Valve Mounting Device

Abstract

To provide a means which enables a fluid in a fluid pipe to be discharged easily without leaking the fluid to the outside and enables change of the route and adjustment of the flow rate of water discharged etc.SOLUTION: A valve attachment device 3 is provided on a fluid pipe 1. A casing 10 is fixed to the fluid pipe 1 by a clamp 20 of the valve attachment device 3. A contact surface 13 of the casing 10 is placed in contact with an outer peripheral surface of the fluid pipe 1. A boring tool 30 in the casing 10 is protruded from the casing 10 through an opening 15 in the contact surface 13 to form a hole 1c in the fluid pipe 1. The fluid in the fluid pipe 1 flows into second fluid pipes 2 through a connector 51 with a valve 52 provided at the casing 10.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to an apparatus for attaching a valve to a fluid pipe, and more particularly to a valve attachment device suitable for changing the piping route of a fluid pipe through which a fluid, such as radioactive contaminated water, for which external leakage is strictly regulated, flows, or for cutting and removing the pipe after relieving the internal pressure.

Background Art

[0002] For example, at the Fukushima Daiichi Nuclear Power Plant, fluid pipes for transporting radioactive contaminated water are laid over a distance of several tens of kilometers. As the decommissioning work progresses, the fluid pipes are cut and removed or the route (flow path) is changed. When cutting or the like is performed, it is necessary to discharge the high-pressure contaminated water in the pipe without spilling it onto the floor or ground. Currently, the area around the location where the fluid pipe is to be cut is surrounded by multiple leak prevention covers, and temporary drainage facilities are installed to perform the cutting operation. Patent Document 1 describes cutting a pipe after crushing and blocking it.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The operation of covering the leak prevention cover is complicated and time-consuming. Also, if water starts to flow out from the cut portion of the fluid pipe, it is difficult to adjust the water discharge flow rate, and the water draining operation cannot be interrupted until the water discharge ends, and it is necessary to increase the number of workers and respond for a long time. In view of such circumstances, an object of the present invention is to provide a means capable of easily discharging, changing the route, adjusting the water discharge flow rate, etc. without leaking the fluid in the fluid pipe to the outside.

Means for Solving the Problems

[0005] To solve the aforementioned problems, the inventors conducted diligent research and consideration, and as a result conceived of installing a valve at a predetermined or arbitrary location in a fluid pipe to discharge the fluid inside the fluid pipe, change its route, adjust the flow rate of the discharged fluid, etc. The present invention is based on the above concept and is a device for installing a valve in a fluid pipe, A casing having a contact surface that forms a partially cylindrical concave surface that matches the outer surface of the fluid tube, with an inner chamber reaching the contact surface and forming an opening, The casing has the aforementioned valve and one or more connectors provided on the casing, A clamp for fixing the casing to the fluid tube such that the contact surface is pressed against the outer circumferential surface of the fluid tube, A drilling tool is housed and held within the casing, the drilling blade at its tip is retractable from the opening, and the connecting end opposite to the drilling blade is connected to a drive means, It is characterized by having the following features.

[0006] The aforementioned drilling tool is driven to create a hole in the fluid tube, thereby establishing communication between the fluid tube and the inside of the casing. Preferably, a second fluid pipe, such as a drain pipe, is connected to the valve. By operating the valve, the fluid in the fluid pipe can be discharged through the casing and the second fluid pipe, its route can be changed, or its flow rate can be adjusted. The valve can also be closed midway through the discharge process to interrupt the fluid discharge operation in the fluid pipe. After that, the valve can be opened to resume the discharge operation.

[0007] Preferably, the clamp comprises a drilling-side clamping body fixed to the casing, a receiving-side clamping body that clamps the fluid pipe between itself and the drilling-side clamping body, and a bolt and nut connecting these clamping bodies, with either the bolt or the nut fixed to either of the clamping bodies. The clamp and, consequently, the valve mounting device can be attached to the fluid pipe by tightening the bolts and nuts. By welding the bolts in place, there is no risk of the bolts falling out of the clamp before the nuts are fitted, and there is no need to prevent the bolts from rotating when tightening the nuts. Therefore, the installation work of the valve mounting device can be simplified, and the construction time can be significantly reduced. Consequently, when applied to decommissioning work at nuclear power plants, the radiation exposure of workers can be reduced.

