Extension bonnet type rotary valve and assembly method for extension bonnet type rotary valve

Abstract

To provide an extension bonnet type rotary valve that has a simple configuration, prevents fluid from flowing from the valve body to the extension bonnet even in vertical piping, and prevents excessive operating torque, and can be applied to both vertical and horizontal piping. [Solution] The extension bonnet type rotary valve 1 has an extension bonnet 20 with a cylindrical end 21 connected inside the valve body 10, and a stem 30 that is rotatably housed inside the extension bonnet 20 and has a tip portion 30a inserted into the valve chamber 14 of the valve body 10 through the cylindrical end 21 and connected to the valve body 14. The valve has a ring-shaped rotary bearing 60 that rotatably supports the stem 30 such that its inner and outer surfaces 61 and 62a are in surface contact with the inner circumferential surface 21a of the cylindrical end 21 and the outer circumferential surface 32a of the stem 30, respectively.

Description

Technical Field

[0001] The present invention relates to a rotary valve having a valve body that rotates while being connected to a stem, and more particularly to an extension bonnet type rotary valve having an extension bonnet connected to a valve body and a method for assembling the extension bonnet type rotary valve.

Background Art

[0002] Conventionally, in order to prevent leakage of fluid from around the axis of the stem, at least a gland packing is provided on the upper part of the bonnet. For example, in a rotary valve through which a cryogenic fluid of -50 °C class flows, in order to prevent the gland packing from freezing and being damaged by the influence of this cryogenic fluid, or so that the operation handle provided on the upper part of the bonnet does not become too cold, a so-called extension bonnet is provided by extending the bonnet, so that the valve body through which the fluid flows and the gland packing are separated from each other.

[0003] For example, Patent Document 1 describes an extension bonnet valve provided with a gland packing on the upper part of an extension bonnet portion (extension bonnet).

[0004] In this extension bonnet valve, on the valve box side of the valve rod penetrating the extension bonnet portion, a small diameter portion is provided at a position on the valve rod corresponding to the end face on the valve box side of the extension bonnet portion, and one or two ring-shaped or split ring-shaped flanges are fitted into this small diameter portion, and a certain small interval is maintained and corresponded between the upper surface of the flange of the ring and the end face on the valve box side of the extension bonnet portion, and between the inner wall of the gland portion and the outer peripheral surface of the ring or split ring, and an extension bonnet valve configured to form a metal seal portion at the end portion on the valve box side of the extension bonnet portion in an abnormally high temperature state by the ring or split ring is described. However, recently there has been a demand for specifications that allow the flow path provided in the valve body to be used in so-called vertical piping, that is, to be usable in both horizontal and vertical piping.

[0005] For example, Patent Document 2 describes a ball valve having an extension bonnet in which a bearing 15 is provided at the lower end of the valve stem 12 and a gland packing 18 is provided on the lower surface side of the extension bonnet 10. It is believed that the ball valve described in Patent Document 2 can prevent fluid from entering the extension bonnet 10 from inside the valve bodies 2 and 3, even when the piping is vertical, thanks to the gland packing 18. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Jitszen No. 62-73176 [Patent Document 2] Publication No. 61-61377 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the ball valve described in Patent Document 2 requires a gland packing 18 to be provided at the connection point between the extension bonnet 10 and the valve bodies 2 and 3, in addition to the gland packing 12 provided at the top, which results in a problem of a complex configuration. Furthermore, in the ball valve described in Patent Document 2, when installed in vertical piping, the long valve stem 13 passed through the inside of the extension bonnet 10 is prone to tilting relative to the central axis of the bearing 15 due to the clearance between the valve stem and the inner surface of the extension bonnet 10, and the clearance between the valve stem and the inner surface of the bearing 15. Therefore, there was a risk that the valve operating torque would increase because the valve stem 15 would contact the inner circumferential surface of the bearing 15 while tilted with respect to the central axis of the bearing 15.

[0008] The present invention was developed to solve the problems of the past, and its objective is to provide an extension bonnet type rotary valve that can be applied to both vertical and horizontal piping, with a simple configuration, which can prevent fluid from flowing from the valve body to the extension bonnet even in vertical piping, and which can prevent the operating torque from becoming excessive. [Means for solving the problem]

[0009] To achieve the above objective, the invention according to claim 1 is an extension bonnet type rotary valve having an extension bonnet with a cylindrical end connected to a valve body, and a stem rotatably housed within the extension bonnet, the tip of which is inserted into the valve chamber of the valve body through the cylindrical end and connected to a valve body, wherein the extension bonnet type rotary valve has a ring-shaped rotary bearing that rotatably supports the stem such that its inner and outer surfaces make surface contact with the inner surface of the cylindrical end and the outer surface of the stem, respectively.

