Ball mounting jig and ball mounting method

Abstract

To provide a ball attachment jig which enables a ball valve body and a ball seat to be attached to a valve chamber part securely through top entry, and to provide a ball attachment method.SOLUTION: A ball attachment jig (1) includes a holding mechanism which holds a ball valve body (104) and a ball seat (168). The holding mechanism has: a seat support part (4) which causes the ball seat (168) to incline; and a release mechanism which releases support by a seat support part (4) when the ball seat (168) is supported by the ball valve body (104) and a retainer (180).SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a ball mounting jig used for mounting a ball valve element and a ball seat of a ball valve by top entry, and a ball mounting method using the jig.

Background Art

[0002] Conventional ball valves include an embodiment in which a ball valve element, a ball seat, and a retainer are inserted into the valve chamber from a widely opened portion above the valve chamber. In addition, when the body has a structure that can be divided in the lateral direction, there is also known a method of attaching the retainer, the ball seat and the ball valve element to the valve chamber from the open side in the separated state, and reassembling the body.

[0003] The present inventors have been developing valves for flowing cryogenic fluids such as liquefied hydrogen (-253°C) for many years. Valves for flowing cryogenic fluids such as liquefied hydrogen are configured to minimize heat conduction and heat transfer from the fluid to achieve a cold insulation effect, and to arrange components vulnerable to low temperatures (such as packings) as far away from the fluid as possible, by making the stem connecting the valve operating portion and the valve element longer (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0005] Ball valves that handle cryogenic fluids have long stems, and the stem housing portion of the body is also long. Furthermore, because the body is integrally constructed by welding, there is a problem in that when introducing the ball valve body, ball seat, and retainer from the upper end opening of the stem housing portion via top entry to the valve chamber portion, which is connected to the lower part of the stem housing portion via a housing opening, it is difficult due to the structural limitations of the body.

[0006] Therefore, one aspect of the present invention aims to provide a ball mounting jig and a ball mounting method using the jig that enable the ball seat to be introduced into the valve chamber along with the ball valve body in a top-entry type ball valve with a long stem housing portion (cylindrical portion). [Means for solving the problem]

[0007] To solve the above problems, a ball mounting jig according to one aspect of the present invention is provided. A ball mounting jig used when introducing a ball valve body and a ball seat into the valve chamber of a ball valve, which has a valve chamber having two or more flow path openings that serve as fluid passages and a housing opening through which a ball valve body can pass, a retainer attached to the flow path opening, and a cylindrical portion connected to the valve chamber via the housing opening, from the cylindrical portion by top entry, The ball mounting jig is configured to introduce the ball valve body and ball seat into the valve chamber portion with the retainer attached. The ball valve body and the ball seat are held by a holding mechanism that moves downward from the cylindrical portion toward the valve chamber portion, The aforementioned holding mechanism is A seat support portion holds the ball valve body along the ball valve body in a state inclined with respect to the rotation axis such that the portion of the ball seat located on the front side with respect to the downward direction is closer to the rotation axis of the ball valve body than the portion located on the rear side, When the ball seat, which has been introduced into the housing opening in an inclined state by the seat support portion together with the ball valve body, is supported by the ball valve body and the retainer, a release mechanism releases the support of the ball seat by the seat support portion. It has.

[0008] To solve the above problems, a ball mounting method according to one aspect of the present invention is: A ball mounting method for mounting a ball valve body and a ball seat to the valve chamber portion of the ball valve by top entry using the ball mounting jig described above, A first step involves lowering the ball seat, which is held by the holding mechanism and tilted by the seat support, and the ball valve body toward the valve chamber portion to which the retainer is attached, and inserting them into the housing opening. After the first step, when the ball seat passing through the housing opening is supported between the ball valve body and the retainer, the second step is to release the support of the ball seat by the seat support portion using the release mechanism. A third step is performed after the second step, in which the ball seat and the ball valve body are lowered. Includes. [Effects of the Invention]

[0009] According to one aspect of the present invention, a ball mounting jig is provided that allows the ball seat to be easily introduced into the valve chamber by top entry together with the ball valve body, even in a ball valve with a long stem housing portion (cylindrical portion), and a ball mounting method using the jig is also provided. [Brief explanation of the drawing]

[0010] [Figure 1] This is an external perspective view of a ball valve to which a ball mounting jig according to one embodiment of the present invention is to be attached, specifically the ball valve body and ball seat. [Figure 2] This is a cross-sectional view taken along the cutting line AA' in Figure 1. [Figure 3] This is a partially enlarged view of Figure 2. [Figure 4] This is a perspective view showing a state where a ball valve element and a ball seat are held on the main part of a ball mounting jig according to an embodiment of the present invention. [Figure 5] This is a diagram showing an operation flow of a ball mounting method using the ball mounting jig shown in Figure 4. [Figure 6] This is a cross-sectional view showing a state where the ball valve element and the ball seat are being inserted into the body using the ball mounting jig shown in Figure 4. [Figure 7] This is a cross-sectional view showing a state where the ball valve element and the ball seat are being inserted into the valve chamber part of the body using the ball mounting jig shown in Figure 4. [Figure 8] This is a partially enlarged view of Figure 7. [Figure 9] This is a cross-sectional view showing a state where the ball valve element and the ball seat are mounted to the valve chamber part of the body using the ball mounting jig shown in Figure 4. [Figure 10] This is a cross-sectional view showing a state where a ball valve element and a ball seat are held on the main part of a ball mounting jig according to another embodiment of the present invention. [Figure 11] This is a cross-sectional view showing a state where the ball valve element and the ball seat are being inserted into the valve chamber part of the body using the ball mounting jig shown in Figure 10. [Figure 12] This is a partially enlarged view of Figure 11. MODE FOR CARRYING OUT THE INVENTION

[0011] [Embodiment 1] Hereinafter, one embodiment of the present invention will be described with reference to Figure 1 to Figure 9. The ball mounting jig according to one aspect of the present invention is a jig used for mounting a ball valve element together with a ball seat to a top-entry type ball valve disposed in the middle of a flow channel formed substantially in the horizontal direction. The fluid flowing through the ball valve may be the aforementioned cryogenic fluid, particularly liquid hydrogen, but is not limited thereto.

