JP2022003270A - Valve body installation method - Google Patents

Abstract

To provide a valve device which can be attached to an interior of a housing in a constant flow state after a fluid pipe is cut in the housing, enclosing the fluid pipe in a sealing state, by a cylindrical cutter and which enables reduction of pressure loss and achieves high long-term reliability even if a clearance between cutting surfaces of the fluid pipe is small.SOLUTION: A valve body 5 includes: a valve element 5v; a valve operation shaft 5j connected to an upper part of the valve body 5v; a valve seat body 5b having a valve seat hole part 5f; a valve seat body extension part 5p extending toward cut surfaces 2a, 2a of a water pipe 2; a valve lid 5a which closes a housing opening 41d of a housing 4; and a sealing member which seals a space between the valve seat body 5b and the housing 4. The valve element 5v is inserted toward the valve seat body 5b installed in the housing 4 to be able to open or close the valve seat hole part 5f. A valve body insertion device 80 has: an insertion device housing 86 connected to the housing 4; an insertion shaft 87 which may move forward or rearward relative to the insertion device housing 86; and a holding part 83 provided at one end of the insertion shaft 87. In a state where the holding part 83 holds a portion, which is located below an upper end of the valve operation shaft 5j, of the valve body 5, the valve body 5 is inserted into the housing 4.SELECTED DRAWING: Figure 3

Description

The present invention relates to a valve device capable of cutting a fluid pipe with a cylindrical cutter in a housing that surrounds the fluid pipe in a sealed manner and mounting the fluid pipe in the housing in a continuous flow state.

In a valve device that can be installed in the housing in a continuous flow state by cutting the fluid pipe with a cylindrical cutter in a housing that surrounds the conventional fluid pipe in a sealed manner, in order to reduce the size and weight of the housing. The flow in the fluid tube was controlled by cutting the fluid tube with a cylindrical cutter having a small diameter as much as possible, inserting the valve body directly into the housing, and blocking the housing by the valve body.
(See, for example, Patent Document 1).

Special Table 2006-515406 (Page 6, Fig. 1-5)

In Patent Document 1, since the fluid tube is cut by using a small-diameter cylindrical cutter, the separation distance of the portion where the cut surface of the fluid tube is closest is small, and the valve body is directly attached to the housing. I had to insert it. However, if the valve body is inserted directly into the housing body, the turbulence of the fluid flowing in the housing body becomes large and the pressure loss increases. There was also a risk that the reliability would be reduced.

The present invention has been made by paying attention to such a problem, and the fluid pipe is cut by a cylindrical cutter in a housing that encloses the fluid pipe in a sealed shape, and the inside of the housing is in a continuous flow state. It is an object of the present invention to provide a valve device that can be attached and has high long-term reliability by reducing pressure loss even when the separation distance between the cut surfaces of the fluid pipe is small.

In order to solve the above problems, the valve device of the present invention is used.
A valve device having a housing that encloses the fluid pipe in a sealed shape, and an insert body that can be inserted into the housing in a continuous flow state by cutting the fluid pipe with a cylindrical cutter in the housing. The insert body includes a valve body and a valve seat body having a valve seat hole portion, and the valve body can open and close the valve seat hole portion to control the fluid, and the valve seat body can control the fluid. The pipe axial width on the proximal end side is characterized in that it is formed larger than the pipe axial width of the valve seat body at a position closest to the fluid pipe cutting surface.
According to this feature, the insert body provided with the valve body and the valve seat body that can be inserted into the closest portion of the fluid tube cut surface cut by the cylindrical cutter is on the proximal end side of the valve seat body. Since the width in the pipe axis direction is formed large and the separation width between the relevant part and the cut surface of the fluid pipe can be minimized, turbulence of the flow in the housing can be suppressed and pressure loss can be reduced, and eventually the valve device can be used. Long-term reliability can be ensured by reducing the acting force.

The valve device of the present invention is
The valve seat body is characterized by having a valve seat body inclined surface that faces the fluid pipe cutting surface and is tapered in a direction in which the valve seat body is inserted.
According to this feature, the surface of the valve seat facing the cut surface of the fluid pipe has a valve seat inclined surface that is tapered in the direction in which the valve seat is inserted, so that the valve body and the valve seat can be separated from each other. The provided valve device can be inserted into the housing, and the separation width between the valve seat body and the fluid pipe cutting surface is reduced by the base end portion of the valve seat body having a large pipe axial width formed by the valve seat body inclined surface. Therefore, it is possible to suppress the turbulence of the flow in the housing.

