JP6896470B2 - How to install the butterfly valve in the flow path switchgear, and the flow path switchgear - Google Patents

Description

The present invention relates to a method of installing a butterfly valve in a flow path switchgear and a flow path switchgear.

In a fluid pipeline composed of a plurality of fluid pipes connected to each other, work such as repair or replacement may be performed on a predetermined fluid pipe. In such a case, the fluid pipe may be cut in an uninterrupted state on both sides of the predetermined section to be constructed, a butterfly valve may be installed in the cut portion, and a bypass flow path may be temporarily provided to perform the construction. Widely known. The butterfly valve includes a tubular valve housing that faces the pipe axis direction and a valve body that is rotatable by a valve shaft that is rotatably attached to the valve housing, and by operating the valve shaft. The valve body rotates so that the opening of the valve housing can be opened and closed.

As an example of the flow path switching device, as shown in Patent Document 1, the outer peripheral surface of the fluid pipe is surrounded by a housing in a sealed shape, and the fluid pipe is cut in the circumferential direction using a cutting tool in the housing. There is something like cutting a butterfly valve at the cutting part. Since this butterfly valve has a thin width dimension in the pipe axis direction of the valve housing, the cutting portion formed in the fluid pipe is in the pipe axis direction so that the cutting surface is close to the valve housing. Since it is sufficient to form the width narrowly, it is not necessary to use a butterfly valve and a large housing for covering the cutting portion, and the flow path opening / closing device can be formed compactly.

Japanese Unexamined Patent Publication No. 2005-147219 ([0018], [0027], FIG. 20)

In the conventional flow path switchgear, the installation work is performed while releasing the pressure of the fluid flowing through the fluid pipe by opening the valve body when the butterfly valve is installed on the cutting part in the uninterrupted state. It was. However, in the flow path opening / closing device as in Patent Document 1, the cutting portion is formed so that the cutting surface is close to the valve housing, so that the valve body cannot be greatly opened. , It was difficult to install the butterfly valve in the uninterrupted state because it is greatly affected by the fluid.

The present invention has been made by paying attention to such a problem, and provides a method of installing a butterfly valve in a flow path switchgear that facilitates installation work of a butterfly valve in a continuous flow state, and a flow path switchgear. The purpose is.

In order to solve the above problems, the method of installing the butterfly valve in the flow path switchgear of the present invention is
This is an installation method in which the butterfly valve is installed in a continuous flow state in a flow path switchgear that opens and closes the flow path of a fluid pipe.
In a housing that is hermetically fitted to a predetermined location of the fluid pipe, a first cutting portion that is cut by an end mill and extends in the circumferential direction of the fluid pipe and a first cutting portion that is cut by an end mill and continuously connected to the first cutting portion A cutting process for forming a cutting portion including a second cutting portion extending in the pipe axis direction of the fluid pipe so as to intersect with each other.
In the housing, the cutting portion is such that the valve housing of the butterfly valve passes through the first cutting portion and the valve body in an open state with the valve housing opened passes through the second cutting portion. It is characterized by having a valve installation step of installing the butterfly valve.
According to this feature, apart from the first cutting part for inserting the valve housing, the second cutting part along the pipe axis direction of the fluid pipe is provided so that the valve body in the open state with the valve housing opened can pass through. By using an end mill, it is possible not only to maintain the structural strength of the fluid pipe by minimizing the area of the cutting part, but also to keep the valve body wide open toward the pipe axis of the fluid pipe. Since the butterfly valve can be installed, the flow in the pipe is not blocked when the valve is installed, and the influence of the fluid on the valve body is reduced, so that the butterfly valve installation work can be easily performed.

In the cutting step, the first cutting portion and the second cutting portion are characterized in that they are cut by the same end mill.
According to this feature, it is not necessary to increase the size of the means for forming the cutting portion, and the first cutting portion and the second cutting portion can be easily formed by using the same end mill.

In the cutting step, at least one of the first cutting portion and the second cutting portion is cut to a width larger than the diameter of the end mill.
According to this feature, since the diameter of the end mill can be reduced, not only the cutting device can be made compact, but also the cutting resistance can be reduced.

In order to solve the above problems, the flow path opening / closing device of the present invention is used.
A flow path switching device including a housing that is hermetically fitted to a predetermined position of a fluid pipe and a butterfly valve that is installed in a cutting portion formed in the fluid pipe in the housing.
The cutting portion is cut by an end mill and extends in the circumferential direction of the fluid pipe so that the valve housing of the butterfly valve can pass through the first cutting portion, and the cutting portion is cut by the end mill and continuously intersects with the first cutting portion. It is characterized in that it includes a second cutting portion that extends in the direction of the pipe axis of the fluid pipe and allows the valve body in the open state to pass through with the valve housing opened.
According to this feature, apart from the first cutting part for inserting the valve housing, the second cutting part along the pipe axis direction of the fluid pipe is provided so that the valve body in the open state with the valve housing opened can pass through. By using an end mill, it is possible not only to maintain the structural strength of the fluid pipe by minimizing the area of the cutting part, but also to keep the valve body wide open toward the pipe axis of the fluid pipe. Since the butterfly valve can be installed or removed, the influence of the fluid on the valve body is reduced without blocking the flow in the pipe when installing or removing the valve, and it is easy to install or remove the butterfly valve. ..

The second cutting portion is characterized in that it is provided on the working opening side of the housing in the fluid pipe.
According to this feature, the butterfly valve can be installed or removed through the working opening without moving the housing.

The second cutting portion is characterized by having a tapered cutting surface that expands in the outer diameter direction of the fluid pipe.
According to this feature, the tapered cutting surface can be used as a guide surface when installing the butterfly valve.

(A) is a partial side sectional view showing the flow path opening / closing device in the first embodiment, and (b) is also a partial front sectional view. (A) is a partial front sectional view showing a state in which the housing and the end mill are attached at an angle to one of the circumferential directions of the fluid pipe, and (b) is a state in which the housing and the end mill are attached at an angle to the other in the circumferential direction. It is a partial front sectional view showing. (A) is a partial side sectional view showing a state in which the cutting means and the first moving device are attached to the housing, and (b) is a sectional view taken along the line AA. (A) to (c) are explanatory views which show the procedure of forming the 2nd cutting part. (A) is a partial side sectional view showing a state in which the cutting means and the second moving device are attached to the housing, and (b) is a sectional view taken along line BB. It is a side sectional view which shows the 2nd moving device. (A) to (c) are explanatory views which show the procedure of forming the 1st cutting part. It is a partial side sectional view which shows the state which attached the offset moving device to a housing. (A) is a side sectional view showing a state in which the repair valve device is removed from the housing, and (b) is a CC sectional view. (A) is a side sectional view showing a state in which a butterfly valve is installed in a cutting portion, and (b) is a C'-C'cross-sectional view. (A) is a top view showing a modified example of Example 1, and (b) is also a partial front sectional view. (A) to (c) are explanatory views which show the 1st moving device in Example 2. FIG. (A) to (c) are explanatory views which show the modification of Example 2. FIG. It is explanatory drawing which shows the modification of the formation procedure of the 2nd cutting part. It is explanatory drawing which shows another modification of the formation procedure of the 2nd cutting part.