[0012] FIG. 1 is an external perspective view of a ball valve which is a target to which a ball valve element is attached together with a ball seat using a ball attachment jig according to the present embodiment. FIG. 2 is a cross-sectional view taken along the line A-A' shown in FIG. 1, showing a state where the ball valve is cut. For convenience of explanation, the drawings also show three-dimensional coordinates defined with a horizontal plane as an XY plane and the zenith direction as a Z direction. In the following, the ball valve in a state where various components constituting the ball valve 110 are installed will be described first, and then the attachment of the ball valve element and the ball seat which are part of the components will be described.

[0013] <Ball Valve> The ball valve 110 includes at least a body 101, a ball valve element 104, a stem 103, a bonnet 102, and an operation unit 109. The body 101 has a plurality of piping structure portions 107 for circulating a fluid, and an upper end opening portion 106b that opens in a direction (Z-axis direction described later) intersecting the direction in which the plurality of piping structure portions 107 face (X-axis direction described later) and allows the ball valve element 104 to pass therethrough, and constitutes a fluid flow path. The stem 103 constitutes a valve shaft extending in the vertical direction shown in FIG. 2, is connected to the ball valve element 104, and extends to the outside beyond the upper end opening portion 106b. The bonnet 102 operably seals the upper end opening portion 106b with the stem 103, and is detachably connected to the upper end portion of the body 101 with bolts or the like. An operation unit 109 is fixed to the bonnet 102, and an operation by the operation unit 109 is transmitted to the ball valve element 104 via the stem 103. The operation is performed by a handle 199 (FIG. 1) disposed on the bonnet 102. Specifically, according to the rotation amount of the handle 199, the ball valve element 104 rotates around a central axis O (FIG. 2) extending in the vertical direction. The flow path is opened and closed by the ball valve element 104, and the state can be changed from the closed state to the open state by rotating 90°. In the state illustrated in FIG. 2, the ball valve element 104 is in an open state, the piping structure portion 107 on the left side of the drawing sheet of the ball valve element 104 communicates with the piping structure portion 107 on the right side of the drawing sheet, and for example, a fluid flows from the left side to the right side of the drawing sheet.

[0014] As shown in Figure 1, the ball valve 110 has a cylindrical external form in which the body 101 is long in the vertical direction and the diameter remains almost constant from the lower end to the upper end. The body 101 is a welded structure that houses the ball valve body 104 in the lower part of the storage space and the stem 103 connected to the ball valve body 104 in the upper part. Specifically, the body 101 has a valve chamber section 105 that houses the ball valve body 104 (Figure 2), a stem storage section 106 that houses the stem 103 (Figure 2) which is connected to the valve chamber section 105 via a communication port 106a, and a piping structure section 107 that extends horizontally from the side of the valve chamber section 105.

[0015] The valve chamber 105 has a hollow central region 151 in which the ball valve body 104 can be rotatably positioned. The central region 151 has an inner surface that contacts the lower surface of the ball valve body 104, and a recess 151a is provided on this inner surface into which a protrusion 104b provided on the lower surface of the ball valve body 104 fits. In addition, a communication opening 106a is provided at the upper part of the central region 151 that communicates the hollow portion of the central region 151 with the internal space of the stem housing 106.

[0016] The valve chamber 105 further has an end region 152 (flow channel opening) between the central region 151 and the piping structure 107, which connects the hollow portion of the central region 151 with the inside of the pipe of the piping structure 107. The end region 152 has a cylindrical inner surface with a pipe axis extending along the left-right direction of the paper in Figure 2, and a ball seat 168 and a retainer 180 that support the ball valve body 104 from the side are disposed on this inner surface. The end region 152 includes an opening that communicates with the pipe of the piping structure 107.

[0017] Figure 3 is an enlarged cross-sectional view of the area C enclosed by the dashed line in Figure 2. The retainer 180 has a seat retainer 182 and a retainer gland 183 arranged from the ball valve body 104 side. The retainer gland 183 is biased toward the ball valve body 104 by a spring 184 and a spring holder 186. A stepped portion 182a is provided on the outer diameter side of the seat retainer 182. The outer diameter side of the retainer gland 183 protrudes toward the ball valve body 104 at the position of the stepped portion 182a of the seat retainer 182, and presses against the end face of the stepped portion 182a of the seat retainer 182 via the retainer packing 185. That is, the force of the spring 184 is transmitted in the order of retainer gland 183, retainer packing 185, and seat retainer 182, working to press the ball seat 168 against the ball valve body 104. This structure ensures tight contact between the ball valve body 104 and the ball seat 168, and between the ball seat 168 and the seat retainer 182. These parts function as seals, preventing fluid leakage from the flow path to the outside.

[0018] The ball seat 168 is made of a resin material or the like, which is softer than metal. Therefore, its outer diameter is supported by an outer ring 167 so that it does not deform when fluid pressure is applied and maintains its shape. The ball seat 168 and the outer ring 167 are fixed to each other by fitting a C-ring 190 into grooves provided on their opposing surfaces.

[0019] The ball valve body 104 is a spherical valve body with a flow path 104a formed through it. The diameter of the flow path 104a is equal to the pipe diameter (length along the Z-axis) of the piping structure 107 extending horizontally (X-axis direction) from the side of the valve chamber 105 and the opening diameter of the end region 152. The ball valve body 104 has an upper surface that connects to the stem 103 and a lower surface on the opposite side, and the lower surface is provided with a convex portion 104b that protrudes downward. Furthermore, the diameter of this convex portion 104b is smaller at the tip portion (protruding end 104b') that is further away from the stem 103 than at the base portion (side) closer to the stem 103. By making the protruding end 104b' smaller in diameter in this way, the protruding end 104b' of the convex portion 104b functions as a guide for fitting into the recess 151a of the valve chamber 105, thus making the installation operation of the ball valve body 104 easier during valve assembly.

[0020] The stem housing section 106 is a cylindrical structure with a tubular axis in the vertical direction (Z direction), and a communication port 106a (housing opening) is provided at its lower end, which communicates with the hollow portion of the central region 151. The opening diameter of the communication port 106a along the horizontal direction is larger than the horizontal diameter of the ball valve body 104. Furthermore, an upper end opening 106b is provided at the upper end of the stem housing section 106, which is larger than the horizontal diameter of the ball valve body 104. In addition, the inner diameter of the intermediate portion 106c, sandwiched between the lower and upper ends of the stem housing section 106, is also larger than the horizontal diameter of the ball valve body 104. Specifically, as shown in Figure 2, the inner diameters of the upper end opening 106b and the intermediate portion 106c are larger than those of the communication port 106a. Thus, because the inner diameter of the stem housing 106 (including the communication port 106a and the upper end opening 106b) is larger than the horizontal diameter of the ball valve body 104, it is possible to lift the ball valve body 104 together with the stem 103 and remove it from the body 101. This allows for maintenance of the ball valve body 104. Conversely, by lowering the ball valve body 104 into the body 101 through the upper end opening 106b, the ball valve body 104 can be installed in the valve chamber 105. In this specification, the type in which the ball valve body 104 etc. can be inserted into and removed from the top of the body 101 is referred to as the "top entry type".