The valve device of the present invention is
The valve body is characterized by having a valve body inclined surface that faces the valve seat hole portion and is inclined in a direction in which the valve body is inserted.
According to this feature, the valve body faces the valve seat hole portion and has a valve body inclined surface that is tapered in the direction in which the valve body is inserted, so that a large pipe axial width is formed. Since the base end portion has high rigidity, it can withstand the moment acted by the fluid, and thus the long-term reliability of the valve body opening / closing control can be ensured.

The valve device of the present invention is
The valve seat hole portion is characterized in that it is formed to have substantially the same diameter as the fluid tube.
According to this feature, since the hole portion of the valve seat is formed to have substantially the same diameter as the fluid pipe, it is possible to reduce the change in the flow-down cross section and suppress the turbulence of the flow in the housing.

The valve device of the present invention is
The valve seat body is characterized by including an extension portion extending toward the cut surface of the fluid pipe.
According to this feature, the fluid is guided by the extension portion extending toward the cut surface of the fluid pipe on the inclined surface of the valve seat, so that the turbulence of the flow in the housing can be suppressed.

It is a partial front sectional view which shows the state which installed the fluid pipe cutting apparatus in the housing attached to the existing fluid pipe. It is a partial cross-sectional view of the arrow A view of FIG. It is a partial front sectional view showing a state in which a valve body is installed in a housing by a valve body insertion device. (A) is a view taken along the line BB of FIG. 3, showing a state in which the valve lid is temporarily fixed by the presser screw, and (b) is a diagram showing a state in which the temporary fixing of the presser screw is released. It is a partial front sectional view showing the process of installing a valve body in a housing and inserting a fixing member into a recess. (A) is a plan view showing a state in which the fixing member is inserted into the concave portion of the housing, and (b) is a partial front sectional view. It is a figure which shows the process of attaching an upper lid to a flange part. (A) is a plan view showing a state in which the upper lid is attached to the flange portion and the installation body attachment process is completed, and (b) is a partial front sectional view. It is a figure which shows the dimensional relationship between the valve seat body of a valve device, and the cut surface of an existing fluid pipe.

The valve device according to the present invention will be described with reference to FIGS. 1 to 9.

As shown in FIGS. 1 to 5, the valve device 1 according to the present invention includes a housing 4 that encloses the existing fluid pipe 2 in a sealed manner, and a valve body 5 as an insertable body that can be inserted into the housing 4. , Have. The valve body 5 includes a valve lid 5a that closes the housing opening 41d of the housing 4, a valve seat 5b having a valve seat hole 5f, a valve body 5v that opens and closes the valve seat hole 5f, and an upper portion of the valve body 5v. A valve operating shaft 5j connected to is provided. Further, the valve device 1 includes a packing housed in the packing box 5h for sealing the valve operating shaft 5j, a packing (not shown) for sealing between the valve body 5v and the valve seat body 5b, and a valve seat body 5b and a casing. A sealing member 5e for sealing between the body 4 and the body 4 is provided. Then, the valve device 1 is hermetically inserted into the housing 4, and the valve operating shaft 5j is rotated to move the valve body 5v, whereby the valve body 5v is provided with a valve seat hole portion in the valve seat body 5b. The flow of the existing fluid pipe 2 can be controlled by opening and closing 5f. However, the sealing between the valve body 5v and the valve seat body 5b is not limited to the packing, and may be, for example, sealing between metals.

Here, the existing fluid pipe 2 is made of, for example, ductile cast iron for waterworks buried in the ground, is formed in a substantially circular shape in cross section, and its inner peripheral surface is covered with an epoxy resin layer. The fluid tube according to the present invention may be made of other metal such as cast iron or steel, or may be made of asbestos, concrete, vinyl chloride, polyethylene or polyolefin. 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. Further, in this embodiment, the fluid in the fluid pipe is clean water, but the fluid is not limited to the clean water of this embodiment, for example, industrial water, agricultural water, sewage, etc., as well as gas or a gas-liquid mixture of gas and liquid. It doesn't matter. Further, the materials of the housing 4 and the valve body 5 may also be suitable for the above.