[0010] The invention according to claim 2 is an extension bonnet type rotary valve in which the rotary bearing has smoothly formed inner and outer surfaces that make surface contact with the inner surface of the cylindrical end and the outer surface of the stem, respectively.

[0011] The invention according to claim 3 is an extension bonnet type rotary valve in which a cylindrical end has an inner circumferential surface that is smaller in diameter than the other end of the extension bonnet, and a rotary bearing has a tapered surface formed at least at the end located on the inner side of the extension bonnet, and is attached to the stem in a manner that restricts the axial movement of the stem.

[0012] The invention according to claim 4 is an extension bonnet type rotary valve in which a rotary bearing has a slit-shaped fluid drainage channel formed connecting both ends.

[0013] The invention according to claim 5 is an extension bonnet type rotary valve in which the rotary bearing is made of a resin material.

[0014] The invention according to claim 6 comprises an extension bonnet having a cylindrical end with a reduced diameter relative to the other end connected to the valve body, a stem rotatably mounted within the extension bonnet and having a tip inserted into the valve body through the cylindrical end connected to a valve body, and a rotating bearing attached to the stem such that a tapered surface is formed at least on the end located on the inner side of the extension bonnet, and the inner and outer surfaces other than the tapered surface are in surface contact with the inner circumferential surface of the cylindrical end and the outer circumferential surface of the stem, and the rotation bearing is attached to the stem in a manner that restricts the axial movement of the stem, and the rotation bearing moves in the axial direction of the stem on the outer circumferential surface of the stem This is an assembly method for an extension bonnet type rotary valve, comprising: a rotary bearing installation step in which the rotary bearing is installed in a restricted state; a stem retaining member installation step in which, with a portion of the stem to which the rotary bearing is installed inserted into the extension bonnet and the tip of the stem exposed in the valve chamber of the valve body, a stem retaining member is attached to the tip of the stem using the space in the valve chamber; and a surface contact position movement guide step in which the stem, with its tip exposed in the valve chamber, is moved by sliding the tapered surface against the inner surface until the inner and outer surfaces of the rotary bearing, other than the tapered surface, are in surface contact with the inner surface of the cylindrical end and the outer surface of the stem.

[0015] The invention according to claim 7 is an assembly method for an extension bonnet type rotary valve, which includes a stem insertion step in which a stem to which a rotary bearing is attached is inserted from the end of the extension bonnet opposite to the cylindrical end toward the cylindrical end which has a smaller diameter inner surface compared to this end, and the tip of the stem is pushed into the valve chamber of the valve body while the tapered surface on the stem insertion side of the rotary bearing is brought into sliding contact with the inner surface of the cylindrical end, and a surface contact position movement guide step in which the stem, which has been pushed into the valve chamber and has its tip exposed in the valve chamber, is pulled back by bringing the tapered surface on the opposite side of the stem insertion side into sliding contact with the inner surface until the inner and outer surfaces of the rotary bearing other than the tapered surface are in surface contact with the inner surface of the cylindrical end and the outer surface of the stem. [Effects of the Invention]

[0016] According to the invention of claim 1, the valve body includes an extension bonnet with a cylindrical end connected to it, a stem rotatably housed within the extension bonnet and having a tip inserted into the valve body through the cylindrical end connected to a valve body, and a ring-shaped rotating bearing that rotatably supports the stem such that its inner and outer surfaces make surface contact with the inner surface of the cylindrical end and the outer surface of the stem, respectively. With this configuration, even in vertical piping, fluid flow from the valve body to the extension bonnet is suppressed by a rotating bearing whose inner and outer surfaces make surface contact with the inner surface of the cylindrical end and the outer surface of the stem, without the need for a sealing member at the connection point between the extension bonnet and the valve body. Furthermore, even with vertical piping, the long stem may tilt relative to the axis of the extension bonnet. To prevent this, a rotating bearing is provided at the cylindrical end where the amplitude of oscillation relative to the axis of the extension bonnet is greater. This bearing eliminates the clearance between the inner surface of the cylindrical end and the stem, allowing the stem to rotate freely so that it aligns with the axis of the extension bonnet. Therefore, according to the invention of claim 1, with a simple configuration, it is possible to prevent fluid from flowing from the valve body to the extension bonnet and to prevent the operating torque from becoming excessive, even in vertical piping, and it can be applied to both vertical and horizontal piping.