[0021] An intermediate cover 160 is installed in the intermediate portion 106c within the stem housing 106, which presses the ball valve body 104 from above. The intermediate cover 160 allows the stem 103 to operate while liquid-tightly or airtightly partitioning the space (valve chamber 105) on the ball valve body 104 side within the body 101. With the stem 103 passing through it, the intermediate cover 160 seals the communication opening 106a from the stem housing 106 side, partitioning the housing space of the body 101, and rotatably houses the ball valve body 104 within the valve chamber 105. The intermediate cover 160 can be constructed from a plate structure having a trunnion plate 161 and a retaining plate 162 in that order from the side closest to the valve chamber 105, but the intermediate cover 160 is not limited to this plate structure. The attachment of the inner cover 160 to the stem housing 106 ensures that the ball valve body 104 is securely housed in the valve chamber 105. Furthermore, since the communication opening 106a is sealed by the inner cover 160, the ball valve body 104 is prevented from unintentionally flying upward, thus preventing liquid hydrogen from leaking into the stem housing 106.

[0022] Furthermore, a vacuum jacket that is airtightly sealed can be provided on the outside of the body 101. The vacuum jacket can be attached to a flange portion 106d that protrudes laterally from the upper end of the stem housing portion 106 shown in Figure 2.

[0023] As mentioned earlier, the ball valve 110 for liquid hydrogen has a long stem 103 to create a large distance between the operating section 109, which contains components sensitive to low temperatures, and the ball valve body 104 through which the fluid passes. The length of the stem housing section 106 in the vertical direction (Z direction) can be determined by the length of the stem 103.

[0024] The above describes the configuration of the ball valve 110. The ball mounting jig of this embodiment is used to attach the ball valve body 104 and the ball seat 168 to the valve chamber portion 105 (Figure 2) of the body 101 in at least one of the cases when manufacturing or maintaining the ball valve 110 described above.

[0025] <Configuration of the ball mounting jig> Figure 4 is an external perspective view of the ball mounting jig 1 in a state where the ball valve body 104 and the ball seat 168 are held. The ball mounting jig 1 comprises a ball holding part 2 (holding mechanism), a seat support part 4 (holding mechanism), and a drive mechanism 7 (holding mechanism).

[0026] The ball holding portion 2 is an axial structure that holds the ball valve body 104. One end of this axial structure is connected to a stem 103 provided on the upper surface of the ball valve body 104.

[0027] The drive mechanism 7 moves the ball holding part 2 along the axial direction (Z-axis direction). The drive mechanism 7 lowers the ball holding part 2, which holds the ball valve body 104, from the stem housing part 106 (cylindrical part) toward the valve chamber part 105 in the negative Z-axis direction. The drive mechanism 7 includes a device such as a crane that moves the ball holding part 2 from outside the body 101 until it is inserted into the stem housing part 106, and a handle mechanism that is responsible for moving the ball holding part 2 until the ball valve body 104 and ball seat 168 descend from the stem housing part 106 to the valve chamber part 105. The device such as a crane can, as an example, be configured to suspend and lower the ball holding part 2, which holds the ball valve body 104. The handle mechanism is a base that is detachably connected to the upper end of the body 101 by bolts or the like, similar to the handle 199 disposed on the bonnet described above, and has an operating part with a handle that holds the ball holding part 2 so that it can move forward and backward in the Z-axis direction. By rotating the handle, the ball-holding portion 2, which is inserted into the base, can be configured to move forward and backward in the Z-axis direction.

[0028] The seat support portion 4 supports the ball seat 168 by pressing it against the ball valve body 104 held by the ball holding portion 2. Specifically, the seat support portion 4 supports the integrated configuration of the ball seat 168, the outer ring 167 that supports its outer diameter side, and the C-ring 190 that supports the ball seat 168 and the outer ring 167. In other words, the seat support portion 4 supports this integrated configuration by pressing it against the ball valve body 104 held by the ball holding portion 2. In the following, unless otherwise specified, this integrated configuration will be collectively referred to simply as "ball seat 168". However, the "ball seat" in the present invention is not necessarily limited to having such a structure, and as long as it includes a member for sealing the flow path opening of the ball valve body (a so-called ball seat), it is arbitrary whether it has other members, and what kind of members it has.

[0029] The seat support section 4 is connected to the ball holding section 2. The seat support section 4 includes a shutter 5 and an air cylinder 6 (release mechanism, cylinder). The shutter 5 supports the ball seat 168 at an inclination with respect to the rotation axis 104c such that the portion 168b located on the front side with respect to the downward direction of the ball seat 168 is closer to the rotation axis 104c of the ball valve body 104 than the portion 168t located on the rear side. The air cylinder 6 releases the support of the ball seat 168 by the shutter 5.

[0030] As shown in Figure 4, the shutter 5 is a plate-like structure having a contact surface 5a that abuts against the end face of the ball seat 168, that is, the surface facing the retainer 180 (Figure 3) within the valve chamber 105. The contact surface 5a abuts not the entire circumference of the annular end face of the ball seat 168, but the arc portion near the upper surface of the ball valve body 104, and the contact surface 5a presses and supports the ball seat 168 toward the ball valve body 104 in a direction that brings it closer to the rotation axis 104c of the ball valve body 104. In this state, the contact surfaces 5a arranged on both sides of the ball valve body 104 are inclined with respect to the YZ plane such that the distance between the contact surfaces 5a is shorter on the front side in the direction in which the ball valve body 104 descends (negative Z-axis direction) than on the rear side. As a result, the ball seats 168, which are arranged on both sides of the ball valve body 104, are also supported at an inclination with respect to the rotation axis 104c such that the portion 168b located on the front side with respect to the downward direction is closer to the rotation axis 104c of the ball valve body 104 than the portion 168t located on the rear side.

[0031] The size of the contact surface 5a of the shutter 5 is preferably such that it can hold the upper half or more of the portion of the ball seat 168 that protrudes upward when the ball seat 168, tilted by the shutter 5, is inserted into the communication opening 106a and supported at three points: the retainer 180 located in the valve chamber 105, the ball valve body 104, and the contact surface 5a. This prevents problems such as the ball seat 168 falling out due to the release of contact by the contact surface 5a.