A method of installing a butterfly valve in the flow path switchgear according to the present invention and a mode for implementing the flow path switchgear will be described below based on Examples 1 and 2. For convenience of explanation, the left side of the paper surface of FIG. 1A is the upstream side of the fluid pipe, and the right side is the downstream side.

The method of installing the butterfly valve in the flow path switchgear according to the first embodiment and the flow path switchgear will be described with reference to FIGS. 1 to 11.

The fluid pipeline used as a water supply is configured by connecting a plurality of connecting members such as a plurality of fluid pipes and valves (only the fluid pipe 1 is shown in the figure) and is buried in the ground. A plurality of branch pipes (not shown) are connected to the fluid pipeline, and these branch pipes are laid in each home / facility.

As shown in FIG. 1, the fluid tube 1 is made of ductile cast iron, is formed in a substantially circular shape in cross section, and its inner peripheral surface is covered with an epoxy resin layer 1a. The fluid pipe according to the present invention may be made of other metals such as cast iron or steel, or may be made of concrete, vinyl chloride, polyethylene, polyolefin, or the like. Furthermore, the inner peripheral surface of the fluid pipe is not limited to the epoxy resin layer, and may be coated with, for example, mortar, or an appropriate material may be coated on the inner peripheral surface of the fluid pipe by powder coating.

The flow path switchgear 2 is a predetermined fluid pipe 1 on the upstream side of the specific fluid pipe to be constructed when the specific fluid pipe is repaired or replaced due to a defect such as deterioration over time. It is installed at a location and is used to temporarily shut off the fluid in the fluid pipe 1. Due to the arrangement of the flow path opening / closing device 2 in this way, the fluid is connected to a specific fluid pipe in the fluid pipe. Since it can be operated so that the fluid does not flow down, it is possible to perform work such as removing or repairing the pipe portion of a specific fluid pipe. Further, when the flow path opening / closing device 2 is installed, it is introduced into the fluid pipe 1 in an uninterrupted state in consideration of the convenience of the supply area. In this embodiment, the fluid in the fluid pipe is clean water, but it is not limited to the clean water in this embodiment, for example, industrial water, agricultural water, sewage, gas or a gas-liquid mixture of gas and liquid. It doesn't matter if there is.

First, the structure of the flow path opening / closing device 2 will be described with reference to FIGS. 1, 9 and 10. The flow path switching device 2 is installed in a housing 3 that is hermetically fitted to a predetermined position of the fluid pipe 1, a cutting portion 10 provided in the fluid pipe 1 in the housing 3, and a cutting portion 10. It is mainly composed of a butterfly valve 4. As will be described in detail later, the cutting portion 10 includes a first cutting portion 11 extending in the circumferential direction of the fluid pipe 1 and a second cutting portion 12 extending in the pipe axial direction of the fluid pipe 1.

The housing 3 can be divided into two upper and lower parts including a first divided housing 31 and a second divided housing 32. The housing 3 has a cylindrical shape having an inner diameter larger than the outer diameter of the fluid pipe 1, and annular sealing members 5 and 5 are arranged on the inner peripheral surfaces of both front and rear ends of the housing 3. When the housing 3 is fitted onto the fluid pipe 1, the sealing members 5 and 5 are pressed in a sealed manner between the inner surface of the housing 3 and the outer surface of the fluid pipe 1. .. The housing 3 is not limited to the two divisions, and may be divided into three or more portions.

Further, the housing 3 is formed with recesses 3A capable of accommodating the outer peripheral edge of the valve housing 41 described later in the butterfly valve 4 in the circumferential direction. The first divided housing 31 is formed with a branch portion 31A extending upward, and the branch portion 31A is formed with a working opening 31B communicating with the inside of the housing 3.

The butterfly valve 4 is rotatable by a valve housing 41 having a substantially circular opening 41a facing the pipe axis direction, a valve shaft (not shown) rotatably attached to the valve housing 41, and a valve shaft. It includes a valve body 43. Specifically, the valve housing 41 includes an upper lid portion 41A that can come into contact with the inner peripheral surface of the branch portion 31A, and a partition wall portion 41B that extends downward from the upper lid portion 41A and is orthogonal to the fluid pipe 1. The opening 41a is formed in the partition wall portion 41B. A seal member 6 is fitted to the peripheral edge of the upper lid portion 41A, and the seal member 6 is pressed into the inner peripheral surface of the branch portion 31A in a sealed manner when the butterfly valve 4 is installed. Further, the peripheral edge portion of the partition wall portion 41B is housed in the recess 3A of the housing 3, and the seal member 7 is fitted, and the seal member 7 is pressure-welded to the inner peripheral surface of the recess 3A in a sealed manner. Will be done.

The valve shaft extends orthogonally in the vertical direction so as to pass through the center of the opening 41a. A valve seat portion 41b is formed on the inner peripheral surface of the opening 41a. A speed reducer 42 is attached to the upper end of the valve shaft so as to project from the work opening 31B to the outside of the housing 3, so that the valve body 43 can be opened and closed with a small torque.

Further, the valve body 43 has a flow stop surface for stopping the flow of the fluid, and the open position (see FIG. 1) in which the stop surface is arranged along the pipe axis of the fluid pipe 1 and the fluid pipe 1 It is rotatable to and from the closed position (not shown) arranged orthogonal to the tube axis of. That is, the valve body 43 can be rotated to open and close the opening 41a by operating the valve shaft. More specifically, when the stop surface of the valve body 43 is arranged orthogonal to the pipe axis of the fluid pipe 1, the outer peripheral surface of the valve body 43 is pressed against the valve seat portion 41b, so that the opening 41a is sealed. Can be closed.

Further, in the circumferential direction of the flange portion of the branch portion 31A, a plurality of retaining bolts 8, 8, ... By locking the bolts 8, 8, ... To the upper end edge of the upper lid portion 41A, the butterfly valve 4 is prevented from being separated from the working opening 31B. A lid member 9 is hermetically attached to the flange portion of the branch portion 31A.