As shown in FIG. 1, the housing 4 attached to the outer peripheral surface of the existing fluid pipe 2 is a so-called split T-shaped pipe, and is a housing in the radial direction of the existing fluid pipe 2 (vertical direction in this embodiment). The structure is divided into an upper portion 41 and a lower portion 42 of the housing. Further, the housing 4 is provided with detachment prevention metal fittings 6 and 6 for preventing the existing fluid tube 2 from detaching.

The upper portion 41 of the housing is formed with a neck portion 41a, a flange portion 41b connected to the neck portion 41a, a housing opening 41d connected to the flange portion 41b and communicated with the inside of the housing, and further at an end portion of the housing opening 41d. Is formed with a housing recess 41c for inserting and fixing the fixing member 7 described later. Then, a fluid pipe cutting device 70, a valve body inserting device 80 (see FIG. 3), and the like can be attached to the flange portion 41b via a fixed flange main body 50 and a working valve 60, which will be described later.

On the other hand, the housing lower portion 42 has a pot-shaped housing bottom portion 42d, and a discharge hole 42b is formed in the center of the housing bottom portion 42d. A valve 49 can be connected to the discharge hole 42b, and as will be described later, chips generated when the existing fluid pipe 2 is cut can be discharged together with the fluid from the discharge hole 42b by operating the valve 49. There is.

In this embodiment, the upper part 41 of the housing, the lower part 42 of the housing, and the like will be referred to, but the division direction of the housing is not limited to the vertical direction, and may be, for example, a horizontal direction or an inclination direction of a predetermined angle. Further, the number of divisions may be 3 or more. Similarly, the piping direction of the existing fluid pipe 2 is not limited to horizontal, and may be, for example, vertical. Further, the cutting direction of the cutter 72, which will be described later, is not limited to the vertical direction, and may be, for example, the horizontal direction. In the following examples, the cutter 72 will be described as an example in which a cylindrical cutter such as a hole saw having good work efficiency is used, but a wire saw, a bite or the like may be used.

Hereinafter, the fixed flange main body 50, the working valve main body 60, and the fluid pipe cutting device 70 will be described. As shown in FIG. 1, in a state where the housing 4 is sealed and attached to the existing fluid pipe 2, the fixed flange main body 50, the work valve main body 60, and the fluid pipe cutting device 70 are attached to the flange portion 41b of the housing upper portion 41. Is attached.

As shown in FIGS. 1 and 2, a sealing member 53 is inserted through the joint surface between the fixed flange portion 51 and the flange portion 41b of the fixed flange body 50 and tightened by bolts and nuts 54. The fixed flange portion 51 and the flange portion 41b are sealed. A plurality of presser screws 52 are hermetically attached in the radial direction of the fixed flange portion 51 at predetermined intervals in the circumferential direction, and as will be described later, when the valve body 5 is inserted into the housing body 4. , The valve body 5 can be temporarily fixed.

As shown in FIG. 1, the joint surface between the work valve housing 61 of the work valve main body 60 and the fixed flange main body 50 is inserted with a seal member 63 and tightened by bolts 55, and the work valve main body 60 and the fixed flange main body are tightened. 50 is sealed. A work valve 62 that can be opened and closed between the housing 4 and the fluid pipe cutting device 70 by sliding in the horizontal direction is attached to the work valve housing 61 of the work valve main body 60 in a hermetically sealed manner.

Further, a sealing member 73 is inserted into the joint surface between the fluid pipe cutting device 70 and the working valve main body 60, and the joint surface is tightened by a bolt 74, and the fluid pipe cutting device 70 and the working valve main body 60 are sealed. To. Further, the cutter 72 attached to the cutter shaft 75 is hermetically attached to the drilling device housing 71 so as to be movable up and down and rotatably. The cutter 72 and the cutter shaft 75 can be rotationally driven by a drive device (not shown) from the outside of the fluid pipe cutting device 70.

Hereinafter, the cutting process of the existing fluid pipe 2 and the mounting process of the valve body 5 will be described.