[0032] The inclination angle of the contact surface 5a of the shutter 5 with respect to the rotation axis 104c (Z axis) is such that the distance between the portions 168b of the ball seats 168, which are arranged on both sides of the ball valve body 104 and are located on the forward side in the downward direction, is smaller than the length between the openings at both ends of the flow path 104a of the ball valve body 104.

[0033] The air cylinder 6 is positioned with its piston portion 6a extending downwards, and the tip of the piston portion 6a is connected to the shutter 5. When the air cylinder 6 pulls up the piston portion 6a, the shutter 5 is pulled up upwards (approximately in the positive Z-axis direction). This releases the contact between the contact surface 5a of the shutter 5 and the end face of the ball seat 168.

[0034] The following describes the details of the ball mounting jig 1, focusing on the timing of raising the shutter 5, along with the method of mounting the ball valve body 104 and ball seat 168 using the ball mounting jig 1. Figure 5 is a diagram showing the processing flow of the mounting method using the ball mounting jig 1.

[0035] The process flow for installing the ball valve body 104 and the ball seat 168 includes steps S1 to S4 shown in Figure 5; Step S1 (First step): The ball valve body 104 held by the ball holding part 2 and the ball seat 168 supported by the seat support part 4 are lowered from the stem housing part 106 toward the valve chamber part 105 to which the retainer 180 is attached, and the ball seat 168, which is supported by the shutter 5 in an inclined position with respect to the rotation axis 104c of the ball valve body 104, is inserted into the communication opening 106a (housing opening). Step S2 (Second step): After step S1, when the ball seat 168 passing through the communication port 106a is supported between the ball valve body 104 and the retainer 180, the support of the ball seat 168 by the shutter 5 is released by the air cylinder 6. Step S3 (third step): After step S2, the ball seat 168 is lowered together with the ball valve body 104 which is held and lowered by the ball holding part 2. Step S4 (Fourth step): After step S3, when the ball valve body 104 and ball seat 168 are attached to the predetermined locations in the valve chamber 105, the ball retaining part 2 is released from the ball valve body 104, and the ball mounting jig 1 rises and exits the body 101.

[0036] Figure 6 shows the state in which the ball mounting jig 1 is inserted into the body 101 (stem housing 106) from the upper end opening 106b (step S1). At this stage, the retainer 180 is already attached to the end region 152 of the valve chamber 105. The distance between the retainers 180 attached to the end regions 152 on both sides of the valve chamber 105 is smaller than the diameter of the communication opening 106a. That is, as shown in Figure 6, the retainer 180 protrudes from the peripheral wall of the communication opening 106a toward the central axis of the stem housing 106.

[0037] As shown in Figure 6, the ball mounting jig 1 is provided with a positioning rod 8 that is inserted into a bolt fastening portion 101b used for attaching the bonnet 102, which is located on the upper end surface 101a corresponding to the edge of the upper end opening 106b of the stem storage portion 106. The positioning rod 8 is arranged in pairs so that it can be inserted into the bolt fastening portions 101b at both ends of the upper end surface 101a, which are on either side of the center of the upper end opening 106b. By inserting the positioning rod 8 into each bolt fastening portion 101b, the axial structure of the ball holding portion 2 is positioned on the central axis of the stem storage portion 106.

[0038] By centering the axial structure of the ball holding portion 2 using the positioning rod 8 in this way, the rotation axis 104c of the ball valve body 104, which lowers the stem housing portion 106 by the ball mounting jig 1, can be aligned with the central axis of the stem housing portion 106.

[0039] The ball seat 168 is pressed and supported by the seat support portion 4 against the ball valve element at a stage before the ball valve element 104 held by the ball holding portion 2 is inserted into the stem accommodating portion 106. At that stage, as shown in FIG. 6, the seat support portion 4 tilts the ball seat 168 by the shutter 5. The ball seats 168 on both sides of the ball valve element 104 are each tilted by the shutter 5 to assume a tapered posture toward the descending direction. As a result, as described above, the distance t2 between the front portions 168b is configured to be shorter than the length t1 between the openings at both ends of the flow passage 104a of the ball valve element 104. Specifically, the distance t2 between the front portions 168b is smaller than the opening diameter of the communication port 106a, and is smaller than the separation distance t3 between the retainers 180 that protrude from the peripheral wall portion of the communication port 106a toward the central axis. That is, the relationship t2<t3<t1 is satisfied.

[0040] FIG. 7 is a cross-sectional view showing a state in which the ball valve element 104 and the ball seat 168 are further lowered toward the valve chamber portion 105 and pass through the communication port 106a. Since the ball seat 168 is tilted as described above, the front portion 168b of the ball seat 168 descends without coming into contact with the upper portion of the retainer 180. For a while after the front portion 168b of the ball seat 168 passes the upper portion of the retainer 180, the front portion 168b of the ball seat 168 is not in contact with the retainer 180, while in the portion of the ball seat 168 above the front portion 168b, the portion spread by the inclination, specifically, at the position where the distance t4 between the ball seats near the vertical center of the ball seat 168 coincides with the separation distance t3 between the retainers 180, the ball seat 168 comes into contact with the retainer 180, and is sandwiched between the ball valve element 104 and the retainer 180 in a staggered state, and in this state, the ball seat 168 is inserted while pushing the retainer 180 open. As a result, the ball seat 168 starts to be supported by the retainer 180.

[0041] In this manner, the ball seat 168 is supported by the ball valve body 104 and the retainer 180, and when the contact with the contact surface 5a of the shutter 5 is released, the contact with the contact surface 5a is released (second step: S2). The release of the contact surface 5a with respect to the ball seat 168 is performed by the air cylinder 6 as described above. The timing of the release of the contact will be explained using Figure 8.

