part that is freely attached and that supports the operating shaft of the closing device in a slidable manner in the penetrating state is provided at the downstream side of the closing work case. The eccentricity equivalent to the eccentricity of the shaft core is provided in a state in which it is eccentric to the axially continuous portion of the inner peripheral surface of the branch pipe part with respect to the axial center of the working pipe part. .

  According to the above configuration, the operating shaft bearing portion of the closing device provided in the connecting portion on the downstream side of the closing work case has an eccentric margin corresponding to the eccentric margin of the setting feed shaft core of the drilling tool. Since it is eccentric to the surface of the inner peripheral surface of the branch pipe portion with respect to the axial center of the pipe portion, the closing means of the closing device can be smoothly fed into the branch pipe portion while the working pipe portion and The connection structure with the work on-off valve or the work on-off valve with the closing work case can be used as it is with the normal connection structure that is connected in a concentric state. Simplification can be achieved.

According to a fourth characteristic configuration of the present invention, a pipe end that removes a fluid pipe or a fluid device connected to the branch pipe part and closes an end opening of the branch pipe part after the flow path blocking step. A pipe end closing process for connecting the closure;
A closing device removing step of pulling out the closing means of the closing device downstream from the work on / off valve and removing the close device with the work on / off valve closed is provided.

  According to the above configuration, the fluid pipe or the fluid device connected to the branch pipe portion is easily removed in a state where the flow path is blocked by the closing means sent to the flow path closing position in the branch pipe portion. In addition, the end opening of the branch pipe portion can be reliably closed with a pipe end closing tool.

  According to a fifth characteristic configuration of the present invention, in the flow path blocking step, the movement blocking means for blocking the blocking means of the blocking device from moving downstream from the flow path blocking position in the branch pipe portion due to fluid pressure. It is in the point provided.

  According to the above configuration, when the blocking means sent in the reduced diameter state to the flow path blocking position in the branch pipe portion is switched to the expanded diameter state, a large fluid pressure acts on the closing means on the downstream side. Since the fluid pressure can be received by the movement blocking means and the closing means can be held at the flow path closing position, the switching operation of the closing means to the expanded state at the flow path closing position can be performed reliably.

  According to a sixth characteristic configuration of the present invention, the drilling tool of the drilling device includes a cylindrical hole saw and a center drill that projects forward from the cutting center from the rotation center position of the base end of the hole saw. In addition, the length of the protrusion of the drill from the cutting action part of the center drill to the cutting action part of the hole saw is configured such that the cutting action by the hole saw starts after the center drill penetrates the pipe wall of the main pipe. It is in the point.

  According to the above configuration, when the insertion port is formed in the pipe wall of the main pipe opposite to the proximal end opening of the branch pipe section, the outer peripheral face of the pipe wall that is farthest from the continuous surface location on the inner peripheral face of the main pipe Drilling with an unstable piece-by-piece condition where drilling with a hole saw is started at one point, but at the start of this drilling, the center drill drills through the tube wall of the main pipe. Since the center position is fixed, the insertion port can be accurately formed in the tube wall of the main pipe.

  According to a seventh feature of the present invention, there is a step between the inner peripheral surface of the working tube portion and the opening peripheral edge of the insertion port on the outer peripheral surface of the main tube wall at the distal end portion of the closing means of the closing device. The taper surface which crosses and guides a part is formed.

Since the insertion port formed in the pipe wall of the main pipe in a state opposite to the proximal end opening of the branch pipe part is smaller in diameter than the inner diameter of the work pipe part, the inner peripheral surface of the work pipe part and the pipe A stepped portion is formed between the peripheral edge of the wall and the opening periphery of the insertion opening.
However, the operating shaft bearing portion of the closing device provided in the connecting plate portion on the downstream side of the closing work case has an eccentric margin corresponding to the eccentric margin of the setting feed shaft core of the drilling tool. Since the center of the branch pipe portion is eccentric with respect to the shaft center on the side where the inner peripheral surface is provided, the closing means of the closing device is reduced in diameter so that the work on-off valve, work pipe portion, main When feeding to the flow path blockage position in the branch pipe portion through the insertion port formed in the tube wall of the tube, the tip portion of the closing means of the closing device comes into contact with the stepped portion. The closing means can be smoothly moved over and moved by the overpass guide action by the formed tapered surface.

Sectional drawing before construction of the water supply piping system which shows 1st Embodiment of this invention Sectional view when working pipe is connected to the main pipe Cross section during water pressure test Sectional view when connecting drilling devices Sectional view when forming an insertion slot with a punching device Enlarged cross-sectional view of the main part when forming an insertion port with a punching device Sectional view when removing the drilling device Sectional view when cleaning the inner surface of the branch pipe with the inner surface cleaning device Sectional view when connecting the closure device Enlarged cross-sectional view of the main part when connecting the closure device Sectional view (a) of closing flange and front view (b) of right half of outer surface Sectional view when the closing means in the reduced diameter state of the closing device is fed into the branch pipe Sectional view when closing the flow path by operating the closing means in the expanded state Enlarged cross-sectional view of the main part when the closing means is operated in the expanded state Sectional view when removing the branch pipe of the branch pipe system connected to the branch pipe section Sectional view when the end of the branch pipe is closed with a flange lid Cross-sectional view when removing the occlusion device Sectional view when connecting the work opening sealing device to the work on / off valve Sectional view when the flange lid is pressed against the connecting flange of the work pipe Sectional view when the on-off valve and the sealing work case are removed after fixing the flange lid