[0008] Preferably, the contact surface is provided with an annular contact-side sealing member surrounding the opening, and the contact-side sealing member includes a cushion packing that can be compressed in the thickness direction. The contact-side sealing member prevents the fluid that exits the hole from leaking out between the outer surface of the fluid pipe and the valve mounting device. By using a cushion packing as the contact-side sealing member, the space between the outer surface of the fluid pipe and the valve mounting device can be reliably sealed without strictly controlling the tightening amount of the bolts and nuts.

[0009] Preferably, an annular internal sealing member that makes close contact with the drilling tool is provided on the inner circumferential surface of the casing opposite to the opening from at least one connector. The internal sealing member seals the space between the inner surface of the casing and the drilling tool, preventing fluid from leaking out from between the inner surface of the casing and the drilling tool. At least one connector is included, which is the connector closest to the opening along the axis of the casing.

[0010] The casing comprises a cylindrical first casing portion including the contact surface and at least one connector, and a cylindrical second casing portion positioned on the opposite side of the first casing portion from the opening and detachably connected to the first casing portion. Preferably, the drilling tool can be pulled out from the first casing portion toward the second casing portion, and the second casing is provided with a holding portion that holds the drilling tool in a manner that allows it to be driven. The drilling tool and the second casing can be reused for valve installation in other locations, thereby reducing costs.

[0011] Preferably, an intermediate valve is provided between the first casing portion and the second casing portion, which allows the insertion of the drilling tool when it is open and can be closed when the drilling tool is withdrawn. After the initial drilling, withdrawing the drilling tool and closing the intermediate valve can more effectively prevent fluid leakage.

[0012] It is preferable that a lid can be attached to the head end of the casing on the side opposite to the opening. The lid can more reliably prevent fluid leakage. The drilling tool may be removable from the head end, and the lid may be attached to the head end after removal. The connecting end of the drilling tool may protrude from the head end of the casing opposite to the opening and be detachably connected to the driving means, and a lid including a housing cylinder that accommodates the connecting end from which the driving means has been separated may be fitted to the head end. In this case, the lid can be fitted to the head end even if the drilling tool remains inside the casing. Alternatively, a cover may be fitted to the intermediate portion of the casing on the head end side of at least one connector, separated from the portion further toward the head end and the drilling tool. The portion further towards the head end from the intermediate section, and the drilling tool, can be reused for valve installation at other locations, thereby reducing costs. [Effects of the Invention]

[0013] According to the present invention, it is possible to easily discharge the fluid inside the fluid pipe, change its route, and adjust the outflow rate without causing the fluid to leak to the outside. [Brief explanation of the drawing]

[0014] [Figure 1]FIG. 1 is a side view showing a valve mounting device according to a first embodiment of the present invention installed in a fluid pipe. [Figure 2] FIG. 2 is a front cross-sectional view taken along line II-II of FIG. 1. [Figure 3] FIG. 3 is a plan view taken along line III-III of FIG. 2. [Figure 4] FIG. 4 is a bottom view of a casing, a drilling tool, and a drilling-side clamping body of the valve mounting device taken along line IV-IV of FIG. 2. [Figure 5] FIG. 5 is an enlarged cross-sectional view of a circular portion V in FIG. 2. [Figure 6] FIG. 6(a) is a cross-sectional view showing a state before using an abutting-side seal member of the clamp. FIG. 6(b) is a cross-sectional view showing a state in which the abutting-side seal member is in use. [Figure 7] FIG. 7 is a front cross-sectional view showing a state in which a hole is drilled in the fluid pipe. [Figure 8] FIG. 8 is a front cross-sectional view showing a state in which the valve mounting device has its drilling tool pulled out and is covered with a lid. [Figure 9] FIG. 9 is a front cross-sectional view showing a state in which the valve mounting device has its drilling tool left in place and is covered with a lid. [Figure 10] FIG. 10 is a front cross-sectional view showing a state in which the valve mounting device has its second casing portion and drilling tool removed and its first casing portion covered with a lid. [Figure 11] FIG. 11 is a side view showing a state in which valve mounting devices are provided at multiple locations on the fluid pipe. [Figure 12] FIG. 12 is a front cross-sectional view showing a state in which a valve mounting device according to a second embodiment of the present invention is installed in a fluid pipe. [Figure 13] FIG. 13 is a front cross-sectional view showing a state in which the valve mounting device of the second embodiment has its drilling tool removed and is covered with a lid. [Figure 14] FIG. 14 is a front cross-sectional view showing a state in which the valve mounting device of the second embodiment has its second casing portion and drilling tool removed and an intermediate valve covered with a lid.