[0042] Figure 8 is an enlarged view of the dashed-line-enclosed area P in Figure 7. In the state shown in Figure 8, the lower end portion 5b of the shutter 5 is not in contact with the peripheral wall portion of the communication opening 106a. The ball mounting jig 1 of this embodiment is designed to support the ball seat 168 in an inclined state by bringing the inclined contact surface 5a of the shutter 5 into contact with the ball seat 168 until just before the lower end portion 5b of the shutter 5 contacts the upper edge of the peripheral wall portion of the communication opening 106a. Then, just before the lower end portion 5b of the shutter 5 contacts the upper edge of the peripheral wall portion of the communication opening 106a, the piston portion 6a of the air cylinder 6 is pulled upward, thereby pulling the shutter 5 upward and releasing the support of the ball seat 168. Thus, the reason for pulling up the shutter 5 just before its lower end 5b contacts the upper edge of the peripheral wall of the communication opening 106a is that if the shutter 5 were to reach the communication opening 106a and, by any chance, become trapped between the ball valve body 104 and the communication opening 106a together with the ball seat 168, then although the shutter 5 could be pulled up afterward, the sliding motion could cause problems such as damage to the sealing surface of the ball seat 168, which would affect the sealing performance. Therefore, it is necessary to set the lower end 5b of the shutter 5 at a height position such that it does not contact the upper edge of the peripheral wall of the communication opening 106a until the ball seat 168 is supported by the ball valve body 104 and the retainer 180.

[0043] The timing for the air cylinder 6 to raise the piston portion 6a can be determined by an operator operating the drive mechanism 7 visually observing the lowered position of the axial structure of the ball holding portion 2 from outside the upper end opening 106b of the body 101, and the operator presses the switch on the air cylinder 6 at that timing. Since the shutter 5 is connected to the ball holding portion 2, the position of the shutter 5 can be determined by determining the position of the ball holding portion 2. In this embodiment, a mark indicating the timing for pressing the switch may be placed on the axial structure of the ball holding portion 2 at a position visible to the operator. However, the air cylinder 6 may be activated in a manner that detects the lowered position of the ball holding portion 2, etc., and mechanically sends a signal, rather than being limited to visual observation.

[0044] Figure 9 shows the state in which the shutter 5 is raised and the ball valve body 104 and ball seat 168 are attached to predetermined locations in the valve chamber 105 (third step: S3). Here, as shown in Figures 8 and 9, the seat support portion 4 has a seat pressing portion 44 that pushes downward the upper end of the ball seat 168 (more specifically, the upper end of the outer ring 167). The seat pressing portion 44 has a surface that is substantially perpendicular to the contact surface 5a of the shutter 5, and while the seat support portion 4 is supporting the ball seat 168, it is in surface contact with the upper end surface of the ball seat 168. That is, even while the ball seat 168 is tilted by the shutter 5, the seat pressing portion 44 is in surface contact with the upper end of the tilted ball seat 168.

[0045] The sheet pressing portion 44 is formed by the lower end surface of the support base portion 40 of the sheet support portion 4. The support base portion 40 is connected to one end of the first restrictor 41 at an intermediate height position. The other end of the restrictor 41 is connected and fixed to the ball holding portion 2. The restrictor 41 supports the support base portion 40 connected to one end so that it can rotate around the connection point. A second restrictor 42 is connected to the support base portion 40 at a position below the said connection point. At one end of the second restrictor 42, the support base portion 40 is connected so that it can rotate around the Y-axis as its central axis, and at the other end, an elongated hole 43 is provided that is long in the X-axis direction. The ball holding portion 2 is slidably connected to the elongated hole 43. These two restricting bodies 41 and 42 allow the seat support 4 to be tilted by the shutter 5 while supporting the ball seat 168, and to release the tilt, and to always be in surface contact with the upper end surface of the ball seat 168, regardless of whether the ball seat 168 is tilted or not.

[0046] Once the tilt caused by the shutter 5 is released, the ball seat 168 descends in conjunction with the descent of the ball valve body 104, with its outer circumferential surface aligned with the end face of the retainer 180 on the ball valve body 104 side. The ball seat 168 also descends with its inner circumferential surface aligned with the outer circumferential surface of the ball valve body 104. Here, since the inner and outer circumferential surfaces of the ball seat 168 have curved surfaces that match the outer circumferential surface (curved surface) of the ball valve body 104 and the end face (curved surface) of the retainer 180, respectively, contact with these surfaces automatically adjusts the ball seat 168 to a predetermined position and a predetermined inclination (vertical) within the valve chamber 105. As a result, the tilt of the ball seat 168 gradually disappears. At this time, the ball seat 168 descends while sliding against the end face (a surface that constitutes part of the outer circumferential surface) of the retainer 180 attached to the valve chamber 105, and therefore receives resistance from the outer circumferential surface of the retainer 180. Furthermore, the ball valve body 104 also provides resistance from its spherical surface. Therefore, the ball mounting jig 1 uses its seat pressing surface 44 to press down on the ball seat 168 to prevent it from flying upward out of the valve chamber 105. In short, as the ball seat 168 descends together with the ball valve body 104, its inclination angle changes due to contact with the ball valve body 104 and the retainer 180. The seat pressing part 44 adjusts the direction in which it presses the ball seat 168 to match this change in inclination angle, changing from the inclined direction to a direction parallel to the rotation axis of the ball valve body 104 (negative Z-axis direction). As a result, the ball seat 168 is supported between the ball valve body 104 and the retainer 180. Even after the shutter 5 releases its support for the ball seat, simply continuing to press down on the ball seat 168 with the seat pressing part 44 in accordance with the ball valve body 104 will automatically position the ball seat 168 in the optimal location within the valve chamber 105. Conversely, the ball seat 168 only needs to be supported by the seat support section 4 (shutter 5) until it reaches a position where automatic alignment of the ball seat 168 is possible.

[0047] As shown in Figure 9, once the ball valve body 104 and ball seat 168 are attached to the predetermined locations in the valve chamber 105, the connection between the ball holding part 2 and the ball valve body 104 is released. This release can be done by inserting a tool for releasing bolt fastenings into the upper end opening 106b by a worker. The ball mounting jig 1 is then lifted upward by a crane or the like and removed from the body 101 (step S4).

[0048] Following the above procedure, the ball mounting jig 1 attaches the ball valve body 104 and the ball seat 168 to the valve chamber 105.

[0049] According to the ball mounting jig 1 of this embodiment 1, by tilting the ball seat as described above using the shutter 5, the ball seat, which is pressed and supported on both sides of the ball valve body, takes on a tapered shape in the downward direction. Therefore, even in a body 101 (valve chamber 105) where a retainer 180 is already attached to the top-entry type valve chamber 105 and the opening size of the communication port 106a above the valve chamber 105 is limited by the retainer 180, both the ball valve body 104 and the ball seat 168 can be introduced into the valve chamber 105 by pushing and expanding the retainers 180 on both sides from the tapered direction, so that the ball valve body 104 and the ball seat 168 can be attached integrally and well to the valve chamber 105. Furthermore, by using the ball mounting jig 1, the ball valve body 104 and the inclined ball seat 168 are lowered through the stem housing 106 and pass through the communication opening 106a. Once the ball seat is supported between the ball valve body and the retainer even after the biasing force by the shutter 5 is released, the inclination by the shutter 5 can be released by the release mechanism. Therefore, even with a long liquid hydrogen ball valve where the stem housing 106 is long and the worker's hands cannot reach the valve chamber 105, the ball seat 168, together with the ball valve body 104, can be easily introduced into the valve chamber 105 by top entry.