[First Embodiment]
FIG. 1 shows a branch pipe portion 2 having a diameter smaller than that of a main pipe 1 at the branch portion of a main pipe (water main pipe) 1 through which clean water, which is an example of fluid, flows. A part, that is, the inner peripheral bottom surfaces 1a and 2a are connected in a state where they are flush or substantially flush with each other, and the connecting pipe 2A of the branch pipe portion 2 has a fluid pipe constituting a branch pipe system. Or the water supply piping system (an example of a fluid piping system) to which the connection flange 3A of the branch piping 3 which is an example of a fluid apparatus is connected in the watertight state is shown.
In this water supply piping system, removal of the branch piping system including a branch flow path blocking method for blocking the flow path of the branch pipe section 2 in a continuous water state (non-continuous flow state) maintaining the flow of clean water in the main pipe 1 The method will be described in detail.

[1] FIG. 2 shows a flow path of the branch pipe part 2 at a portion of the outer peripheral surface of the pipe wall of the main pipe 1 facing the base end opening 2b of the branch pipe part 2 in the direction of the branch axis X1. The working pipe portion 4 having the same or substantially the same inner diameter as that of the upstream branch pipe portion including the planned shut-off portion is connected to the branch pipe portion 2 with respect to the branch axis X1 of the branch pipe portion 2. The working pipe part connecting step is shown in which the inner peripheral bottom surface (a series of surface locations on the inner peripheral surface) 2a is arranged in an upwardly spaced state away from the inner peripheral bottom surface 2a.

  The eccentric margin of the axis X2 of the working tube portion 4 is within the dimension of the gap S formed between the inner peripheral surface of the working tube portion 4 and the outer surface of the closing means B1 in a reduced diameter state. Setting (in FIGS. 9 and 10, since the closing means B1 is in sliding contact with the inner peripheral surface of the working pipe section 4, the uppermost surface of the closing means B1 and the working pipe section 4 that is opposed to this in the radial direction are arranged. It is configured in the same manner as the eccentricity h of the setting feed shaft core X of the punching tool A1 of the punching device A in which the gap S appears with a deviation from the inner peripheral surface.

  The base end portion (upstream end portion) of the working pipe portion 4 is integrally formed with an annular joining flange 4A that abuts on a continuous portion of the outer peripheral surface of the pipe wall of the main pipe 1, and all of the joining flange 4A. By circumferential welding, the working pipe portion 4 is fixed to the outer peripheral surface of the pipe wall of the main pipe 1 in a watertight state, and the hydraulic pressure test shown in FIG. 3 is applied to the distal end portion (downstream end portion) of the working pipe portion 4. A connecting flange 4B capable of selectively connecting the lid 5 to the valve case 6A of the work on-off valve 6 shown in FIG. 4 and the flange lid 51 shown in FIG. 18 is integrally formed.

  As shown in FIGS. 20 and 6, the downstream corner of the outer periphery of the connecting flange 4 </ b> B has an annular corner on the inner side of the connecting tube portion 6 </ b> B of the valve case 6 </ b> A that is externally fitted to the connecting flange 4 </ b> B. A taper-shaped seal receiving surface 4a for holding the sealing material 7 in a watertight state is formed between the valve case 6A and the upstream corner portion of the outer peripheral portion of the connecting flange 4B. The valve case 6A is connected to the side where the sealing material 7 is compressed by contacting the taper pressing surface 8a on the front end side of the fixing bolt 8 screwed from the outside in the radial direction to a plurality of locations in the circumferential direction of the cylindrical portion 6B. A tapered contact surface 4b for attracting and fixing to 4B is formed.

  Note that a plurality of screw holes 4c for penetrating the flange lid 51 for sealing the tip opening of the work tube portion 4 in a watertight state in the final process are formed through a plurality of locations in the circumferential direction of the connecting flange 4B. It is necessary to prevent water from being ejected from each screw hole 4c. Therefore, in this embodiment, the taper guide portion 11a that engages with the screw hole 51a of the flange lid 51 and performs centering, and the O-ring 12 that seals the periphery of the screw hole 4c on the outer surface of the connecting flange 4B are provided. A guide bolt 11 is detachably screwed.

[2] FIG. 3 shows that a hydraulic test lid 5 for sealing the downstream opening of the working pipe portion 4 in a watertight state is fixedly connected to the connection flange 4B of the working pipe portion 4 with bolts 9, and the hydraulic test lid is 5 shows a water pressure test process in which a water supply hose (not shown) is connected to the water supply / drain port 10 provided in 5 and pressure water is supplied into the work pipe 4 to check for leakage.

  After completion of the water pressure test, a drain hose (not shown) is connected to the water supply / drain port 10 of the water pressure test lid 5 to discharge the pressure water in the work pipe 4 and then the work pipe 4 is connected. The hydraulic pressure test lid 5 is removed from the flange 4B.

[3] FIGS. 4 to 6 are opposed to the base end opening 2b of the branch pipe part 2 by the punching device A connected to the connection flange 4B of the work pipe part 4 via the work on-off valve 6. The insertion port formation process which forms the insertion port 13 in the pipe wall of the main pipe 1 to perform is shown.