[0017] According to the invention of claim 2, the rotating bearing has smoothly formed inner and outer surfaces that make surface contact with the inner surface of the cylindrical end and the outer surface of the stem, respectively. As a result, the rotating bearing can rotate the stem while maintaining close contact with the inner surface of the cylindrical end and the outer surface of the stem, thereby improving the sealing performance of the rotating bearing and further reducing the operating torque.

[0018] According to the invention according to claim 3, the cylindrical end portion has an inner peripheral surface with a reduced diameter with respect to the other end portion of the extension bonnet, and the rotary bearing has a tapered surface formed at least at the end portion located inside the extension bonnet, and is attached to the stem while restricting the axial movement of the stem. When the stem with the rotary bearing attached is inserted from one end of the extension bonnet and assembled to the extension bonnet, when the rotary bearing passes through the reduced-diameter cylindrical end portion of the extension bonnet, the tapered surface starts to contact the inner peripheral surface of the cylindrical end portion, and by this tapered surface, the outer peripheral surface of the rotary bearing is guided to a position where it is in surface contact with the inner peripheral surface of the cylindrical end portion. Therefore, when the stem with the rotary bearing attached is inserted from one end of the extension bonnet and assembled to the extension bonnet, the rotary bearing can pass through the inside of the cylindrical end portion without being caught by the reduced-diameter cylindrical end portion, and the stem can be easily moved to a position where the outer peripheral surface of the rotary bearing is in surface contact with the inner peripheral surface of the cylindrical end portion. As a result, the stem with the rotary bearing attached can be easily assembled to the extension bonnet.

[0019] According to the invention according to claim 4, since the rotary bearing has a slit-shaped fluid drainage channel connecting both ends, even when fluid flows into the extension bonnet and vaporizes, etc., causing the pressure inside the extension bonnet to rise, gas can escape from the inside of the extension bonnet into the valve body through the fluid drainage channel, thus suppressing the pressure rise inside the extension bonnet. Also, when a tapered surface is formed at the end portion of the rotary bearing located inside the extension bonnet, the internal space of the extension bonnet converges due to the tapered surface, becoming the gas inlet side. Therefore, it becomes easier to guide the gas inside the extension bonnet to the inlet, and when the pressure inside the extension bonnet rises, the gas can be efficiently released to the valve body.

[0020] According to the invention according to claim 5, the rotary bearing is made of a resin material, so that a resin material with high heat resistance, chemical resistance and a small friction coefficient can be applied. While exerting durable performance against fluids at low or high temperatures, even when the inner peripheral surface of the cylindrical end portion and the outer peripheral surface of the stem are in a state of surface contact with each other, the friction resistance can be suppressed and the stem can be rotated.

[0021] According to the invention according to claim 6, a rotary bearing mounting step of mounting the rotary bearing on the outer peripheral surface of the stem in a state where movement in the axial direction of the stem is restricted, and a part of the stem on which the rotary bearing is mounted is inserted into the extension bonnet, and the tip of the stem is exposed in the valve chamber of the valve body. A stem retaining member mounting step of mounting a stem retaining member on the tip of the stem using the space in the valve chamber, and a surface contact position moving guide step of moving the stem with the tip exposed in the valve chamber by bringing the tapered surface into sliding contact with the inner peripheral surface until the inner and outer peripheral surfaces other than the tapered surface of the rotary bearing are in surface contact with the inner peripheral surface of the cylindrical end portion and the outer peripheral surface of the stem. By including such steps, when inserting the stem with the rotary bearing attached from one end of the extension bonnet and assembling it to the extension bonnet, in order to attach a retaining member to prevent the stem from coming out to the tip of the stem, when the rotary bearing passes through the reduced-diameter cylindrical end portion of the extension bonnet, the tapered surface starts to contact the inner peripheral surface of the cylindrical end portion, and the outer peripheral surface of the rotary bearing is guided to a position where it is in surface contact with the inner peripheral surface of the cylindrical end portion by this tapered surface. For this reason, the rotary bearing can pass through the inside of the cylindrical end portion without being caught by the reduced-diameter cylindrical end portion, and the stem can be easily moved to a position where the outer peripheral surface of the rotary bearing is in surface contact with the inner peripheral surface of the cylindrical end portion. As a result, the stem with the rotary bearing attached can be easily assembled to the extension bonnet so that the inner and outer peripheral surfaces other than the tapered surface of the rotary bearing are in surface contact with the inner peripheral surface of the cylindrical end portion and the outer peripheral surface of the stem.