Movement restricting members 60, 60 fixed to the outer peripheral surface of the fluid pipe 1 are arranged on both ends of the flow path opening / closing device 2 configured in this manner in the pipe axial direction. 60 regulates the flow path opening / closing device 2 from moving in the direction of the pipe axis of the fluid pipe 1. Specifically, the movement restricting member 60 is composed of two members divided into upper and lower parts, and a plurality of screws 60a capable of advancing and retreating in the radial direction of the movement restricting member 60 are arranged in the circumferential direction. It can be firmly attached by advancing in the inner diameter direction and biting into the outer peripheral surface of the fluid pipe 1. Further, the movement restricting member 60 has a hook-shaped locking portion 61 that fits outside a part of the convex portion 3a protruding toward the outer diameter side in the circumferential direction of the housing 3, and the movement restricting member 60. It is regulated that the housing 3 is separated from the housing 3 in the pipe axis direction. The movement restricting member 60 is not limited to the two divisions, and may be divided into three or more members. Further, the number of screws 60a is not limited to the number shown in the figure, and is set to an appropriate number.

Next, a method of installing the flow path opening / closing device 2 will be described with reference to FIGS. 2 to 10.

As shown in FIGS. 2 (a) and 3 (a), first, the housing 3 is fitted in a sealed shape at a predetermined position of the fluid pipe 1, and the cutting device 20 and the repair valve are fitted to the housing 3. The device 70 and the first moving device 50 are attached.

The cutting device 20 rotates an end mill 21 capable of cutting on both the front end surface and the outer peripheral surface, a rod 22 connected above the end mill 21, a guide body 23 for guiding the rod 22 in the vertical direction, and the end mill 21. It includes a rotation motor 25 for driving, an operation end portion 22a for manually advancing and retreating the rod 22 in the vertical direction, and a tubular connecting body 24 connected to the upper part of the repair valve device 70. The end mill 21 is housed in the connecting body 24, the rod 22 penetrates the connecting body 24, and the guide body 23, the rotating motor 25, and the operating end 22a are arranged outside the connecting body 24. Although the driven operating end 22a is illustrated as a means for moving the rod 22 up and down in the vertical direction, for example, the rod 22 may be moved up and down by a driving force of a motor or the like.

The repair valve device 70 includes a ball valve 71 having a valve housing and a ball-shaped valve body having an opening, and a plate-shaped body 72 fixed below the ball valve 71, in the branch portion 31A. Is inserted into. The ball valve 71 can be switched between an open state in which the opening faces in the vertical direction and a closed state in which the opening faces in the front-rear or left-right direction by operating the valve body with the handle 73. Further, the plate-shaped body 72 includes a side wall portion 72a that extends substantially horizontally so as to close the work opening 31B and extends upward along the inner peripheral surface of the branch portion 31A from the outer peripheral edge thereof, and is in an advanced state. The repair valve device 70 is connected to the branch portion 31A by locking the retaining bolts 8, 8, ... To the upper end portion of the side wall portion 72a. An annular sealing member 74 is press-contacted between the outer peripheral surface of the side wall portion 72a of the plate-shaped body 72 and the inner peripheral surface of the branch portion 31A (see FIG. 4), whereby the housing 3 is sealed. Will be done.

As shown in FIG. 2A, the housing 3, the cutting device 20, and the repair valve device 70 are predetermined clockwise with respect to the virtual line H in the vertical vertical direction, which is one of the circumferential directions of the fluid pipe 1. It is attached to the fluid pipe 1 in a first inclined state with an angle α (5 ° in this embodiment).

The first moving device 50 is arranged with a fixing jig 51 fixed at a position separated from the flow path opening / closing device 2 on the outer peripheral surface of the fluid pipe 1 and parallel to the fluid pipe 1 from the fixing jig 51. The hydraulic jack 52 and the side cross-sectional view U-shape that is provided at the tip (downstream side) of the hydraulic jack 52 and is externally fitted to a part of the convex portion 3a that protrudes toward the outer diameter side in the circumferential direction of the housing 3. 53 (see FIG. 3B) and the fitting member 53 of the above. Specifically, the fixing jig 51 is composed of two members divided into upper and lower parts, and a plurality of screws 54, 54, ... That can advance and retreat in the radial direction of the fixing jig 51 are formed in the circumferential direction. , Each screw 54, 54, ... Is advanced in the inner diameter direction and bites into the outer peripheral surface of the fluid pipe 1 so that it can be firmly attached. Then, by expanding and contracting the hydraulic jack 52, the flow path opening / closing device 2 can be moved in the pipe axis direction of the fluid pipe 1. That is, the first moving device 50 functions as a means for moving the cutting means in the pipe axis direction of the fluid pipe 1. The fixing jig 51 is not limited to the two divisions, and may be divided into three or more members. Further, the number of screws 54 is not limited to the number shown in the figure, and is set to an appropriate number.

When the first moving device 50 is attached, the expansion / contraction stroke of the hydraulic jack 52 is attached at an intermediate position, that is, the distance between the fixing jig 51 and the fitting member 53 is an intermediate distance, and the first moving device 50 is attached. When operating the moving device 50, the fixing jig 51 and the fitting member 53 are moved to the state where they are closest to each other, that is, the proximity limit distance, and then the fixing jig 51 and the fitting member 53 are operated. It is operated until the distance from and is the farthest, that is, the state of the separation limit distance is reached. That is, the distance at which the first moving device 50 moves the cutting device 20 (end mill 21) in the pipe axis direction of the fluid pipe 1 is equal to the expansion / contraction allowance of the hydraulic jack 52. Furthermore, the hydraulic jack 52 and the fitting member 53 may be provided one or two or more in the circumferential direction of the fixing jig 51, respectively, and can be freely changed according to the weight and shape of the flow path opening / closing device 2. can do.

Further, in the present embodiment, the hydraulic jack 52 is exemplified as a means for applying a moving force in the pipe axis direction to the housing 3, but the present invention is not limited to this, and the housing 3 is directed in the pipe axis direction. It may be a member that can give a moving force of the above, and may be, for example, a member that expands and contracts in the pipe axis direction by a screw.

Next, the cutting process for forming the cutting portion 10 will be described. First, in the first inclined state of the housing 3, the cutting device 20 and the repair valve device 70 shown in FIG. 2A, the ball valve 71 is opened, the end mill 21 is rotated, and FIG. As shown in a), the rod 22 is lowered and cut so as to penetrate the side wall of the fluid pipe 1 in the orthogonal direction at the tip surface of the end mill 21. At this time, the fluid in the fluid pipe 1 flows into the housing 3, but as described above, since the housing 3 is sealed, it is possible to prevent the fluid from flowing out of the housing 3. When cutting, the drain valve (not shown) is opened to discharge chips.