  Specifically, the connecting cylinder portion 6B of the valve case 6A of the working on-off valve 6 is externally fitted to the connecting flange 4B of the working tube portion 4, and a plurality of fixed portions provided on the connecting cylinder portion 6B are fixed. By tightening the bolt 8, the connection flange 4B of the work pipe 4 and the valve case 6A of the work on / off valve 6 are fixedly connected in a watertight state. Thereafter, the joint flange 15 provided at the downstream end of the valve case 6A of the work on / off valve 6 is provided with a joint flange 15 having a common mounting screw hole 15a for the cleaning work case 25 or the closing work case 30 described later. In the watertight state, the bolt 16 and the nut 17 are fixedly connected so as to be detachable, and a drilling work case 14 having a storage space S1 in which the punching tool A1 of the punching device A can be stored is connected to the joint flange 15 in a watertight state. The bolt 16 is detachably fixedly connected.

  A connecting flange 14A integrally formed at the upstream end of the drilling work case 14 and the case axis X3 of the drilling work case 14 are matched (or substantially matched) with the joint flange 15 and the axis X2 of the work tube portion 4. ) In a watertight state with bolts 16, and a connecting flange (an example of a downstream connecting portion) 14 </ b> B integrally formed at the downstream end of the drilling work case 14 is connected to the drilling device A. A connecting flange (an example of a connecting portion) 18A formed at the front end portion of the drilling device main body 18 matches (or substantially matches) the set feed shaft core X of the punching tool A1 with the shaft core X2 of the working tube portion 4. In this state, the bolts 16 and nuts 17 are fixedly connected in a watertight state so as to be detachable.

  The setting feed shaft core X of the punching tool A1 of the punching device A is set within the dimension of the gap formed between the inner peripheral surface of the working tube portion 4 and the outer peripheral surface of the closing means B1 in the reduced diameter state. With the eccentricity h, the eccentricity h is eccentric to the upper side away from the inner peripheral bottom surface 2a of the branch pipe part 2 with respect to the branch axis X1 of the branch pipe part 2.

  Then, the operating shaft 6 of the piercing device A located in the storage space S1 of the piercing work case 14 is operated to open while the rotary shaft 19 of the piercing device A is driven to rotate. Further, the insertion port 13 is formed in the pipe wall of the main pipe 1 facing the proximal end opening 2 b of the branch pipe section 2 by feeding the main pipe 1 through the working pipe section 4.

  When the punching tool A1 passes through the tube wall of the main pipe 1 facing the proximal end opening 2b of the branch pipe part 2, the setting feed axis X of the punching tool A1 becomes the branch axis X1 of the branch pipe part 2. On the other hand, the perforation acting part of the drilling tool A1 is the inner peripheral bottom surface of the main pipe 1 (a part where the inner peripheral surface is continuously provided) 1a by the amount eccentric to the upper side away from the inner peripheral bottom surface 2a of the branch pipe part 2a. Therefore, a gap is secured between the drilling tool A1 penetrating the tube wall of the main pipe 1 and the inner peripheral bottom face 1a of the main pipe 1.

  Therefore, since the piercing part of the piercing tool A1 is not fed into the inner peripheral bottom surface 1a of the main pipe 1 in a sliding contact state, it is confirmed that the piercing work has been completed by utilizing the rapid change in the feeding resistance of the piercing tool A1. A person can capture clearly and sensuously.

  The drilling tool A1 is a cylindrical hole saw provided with a mounting base 20A fixedly connected to a connecting plate 19A on the distal end side of the rotary shaft 19 of the punching device A by bolts and nuts and a cutting tip 20B constituting a cutting action portion. 20 and a cutting tip 21A that constitutes a cutting action portion, and a center drill 21 that protrudes further forward than the cutting tip 20B from the rotation center position of the attachment base end portion 20A of the hole saw 20. The projecting length from the cutting tip 21A of the center drill 21 to the cutting tip 20B of the hole saw 20 is set to a dimension at which the cutting action by the hole saw 20 starts after the center drill 21 penetrates the tube wall of the main pipe 1. It is configured.

[4] FIG. 7 shows that the rotary shaft 19 of the punching device A is contracted, and the punching tool A1 holding the tube wall section 1A is passed through the working tube portion 4 and the work opening / closing valve 6 in the valve opening operation state. After pulling back into the storage space S1 of the drilling work case 14, the valve body 6D of the work on-off valve 6 is closed to remove the punching device main body 18 of the drilling device A from the drilling work case 14, and to perform the drilling work. The case 14 is removed from the joint flange 15 on the working on-off valve 6 side.

[5] FIG. 8 shows the insertion of the blocking means B1 including the channel blocking scheduled position on the inner peripheral surface of the branch pipe portion 2 by the inner surface cleaning device C connected to the joint flange 15 on the working on-off valve 6 side. The inner surface cleaning process which cleans a work area is shown.

  Specifically, a storage space S <b> 2 capable of storing a scraping body 24, which is an example of a cleaning tool of the inner surface cleaning device C, is provided in the joint flange 15 connected to the work on / off valve 6 in the valve closing operation state. With the connecting flange 25A integrally formed at the upstream end of the cleaning work case 25, the case axis X4 of the cleaning work case 25 matches (or substantially matches) the axis X2 of the work tube part 4. The bolt 16 is fixedly connected in a watertight state.