[0022] According to the invention of claim 7, in addition to the above steps, the stem to which the rotating bearing is attached is inserted from the end of the extension bonnet opposite to the cylindrical end toward the cylindrical end, and the tip of the stem is pushed into the valve chamber of the valve body while the tapered surface on the stem insertion side of the rotating bearing is brought into sliding contact with the inner circumferential surface of the cylindrical end, and the surface contact position movement guide step is to pull back the stem, which has been pushed into the valve chamber and has its tip exposed therein, by bringing the tapered surface on the opposite side of the stem insertion side into sliding contact with the inner circumferential surface until the inner and outer circumferential surfaces of the rotating bearing other than the tapered surface of the cylindrical end and the outer circumferential surface of the stem are brought into surface contact with the inner circumferential surface. By including this process, a retaining member is attached to the tip of the stem to prevent it from coming loose. When the stem is inserted from the end opposite the cylindrical end of the extension bonnet and then pulled back, the rotating bearing, due to the tapered surfaces formed on both ends of the rotating bearing, passes through the inner surface of the cylindrical end without getting caught on it and returns to a position where it makes surface contact with the inner surface of the cylindrical end again. Therefore, the rotating bearing does not get caught on the reduced diameter cylindrical end, and a retaining member can be attached to the tip of the stem, allowing the stem to be easily moved to a position where the outer surface of the rotating bearing makes surface contact with the inner surface of the cylindrical end. As a result, the stem with the rotating bearing attached can be easily assembled to the extension bonnet so that the rotating bearing makes surface contact with the inner surface of the cylindrical end and the outer surface of the stem, with the outer surfaces of both the inner and outer surfaces other than the tapered surface being in contact. [Brief explanation of the drawing]

[0023] [Figure 1] This is a perspective view of an extension bonnet type rotary valve according to Embodiment 1 of the present invention. [Figure 2] Figure 1 shows a cross-sectional view of an extension bonnet type rotary valve, where (a) shows the horizontal piping configuration and (b) shows the vertical piping configuration. [Figure 3] Figure 2 is an enlarged view of the area around the rotating bearing in the extension bonnet type rotary valve shown. [Figure 4] This is a perspective view of a rotating bearing. [Figure 5] This is a diagram illustrating the assembly procedure for an extension bonnet type rotary valve according to Embodiment 1 of the present invention. [Figure 6] This is a diagram illustrating the assembly procedure for an extension bonnet type rotary valve according to Embodiment 1 of the present invention. [Figure 7] Figure 6(e) is a cross-sectional view of an extension bonnet type rotary valve in the process of assembly. [Figure 8] This is a perspective view of an extension bonnet type rotary valve according to Embodiment 2 of the present invention. [Figure 9] Figure 8 is a perspective view of the rotating bearing. [Figure 10] This is a diagram illustrating the assembly procedure for an extension bonnet type rotary valve according to Embodiment 2 of the present invention. [Figure 11] This is a diagram illustrating the assembly procedure for an extension bonnet type rotary valve according to Embodiment 2 of the present invention. [Figure 12] This is a diagram illustrating the extension bonnet type rotary valve, which is a comparative product. [Modes for carrying out the invention]