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment (Figures 1-11)> As shown in Figure 1, for example, in a nuclear power plant undergoing decommissioning, a fluid pipe 1 for transporting radioactive contaminated water (fluid) is laid over a distance of several tens of kilometers. The material of the fluid pipe 1 is not particularly limited and may be resin or metal. Valve mounting devices 3 are installed at predetermined or arbitrary locations on the fluid pipe 1 in order to cut and remove the fluid pipe 1 or change its route (flow path) in accordance with the progress of the decommissioning work.

[0016] As shown in Figure 2, the valve mounting device 3 comprises a casing 10, a clamp 20, and a drilling tool 30. The casing 10 is formed in a cylindrical shape perpendicular to the fluid pipe 1. More specifically, as shown in Figure 2, the casing 10 includes a first casing section 11 on the side closer to the fluid pipe 1 and a second casing section 12 on the side further from the fluid pipe 1. Each casing section 11, 12 is formed in a generally cylindrical shape. These casing sections 11, 12 are arranged in a line on the same axis, with their opposing end faces abutting against each other and connected by bolts 14. By removing the bolts 14, the casing sections 11, 12 can be separated. In other words, the casing 10 can be divided in the middle of the axial direction (up and down direction in Figure 2). As shown in Figure 5, an annular sealing material 16 is provided between the opposing end faces of the casing sections 11, 12.

[0017] As shown in Figure 2, the end face of the first casing portion 11 facing the fluid pipe 1 constitutes a contact surface 13. The contact surface 13 is a partially cylindrical concave surface that matches the outer circumferential surface forming the cylindrical surface of the fluid pipe 1. The inner chamber 11b of the first casing portion 11 reaches the contact surface 13, forming an opening 15. The contact surface 13 is annular in shape, surrounding the opening 15.

[0018] As shown in Figure 4, a contact-side sealing member 41 is attached to the contact surface 13. The contact-side sealing member 41 is formed in a rectangular ring shape by assembling, for example, four straight sealing members in a "well" shape. The contact-side sealing member 41 may also be a circular ring. The annular contact-side sealing member 41 surrounds the opening 15.

[0019] As shown in Figure 6, the contact-side sealing member 41 includes a cushion packing 41a and adhesive layers 41b and 41c laminated on both sides thereof. The cushion packing 41a is compressible and deformable in the thickness direction. The back adhesive layer 41b laminated on the back surface of the cushion packing 41a is adhered to the contact surface 13. As shown in Figure 6(a), a release liner 41d is provided on the surface of the adhesive layer 41c laminated on the front surface of the cushion packing 41a facing the fluid pipe 1. As shown in Figure 6(b), when attached to the fluid pipe 1, the release liner 41d is peeled off and the adhesive layer 41c is adhered to the outer surface of the fluid pipe 1. The adhesive layer 41c may be omitted, and the cushion packing 41a may be in direct contact with the outer surface of the fluid pipe 1.

[0020] The second casing section 12 is positioned closer to the head end (opposite the opening) than the first casing section 11. An annular headpiece 19 is provided at the head end (upper end in Figure 2) of the second casing section 12.

[0021] As shown in Figures 2 and 3, one or more (in this case, three) connectors 51 are provided on the peripheral wall of the casing 10. Each connector 51 is formed in a cylindrical shape that protrudes radially from the casing 10. A valve 52 is provided at each connector 51, and a fluid pipe 2 is connected to it. The three (or more) valve-equipped connectors 51 are spaced apart from each other in the axial direction (up and down in Figure 2) of the casing 10.

[0022] When distinguishing between these connectors 51 with valves 52 and the fluid pipe 2, the designations A, B, and C are added to their respective reference numerals. As shown in Figure 2, the two lower (contact surface side) and middle connectors 51A and 51B and valves 52A and 52B are provided on the peripheral wall 11a of the first casing portion 11. The internal passages of the connectors 51A and 51B are connected to the inner chamber 11b of the first casing portion 10. The valves 52A and 51B open and close, or adjust the opening degree of, the corresponding connectors 51A and 51B, respectively.