First, the cutting process will be described. As shown in FIG. 1, the existing fluid pipe 2 is cut in a continuous flow state by a cutter 72 with the working valve 62 open. Since the cutter 72 has a cylindrical shape, the pipe cutting portion of the existing fluid pipe 2 is formed in an arc shape along the cylindrical cutter 72 when viewed from the direction of the cutter shaft 75. The chips generated when cutting the existing fluid pipe 2 are discharged together with the fluid by operating the valve 49 attached to the discharge hole 42b provided in the center of the lower portion 42 of the housing.

After cutting the existing fluid pipe 2, the cutter 72 is raised, the working valve 62 of the working valve housing 61 is closed, and the space between the housing 4 and the fluid pipe cutting device 70 is sealed. After that, the fluid in the fluid pipe cutting device 70 is discharged, the fluid pipe cutting device 70 is removed from the work valve main body 60, and the cutting process work of the existing fluid pipe 2 is completed.

Next, as shown in FIG. 3, the valve body insertion device 80 is hermetically attached to the upper part of the work valve body 60. In the valve body insertion device 80, a holding portion 83 for holding the valve body 5 is attached to one end of the insertion device housing 86, the insertion shaft 87, and the insertion shaft 87 by a mounting bolt 88, and the other of the insertion shaft 87 is attached. At the end, a screw portion 89 screwed into the insertion shaft 87 and a handle 90 for rotating the screw portion 89 are provided, and the handle 90 is rotated to raise and lower the insertion shaft 87 to move the valve body 5 up and down. Can be inserted and removed from the housing 4.

When the handle 90 is rotated to lower the insertion shaft 87, and the valve body 5 in which the fixing members 7 and 7 are installed is inserted and installed in the housing 4, it is fixed as shown in FIG. 4A. The presser screw 52 provided on the flange body 50 is screwed in, and the valve lid inclined surface 5c formed on the outer peripheral portion of the valve lid 5a of the valve body 5 is temporarily fixed by the presser screw 52. After that, the fluid in the valve body insertion device 80 is discharged, the insertion device lid 84 is removed, the mounting bolt 88 that connects the holding portion 83 and the insertion shaft 87 is removed from the work hole 85, and the valve body insertion device 80 is operated. After removing from the valve body 60, the holding portion 83 of the valve body insertion device 80 is removed from the valve body 5 (see FIG. 3).

Next, as shown in FIG. 5, when the valve body insertion device 80 is removed from the work valve body 60, it is fixed in a substantially rectangular shape in a plan view in the housing recess 41c formed in the housing upper portion 41 described later. Install members 7 and 7. Then, by attaching the fixing member 7 so as to straddle the valve lid 5a and the housing recess 41c, the fixing member 7 can hold the fluid force applied to the valve lid 5a. At this time, the work space inside the work valve housing 61b of the work valve housing 61 is narrow due to the presence of the packing box 5h and the like, and the distance from the work valve housing flange 61a of the work valve housing 61 to the fixing member is also large. Since it is far away, it is difficult to insert the fixing member 7. Therefore, the work jig 92 can be inserted between the valve lid 5a and the fixing member 7, and the fixing member 7 can be inserted into the housing recess 41c. As shown in FIGS. 5 and 6, the fixing member 7 is provided with a tapered portion 7d, so that the work jig 92 can be easily inserted even in a narrow work space. Further, the fixing member 7 is provided with a plurality of holes 7e and 7e. By inserting a work jig (not shown) into the holes 7e and 7e, not only the fixing member 7 can be inserted into the housing recess 41c even if the work space is narrow, but also the fixing member 7 can be inserted from the housing recess 41c. It can be easily removed.

Subsequently, as shown in FIG. 6, the fixing members 7 and 7 are locked by the plurality of bolts 7a and 7a. After that, the presser screw 52 is loosened (see FIG. 4B), and the fixing flange main body 50 and the working valve main body 60 are removed. Since the fixed flange main body 50 can be removed in this way, the fixed flange main body 50 and the plurality of presser screws 52 provided on the fixed flange main body 50 are left in the housing 4, and the structure of the installed body is not deteriorated over time. Not only can it be simplified, but the removed fixed flange main body 50 and a plurality of presser screws 52 can be attached to other housings and reused.