Next, as shown in FIG. 4B, the above-mentioned first moving device 50 is operated until the fixing jig 51 and the fitting member 53 are in a state of the proximity limit distance, and the fixing jig 51 is fitted with a housing. Attract 3 As a result, the cutting device 20 is moved together with the housing 3 in the pipe axis direction of the fluid pipe 1, and the side wall of the fluid pipe 1 is cut along the pipe axis direction by the outer peripheral surface of the end mill 21.

Then, as shown in FIG. 4C, when the first moving device 50 is operated until the fixing jig 51 and the fitting member 53 are in the state of the separation limit distance, the first moving device 50 is operated in the pipe axis direction with a predetermined dimension. One cutting surface 12a of the extending second cutting portion 12 is formed. After that, the first moving device 50 is operated until the end mill 21 is located at the central portion in the longitudinal direction of the second cutting portion 12 (the fixing jig 51 and the fitting member 53 are moved in a direction close to each other). Then, it is preferable to temporarily retract the end mill 21, but the end mill 21 may be moved to the next step without being retracted.

Next, the housing 3, the cutting device 20, and the repair valve device 70 are moved from the first inclined state shown in FIG. 2 (a) to the virtual line H in the vertical vertical direction as shown in FIG. 2 (b). On the other hand, the fluid tube 1 is reattached to the fluid tube 1 in a second inclined state in which the fluid tube 1 is swung by a predetermined angle −α (−5 ° in this embodiment) counterclockwise, which is the other side in the circumferential direction.

Next, in the second inclined state of the housing 3, the cutting device 20 and the repair valve device 70 shown in FIG. 2B, the end mill 21 is rotated and the rod 22 is lowered in the same manner as described above. Then, the tip surface of the end mill 21 is cut so as to penetrate the side wall of the fluid pipe 1 in the orthogonal direction (see FIG. 4A).

Next, the first moving device 50 described above is operated until the fixing jig 51 and the fitting member 53 are in the state of the proximity limit distance, and the housing 3 is attracted to the fixing jig 51. As a result, the cutting device 20 is moved together with the housing 3 in the pipe axis direction of the fluid pipe 1, and the side wall of the fluid pipe 1 is cut along the pipe axis direction by the outer peripheral surface of the end mill 21 (see FIG. 4B). ).

Then, when the first moving device 50 is operated until the fixing jig 51 and the fitting member 53 reach the state of the separation limit distance, the other cutting surface of the second cutting portion 12 extending in the pipe axis direction with a predetermined dimension. 12a is formed (see FIG. 4C). After that, the first moving device 50 is operated until the end mill 21 is located at the central portion in the longitudinal direction of the second cutting portion 12.

In FIG. 5B, the configuration of the repair valve device 70 and the cutting device 20 is not shown for convenience of explanation. Furthermore, the operation of the end mill 21 for forming the second cutting portion 12 is not limited to the above, and may be operated, for example, from the state of the proximity limit distance to the state of the separation limit distance, or the separation limit distance. It may operate from the state of to the state of the proximity limit distance.

Next, as shown in FIG. 5A, the end mill 21 is retracted into the connecting body 24, the ball valve 71 is closed, the first moving device 50 is removed, and the movement restricting members 62, 60'are used. The second moving device 80 and the supports 90, 90 are attached to the fluid pipe 1. The movement restricting member 62 has the same structure as the movement restricting member 60 except that it has a large-diameter flange portion 62a having a plurality of female screw portions 62b along the circumferential direction and does not have a locking portion 61. It has become. Further, the movement restricting member 60'has the same structure as the movement restricting member 60 except that it does not have the locking portion 61. Further, the supports 90, 90 have the same structure as the movement restricting member 60, and are made of a metal material or the like so as to oppose the external force applied at the time of cutting, and are separated in the front-rear direction of the movement restricting members 62, 60'. And supports the fluid pipe 1. The supports 90 and 90 may be made of concrete such as a thrust block.

As shown in FIGS. 5A and 6, the second moving device 80 includes a drive transmission unit 81 fixed to the upper portion of the movement restricting member 60'(downstream side in this embodiment) and a housing 3. It is mainly composed of a driven sprocket 82 connected to one side end portion (downstream side end portion of the housing 3 in this embodiment).

Specifically, the drive transmission unit 81 has a rotation shaft 83 that is rotatable by a drive motor, a speed reducer, or the like (not shown) and is arranged in parallel with the pipe axis direction of the fluid pipe 1, and a rotation shaft 83. The drive sprocket 84 provided and the endless chain 85 wound around the driven sprocket 82 and the drive sprocket 84 are provided, and the drive sprocket 84 rotates about the rotation shaft 83. A rotational driving force is applied to the driven sprocket 82 via the endless chain 85, and the driven sprocket 82 rotates in the circumferential direction of the fluid pipe 1. That is, the second moving device 80 functions as a means for moving the cutting means in the circumferential direction of the fluid pipe 1. Further, a plurality of rollers 86 are rotatably arranged between the movement restricting member 62 (upstream side in this embodiment) and the housing 3, so that the housing 3 smoothly rotates in the circumferential direction. Is assisting.

Next, the ball valve 71 is opened, and the end mill 21 is inserted into the second cutting portion 12 as shown in FIG. 7A. At this time, the end mill 21 is arranged on the upstream side of the central portion in the longitudinal direction of the second cutting portion 12.

Next, as shown in FIGS. 7B and 7C, with the end mill 21 arranged in the second cutting portion 12, the housing 3 is rotated in a predetermined rotation direction (counterclockwise when viewed from the front). The second moving device 80 is driven so as to rotate. As a result, the cutting device 20 is rotated counterclockwise together with the housing 3 in the circumferential direction of the fluid pipe 1, and the left half of the side wall of the fluid pipe 1 when viewed from the front is cut by the outer peripheral surface of the end mill 21.

Then, the second moving device 80 is further driven so as to rotate the housing 3 by approximately 360 degrees from the state shown in FIG. 7 (c). As a result, the cutting device 20 is rotated about 360 degrees in the circumferential direction of the fluid pipe 1 together with the housing 3, and the right half of the side wall of the fluid pipe 1 when viewed from the front is also cut by the outer peripheral surface of the end mill 21. Then, it is preferable that the end mill 21 is temporarily retracted from the second cutting portion 12, but the end mill 21 may be moved to the next step without being retracted.