[0023] An upper connector 51C is provided on the peripheral wall 12a of the second casing section 12. The internal passage of the connector 52C is connected to the inner chamber 12b of the second casing section 12. A valve 52C is provided on the connector 51C. The valve 52C opens and closes the connector 51C, or adjusts its opening degree.

[0024] As shown in Figure 3, the axes of the three connectors 51A, 51B, and 51C are oriented at different angles in the circumferential direction of the casing 10, but the present invention is not limited thereto. Note that the orientation of connectors 51A, 51B, and 51C in Figures 1 and 2, etc., disregards consistency with Figure 3 for illustrative purposes.

[0025] As shown in Figure 2, a clamp 20 is attached to the casing 10. The clamp 20 fixes the casing 10 to the fluid pipe 1, with the contact surface 13 facing the outer surface of the fluid pipe 1. The clamp 20 includes a pair of openable and closable perforating-side clamping bodies 21 and receiving-side clamping bodies 22, and a bolt 25 and nut 26 that fix these clamping bodies 21 and 22 together in a closed state. The clamp 20 opens when the clamping bodies 21 and 22 are separated or moved apart, and closes when the clamping bodies 21 and 22 come together. Unless otherwise specified, the clamp 20 will be assumed to be in the closed position.

[0026] As shown in Figure 2, the perforating-side clamping body 21 integrally has a contact plate 21a and a projection 21f. The contact plate 21a is formed in a semicircular shape. As shown in Figure 4, a fitting hole 21c is formed in the center of the contact plate 21a. Projections 21f protrude outward from both ends of the contact plate 21a. The end portion of the first casing portion 11 including the contact surface 13 (the lower end portion in Figure 2) is inserted into the fitting hole 21c and welded to the peripheral edge of the fitting hole 21c on the contact plate 21a. The inner surface of the contact plate 21a is continuous with the contact surface 13 without any step difference and constitutes an extension of the contact surface 13. The contact-side sealing member 41 may protrude from the inner surface of the contact plate 21a as part of the contact surface.

[0027] As shown in Figure 2, the receiving clamping body 22 integrally has a semicircular contact plate 22a and projections 22f protruding outward from both ends thereof. A pair of contact plates 21a and 22a are applied to the outer surface of the fluid pipe 1, respectively, so as to sandwich the fluid pipe 1 from both the upper and lower sides. The projections 21f and 22f on the same side are close to each other and facing each other. These projections 21f and 22f are connected by a bolt 25 and a nut 26. The head 25a of the bolt 25 is welded and fixed to the lower projection 22f of the projections 21f and 22f. The neck portion 25b of the bolt 25 is passed through the insertion hole 21g of the upper projection 21f, and a nut 26 is screwed onto it. In this way, the clamp 20 is fixed to the fluid pipe 1. Consequently, the casing 10 is fixed to the fluid pipe 1.

[0028] As shown in Figure 2, a drilling tool 30 is housed within the casing 10. The drilling tool 30 includes a shaft 31, a drilling blade 32, and a connecting projection 33 (connecting end). The shaft 31 is formed in a straight rod shape and is positioned on the axis of the casing 10. The casing 10 is provided with two stages of bearings 61 and 62 spaced apart in the axial direction. Specifically, bearings 61 and 62 are provided at both axial ends of the second casing section 12. These bearings 61 and 62 hold the shaft 31 so that it can rotate relative to the casing 10 and move up and down in the axial direction. The bearings 61 and 62 constitute a holding section that holds the drilling tool 30 in a manner that allows it to be driven. Preferably, as shown in Figure 5, annular bearing packings 63 (bearing seal members) are provided between the upper ends and lower ends of the outer and inner rings of the bearings 61 and 62, respectively.