Finally, as shown in FIGS. 7 and 8, the upper lid 43 is attached to the flange portion 41b with bolts and nuts 43b, and the attachment process of the installation body is completed. Further, at a position where the upper lid 43 faces the fixing member 7, an upper lid convex portion 43a for holding the fixing member 7 is provided. Since the fixing member 7 is also held by the upper lid convex portion 43a in a state where the upper lid 43 is fastened to the flange portion 41b with bolts and nuts 43b, the pressure received by the fixing member 7 can be reduced. Although the upper lid 43 is formed with the upper lid convex portion 43c so as to hold not only the fixing member 7 but also the valve lid 5a, it may be omitted.

Hereinafter, the operation and effect of the valve device 1 according to the present invention will be described. As shown in FIG. 9, the valve body 5 can be cut by a cylindrical cutter 72 in the housing 4 that encloses the existing fluid pipe 2 in a sealed manner, and can be inserted into the housing 4 in a continuous flow state. It is composed.

Here, when the existing fluid pipe 2 is cut in the radial direction with a cylindrical cutter 72, as shown in FIG. 9, the separation distance between the fluid pipe cutting surfaces 2a and 2a in the pipe axial direction is the existing fluid pipe 2. The maximum is at the top and bottom of the pipe, and the minimum separation distance L1 is obtained at a position substantially intermediate between the top and bottom of the existing fluid pipe 2. The minimum separation distance L1 determines the sizes of the valve seat 5b and the valve body 5v of the valve device 1 that can be inserted into the housing 4.

For example, when the width of the valve seat 5b in the pipe axis direction is large, the existing fluid pipe 2 is cut by a cutter 72 having a large diameter so that the valve seat 5b can pass through while ensuring the minimum separation distance L1. Need to be. However, in order to cut the existing fluid pipe 2 with the cutter 72 having a large diameter, it is necessary to enlarge the housing 4 that encloses the existing fluid pipe 2 in a sealed manner. Therefore, the cost of the valve device 1 increases, and the amount of earth and sand excavated for burying the large valve device 1 also increases, so that the installation cost also increases. Further, as the housing 4 becomes larger, the surface area of the valve body 5 inserted into the housing also becomes larger, so that the force of the fluid acting on the valve body 5 also increases, and it is necessary to further reinforce the valve seat body 5b. The cost of the device 1 will also increase more and more.

On the contrary, when the housing 4 that encloses the existing fluid pipe 2 in a sealed shape is made small and the existing fluid pipe 2 is cut by a cylindrical cutter 72 having a small diameter, the minimum separation distance L1 is also reduced, so that the valve seat 5b, It is necessary to make the valve body 5v thin. As a result, the structural strength of the valve seat 5b and the valve body 5v is limited to a low level, and the long-term reliability is lowered.

Therefore, in the valve device 1 of the present invention, as shown in FIG. 9, the pipe axial width L2 of the valve seat body at the position closest to the fluid pipe cutting surface 2a is smaller than the minimum separation distance L1 of the existing fluid pipe 2. By forming and miniaturizing the housing 4, the valve seat body 5b and the valve body 5v can also be miniaturized. By making the housing 4 smaller, the cost of the valve device 1 and the installation cost of the valve device 1 can be reduced, and the surface areas of the valve seat 5b and the valve body 5v are reduced to reduce the surface areas of the valve seat 5b and the valve body 5v. The force applied to the valve can be reduced.

On the other hand, since the valve seat 5b and the valve body 5v are in a cantilever state, the structural strength of the valve seat 5b and the valve body 5v is limited to be low by making the housing 4 smaller. Therefore, in order to withstand the high stress generated in the valve seat 5b and the valve body 5v, the valve seat 5b faces the fluid pipe cutting surface 2a and is tapered in the direction in which the valve seat 5b is inserted. An inclined valve seat body inclined surface 5q is provided, and the pipe axial width L3 on the proximal end side of the valve seat body 5b is set from the pipe axial width L2 of the valve seat body 5b at a position closest to the fluid pipe cutting surface 2a. It is formed large. Similarly, the valve body 5v is provided with a valve body inclined surface 5r that faces the valve seat hole portion 5f and is tapered in the direction in which the valve body 5v is inserted, and is provided with a valve body inclined surface 5r in the direction of the pipe axis on the base end portion side of the valve body 5v. The width L4 is formed to be larger than the pipe axial width L2 of the valve seat body 5b at the position closest to the fluid pipe cutting surface 2a.