Next, as shown in FIG. 8, by screwing the push bolt 63 inserted into the female screw portion 62b on the upper side of the flange 62a of the movement restricting member 62, the housing 3 is piped by the tip of the push bolt 63. It is offset by a predetermined length in the axial direction. Similarly, an interposition member 64 having a female screw portion 64b and extending in the pipe axis direction is screwed into the tip of the push bolt 62 inserted into the female screw portion 62b on the lower side of the flange 62a, and the push bolt 63 is screwed. By inserting the housing 3, the housing 3 is offset-moved by the tip of the interposition member 64. That is, the movement restricting member 62, the push bolt 63, and the interposing member 64 constitute an offset moving device.

Next, the end mill 21 is inserted into the second cutting portion 12 in the same manner as described above. At this time, the end mill 21 is arranged at the central portion in the longitudinal direction of the second cutting portion 12 (see FIG. 7A).

Next, with the end mill 21 arranged in the second cutting portion 12, the second moving device 80 is driven so as to rotate the housing 3 in a predetermined rotation direction (counterclockwise when viewed from the front). As a result, the cutting device 20 is rotated counterclockwise together with the housing 3 in the circumferential direction of the fluid pipe 1, and the left half of the side wall of the fluid pipe 1 when viewed from the front is cut by the outer peripheral surface of the end mill 21 (FIG. 7 (b), (c)).

Then, the second moving device 80 is further driven so as to rotate the housing 3 by approximately 360 degrees from the state shown in FIG. 7 (c). As a result, the cutting device 20 is rotated about 360 degrees in the circumferential direction of the fluid pipe 1 together with the housing 3, and the right half of the side wall of the fluid pipe 1 when viewed from the front is also cut by the outer peripheral surface of the end mill 21. Complete.

The second moving device 80 may be rotated by approximately 360 degrees in the above-mentioned rotation direction (counterclockwise when viewed from the front), or from the state of FIG. 7C, the second moving device 80 may be rotated. May be rotated in the direction opposite to the above (clockwise when viewed from the front).

That is, as shown in FIG. 9, the first cutting portion 11 is formed over the entire circumference of the fluid pipe 1. More specifically, since the first cutting portion 11 is formed from the central portion in the longitudinal direction of the second cutting portion 12 to the entire circumference of the fluid pipe 1, the cutting portion 10 includes the first cutting portion 11 and the second cutting. The shape is orthogonal to the portion 12 so as to be continuous (see FIG. 9). The longitudinal dimension of the second cutting portion 12 in the pipe axis direction (expansion / contraction allowance of the hydraulic jack 52) is shorter than the longitudinal dimension of the first cutting portion 11 in the circumferential direction (length of the outer circumference of the fluid pipe 1). At the same time, it is slightly longer than the diameter of the valve body 43 (dimension L2 described later).

Further, as described above, according to the cutting process of the second cutting portion 12, as shown in FIG. 9B, the circumference of the end mill 21 described above is located at the end portion of the second cutting portion 12 in the pipe axial direction. A curved portion 12b curved along the surface shape is formed. More specifically, the curved portion 12b is formed in a substantially ω shape in a plan view in which concave surfaces having substantially the same diameter as the end mill 21 which is a tubular body are arranged side by side in the circumferential direction. In this way, the curved portion 12b curved along the peripheral surface shape of the end mill 21 is formed at the end portion of the second cutting portion 12 in the pipe axial direction, and the formation of the second cutting portion 12 causes the fluid pipe 1 to form. The internal stress generated in the pipe body can be dispersed without being locally concentrated.

Further, according to the above-mentioned cutting process, the first cutting portion 11 and the second cutting portion 12 are cut to a width larger than the diameter of the end mill 21, and by doing so, the diameter of the end mill 21 can be reduced. Not only can the cutting device 20 be made compact, but also the cutting resistance can be reduced. Not limited to this embodiment, either one of the first cutting portion 11 and the second cutting portion 12 may be cut to a width larger than the diameter of the end mill 21.

Further, as described above, the second cutting portion 12 is tilted by swinging the housing 3 and the cutting device 20 in the circumferential direction of the fluid pipe 1 by a predetermined angle ± α (5 ° and −5 ° in this embodiment). The cutting surfaces 12a and 12a extending in the pipe axis direction of the second cutting portion 12 by cutting are formed in a tapered shape that expands in the outer diameter direction. By doing so, the tapered cutting surfaces 12a and 12a can be used as guide surfaces when the butterfly valve 4 is installed.

Further, since the end mill 21 cuts over the entire circumference of the fluid pipe 1, the fluid pipe 1 is divided into a fluid pipe 1F on the upstream side and a fluid pipe 1R on the downstream side. Since it is supported, the housing 3 is prevented from being displaced due to the division of the fluid pipe 1.

Next, a support 91 (see FIG. 9A) is auxiliary arranged below the housing 3 to increase the support strength. It is preferable that the support 91 can be moved up and down by using a jack or the like. Further, the second moving device 80 is removed, and the ball valve 71 is closed and the cutting device 20 is removed. Further, the movement restricting members 62, 60'are removed, and the movement restricting members 60, 60 are installed in place of the movement restricting members 62, 60'.

After that, as shown in FIG. 9A, the work valve 100 is placed on the flange of the branch portion 31A and connected in a sealed manner with bolts, nuts, etc., and the tubular body 103 is above the work valve 100. Connect in a sealed manner. The work valve 100 includes a valve box 101 having a communication port 101a and a valve accommodating portion 101b communicating with the working opening 31B, and a valve body 102 capable of opening and closing the communication port 101a by advancing and retreating from the valve accommodating portion 101b. I have. Further, the communication port 101a of the work valve 100 is formed in a size that allows the repair valve device 70 to be inserted, and the internal space of the tubular body 103 is formed in a size that can accommodate the repair valve device 70. There is.

Then, an attachment 104 attached to the tip of a rod that can move up and down, which is not shown here, is connected to the upper part of the repair valve device 70, and each retaining bolt 8 is regressed to connect the repair valve device 70 and the branch portion 31A. The connection is released, and the rod is moved upward to pull up the repair valve device 70 into the tubular body 103. After that, the repair valve device 70 can be removed by closing the communication port 101a with the valve body 102 and sealing the housing 3.

Next, the valve installation process will be described. After removing the repair valve device 70 and the attachment 104, as shown in FIG. 10A, another attachment 105 is attached to the tip of the rod, and the butterfly valve 4 is attached to the lower end of the attachment 105. Then, the valve body 102 is opened to open the communication port 101a, and the rod is moved downward to insert and install the butterfly valve 4 in the cutting portion 10.