[0024] An embodiment of the extension bonnet type rotary valve according to the present invention will be described in detail with reference to Figures 1 to 4. This disclosure is not limited to the embodiments shown below. Furthermore, it should be noted that the drawings are schematic, and the dimensional relationships and proportions of each element may differ from reality. Additionally, there may be differences in dimensional relationships and proportions between different drawings. Figure 1 is a perspective view of an extension bonnet type rotary valve 1 according to Embodiment 1 of the present invention. Figure 2 is a cross-sectional view of the extension bonnet type rotary valve 1 shown in Figure 1, where (a) shows the horizontal piping and (b) shows the vertical piping. Figure 3 is an enlarged view of the area around the rotary bearing 60 provided in the extension bonnet type rotary valve 1 shown in Figure 2. Figure 4 is a perspective view of the rotary bearing 60. The extension bonnet type rotary valve 1 according to Embodiment 1 of the present invention is used, for example, to control low-temperature fluids in the -50°C class, and comprises a valve body 10, an extension bonnet 20 connected to the valve body 10, a stem 30 rotatably inserted into the extension bonnet 20, a valve body 40 connected to the tip 30a of the stem 30 and rotating together with the stem 30, and an operating handle (not shown) detachably provided at the end of the stem 30 protruding from the upper end opening 20a of the extension bonnet 20. Note that the description regarding the vertical direction is based on the extension bonnet type rotary valve 1 in Figure 1, but the description of direction is just one example.

[0025] <About Valve Body 10> The valve body 10 has an inlet-side passage 11 and an outlet-side passage 12 of approximately the same diameter inside, which are connected or blocked via a valve body 40. Flange portions 11a and 12a are provided at the inlet side of the inlet-side passage 11 and the outlet side of the outlet-side passage 12, which serve as connection points to the piping. The valve body 10 has a cylindrical connecting portion 13 that forms a connection to the extension bonnet 20, with an opening formed therein corresponding to the position where the valve body 40 is installed, through which the stem 30 connected to the valve body 40 is inserted.

[0026] In this embodiment 1, the valve body 10 is configured to be divided into two parts: an inlet body 10A on the inlet side in the flow direction and an outlet body 10B on the outlet side in the flow direction. The inlet-side body 10A includes a cylindrical connecting section 13. The inlet body 10A and the outlet body 10B are connected by bolts, and when separated from each other, the valve body 40 can be assembled inside the inlet body 10A.

[0027] In this embodiment 1, the valve body 40 is a ball valve body, and a through passage 42 is formed in the substantially spherical portion 41, which penetrates to substantially the same diameter as the inlet side passage 11 and the outlet side passage 12. The valve body 40 is rotatably supported by annular ball seats 51 and 52, respectively, which are provided on the sides connected to the through passages 42 of the inlet side passage 11 and the outlet side passage 12, so that it can rotate together with the rotation of the stem 30 by operating the handle within the valve chamber 14 provided in the valve body 10.

[0028] <About Extension Bonnet 20> The extension bonnet 20 is roughly cylindrical in shape, with the stem 30 rotatably inserted inside, and its cylindrical end 21 is connected to the inside of the valve body 10.

[0029] The cylindrical end portion 21 has an inner circumferential surface 21a that is smaller in diameter than the other end portion of the extension bonnet 20, and the outer circumferential surface 21b has a connecting step surface 22 that the upper end surface of the cylindrical connecting portion 13 of the valve body 10 abuts against when the cylindrical connecting portion 13 is fitted and connected. The extension bonnet 20 is connected to the valve body 10 by welding or the like, by bringing the upper end surface of the cylindrical connecting portion 13 of the valve body 10 into contact with the connecting stepped surface 22. Such an extension bonnet 20 is formed in a long neck shape with an enlarged axial dimension, and a gland packing P is provided at its upper end to seal the upper end opening 20a with the stem 30 inserted through it, thereby increasing the distance between the valve body 10 through which the low-temperature fluid flows and the gland packing P.

[0030] <About Stem 30> The stem 30 is provided with an enlarged axial dimension to correspond to the extension bonnet 20, and an annular groove 32 is formed at the end that connects to the valve body 40, into which the rotating bearing 60 described later is fitted. This annular groove 32 has a bottom surface 32a and upright side surfaces 32b on both sides of the bottom surface 32a, and is formed in an annular shape on the outer surface of the stem 30.

[0031] The annular groove 32 is dimensionally adjusted to correspond to the rotating bearing 60. In other words, the axial length of the annular groove 32 is adjusted to be approximately equal to, or slightly larger than, the axial length of the rotating bearing 60. The depth of the annular groove 32 is set to a depth that restricts the axial movement of the rotating bearing 60 by causing both end faces of the rotating bearing 60 to abut against each side surface 32b of the annular groove 32.