Further, by forming a large pipe axial width L3 on the proximal end side of the valve seat 5b, the valve seat 5b can be brought closer to the fluid pipe cutting surface 2a, so that the valve seat 5b breaks the inside of the housing. Since the area change can be reduced and the turbulence of the flow in the housing 4 can be suppressed, the pressure loss can be reduced.

Further, as shown in FIG. 9, the valve seat body 5b is provided with a valve seat body extending portion 5p extending toward the fluid pipe cutting surface 2a. Since the valve seat extension portion 5p extends in the circumferential direction toward the fluid pipe cutting surface 2a along the fluid pipe cutting surface 2a, the flow from the existing fluid pipe 2 flows from the valve seat extension portion 5p. Guided by, the turbulence of the flow in the housing can be suppressed, the pressure loss can be reduced, and the force acting on the valve body can be reduced, and long-term reliability can be ensured. Further, by forming the valve seat hole portion 5f so as to have the same cross section as the fluid pipe, it is possible to reduce the change in the cross-sectional area of the flow path, suppress the turbulence of the flow in the housing, and reduce the pressure loss. .. The valve seat hole portion 5f preferably has the same diameter as the inner diameter of the fluid pipe, but may be appropriately adjusted to the outer diameter of the fluid pipe or the like.

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 that do not deviate from the gist of the present invention are included in the present invention. Will be.

In FIG. 9, the surface of the valve seat 5b facing the fluid pipe cutting surface 2a is formed as a valve seat inclined surface 5q that is tapered in the direction in which the valve seat 5b is inserted into the housing 4. .. However, the surface of the valve seat 5b facing the fluid pipe cutting surface 2a is not limited to the inclined surface, and the portion above the position where the valve seat 5b is closest to the fluid pipe cutting surface 2a is formed wide in a stepped manner. You may. Further, the pipe axial width L3 on the proximal end side of the valve seat body 5b can be further formed to be larger than the minimum separation distance L1 of the existing fluid pipe 2. For example, above the position where the valve seat 5b is closest to the fluid pipe cutting surface 2a, the valve seat 5b or the valve seat extension 5p, or the valve seat 5b and the valve seat extension 5p are pipes. The axial width is further increased to minimize the separation distance between the valve seat body 5b and the fluid pipe cutting surface 2a or the separation distance between the valve seat extension portion 5p and the fluid pipe cutting surface 2a, and the inside of the housing 4 is minimized. The turbulence of the flow can be further suppressed and the pressure loss can be reduced.

1 Valve device 2 Existing fluid pipe (fluid pipe)
4 Housing 5 Valve body (insertion body)
5a Operculum 5b Valve seat body 5f Valve seat hole 5p Valve seat extension 5q Valve seat tilt surface 5r Valve body tilt surface 5v Valve body 72 Cutter

Claims (5)

In the case of the divided structure that surrounds the water pipe in a sealed shape, the valve body is located at the separated portion between the cut surfaces of the water pipe, which is cut by a cylindrical rotatable cutter in a continuous flow state and formed in an arc shape. Is a method of installing a valve body by inserting and installing the valve body by a valve body insertion device, wherein the valve body has a valve body, a valve operating shaft connected to the upper part of the valve body, and a valve seat having a valve seat hole portion. Between the body, the valve seat extending portion extending toward the cut surface of the water pipe, the valve lid that closes the housing opening of the housing, and the valve seat body and the housing. The valve body is provided with a sealing member for sealing the valve body, and the valve body can be opened and closed by inserting the valve body toward the valve seat body installed in the housing. The insertion device has an insertion device housing connected to the housing, an insertion shaft that can move forward and backward with respect to the insertion device housing, and a holding portion provided at one end of the insertion shaft. A method for installing a valve body, which comprises inserting the valve body into the housing while the portion is held below the upper end of the valve operating shaft in the valve body. The method for installing a valve body according to claim 1, wherein the holding portion extends downward so as to straddle the valve operating shaft. 1. How to install the valve body as described in. The method for installing a valve body according to claim 3, wherein the removal operation is an operation of removing a mounting bolt that connects the insertion shaft and the holding portion. The method for installing a valve body according to claim 3 or 4, wherein after the removal operation, the insertion device housing and the insertion shaft are removed, and the holding portion is removed from the valve body.

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