  The connecting flange 25B formed integrally with the downstream end of the cleaning work case 25 is provided with a bearing portion 27A for penetrating and supporting the operation shaft 26 of the cleaning device C in a watertight manner so as to be slidable and swingable. The cleaning flange 27 is fixedly connected in a watertight manner with a bolt 16 and a nut 17 so that the bearing center thereof is aligned with the axis X2 of the work tube portion 4.

  Then, the operating shaft 26 of the inner surface cleaning device C is pushed in to operate, and the scraping body 24 of the inner surface cleaning device C located in the storage space S2 of the cleaning work case 25 is in the valve opening operation state. 6. The work pipe section 4 and the main pipe 1 are fed into the branch pipe section 2, and in this state, the operation handle 28 of the operation shaft 26 is swung to shut off the flow path on the inner peripheral surface of the branch pipe section 2. Scrape off deposits such as rust on the insertion work area of the closing means B1 including the planned position, and clean the inner surface so that the blocking means B1 can reliably block the flow path of the branch pipe portion 2. .

  When the scraping body 24 of the inner surface cleaning device C is fed into the branch pipe portion 2 and the scraping body 24 cannot be smoothly fed only by human force, for example, the engagement provided on the joint flange 15 is used. A forcible feeding device (for example, two locking hooks and a chain capable of winding and unwinding) is provided to apply a forcible feeding force to the operating shaft 26 across the stopping portion and the locking portion provided on the operating shaft 26. It may be carried out by attaching a hand-wound winch or the like.

  Further, in this inner surface cleaning process, since the swing operation range of the operation shaft 26 using the sealing O-ring 27a provided on the bearing portion 27A of the cleaning flange 27 as a fulcrum is large, The bearing center of the bearing portion 27A is centered on the axis X2 of the work tube portion 4 that is eccentric with the eccentricity h of the setting feed shaft core X of the drilling tool A1 with respect to the branch axis X1 of the branch tube portion 2. Even if they are matched (or substantially matched), the scraper 24 can be fed into the branch pipe part 2, and the insertion work area of the blocking means B 1 including the planned flow path blocking position on the inner peripheral surface of the branch pipe part 2 can be obtained. It can be reliably cleaned.

  When the swing operation range of the operation shaft 26 is reduced, the bearing center of the bearing portion 27A of the cleaning flange 27 is matched (or substantially matched) with the branch axis X1 of the branch pipe portion 2. In addition, the inner peripheral bottom surface of the branch pipe portion 2 with an eccentric margin corresponding to the eccentric margin h of the setting feed shaft core X of the drilling tool A1 with respect to the center of the cleaning flange 25 is the bearing center of the bearing portion 27A. You may provide in the state made eccentric to the downward side which is 2a side.

  9 to 14 show a closing device connecting step of connecting the closing device B to the joint flange 15 connected to the working on-off valve 6, and the closing pipe B 2 by the closing means B1 of the closing device B. A flow path blocking process for blocking a flow path at a flow path blocking scheduled position on the inner peripheral surface is shown.

  Specifically, as shown in FIG. 9, a storage space S3 capable of storing the closing means B1 of the closing device B is provided in the joint flange 15 connected to the working on-off valve 6 in the valve closing operation state. The connection flange 30A integrally formed at the upstream end of the closing work case 30 is bolted in a state where the case axis X5 of the closing work case 30 is matched (or substantially matched) with the axis X2 of the working tube part 4. 16 is fixedly connected in a watertight state.

  The connecting flange 30B integrally formed at the downstream end of the closing work case 30 is provided with a bearing portion 32A for penetrating and supporting the operating shaft 31 of the closing device B in a watertight state so as to be slidable and swingable. The closed flange (an example of the downstream connecting portion) 32 is in a watertight state with the bolt 16 and the nut 17 in a state where the bearing center thereof matches (or substantially matches) the branch axis X1 of the branch pipe portion 2. It is fixedly connected in a detachable manner.

  The center of the closing flange 32 itself is concentric with the case axis X5 of the closing work case 30, and the bearing portion 32A is branched from the set feed axis X6 of the closing means B1 as shown in FIG. The eccentricity margin of the setting feed shaft core X of the drilling tool A1 with respect to the center of the closing flange 32 so that the bearing center of the bearing portion 32A matches (or substantially matches) the branch axis X1 of the pipe portion 2. An eccentricity equivalent to h is provided in a state of being eccentric to the lower side which is the inner peripheral bottom surface 2a side of the branch pipe part 2, and a sealing O-ring 32a provided to the bearing part 32A is provided. As a fulcrum, the operation shaft 31 is configured to be swingable.

  The operating shaft 31 of the closing device B includes a cylindrical outer operating shaft 31A and an inner operating shaft 31B that slidably passes through the outer operating shaft 31A in the axial direction. On the inner end side (the left end side in FIG. 9) of the inner operation shaft 31B, there is provided a closing means B1 for blocking the flow path of the branch pipe portion 2, and both the closing means B1 are operated from the outside. An operating means B2 for operating via the shafts 31A and 31B is provided.

  To constitute the closing means B1 of the closing device B, as shown in FIG. 10, a first pressing member 33 having an annular pressing surface 33a is screwed and fixed to the inner end portion of the outer operation shaft 31A. A second pressing member 34 having an annular pressing surface 34a opposite to the pressing surface 33a of the first pressing member 33 in the axial direction is screwed and fixed to the inner end portion of the inner operation shaft 31B. Between the pressing surfaces 33a and 34a of the pressing members 33 and 34, the branch pipe is elastically deformed into a diameter-expanded state in accordance with the pinching force from the axial direction by the relative proximity movement of the pressing members 33 and 34. A rubber elastic blocking body 35 that blocks the flow path of the portion 2 is externally provided.