At this time, as shown in FIG. 10B, the stop surface of the valve body 43 is in an open state arranged along the pipe axis of the fluid pipe 1, and the valve housing 41 of the butterfly valve 4 is first. The butterfly valve 4 is installed in the cutting portion 10 so that the valve body 43 passes through the cutting portion 11 and the second cutting portion 12.

Specifically, as shown in FIGS. 10A and 10B, the longest dimension L1 in the pipe axial direction (longitudinal direction) of the second cutting portion 12 is larger than the diameter dimension L2 of the valve body 43. It is formed. Further, since the width dimension L3 in the pipe axis direction (short direction) of the first cutting portion 11 is formed to be larger than the thickness dimension L4 in the pipe axis direction of the valve housing 41, the valve body 43 in the open state is formed. The valve housing 41 can pass through the first cutting portion 11 without interfering with the fluid pipes 1F and 1R, and can pass through the second cutting portion 12 without interfering with the pipe wall of the fluid pipe 1. Further, the first cutting portion 11 and the second cutting portion 12 are formed by cutting over two rows each using the same end mill 21 as described above, and in this embodiment, the pipe axis direction of the first cutting portion 11 The cutting width dimension L3 of is formed to be larger than the cutting width dimension L5 in the circumferential direction of the second cutting portion 12. Not limited to this, the cutting width dimension L3 in the pipe axis direction of the first cutting portion 11 is the circumferential direction of the second cutting portion 12, depending on the dimensions of the valve housing 41 and the valve body 43 of the butterfly valve 4 to be installed. It may be formed to be substantially the same size as the cutting width dimension L5 of the above, or the cutting width dimension L3 in the pipe axis direction of the first cutting portion 11 is smaller than the cutting width dimension L5 in the circumferential direction of the second cutting portion 12. It may be formed in.

After inserting the butterfly valve 4 into the cutting portion 10, when each retaining bolt 8 is advanced, the butterfly valve 4 is pressed against the housing 3, and the seal member 6 fixed to the peripheral edge of the upper lid portion 41A is attached to the branch portion 31A. Since the sealing member 7 fixed to the peripheral edge of the partition wall portion 41B is pressed into the inner peripheral surface of the housing 3 (recessed portion 3A) in a sealed manner, the housing 3 is pressed into the inner peripheral surface in a sealed manner. Is sealed and the valve installation process is completed. In the state where the butterfly valve 4 is installed in the cutting portion 10, the valve body 43 is arranged in the fluid pipe 1, and the diameter (dimension L2) of the valve body 43 is smaller than the inner diameter of the fluid pipe 1. , It can rotate without interfering with the fluid pipe 1.

After that, the work valve 100 and the tubular body 103 are removed, and the lid member 9 and the speed reducer 42 are attached to configure the flow path opening / closing device 2 (see FIG. 1).

As described above, the method of installing the butterfly valve 4 in the flow path opening / closing device 2 is that the butterfly valve 4 is cut by an end mill 21 in a housing 3 that is hermetically fitted in a predetermined position of the fluid pipe 1. A cutting portion consisting of a first cutting portion 11 extending in the circumferential direction and a second cutting portion 12 cut by an end mill 21 and extending in the pipe axis direction of the fluid pipe 1 so as to continuously intersect the first cutting portion 11. In the cutting process of forming 10 and in the housing 3, the valve housing 41 of the butterfly valve 4 passes through the first cutting portion 11, and the valve body 43 in the open state in which the valve housing 41 is opened is second-cut. It has a valve installation step of installing a butterfly valve 4 in a cutting portion 10 so as to pass through the portion 12.

In this way, apart from the first cutting portion 11 for inserting the valve housing 41, the second cutting portion 11 along the pipe axis direction of the fluid pipe 1 so that the valve body 43 in the open state with the valve housing 41 opened can pass through. By providing the cutting portion 12 using the end mill 21, not only the structural strength of the fluid pipe 1 can be maintained while the region of the cutting portion 10 is minimized, but also the valve body 43 can be used as the pipe shaft of the fluid pipe 1. Since the butterfly valve 4 can be installed in a state where it is wide open in the direction, the influence of the fluid on the valve body 43 is reduced without blocking the flow in the pipe when the butterfly valve is installed, and the butterfly valve is installed. It is easy to perform the installation work of 4.

Further, in the cutting process, the first cutting portion 11 and the second cutting portion 12 are cut by the same end mill 21, and by doing so, it is not necessary to increase the size of the cutting means, and the same end mill is used. The first cutting portion 11 and the second cutting portion 12 can be easily formed by using the 21. Here, "same end mill" means an end mill of the same type and specifications, and even a replaced end mill is included as long as it has the same type and specifications.

When the butterfly valve 4 is no longer needed or deteriorates over time, the butterfly valve 4 may be removed from the housing 3, but in this case as well, the valve body 43 is pulled up with the valve body 43 wide open. As a result, the influence of the fluid on the valve body 43 is reduced without blocking the flow in the pipe, and the butterfly valve 4 can be easily removed.

Further, the cutting portion 10 only needs to be able to insert the butterfly valve 4 in the open state of the valve body 43. That is, the first cutting portion 11 and the second cutting portion 12 need only have a size capable of inserting the valve housing 41 and the valve body 43 in the open state. Therefore, for example, a large hole saw is used to form the cutting portion. Compared with the case, the housing 3 covering the butterfly valve 4 and the cutting portion 10 can be made more compact. Further, since the cutting region for forming the cutting portion 10 can be minimized, the amount of waste of sections and chips generated by cutting can be reduced.

Further, in the cutting step, after forming the second cutting portion 12, the first cutting portion 11 is formed over the entire circumference of the fluid pipe 1. According to this, after the second cutting portion 12 is formed in a state where the fluid pipe 1 is continuous in the pipe axis direction before the division, the fluid pipe 1 is divided by forming the first cutting portion 11, so that the second cutting portion 1 is formed. Compared with forming the second cutting portion 12 in the fluid pipes 1F and 1R in the state where the 1 cutting portion 11 is formed and divided into the fluid pipes 1F and 1R, the forming work of the second cutting portion 12 is simpler. .. Further, since the second cutting portion 12 is formed before the fluid pipe 1 is divided by the formation of the first cutting portion 11, the second cutting portion 12 can be formed in a stable state of the fluid pipe 1.

Further, the first cutting portion 11 and the second cutting portion 12 are substantially orthogonal to each other. Specifically, the first cutting portion 11 extends in a direction orthogonal to the pipe axis direction of the fluid pipe 1, and the second cutting portion 12 is orthogonal to the first cutting portion 11, that is, the pipe shaft of the fluid pipe 1. When the butterfly valve 4 is installed or removed, the region of the valve body 43 that is orthogonal (opposite) to the fluid in the fluid pipe 1 can be made small, and the pressure of the fluid that the valve body 43 receives can be made as small as possible. .. Further, as shown in FIG. 10B, since the valve body 43 is formed so as to decrease in thickness from the central portion to the peripheral portion, the valve body 43 is not easily affected by the fluid.