[0029] As shown in Figure 2, the inner diameter of the inner chamber 11b of the first casing portion 11 is sufficiently larger than the outer diameter of the shaft 31 and, consequently, the drilling tool 30. The inner chamber 11b serves as a collection chamber for chips generated during drilling by the drilling tool 30. A drilling tool 32 is provided at the tip (lower end) of the shaft 31. The drilling tool 32 is composed of a drill coaxial with the shaft 31. As shown in Figures 2 and 7, the drilling tool 32 can extend and retract from the opening 15 as the shaft 31 moves up and down.

[0030] As shown in Figure 2, the handle end (upper end) of the shaft 31 protrudes from the head end (upper end) of the casing 10. A stopper 34 is provided on the outer circumference of the handle end of the shaft 31. The stopper 34 is formed in an annular shape and protrudes radially from the shaft 31. For example, a snap ring is used as the stopper 34. As shown in Figure 7, when the drilling tool 30 is lowered, the stopper 34 abuts against the head end of the casing 10. Specifically, the stopper 34 enters the headpiece 19 and abuts against the inner ring of the bearing 62. This restricts the height to which the drilling tool 30 can be lowered (the position to which it can move toward the tip). Consequently, the amount of protrusion of the drilling blade 32 from the opening 15 is restricted.

[0031] As shown in Figure 2, a connecting projection 33 is provided on the handle end face of the shaft 31. The connecting projection 33 is coaxial with the shaft 31 and protrudes from the shaft 31 toward the handle (upward in Figure 2). The electric drill body 4 (driving means) is detachably connected to the connecting projection 33. The drilling tool 30 can rotate at high speed relative to the casing 10 by driving the electric drill body 4.

[0032] The drilling tool 30 can be pulled out upward (towards the second casing portion) from at least the first casing portion 11 of the casing 10. Preferably, as shown in Figure 8, the drilling tool 30 can be separated from the casing 10 by pulling it upward from the head end of the casing 10.

[0033] As shown in Figures 2 and 5, annular internal sealing members 42 and 43 are provided inside the casing 10. The internal sealing members 42 and 43 are in close contact with the entire circumference of the outer surface of the shaft 31. This ensures a liquid-tight seal in the clearance between the inner surface of the casing 10 and the outer surface of the shaft 31. The internal sealing members 42 and 43 are oil seals, dust seals, or other lipped seals or labyrinth seals.

[0034] As shown in Figure 2, the two internal sealing members 42 and 43 are spaced apart in the axial direction of the casing 10. Specifically, the internal sealing members 42 and 43 are located close to the bearings 61 and 62 at both axial ends of the second casing portion 12, respectively, and are positioned inside the second casing portion 12 beyond the bearings 61 and 62. Therefore, the lower internal sealing member 42 is positioned on the head side (opposite side from the opening 15) of the connectors 51A and 51B. The upper internal sealing member 43 is positioned on the head side (opposite side from the opening 15) of the connector 51C.

[0035] As shown in Figures 8 to 10, the valve mounting device 3 is equipped with several types of covers 70, 71, and 72. One of these covers 70, 71, or 72 is selected according to the situation and attached to the casing 10, thereby closing the casing 10. As shown in Figures 8 and 10, the flat covers 70 and 71 are formed in a disc shape.

[0036] As shown in Figure 9, the convex lid 72 integrally comprises a lid edge 73 and a housing cylinder 74. The lid edge 73 is formed in an annular shape. The housing cylinder 74 is provided in the center of the lid edge 73. The housing cylinder 74 is formed in a cylindrical shape with an opening at the bottom and a closed top end, and protrudes upward from the lid edge 73.

[0037] The valve mounting device 3 is used as follows when cutting, removing, or changing the route of the fluid pipe 1. The valve mounting device 3 is installed at a predetermined or arbitrary location on the fluid pipe 1. Specifically, the pair of clamping bodies 21 and 22 of the clamp 20 are placed against the outer surface of the fluid pipe 1, sandwiching it from above and below. At this time, the bolt 25 is passed through the insertion hole 21g. Then, the nut 26 is tightened onto the bolt 25. Since the bolt 25 is welded and fixed to the receiving clamping body 22, there is no risk of it falling off, and there is no need to prevent the head 25a of the bolt 25 from rotating when tightening the nut 26. This allows the valve mounting device 3 to be easily and quickly attached to the fluid pipe 1. Furthermore, the installation work can be easily carried out even in narrow spaces. For example, the valve mounting device 3 can be installed in a space of about 100 mm in width. Therefore, the construction time can be significantly reduced, and the radiation exposure of workers can be reduced.