  A step formed on the outer peripheral portion of the distal end portion of the second pressing member 34 between the inner peripheral surface of the working tube portion 4 and the opening peripheral edge of the insertion port 13 on the outer peripheral surface of the tube wall of the main tube 1. A tapered surface 34b is formed to get over and guide the portion 40.

  As shown in FIG. 9, FIG. 12, and FIG. 14, the operation means B2 is formed on the outer end surface of the outer operation shaft 31A on the screw portion 31b formed on the outer end side shaft portion of the inner operation shaft 31B. In accordance with the screwing operation in the contact state, a diameter-enlarging operation nut 36 for manipulating force that moves the inner operation shaft 31B to the outer side in the axial direction with respect to the outer operation shaft 31A is screwed.

  A mounting plate 38 having a pair of hydraulic jacks 37 for mechanical force operation is detachably screwed and fixed to the outer end side of the screw portion 31b of the inner operation shaft 31B. The outer end side shaft portion is fitted with a receiving member 39 that can come into contact with the tip of the piston rod 37A of both hydraulic jacks 37. The receiving member 39 has a periphery of the outer end side shaft portion of the outer operation shaft 31A. Engagement pieces 41 engaging with engagement recesses 31a formed at two locations in the direction are fixed by bolts 42 so as to be detachable.

Between the closing flange 32 and the receiving member 39, as shown in FIGS. 11, 12, and 14, the closing means B <b> 1 of the closing device B is water pressure and the flow path closing position in the branch pipe portion 2. A movement blocking means D is provided for blocking the movement to the downstream side.
The movement blocking means D includes a screw cylinder 45 fixed to a plurality of locations in the circumferential direction of the outer surface of the closing flange 32, a thrust stop bolt 46 screwed and fixed to each screw cylinder 45, and each screw cylinder. 45, bolt insertion holes 39a formed at a plurality of locations on the receiving member 39 facing each other in the axial direction, and thrust stop bolts 46 inserted into the respective bolt insertion holes 39a in a state where both side surfaces of the receiving member 39 are clamped and fixed. And a fixing nut 47 that is screwed onto the screw.

  Then, the operating shaft 31 of the closing device B is pushed in, and the closing device B1 of the closing device B located in the storage space S3 of the closing work case 30 is in the valve opening operation state. It is fed into the branch pipe section 2 through the pipe section 4, the insertion port 13 and the main pipe 1.

  At this time, a thrust stop bolt 46 is screwed and fixed to each screw cylinder 45 of the closing flange 32, so that each closing means B1 is sent to the flow path closing position in the branch pipe portion 2. The tip of the thrust stop bolt 46 is inserted into the bolt insertion hole 39a of the receiving member 39, and when the closing means B1 reaches the flow path closing position in the branch pipe portion 2, it is screwed into each thrust stop bolt 46. The both side surfaces of the receiving member 39 are clamped and fixed by the fixing nut 47.

Next, the diameter expansion operation nut 36 is screwed to the tightening side by an artificial force while the closing means B1 is fixedly held at the flow path closing position in the branch pipe portion 2, or the hydraulic jack 37 Is extended by oil pressure, the inner operation shaft 31B is pulled outward with respect to the outer operation shaft 31A, and the elastic closing member 35 is in a diameter-expanded state due to the relative proximity movement of the pressing members 33 and 34 associated therewith. And the flow path of the branch pipe portion 2 is blocked.
At this time, due to the movement blocking means D provided between the closing flange 32 and the receiving member 39, the closing means B1 of the closing device B is downstream of the flow path closing position in the branch pipe portion 2 due to water pressure. Can be prevented from moving to the side.

  The operating shaft 31 is configured to be swingable with a sealing O-ring 32a provided on the bearing portion 32A of the closing flange 32 as a fulcrum, so that the closing means in the storage space S3 of the closing work case 30 is provided. When B1 is fed into the branch pipe part 2 through the work opening / closing valve 6, the work pipe part 4, the insertion port 13, and the main pipe 1 in the valve opening operation state, the operation is performed on the set feed shaft core X6 of the closing means B1. The shaft 31 is moved in an inclined state in which the axis of the shaft 31 is inclined, that is, the tip of the closing means B1 is slidably in contact with the inner peripheral surface of the working tube portion 4, the inner peripheral surface of the branch tube portion 2, etc. When the elastic closing body 35 is elastically deformed in the expanded state at the flow path closing position in the portion 2, the axis of the operation shaft 31 matches (or substantially matches) the set feed axis X6 of the closing means B1 and branches. The flow path of the pipe part 2 will be interrupted | blocked reliably.

  In short, the setting feed shaft core of the closing means B1 in which the bearing center of the bearing portion 32A that slidably supports the operation shaft 31 of the closing device B matches (or substantially matches) the branch axis X1 of the branch pipe portion 2. What is necessary is just to be X6.

  In the case where the closing means B1 of the closing device B is fed into the branch pipe portion 2, if the closing means B1 cannot be smoothly fed only by human force, for example, the closing work is performed as in the inner surface cleaning step. A forced feeding device that applies a forced feeding force to the operating shaft 31 across the locking portion provided on the case 30 and the locking portion provided on the receiving member 39 (for example, two locking hooks can be wound and fed out) It may be carried out by attaching a hand-wound winch equipped with a simple chain.