Further, in the state where the flow path opening / closing device 2 is configured, the second cutting portion 12 is provided on the working opening 31B side of the housing 3 in the fluid pipe 1, so that the housing 3 is not moved. The butterfly valve 4 can be removed through the work opening 31B. Further, for example, when the butterfly valve 4 installed in the housing 3 is removed and then a new butterfly valve 4 is installed, the butterfly valve 4 is installed through the work opening 31B without moving the housing 3. Can be installed.

Further, as described above, the distance by which the first moving device 50 moves the cutting device 20 in the pipe axis direction of the fluid pipe 1 (dimension L1 in the pipe axis direction of the second cutting portion 12) is the expansion / contraction allowance of the hydraulic jack 52. Since it is equal to the minute, the dimension L1 in the pipe axis direction of the second cutting portion 12 can be easily changed simply by changing to a hydraulic jack (expansion / contraction means) having a different expansion / contraction allowance.

Next, a modified example of the operation of the end mill 21 when forming the second cutting portion 12 according to the first embodiment will be described. As shown in FIGS. 11A and 11B, a slide member 75 movable in the direction orthogonal to the pipe axis with respect to the plate-shaped body 72 is provided on the upper surface of the plate-shaped body 72 fixedly installed in the housing 3. It is installed in a sealed state, and the lower end of the valve housing of the ball valve 71 is hermetically fixed to the upper surface of the slide member 75. More specifically, the long-axis bolt 77 inserted into the insertion hole 75b of the slide member 75 in the direction orthogonal to the pipe axis is screwed into the long-axis nut 76 fixed to the plate-shaped body 72, and the long-axis bolt 77 is screwed into the long-axis nut 76. Is screwed into the long shaft nut 76 so that it can be moved in the direction orthogonal to the pipe axis.

By doing so, the end mill 21 can be slid by a predetermined dimension (β in the figure) in a substantially horizontal direction substantially orthogonal to the pipe axis as the slide member 75 moves. Therefore, the housing 3 can be moved as described above. The second cutting portion 12 wider than the end mill 21 can be formed without inclining the fluid pipe 1.

Next, a method of installing the butterfly valve in the flow path switching device according to the second embodiment will be described with reference to FIG. The same components as those shown in the above embodiment are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 12, the first moving device 500 as a means for moving the cutting means in the pipe axis direction of the fluid pipe 1 is arranged above the working valve 100 connected to the branch portion 31A. The first moving device 500 includes a base plate 501 connected to the upper part of the working valve 100, a movable plate 502 provided so as to be movable relative to the base plate 501, and a driving means 503 for applying a driving force to the movable plate 502. The cutting device 20 is connected to the upper part of the movable plate 502.

A slit 501a communicating with the work opening 31B is formed in the central portion of the base plate 501, and rails 504 and 504 extending along the pipe axis direction of the fluid pipe 1 are slit 501a on the upper surface of the base plate 501. They are arranged in parallel with each other in between. A packing is fixed around the slit 501a.

The movable plate 502 has a slit 502a communicating with the work opening 31B and recesses 505 and 505 fitted to the rails 504 and 504, and can be slidably moved on the rails 504 and 504. Further, the movable plate 502 is formed by a structural portion 509 having a screw hole 508 protruding upward. The movable plate 502 slides in a state of being in contact with the packing of the slit 501a in the base plate 501 in a sealed manner.

The drive means 503 is a screw rod attached to the upper surface of the base plate 501 so as to be rotatable and axially immovable between two standing pieces 506 and 506 separated in the pipe axis direction and standing pieces 506 and 506. The screw rod 507 is screwed into the screw hole 508 of the structural portion 509 of the movable plate 502. That is, the movable plate 502 slides in the pipe axis direction of the fluid pipe 1 by rotating the screw rod 507 around the axis. A handle 507a is attached to one end of the screw rod 507 so that the handle 507a can be gripped and the screw rod 507 can be rotated.

By sliding the movable plate 502 with respect to the base plate 501 in this way, the cutting device 20 can be moved in the pipe axis direction of the fluid pipe 1. That is, since it is not necessary to move the housing 3 in the pipe axis direction, it is possible to shift to the cutting work of the first cutting portion 11 without removing the first moving device 500 after forming the second cutting portion 12. it can.

In this embodiment, the movable plate 502 is moved in the pipe axial direction by the screw rod 507, but the movable plate 502 may be moved in the pipe axial direction by a hydraulic jack or the like.

Further, the first moving device 500 is not limited to being connected to the upper part of the working valve 100, and may be directly connected to the branch portion 31A of the housing 3'as shown in FIG. Specifically, below the base plate 501', an annular projecting piece 501b to be inserted into the working opening 31B is provided, and a recess 501c provided in the projecting piece 501b (see FIG. 13C). ) Is connected by inserting retaining bolts 8, 8, .... A packing 501d (see FIG. 13C) is disposed on the outer peripheral surface of the projecting piece 501b, and is pressed against the inner peripheral surface of the branch portion 31A. A cutting device 20 is connected above the movable plate 502 via a ball valve 71.

As described above, instead of the working valve 100 which is wide in the pipe axis direction as shown in the second embodiment, the ball valve 71 which is narrower in the pipe axis direction than the working valve 100 is used, which is necessary in the cutting process. The height of the work space (excavation area) in the pipe radial direction can be suppressed.

Although examples of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these examples, and any changes or additions within the scope of the gist of the present invention are included in the present invention. Is done.

For example, in the step of cutting the second cutting portion 12, the process is not limited to the above-described embodiment, and may be formed by the procedure according to the modified example shown in FIG. That is, in the first inclined state of the housing 3, the cutting device 20, and the repair valve device 70 described above, in the end mill 21, the fixing jig 51 and the fitting member 53 are first brought into contact with each other by the first moving device 50. (Position a in the figure), the cutting of the second cutting portion 12 is started.

Next, in the end mill 21, after the fixing jig 51 and the fitting member 53 are cut to the position of the separation limit distance (the position shown in the figure b) by the first moving device 50, the housing 3, the cutting device 20, and the repair valve device are further cut. The 70 is cut while swinging an angle to the position in the second inclined state (position c in the figure) described above.

Further, the end mill 21 forms the second cutting portion 112 by cutting the fixing jig 51 and the fitting member 53 to the position of the proximity limit distance (position d in the drawing) by the first moving device 50.