[0038] When applying the clamping body 21 to the fluid pipe 1, the release paper 41d should be peeled off beforehand. This allows the adhesive layer 41c of the contact-side sealing member 41 to adhere to the outer surface of the fluid pipe 1. Tightening the nut 26 compresses the cushion packing 41a of the contact-side sealing member 41 in the thickness direction. This ensures a reliable seal between the outer surface of the fluid pipe 1 and the valve mounting device 3, even without strictly controlling the amount of tightening of the nut 26.

[0039] Next, the electric drill body 4 is connected to the connecting projection 33, and the drilling blade 33 is lowered while rotating at high speed by the drive of the electric drill body 4, causing it to protrude from the opening 15. This creates a drill hole 1c in the fluid pipe 1 by the drilling blade 33. As the drilling tool 30 is lowered, the stopper 34 eventually hits the head end (upper end) of the casing 10, preventing further lowering. This prevents excessive pushing of the drilling tool 30 and avoids drilling a hole in the pipe wall 180° opposite to the drilled hole 1c in the fluid pipe 1. Therefore, it does not require a high level of skill from the operator. Afterward, the electric drill body 4 is separated from the connecting projection 33 of the drilling tool 30 and removed. The chips generated during drilling are collected in the inner chamber 11b of the first casing section 11. This prevents the chips from flowing into the second fluid pipe 2.

[0040] The fluid pipe 1 and the inner chamber of the casing 10 are connected through the aforementioned drilled hole 1c. Valve 52 is left open. This allows the radioactive contaminated water (fluid) in fluid pipe 1 to be discharged through the inner chamber of casing 10 and the second fluid pipe 2, or its route to be changed. The flow rate can also be adjusted by adjusting the opening of valve 52. The contact-side sealing member 41 prevents the radioactive contaminated water (fluid) from leaking out between the outer surface of the fluid pipe 1 and the valve mounting device 3.

[0041] Preferably, by opening one or both of the lower and middle valves 52A and 52B, the radioactive contaminated water (fluid) in the fluid pipe 1 is discharged or its route is changed from the inner chamber 11b of the first casing section 10 through the second fluid pipes 2A and 2B. This allows the fluid pipe 1 to be drained, or the water pressure inside the fluid pipe 1 to be reduced. As a result, it is possible to suppress the radioactive contaminated water from rising from the inner chamber 11b of the first casing section 11 and flowing into the inner chamber 12b of the second casing section 11. Even if the radioactive contaminated water tries to rise further from the inner chamber 11b of the first casing section 11, the internal sealing member 42 can prevent it from flowing into the inner chamber 12b of the second casing section 11.

[0042] More preferably, the upper valve 52C is also left open. This allows the radioactive contaminated water to be guided to the second fluid pipe 2C and discharged if it flows into the inner chamber 12b of the second casing section 11. Furthermore, the internal sealing member 43 prevents the radioactive contaminated water from rising any further. This allows for the discharge or rerouting of radioactive contaminated water without any leakage to the outside.

[0043] If the discharge of the radioactive contaminated water from the fluid pipe 1 takes a long time, the valve 52 can be closed midway through to interrupt the discharge process. Afterwards, the valve 52 can be opened to resume the discharge process.

[0044] As shown in Figure 8, after drilling the hole 1c, or when the discharge operation is interrupted, a flat cover 70 is attached to the head end (upper end) of the casing 10 as needed. In that case, first, the drilling tool 30 is pulled out upwards from the casing 10. Also, the headpiece 19 is removed. In place of the headpiece 19, the flat cover 70 is attached to the head end of the casing 10 by bolting it on. This closes the head end. The removed drilling tool 30 can be reused for drilling in other locations and even for valve installation work.

[0045] When it is desired to avoid exposing the drilling tool 30 to the outside of the valve mounting device 3, a convex cover 72 is used instead of the flat cover 70 (Figure 8), as shown in Figure 9. In this case, only the headpiece 19 is removed without pulling the drilling tool 30 out of the casing 10. The convex cover 72 is then attached to the head end of the casing 10 in place of the headpiece 19. That is, the convex cover 72 is placed over the head end while housing the connecting projection 33, which has been separated from the electric drill body 4, in the housing cylinder 74. The lid edge 73 of the convex cover 72 is bolted to the head end. This allows the head end to be closed while the drilling tool 30 remains inside the casing 10.