[7] FIG. 15 shows a branch pipe removing step of removing the branch pipe 3 of the branch pipe system connected to the connecting flange 2A of the branch pipe section 2, and FIG. 16 shows a branch from which the branch pipe 3 is removed. A pipe end closing process is shown in which a flange lid 50, which is a pipe end closing tool for closing the end opening of the branch pipe part 2 in a watertight state, is fixedly connected to the connection flange 2A of the pipe part 2 with bolts 16 and nuts 17.

[8] FIG. 17 shows a blockade in which the closing device B1 of the closing device B is pulled out to the downstream side of the working on / off valve 6 in a reduced diameter state and the closing device B is removed with the working on / off valve 6 closed. The apparatus removal process is shown.

  Specifically, when the diameter expansion operation nut 36 is screwed to the side loosened by human force, or when the hydraulic jack 37 is contracted by hydraulic pressure, the inner operation shaft 31B is moved with respect to the outer operation shaft 31A. The elastic blocking body 35 is elastically restored to the original reduced diameter state by the relative separation movement of the pressing members 33 and 34 accompanying this movement, and the blocking of the flow path of the branch pipe portion 2 is released.

  Next, of the fixing nuts 47 screwed into the thrust stop bolts 46 in a state in which both side surfaces of the receiving member 39 are clamped and fixed, the fixing nuts 47 positioned on the outer surface of the receiving member 39 are inserted into the thrust stop bolts 46. The movement preventing function to the outside by the movement preventing means D is released.

  After that, the closing means B1 at the flow path closing position in the branch pipe part 2 is passed through the main pipe 1, the insertion port 13, the work pipe part 4, and the work opening / closing valve 6 in the valve opening operation state. It is pulled out into the storage space S3, the valve body 6D of the work opening / closing valve 6 is closed, the closing flange 32 of the closing device B is removed from the closing work case 30, and the closing work case 30 is opened and closed. The joint flange 15 connected to the valve 6 is removed, and the joint flange 15 is removed from the connection flange 6C of the work on-off valve 6.

FIGS. 18 and 19 show a work opening sealing step in which the work opening sealing device E connected to the connection flange 6C of the work opening / closing valve 6 seals the tip opening of the work pipe portion 4 in a watertight state. FIG. 20 shows a step of removing the work opening sealing device E and the work opening / closing valve 6 after sealing the distal end opening of the work pipe portion 4.

Specifically, upstream of the sealed work case 52 provided with a storage space S4 in which the flange lid 51 that seals the opening at the tip end of the work tube portion 4 in a watertight state can be accommodated in the connecting flange 6C of the work on-off valve 6. The connecting flange 52A on the side is fixedly connected in a watertight state with the bolt 16 and the nut 17 in a state in which the case axis X7 of the sealing work case 52 is matched (or substantially matched) with the axis X2 of the work tube portion 4. ing.
An operation shaft 53 detachably connected to a mounting portion 51A on the outer side surface of the flange lid 51 is slidably supported along the case axis X7 in the connection flange 52B on the downstream side of the sealing work case 52. The connecting flange 54A on the upstream side of the sliding support case 54 is fixedly connected in a watertight state with the bolt 16 and the nut 17 and the connecting flange 54B on the downstream side of the sliding support case 54 and the operation shaft 53 are connected. A flange lid 51 located in the storage space S4 of the sealing work case 52 is applied to the connecting flange 4B of the work tube section 4 by applying a pushing force to the operation shaft 53 over the mounting rod 55 provided at the outer end. A feed bolt 56 </ b> A and a feed nut 56 </ b> B, which are examples of the feed means 56 for press contact, are provided.

  Then, as shown in the enlarged sectional view of FIG. 18, when the flange lid 51 comes close to the connection flange 4B of the work tube portion 4 by the operation of feeding the operation shaft 53 by the feed bolt 56A and the feed nut 56B, the connection flange 4B. The taper guide portion 11a of the guide bolt 11 screwed into the screw hole 4c is engaged with the screw hole 51a of the flange lid 51, and the connection positional relationship between the connection flange 4B of the work tube portion 4 and the flange lid 51 is determined. Determine.

  In this state, the guide bolt 11 is removed and, as shown in FIG. 19, the connection flange 4 </ b> B and the flange lid 51 of the work pipe portion 4 are fixedly connected in a watertight state with a normal bolt 9, and then the work on / off valve 6. The sealing work case 52 is removed from the connection flange 6 </ b> C, and the work on / off valve 6 is removed from the connection flange 4 </ b> B of the work pipe 4.