[0050] [Embodiment 2] Other embodiments of the present invention will be described below with reference to Figures 10 to 12. For the sake of clarity, components having the same function as those described in the above embodiments will be denoted by the same reference numerals, and their descriptions will not be repeated.

[0051] In the above-described embodiment 1, the sheet support section 4 is configured to release the tilt of the shutter 5 using an air cylinder 6. In contrast, in this embodiment, the sheet support section 4 is configured to release the tilt of the shutter 5 using a different configuration than the air cylinder 6.

[0052] Figure 10 is an enlarged cross-sectional view showing how the ball valve body 104 and ball seat 168 are attached to the valve chamber portion 105 of the body 101 using the ball mounting jig 1 of this embodiment. Figure 10 shows the stage where the ball valve body 104 and ball seat 168 have descended the stem housing portion 106 and are inserted into the communication opening 106a, and corresponds to Figure 6 in Embodiment 1. In this embodiment, the seat support portion 4 has a locking mechanism 50 that, together with the shutter 5, fixes the shutter 5 in an inclined state. The shutter 5 has the same configuration as described in Embodiment 1, so its description is omitted here.

[0053] The locking mechanism 50 is configured to lower the tilted shutter 5 to a position where it can contact the end face of the ball seat 168 and press the ball seat 168 against the ball valve body 104 for support, and to maintain that position. The position (height) of the shutter 5 can be changed by extending or contracting a spring located above the locking mechanism 50 in the direction of tilt. By extending the spring, the position of the shutter 5 can be set to face the upper part of the end face of the ball seat 168 (the rearward part 168t). The locking mechanism 50 is configured to maintain the spring in the extended position.

[0054] Furthermore, the sheet support section 4 has a mechanism for releasing the tilt of the shutter 5, which includes a contact section 61 that contacts the upper surface of the peripheral wall of the communication opening 106a, and a release section 62 connected to the contact section 61, the release section 62 which acts on the locking mechanism 50 when the contact section 61 contacts the upper surface of the peripheral wall of the communication opening 106a, thereby releasing the fixed tilted state of the shutter 5.

[0055] Figure 11 shows a state in which the ball valve body 104 and ball seat 168 are further inserted into the valve chamber 105 than in the state shown in Figure 10. The state in Figure 11 is the stage in which the ball seat 168 has begun to receive support from the retainer 180. Here, Figure 12 is an enlarged cross-sectional view of the area P enclosed by the dashed line in Figure 11, but for the sake of explanation, it is shown as a cross-sectional view from an oblique angle.

[0056] As shown in Figure 12, the tip of the contact portion 61 is positioned to contact the upper surface of the peripheral wall of the communication opening 106a. The contact of the tip of the contact portion 61 with the upper surface of the peripheral wall of the communication opening 106a restricts the further descent of the contact portion 61. Meanwhile, the ball holding portion 2 continues to descend, and the other components of the sheet support portion 4 also continue to descend. Therefore, the contact portion 61 moves the release portion 62 to slide in the negative X-axis direction shown in Figure 12, and rotates the locking mechanism 50 in the direction indicated by the arrow. Here, the locking mechanism 50 has a hook-type structure as shown in Figure 12, and maintains the tilted position of the shutter 5 by engaging with the projection 46. The release portion 62 can disengage the locking mechanism 50 from the projection 46 by rotating the locking mechanism 50 in the direction indicated by the arrow. As a result, the aforementioned spring contracts, the shutter 5 rises upward, and no longer contacts the ball sheet 168. The subsequent operations are described in Embodiment 1, so they will not be explained here.

[0057] Furthermore, the contact portion 61 is designed so that the position of its tip can be adjusted. For example, the tip is screwed into the base, and the amount of protrusion of the tip relative to the base can be adjusted by adjusting the degree of screwing. By adjusting the position of the tip of the contact portion 61 in this way, it is possible to adjust the timing of the shutter 5 rising, that is, the timing of the release of the tilt support by the shutter 5. Timing adjustment becomes necessary when the contact area with the end face of the ball seat 168 changes, such as when the size of the contact surface 5a of the shutter 5 changes.

[0058] As described above, using the ball mounting jig 1 of this embodiment provides the same effects as the ball mounting jig 1 of Embodiment 1.

[0059] [Variation] As shown in Figures 6 and 10, the ball mounting jig 1 in each of the above embodiments tilts the ball seat 168 by pressing it against the upper part (the rear portion 168t) of the arc-shaped end face of the ball seat 168 while the contact surface 5a of the shutter 5 is tilted. However, the invention is not limited to this embodiment, and any configuration that supports the ball seat 168 at an inclination and releases the inclination when the ball seat 168 reaches a certain position (height) during its descent is acceptable.

[0060] For example, the seat support portion may be equipped with a suction check that is detachably attached to the outer circumferential surface of the ball seat 168 (more precisely, the outer circumferential surface of the outer ring 167 in an integrated configuration of the ball seat 168, the outer ring 167 that supports its outer diameter side, and the C-ring 190 that supports the ball seat 168 and the outer ring 167), and the suction check supports the ball seat 168 by tilting while adhering to its outer circumferential surface.

[0061] In this modified example, the suction check is drawn in by a suction pump located outside the body, and the suction force presses and supports the ball seat 168 against the ball valve body 104. To ensure sufficient suction, it is preferable that multiple suction checks are arranged circumferentially above the outer surface of the ball seat 168.

[0062] In this modified ball mounting jig, by providing a control device for controlling suction, the suction of the suction check can be stopped when the ball seat 168 begins to receive support from the retainer 180 in the valve chamber 105. Subsequent operations can be carried out in the same manner as described in Embodiment 1.

[0063] Furthermore, while the above example shows the ball seat 168 being supported along the ball valve body 104 by a shutter 5 or a suction check, the support of the ball seat is not limited to these methods, and other methods can be applied. For example, a predetermined hole can be provided on the outer circumference of the outer ring 167, and some kind of retaining means can be fixed to that hole. For example, a bolt or a clipper that expands within the hole to hold the object and contracts to release the hold can be applied.