[0046] As shown in Figure 10, the second casing portion 12 may be separated from the first casing portion 11 together with the drilling tool 30. After separation, the end portion of the first casing portion 11 on the second casing portion side (the intermediate portion of the casing 10 on the head end side of at least one connector 51) is closed by attaching a flat cover 71. The same flat cover 71 as the flat cover 70 may be used.

[0047] As shown in Figure 11, the separated second casing portion 12 (the portion further towards the head end than the intermediate portion) and the drilling tool 30 can be reused for drilling and valve installation at other locations in the fluid pipe 1. This allows valves 52 to be installed at multiple locations separated in the axial direction of the fluid pipe 1. Cost reduction can be achieved by reusing the relatively expensive drilling tool 30 and the second casing section 12, which includes the internal sealing members 42, 43 and bearings 61, 62, for multiple valve installation operations.

[0048] As described above, the radioactive contaminated water inside the fluid pipe 1 is discharged, or the internal pressure is sufficiently reduced, after which the fluid pipe 1 is cut and removed or its route is changed. This ensures that the scattering of radioactive contaminated water during cutting is avoided.

[0049] Next, other embodiments of the present invention will be described. In the following embodiments, components that overlap with those described above are denoted by the same reference numerals in the drawings and their descriptions are omitted. <Second Embodiment (Figures 12-14)> As shown in Figure 12, in the valve mounting device 3B according to the second embodiment, an intermediate valve 80 is interposed between the first casing portion 11 and the second casing portion 12 of the casing 10. The intermediate valve 80 is configured as a manually operated gate valve.

[0050] More specifically, the intermediate valve 80 comprises a valve body 81, a valve element 82, a valve stem 83, and a handle 84. The valve body 81 is formed in a generally circular box shape with openings at both the upper and lower ends. The lower end of the valve body 81 is connected to the first casing portion 11 by bolting via an annular connecting piece 17. The upper end of the valve body 81 is connected to the second casing portion 12 by bolting via an annular connecting piece 18. In the valve mounting device 3B, an internal sealing member 42 is provided in the connecting piece 18. Although the internal sealing member 43 on the head end side (see Figure 2) is omitted, an internal sealing member 43 may be provided in the second casing portion 12.

[0051] A valve body 82 is housed inside a valve casing 81. The valve body 82 is connected to and supported by a valve stem 83. The valve stem 82 extends in a direction perpendicular to the axial direction of the casing 10 and protrudes from the valve casing 81, with a handle 84 provided at its protruding end. By turning the handle 84, the valve stem 83 and thus the valve body 82 move forward and backward in the aforementioned perpendicular direction, causing the valve body 82 to seat on and off a seat portion 85 on the inner surface of the valve casing 81. This opens and closes the intermediate valve 80.

[0052] As shown in Figure 12, the valve body 82 in the dismounted state does not interfere with the drilling tool 30, and the intermediate valve 80 in the open state allows the drilling tool 30 to be inserted. This allows the drilling tool 30 to be driven and drilled into the fluid pipe 1.

[0053] As shown in Figure 13, for example, when the head end of the casing 10 is closed due to an interruption in discharge work, the piercing tool 30 is withdrawn. This allows the valve body 82 to seat on the valve seat 85 and close the intermediate valve 80. A cover 70 is provided at the head end (upper end) of the casing 10. According to the second embodiment, in addition to the cover 70, closing the intermediate valve 80 can more reliably prevent leakage of radioactive contaminated water (fluid).

[0054] As shown in Figure 14, the second casing portion 12 and the connecting piece 18 may be separated from the intermediate valve 80 together with the drilling tool 30. In this case, the separated intermediate valve 80 is closed by providing a flat cover 71 at the end of the second casing portion (the intermediate portion on the head end side of at least one connector 51 in the casing 10). The separated second casing portion 12 and connecting piece 18 (the portion further towards the head end than the intermediate portion), as well as the drilling tool 30, can be reused for valve installation at other locations, as in the first embodiment.