[Other Embodiments]
(1) The setting feed shaft core X of the punching tool A1 is offset within the dimension of the gap S formed between the outer periphery of the closing means B1 in the reduced diameter state and the inner peripheral surface of the working tube portion 4. In the first embodiment, when the center h is eccentric to the side away from the inner peripheral bottom surface 2a of the branch pipe part 2 with respect to the branch axis X1 of the branch pipe part 2, in the above-described first embodiment, the work pipe part 4 The axial center X2 of the branch pipe part 2 is biased toward the side away from the inner peripheral bottom surface 2a of the branch pipe part 2 by the eccentric margin of the setting feed axis X of the punching tool A1 with respect to the branch axis X1 of the branch pipe part 2. A drilling work case 14 capable of accommodating the punching tool A1 of the punching apparatus A is connected to the outer peripheral surface of the pipe wall of the main pipe 1 in a state of being cored, and the shaft of the working pipe part 4 is connected to the punching tool A1 of the punching apparatus A. Although connected in a concentric state with the core X2, the eccentric means (a) or (b) below may be adopted.
(A) The working pipe portion 4 is connected to the outer peripheral surface of the pipe wall of the main pipe 1 in a concentric state with the branch axis X1 of the branch pipe portion 2, and the working on-off valve 6 is connected to the punching device A. A piercing work case 14 that can accommodate the piercing tool A1 has a branch pipe whose case axis X3 is eccentric to the branch axis X1 of the piercing tool A1 with respect to the branch axis X1 of the branch pipe part 2 at an eccentricity h of the set feeding axis X The parts 2 are connected in an eccentric state to the side away from the inner peripheral bottom surface 2a.
(B) The working pipe portion 4 is connected to the outer peripheral surface of the pipe wall of the main pipe 1 in a concentric state with the branch axis X1 of the branch pipe portion 2, and the working on-off valve 6 is connected to the punching device A. A drilling work case 14 capable of storing the drilling tool A1 is connected to the branch pipe part 2 and the work pipe part 4 in a concentric state, and the punching device main body 18 is branched to the drilling work case 14 with its axial core branched. It connects with the branch axis X1 of the pipe part 2 in the state eccentrically shifted to the side away from the inner peripheral bottom face 2a of the branch pipe part 2 by the eccentricity h of the setting feed axis X of the punching tool A1.
In the case of the eccentric means (a) and (b) described above, the inner diameter of the working tube portion 4 is slightly larger than the inner diameter of the branch tube portion 2.

  (2) In setting the feeding axis X6 of the closing means B1 of the closing device B to a position that matches (or substantially matches) the branch axis X1 of the branch pipe portion 2, in the first embodiment described above, A closing work case 30 capable of accommodating the closing means B1 of the closing device B is detachably attached to the work opening / closing valve 6 in a concentric state with the work pipe portion 4, and the downstream side of the closing work case 30 is connected. A bearing portion 32A that slidably supports the operating shaft 31 of the closing device B in a penetrating state with respect to the closing flange 32 that is a plate portion, the bearing center of which is the setting feed shaft core X of the drilling tool A1. Although provided with the eccentricity equivalent to the eccentricity h in the state of being eccentric to the inner peripheral bottom surface 2a side of the branch pipe part 2 with respect to the work pipe part 4, The closing work case 30 has its case axis X5 set as the punching tool A1. An eccentric margin corresponding to the eccentric margin h of the insertion shaft core X is connected to the working tube portion 4 in an eccentric state toward the inner peripheral bottom surface 2a side of the branch tube portion 2, and the closing flange 32 is closed. The center of itself may be concentric with the case axis X5 of the closing work case 30, and the bearing center of the bearing portion 32A may be arranged at the center of the closing flange 32.

  (3) In the first embodiment described above, the construction for removing the fluid pipes and fluid devices of the branch piping system connected to the branch pipe section 2 has been described. The present invention can also be applied to a construction in which a part or the whole of a fluid pipe or a fluid device constituting the piping system is changed to a new fluid pipe or fluid device.

  (4) In the first embodiment described above, the operation shaft 31 of the closing device B is configured to be swingable with the sealing O-ring 32a provided in the bearing portion 32A as a fulcrum. The push-pull operation may be performed in a state in which the shaft core always matches (or substantially matches) the set feed shaft core X6 of the closing means B1.

(5) In the first embodiment described above, the inner peripheral bottom face 1a of the main pipe 1 and the inner peripheral bottom face 2a of the branch pipe portion 2 are arranged in a line or substantially flush with each other. The surface continuous portion where a part of the inner peripheral surface of the main pipe 1 and the inner peripheral surface of the branch pipe portion 2 are flush or substantially flush may be located on the upper side or the side portion of the main pipe 1.
In addition, when the said surface series installation location is located in the upper part of the main pipe 1, the inner peripheral ceiling surface of the horizontal main pipe 1 and the inner peripheral ceiling surface of the horizontal branch pipe part 2 are flush or substantially flush. In addition, when the surface continuous portion is located on the side of the main pipe 1, the branch pipe section 2 is connected to the horizontal main pipe 1 in the vertical direction. It becomes a form.

  (6) The drilling work case 14, the cleaning work case 25, and the closing work case 30 described in the first embodiment described above are the most suitable for the respective work conditions (the drilling work condition, the cleaning work condition, and the closing work condition). The drilling work case 14, the cleaning work case 25, and the closing work case 30 may be configured in the same structure in a state satisfying the respective work conditions. The case may be configured so that it can be used for drilling work, cleaning work, and closing work.

  In the present invention, even if a part of the inner peripheral surface of the pipe and the inner peripheral surface of the branch pipe portion are flush or substantially flush with each other, the operator can surely capture the completion of the drilling operation. In addition, the blocking means of the closing device can be smoothly used as a branch flow path blocking method for a fluid piping system that can smoothly block the flow path by smoothly feeding the blocking means into the branch pipe section.