[0064] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims, and these modifications are also included within the technical scope of the present invention.

[0065] 〔summary〕 The ball mounting jig according to embodiment 1 of the present invention is A ball mounting jig used when introducing a ball valve body and a ball seat into the valve chamber of a ball valve, which has a valve chamber having two or more flow path openings (end regions 152) that serve as fluid passages and a housing opening through which a ball valve body can pass, a retainer attached to the flow path opening, and a cylindrical portion connected to the valve chamber via the housing opening, from the cylindrical portion by top entry, The ball mounting jig is configured to introduce the ball valve body and ball seat into the valve chamber portion with the retainer attached. The ball valve body and the ball seat are held by a holding mechanism that moves downward from the cylindrical portion toward the valve chamber portion, The aforementioned holding mechanism is A seat support portion holds the ball valve body along the ball valve body in a state inclined with respect to the rotation axis such that the portion of the ball seat located on the front side with respect to the downward direction is closer to the rotation axis of the ball valve body than the portion located on the rear side, When the ball seat, which has been introduced into the housing opening in an inclined state by the seat support portion together with the ball valve body, is supported by the ball valve body and the retainer, a release mechanism releases the support of the ball seat by the seat support portion. It has.

[0066] According to the configuration of Embodiment 1, even if the ball valve has a longer stem housing portion (cylindrical portion) compared to a top-entry type ball valve, the ball seat can be introduced into the valve chamber together with the ball valve body in a good manner.

[0067] Specifically, by using the seat support portion to tilt the ball seat as described above, the ball valve body and the ball seat, which is pressed and supported by the ball seat, take on a tapered shape in the downward direction. Therefore, when inserting into the housing opening and valve chamber, the ball seat does not come into undesirable contact with the housing opening or the retainer near the housing opening, thus preventing insertion from being hindered.

[0068] Furthermore, when the ball seat is supported between the ball valve body and the retainer, the release mechanism releases the support of the ball seat by the seat support. As a result, the ball seat, now released from the support of the seat support, is inserted into the valve chamber along with the ball valve body, and is supported by the ball valve body and the retainer, and is installed in the appropriate location.

[0069] The ball mounting jig according to embodiment 2 of the present invention, in embodiment 1, The holding mechanism (seat support portion 4) further includes a seat pressing portion that pushes the ball seat downward in accordance with the descent of the ball valve body.

[0070] According to the configuration of the second embodiment described above, the ball seat can be pushed downward by the seat pressing portion, so that the ball seat can be lowered together with the ball valve body, overcoming the resistance caused by the contact between the retainer attached to the valve chamber and the ball seat.

[0071] The ball mounting jig according to embodiment 3 of the present invention, in embodiment 2, As the ball seat descends together with the ball valve body after the support from the seat support is released by the release mechanism, the inclination angle changes due to contact between the ball valve body and the retainer. The aforementioned seat pressing section changes the direction in which it presses the ball seat from the inclined direction to a direction parallel to the rotation axis, in accordance with the change in the inclination angle.

[0072] Once the support from the seat support is released, the ball seat continues to descend while being supported by the ball valve body and the retainer, so that the ball seat becomes parallel to the rotation axis of the ball valve body. According to the configuration of embodiment 3, the direction in which the seat pusher pushes changes in accordance with the change in the inclination angle of the ball seat, so that the seat support can support the ball seat until the ball seat is attached to a predetermined location.

[0073] The ball mounting jig according to embodiment 4 of the present invention is, in embodiments 1 to 3, The sheet support portion has a shutter having a contact surface that contacts the end face of the ball sheet, and the contact surface of the shutter is configured to be inclined. The release mechanism is configured to release the contact between the contact surface of the shutter and the end surface.

[0074] According to the configuration of the above embodiment 4, tilting or releasing the tilt can be achieved by whether or not the shutter comes into contact with the ball seat.

[0075] The ball mounting jig according to embodiment 5 of the present invention, in embodiment 4, The release mechanism pulls the shutter upward above the housing opening, thereby releasing the contact between the contact surface and the end surface.

[0076] According to the configuration of the above embodiment 5, the contact between the contact surface and the end surface can be released by raising the shutter into the space of the stem storage section.

[0077] The ball mounting jig according to embodiment 6 of the present invention is, in embodiment 4 or embodiment 5, The release mechanism has a cylinder connected to the shutter, The shutter is pulled up above the housing opening by the cylinder.

[0078] According to the configuration of embodiment 6, the support by the sheet support is released when the shutter is lifted by the cylinder.

[0079] A ball mounting method for mounting a ball valve body and a ball seat to the valve chamber portion of a ball valve by top entry using a ball mounting jig according to any of the embodiments 1 to 6 described above, A first step involves lowering the ball seat, which is held by the holding mechanism and tilted by the seat support, and the ball valve body toward the valve chamber portion to which the retainer is attached, and inserting them into the housing opening. After the first step, when the ball seat passing through the housing opening is supported between the ball valve body and the retainer, the second step is to release the support of the ball seat by the seat support portion using the release mechanism. A third step is performed after the second step, in which the ball seat and the ball valve body are lowered. Includes.

[0080] According to the configuration of embodiment 7 described above, even if the ball valve has a long stem housing portion (cylindrical portion) compared to a top-entry type ball valve, the ball seat can be introduced into the valve chamber well together with the ball valve body.

[0081] Specifically, by using the seat support portion to tilt the ball seat as described above, the ball valve body and the ball seat, which is pressed and supported by the ball seat, take on a tapered shape in the downward direction. Therefore, when inserting into the housing opening and valve chamber, the ball seat does not come into undesirable contact with the housing opening or the retainer near the housing opening, thus preventing insertion from being hindered.