[0055] The present invention is not limited to the embodiments described above, and various modifications can be made without departing from its spirit. For example, the number of connectors 51 with valves 52 in the valve mounting device is not limited to three; it may be one, two, or four or more. The first casing portion 11 is provided with at least one connector with a valve, including the connector 51A with a valve 52A closest to the opening 15. In the clamp 20, the nut 26 may be fixed to either the clamping body 21 or 22 by welding or the like, or the nut 26 may be tightened by turning a bolt 25 around it. A female screw hole for the nut may be formed in either the clamping body 21 or 22. This valve mounting device can also be installed at the lower end of a U-shaped bend in a fluid pipe and used as a drain pipe. The fluid inside the fluid tube may be a gas. The casing is not limited to a cylindrical shape; it may also be box-shaped. The casing is not limited to two stages; it may have one stage, or it may have three or more stages. [Industrial applicability]

[0056] This invention can be applied, for example, to the decommissioning work of a nuclear power plant. [Explanation of Symbols]

[0057] 1 Fluid tube 1c Drill hole (hole) 2,2A~2C drain pipe 3.3B Valve mounting device 4. Electric drill body 10 Casing 11. First Casing Section 11a Surrounding wall 11b Inner room 12. Second Casing Section 12a Peripheral wall 12b Inner room 13 Contact surface 15 Aperture 20 clamps 21 Perforation side clamping body 21a Contact plate 21c mating hole 21f protrusion 21g insertion hole 22 Receiving clamping body 22f protrusion 25 volts 25a head 25b Lower neck 26 nuts 30 Drilling tool 32 Perforating blades 33. Connecting projection (connecting end) 34 Stopper 41 Contact-side sealing member 41a Cushion packing 41b,41c Adhesive layer 41d Release paper 42,43 Internal sealing member 51, 51A~51C connectors 52, 52A~52C valves 61,62 Bearings 63 Bearing packing (bearing sealing component) 70,71 Flat lid (lid) 72 Convex lid (lid) 73 Lid edge 74. Storage cylinder section 80 Intermediate valve

Claims

1. 1. An apparatus for attaching a valve to a fluid conduit, comprising: a casing having a contact surface that is a partially cylindrical concave surface that matches the outer circumferential surface of the fluid pipe, and an opening formed in an inner chamber that reaches the contact surface; one or more connectors having the valve and provided on the casing; a clamp that fixes the casing to the fluid pipe such that the abutment surface is applied to an outer circumferential surface of the fluid pipe; a drilling tool that is housed and held in the casing, has a drilling blade at its tip that can be protruded and retracted through the opening, and has a connection end opposite to the drilling blade that is connected to a drive means; A valve mounting device comprising:

2. The valve mounting device described in claim 1, characterized in that the clamp has a drilling-side clamp fixed to the casing, a receiving-side clamp that clamps the fluid pipe between the drilling-side clamp, and a bolt and nut that connect these clamps, and the bolt or the nut is fixed to either one of the clamps.

3. a ring-shaped contact-side seal member surrounding the opening is provided on the contact surface; 3. The valve mounting device according to claim 1, wherein the contact side seal member includes a cushion packing that is compressible in a thickness direction.

4. The valve mounting device according to any one of claims 1 to 3, characterized in that an annular internal seal member that fits tightly against the drilling tool is provided on the inner surface of the casing on the opposite side of the opening from at least one connector.

5. the casing has a cylindrical first casing portion including the abutment surface and at least one connector, and a cylindrical second casing portion disposed on the opposite side of the first casing portion from the opening and separably connected to the first casing portion, A valve mounting device as described in any one of claims 1 to 6, characterized in that the drilling tool can be pulled out from the first casing portion toward the second casing portion, and the second casing is provided with a holding portion that holds the drilling tool so as to allow it to be driven.

6. A valve mounting device as described in any one of claims 1 to 5, characterized in that an intermediate valve is provided between the first casing portion and the second casing portion, the intermediate valve allowing the insertion of the drilling tool in an open state and being closable when the drilling tool is withdrawn.

7. A valve mounting device as described in any one of claims 1 to 6, characterized in that a lid can be attached to the head end of the casing opposite the opening, or a lid can be attached to an intermediate portion of the casing closer to the head end than at least one connector, separated from the portion further toward the head end than the intermediate portion and from the drilling tool.

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