A punching device A1 punching device B closing device B1 closing means D movement preventing means h eccentricity S gap X setting axis of punching tool feeding shaft core X1 branching shaft core X2 of branching tube portion shaft core X3 of working tube portion punching work case Case shaft core X5 Case shaft core X6 for closing work case Setting feed shaft core 1 for the closing means 1 Main pipe (water main)
2 Branch pipe section 2a Inner peripheral surface series location (inner peripheral bottom)
2b Base end opening 4 Working pipe part 6 Working on-off valve 13 Insertion port 14 Drilling work case 14B Downstream side connection part (connection flange)
18A Connection (connection flange)
20 Hole saw 20B Cutting action part (cutting tip)
21 Center drill 21A Cutting action part (cutting tip)
30 Closing work case 31 Operation shaft 32 Downstream side connecting part (closing flange)
32A Bearing part 40 Step part 50 Pipe end closing tool (flange cover)

Claims (7)

A branch pipe portion having a smaller diameter than a main pipe through which a fluid flows is continuously provided in a state in which a part of the inner peripheral surface thereof is flush or substantially flush with the pipe wall outer peripheral surface of the main pipe. A work tube portion connecting step for continuously connecting the work tube portion in a state opposite to the base end opening in the branch axis direction;
A piercing device is connected to the working on-off valve connected to the working pipe portion, and a piercing tool of the piercing device is fed through the working on-off valve and the working pipe portion, so that a base end opening of the branch pipe portion is provided. An insertion port forming step of forming an insertion port in the opposite main pipe wall;
A piercing device removing step of pulling out the piercing tool of the piercing device downstream from the work on-off valve, and removing the piercing device in a state in which the work on-off valve is closed;
A closing device connecting step for connecting a closing device having a closing means capable of switching between a diameter-expanded state and a diameter-reduced state capable of blocking the flow path of the branch pipe portion to the on-off valve;
With the closing means of the closing device reduced in diameter, it is sent to the flow path closing position in the branch pipe section through the insertion opening formed in the work opening / closing valve, working pipe section, and main pipe wall, and the closing means is expanded in diameter. A channel blocking step for switching to a state and blocking the channel;
A branch flow path blocking method for a fluid piping system comprising:
In the insertion port forming step,
The setting feed shaft core of the piercing tool of the piercing device is branched at an eccentric margin within the dimension of the gap formed between the outer periphery of the closing means in the reduced diameter state and the inner peripheral surface of the working tube portion. It is eccentric with respect to the branch axis of the pipe part on the side away from the surface series location of the inner peripheral surface of the branch pipe part,
In the closing device connecting step,
A branch flow path blocking method for a fluid piping system, characterized in that the set feed shaft core of the closing means of the closing device is set to a position that matches or substantially matches the branch shaft core of the branch pipe section. In the work tube portion connecting step, the work tube portion has an axial center of the branch tube portion that is offset by the eccentricity of the setting feed shaft core of the drilling tool with respect to the branch shaft core of the branch tube portion. It is connected to the outer peripheral surface of the pipe wall of the main pipe in a state where it is eccentric to the side away from the surface series location of the peripheral surface,
Further, in the insertion port forming step, a piercing work case that can accommodate a piercing tool of a piercing device is detachably attached to the work on-off valve, and a downstream connection portion of the piercing work case is attached to the work opening / closing valve. 2. The branch flow passage block of the fluid piping system according to claim 1, wherein the connecting portion of the punching device is detachably fixedly connected in a state where the set feed shaft core of the drilling tool is aligned with the shaft core of the working pipe portion. Method.   In the closing device connecting step, a closing work case capable of accommodating closing means of the closing device is detachably attached to the work opening and closing valve in a concentric state with the working pipe portion. The connecting portion on the downstream side of the work case is provided with a bearing portion that slidably supports the operating shaft of the closing device in a penetrating state, and the center of the bearing portion is offset corresponding to the eccentricity of the setting feed shaft core of the drilling tool. 3. The branch flow path block of the fluid piping system according to claim 2, wherein the core pipe is provided in a state where it is eccentric to the axially continuous portion of the inner peripheral surface of the branch pipe portion with respect to the shaft core of the work pipe portion. Method. A tube end closing step of removing a fluid pipe or a fluid device connected to the branch pipe portion after the flow path blocking step, and connecting a pipe end closure for closing the end opening of the branch pipe portion to the branch pipe portion; ,
The closing device removing step of pulling out the closing means of the closing device to the downstream side of the work on / off valve and removing the close device with the work on / off valve closed is provided. 2. A branch flow path blocking method for a fluid piping system according to item 1.   5. The movement blocking means for blocking the blocking means of the blocking device from moving downstream of the flow path blocking position in the branch pipe portion due to fluid pressure in the flow path blocking step. A branch flow path blocking method for a fluid piping system according to any one of the preceding claims.   The drilling tool of the drilling device includes a cylindrical hole saw and a center drill protruding forward from the cutting action part from the rotation center position of the base end of the hole saw, and the cutting action part of the center drill The drill protrusion length from the cutting action part of a hole saw to the dimension which the cutting action by the said hole saw is started after the said center drill penetrates the pipe wall of a main pipe. The branch flow path blocking method for the fluid piping system according to claim 1.   A tapered surface is formed at the distal end of the closing means of the closing device so as to get over the stepped portion between the inner peripheral surface of the working tube portion and the opening peripheral edge of the insertion port in the outer peripheral surface of the tube wall of the main tube. The method for blocking a branch flow path of a fluid piping system according to claim 3.

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