[0082] Furthermore, when the ball seat is supported between the ball valve body and the retainer, the release mechanism releases the support of the ball seat by the seat support. As a result, the ball seat, with its tilted support released by the seat support, is inserted into the valve chamber along with the ball valve body, and is supported by the ball valve body and the retainer, and is installed in the appropriate position. [Explanation of Symbols]

[0083] 1. Ball mounting jig 2 Ball holding section 4. Seat support section 5 Shutter 5a Contact surface 5b Lower end 6 Air Cylinder 6a Piston section 7. Drive mechanism 8 Positioning rod 40 Support base section 41. First Regulatory Body 42 Second Regulatory Body 43 long hole 46. ​​Protrusion 50 Locking mechanism 61 Contact area 62 Release section 101 Body 101a Upper end surface 103 Stem 104 Ball valve body 104b Convex part 104c Rotation axis 105 Valve chamber 106 Stem storage compartment 106a Communication port 106b Top opening 110 Ball Valve 152 End region (flow channel opening) 168 Ball Sheets 180 Retainer

Claims

1. A ball mounting jig used when introducing a ball valve body and a ball seat into the valve chamber of a ball valve, which has a valve chamber having two or more flow path openings that serve as fluid passages and a housing opening through which a ball valve body can pass, a retainer attached to the flow path opening, and a cylindrical portion connected to the valve chamber via the housing opening, from the cylindrical portion by top entry, The ball mounting jig is configured to introduce the ball valve body and ball seat into the valve chamber portion with the retainer attached. The ball valve body and the ball seat are held by a holding mechanism that moves downward from the cylindrical portion toward the valve chamber portion, The aforementioned holding mechanism is A seat support portion holds the ball valve body along the ball valve body in a state inclined with respect to the rotation axis such that the portion of the ball seat located on the front side with respect to the downward direction is closer to the rotation axis of the ball valve body than the portion located on the rear side, When the ball seat, which has been introduced into the housing opening in an inclined state by the seat support portion together with the ball valve body, is supported by the ball valve body and the retainer, a release mechanism is provided to release the support of the ball seat by the seat support portion before the ball valve body and the ball seat are positioned at predetermined locations in the valve chamber. It has, The retaining mechanism further lowers the ball valve body and the ball seat even after the release mechanism has released the support of the ball seat by the seat support portion. Ball mounting jig.

2. The holding mechanism further includes a seat pressing portion that pushes the ball seat downward in accordance with the descent of the ball valve body. The ball mounting jig according to claim 1.

3. A ball mounting jig for introducing a ball valve body and a ball seat into the valve chamber of a ball valve, which has a valve chamber having two or more flow path openings that form a fluid passage and a housing opening through which a ball valve body can pass, a retainer attached to the flow path opening, and a cylindrical portion connected to the valve chamber via the housing opening, by top entry from the cylindrical portion, The ball mounting jig is configured to introduce the ball valve body and ball seat into the valve chamber portion with the retainer attached. The ball valve body and the ball seat are held by a holding mechanism that moves downward from the cylindrical portion toward the valve chamber portion, The aforementioned holding mechanism is A seat support portion holds the ball valve body along the ball valve body in a state inclined with respect to the rotation axis such that the portion of the ball seat located on the front side with respect to the downward direction is closer to the rotation axis of the ball valve body than the portion located on the rear side, When the ball seat, which has been introduced into the housing opening in an inclined state by the seat support portion together with the ball valve body, is supported by the ball valve body and the retainer, a release mechanism releases the support of the ball seat by the seat support portion. It has, The holding mechanism further includes a seat pressing portion that pushes the ball seat downward in accordance with the descent of the ball valve body. As the ball seat descends together with the ball valve body after the support from the seat support is released by the release mechanism, the inclination angle changes due to contact between the ball valve body and the retainer. The aforementioned seat pressing section changes the direction in which it presses the ball seat from the inclined direction to a direction parallel to the rotation axis in accordance with the change in the inclination angle. Ball mounting jig.

4. A ball mounting jig for introducing a ball valve body and a ball seat into the valve chamber of a ball valve, which has a valve chamber having two or more flow path openings that form a fluid flow path and a housing opening through which a ball valve body can pass, a retainer attached to the flow path opening, and a cylindrical portion connected to the valve chamber via the housing opening, by top entry from the cylindrical portion, The ball mounting jig is configured to introduce the ball valve body and ball seat into the valve chamber portion with the retainer attached. The ball valve body and the ball seat are held by a holding mechanism that moves downward from the cylindrical portion toward the valve chamber portion, The aforementioned holding mechanism is A seat support portion holds the ball valve body along the ball valve body in a state inclined with respect to the rotation axis such that the portion of the ball seat located on the front side with respect to the downward direction is closer to the rotation axis of the ball valve body than the portion located on the rear side, When the ball seat, which has been introduced into the housing opening in an inclined state by the seat support portion together with the ball valve body, is supported by the ball valve body and the retainer, a release mechanism releases the support of the ball seat by the seat support portion. It has, The sheet support portion has a shutter having a contact surface that contacts the end face of the ball sheet, and the contact surface of the shutter is configured to be inclined. The release mechanism is configured to release the contact between the contact surface of the shutter and the end surface. Ball mounting jig.

5. The release mechanism pulls the shutter upward above the housing opening to release the contact between the contact surface and the end surface. The ball mounting jig according to claim 4.

6. The release mechanism has a cylinder connected to the shutter, The shutter is raised above the housing opening by the cylinder. The ball mounting jig according to claim 5.

7. A ball mounting method for a ball valve having a valve chamber having two or more flow path openings that form a fluid flow path and a housing opening through which a ball valve body can pass, a retainer attached to the flow path opening, and a cylindrical portion connected to the valve chamber via the housing opening, wherein a ball valve body and a ball seat are mounted in the valve chamber by top entry from the cylindrical portion, the method comprising: a ball mounting jig, the valve chamber having two or more flow path openings that form a fluid flow path and a housing opening through which a ball valve body can pass, a retainer attached to the flow path opening, and a cylindrical portion connected to the valve chamber via the housing opening, The ball mounting jig is configured to introduce the ball valve body and ball seat into the valve chamber portion with the retainer attached. The ball mounting jig includes a holding mechanism that holds the ball valve body and the ball seat and moves downward from the cylindrical portion toward the valve chamber portion. The aforementioned holding mechanism is A seat support portion holds the ball valve body along the ball valve body in a state inclined with respect to the rotation axis such that the portion of the ball seat located on the front side with respect to the downward direction is closer to the rotation axis of the ball valve body than the portion located on the rear side, When the ball seat, which has been introduced into the housing opening in an inclined state by the seat support portion together with the ball valve body, is supported by the ball valve body and the retainer, a release mechanism releases the support of the ball seat by the seat support portion. It has, The aforementioned ball mounting method is: A first step involves lowering the ball seat, which is held by the holding mechanism and tilted by the seat support, and the ball valve body toward the valve chamber portion to which the retainer is attached, and inserting them into the housing opening. After the first step, when the ball seat passing through the housing opening is supported between the ball valve body and the retainer, the second step is to release the support of the ball seat by the seat support portion using the release mechanism. A third step is performed after the second step, in which the ball seat and the ball valve body are lowered. including, How to attach the ball.

Images