In the second cutting portion 112 formed in this way, as shown in FIG. 14, the curved portion 112d at one end in the pipe axial direction is formed in a substantially U shape in a plan view, and one in the pipe axial direction. The curved portion 112b at the end of the is formed in a substantially ω shape in a plan view.

Further, for example, in the step of cutting the second cutting portion 12, it may be formed by the procedure according to another modification shown in FIG. That is, in the first tilted state of the housing 3, the cutting device 20, and the repair valve device 70 described above, in the end mill 21, the fixing jig 51 and the fitting member 53 are first located at an intermediate distance by the first moving device 50. Cutting of the second cutting portion 12 is started from the position (position shown in the figure e).

Next, in the end mill 21, after the fixing jig 51 and the fitting member 53 are cut to the position of the separation limit distance (position in the figure f) by the first moving device 50, the housing 3, the cutting device 20, and the repair valve device are further cut. The 70 is cut while swinging an angle to the position in the second inclined state (position g in the figure) described above.

Further, in the end mill 21, after the fixing jig 51 and the fitting member 53 are cut to the position of the proximity limit distance (position shown in the figure h) by the first moving device 50, the housing 3, the cutting device 20, and the repair valve device are further cut. The 70 is cut while swinging an angle to the position in the first inclined state (position i in the figure). Next, the end mill 21 forms the second cutting portion 212 by cutting the fixing jig 51 and the fitting member 53 to a position at an intermediate distance (position shown in the figure e), that is, a cutting start position by the first moving device 50. To do.

In the second cutting portion 212 formed in this way, as shown in FIG. 15, both the curved portions 212d and 212d at both ends in the pipe axial direction are formed in a substantially U shape in a plan view.

The second cutting portion 212 shown in FIG. 15 is the first of the housing 3, the cutting device 20, and the repair valve device 70 after cutting to the positions a to e as described above in the procedure according to FIG. It may be formed by cutting while swinging an angle to the tilted position (position i in FIG. 15).

Further, for example, in the above-described embodiment, a mode in which the second cutting portion 12 is formed and then the first cutting portion 11 is formed is exemplified in the cutting step, but the present invention is not limited to this, and for example, After forming the first cutting portion 11, the second cutting portion 12 may be formed.

Further, for example, in the above embodiment, in the cutting step, the second cutting portion 12 is formed by cutting the end mill 21 in two rows in the circumferential direction. For example, the end mill 21 is cut in only one row or three or more rows in the circumferential direction. The second cutting portion 12 may be formed by cutting over. Similarly, the first cutting portion 11 is formed by cutting the end mill 21 in two rows in the pipe axis direction, but for example, by cutting the end mill 21 in only one row or three or more rows in the pipe axis direction, the first cutting portion 11 is formed. 1 The cutting portion 11 may be formed.

By cutting the end mill 21 in parallel a predetermined number of times in this way, even if the end mill 21 is a compact cutting device 20 having a relatively small diameter, it can be adapted to the shapes of the valve housing 41 and the valve body 43 of the butterfly valve 4. The first cutting portion 11 and the second cutting portion 12 having appropriate dimensions can be formed.

Further, although the first cutting portion 11 is formed over the entire circumference of the fluid pipe 1 so as to divide the fluid pipe 1, the present invention is not limited to this, and the butterfly valve 4 is not limited thereto. If the valve housing 41 in the above can be passed through, a part of the fluid pipe 1 in the circumferential direction may be cut out. In this case, the outer shape of the valve housing is continuously and sealedly contacted with the inner peripheral surface of the fluid pipe 1 and the inner peripheral surface of the housing 3, or the inner peripheral surface of the fluid pipe 1 and the cutting surface. It is preferable to continuously contact the particles in a sealed shape to improve the sealing property.

Further, in the above embodiment, the embodiment in which the first cutting portion 11 and the second cutting portion 12 are orthogonal to each other is illustrated, but the present invention is not limited to this, and the stop surface of the valve body 43 is a fluid pipe. For example, the first cutting portion 11 and the second cutting portion 12 may intersect at an angle as long as they can be arranged so as not to be orthogonal to each other.

In this embodiment, the second cutting portion 12 is formed so that the width on the upstream side extending from the first cutting portion 11 in the pipe axis direction and the width on the downstream side are substantially the same, but the first cutting The width on the upstream side extending from the portion 11 in the pipe axis direction and the width on the downstream side may be different from each other. For example, when the valve shaft is connected to one surface side of the valve body 43, when the valve body 43 is opened, the width of the valve body 43 protruding from the valve housing 41 in the pipe axis direction increases. Although it will be different on the upstream side and the downstream side, the second extending from the first cutting portion 11 according to the width of the upstream side and the width of the downstream side of the valve body 43 protruding from the valve housing 41 in the pipe axis direction. It is preferable to form the cutting portion 12 so that the width on the upstream side and the width on the downstream side are different from each other from the viewpoint of minimizing the cutting portion 10.

Further, in the above embodiment, the embodiment in which the butterfly valve 4 is inserted and installed from above the fluid pipe 1 is illustrated, but if it is from the direction intersecting the fluid pipe 1, any of the vertical, horizontal, and diagonal directions is used. It may be inserted from.

1 Fluid pipe 2 Flow path switching device 3, 3'Housing 4 Butterfly valve 10 Cutting part 11 1st cutting part 12 2nd cutting part 12a Cutting surface 21 End mill 31A Branch part 31B Work opening 41 Valve housing 43 Valve body 50 1st moving device 80 2nd moving device 112,212 2nd cutting part 500 1st moving device

Claims (2)

This is an installation method in which the butterfly valve is installed in a continuous flow state in a flow path switchgear that opens and closes the flow path of a fluid pipe.
In a housing that is hermetically fitted to a predetermined location of the fluid pipe, a first cutting portion that is cut by an end mill and extends in the circumferential direction of the fluid pipe and a first cutting portion that is cut by an end mill and continuously connected to the first cutting portion A cutting process for forming a cutting portion including a second cutting portion extending in the pipe axis direction of the fluid pipe so as to intersect with each other.
In the housing, the cutting portion is such that the valve housing of the butterfly valve passes through the first cutting portion and the valve body in an open state with the valve housing opened passes through the second cutting portion. In the cutting process, at least one of the first cutting portion and the second cutting portion is cut to a width larger than the diameter of the end mill. A method of installing a butterfly valve in a characteristic flow path opening / closing device. The method for installing a butterfly valve in a flow path switching device according to claim 1, wherein in the cutting step, the first cutting portion and the second cutting portion are cut by the same end mill.

Images