[0032] Further below the annular groove 32, a valve body connecting portion 43 is provided, which is connected to the valve body 40. Between the valve body connecting portion 43 and the annular groove portion 32, there is a pin hole 45 into which a retaining pin 44, which functions as a stem retaining member to prevent the stem 30 from coming out of the upper end opening 20a of the extension bonnet 20, is fitted with both ends protruding. The retaining pin 44 fitted into the pin hole 45 is designed to prevent the stem 30 from coming out of the upper end opening 20a of the extension bonnet 20 when an external force acts on the stem 30 to pull it out of the upper end opening 20a of the extension bonnet 20. This retaining pin 44 comes into contact with a locking annular projection 13a provided on the inner circumferential surface of the cylindrical connecting portion 13 of the valve body 10.

[0033] For example, when a high-pressure, low-temperature fluid flows, the low-temperature fluid may enter the area between the valve chamber 14 and the valve body 40 (the so-called cavity) from the flow path through gaps such as the through passage 42 of the valve body 40 and the annular ball seats 51 and 52 at an intermediate opening, or through gaps created by the movement of the valve body 40 when fully closed. When this pressure acts on the stem 30, an upward force may be applied to the stem 30, that is, a force that causes it to pop out from the top of the extension bonnet 20. Therefore, a retaining pin 44 is provided at the tip 30a of the stem 30 to prevent the stem 30 from rising when a force is applied in the direction that would cause the stem 30 to fly out. Such retaining pins 44 are made longer than the inner diameter of the locking annular projection 13a of the valve body 10, so that they catch on the locking annular projection 13a when the stem 30 rises. On the other hand, the inner diameter of the locking annular projection 13a is approximately equal to or slightly larger than the inner diameter of the cylindrical end portion 21 of the extension bonnet 20, so that the stem 30 with the retaining pin 44 attached cannot be inserted through the extension bonnet 20. Therefore, when assembling the extension bonnet type rotary valve 1 of this embodiment 1, it is necessary to pass the stem 30 through the extension bonnet 20 without attaching the retaining pin 44, lower the tip 30a of the stem 30 into the valve chamber 14, and then attach the retaining pin 44 to the tip 30a of the stem 30.

[0034] Furthermore, as a stem retaining member, any member other than the retaining pin 44 may be used as long as it can prevent the stem 30 from popping out. For example, an annular ring may be attached to the outer circumference of the tip side of the stem 30 as a stem retaining member to prevent the stem 30 from popping out.

[0035] <About Rotary Bearing 60> The rotating bearing 60 is ring-shaped and combines the function of supporting the rotation of the stem 30 with the function of acting as a seal to suppress the inflow of low-temperature fluid from the valve body 10 to the extension bonnet 20.

[0036] The rotating bearing 60 is a substantially cylindrical member made of, for example, a fluororesin with high heat resistance, chemical resistance, and a low coefficient of friction, and in this embodiment 1, tapered surfaces 62b and 62c are formed at both ends. The rotating bearing 60 is not limited to fluororesin; other materials may be used, but it is more preferable to use a material with high heat resistance, chemical resistance, and a low coefficient of friction. The rotating bearing 60 is mounted on the stem 30 such that its inner and outer surfaces make surface contact with the inner circumferential surface 21a of the cylindrical end portion 21 of the extension bonnet 20 and the outer circumferential surface 21b of the stem 30, and that its axial movement is restricted.

[0037] More specifically, the rotating bearing 60 is fitted into the annular groove 32 of the stem 30, and its outer surface 62a for surface contact is in surface contact with the inner surface 21a of the cylindrical end 21 of the extension bonnet 20. In other words, when the rotating bearing 60 is fitted into the annular groove 32, its inner circumferential surface 61 comes into surface contact with the bottom surface 42a of the annular groove 32. Also, when the stem 30 is positioned in the axial mounting completion position of the extension bonnet 20, the outer circumferential surface 62 of the rotating bearing 60 comes into surface contact with the inner circumferential surface 21a of the cylindrical end 21.

[0038] In this manner, the rotating bearing 60 is positioned so that its outer surface 21b is in surface contact with the inner surface 21a of the reduced diameter cylindrical end 21 of the extension bonnet 20. Therefore, even if the rotating bearing 60 is fitted into the annular groove 32 to restrict axial movement, that is, even if the position of the outer peripheral surface 21b is lowered radially by the depth of the annular groove 32, the radial thickness is kept low, and surface contact can be made with the inner peripheral surface of the extension bonnet 20.

[0039] The outer circumferential surface 62 of the rotating bearing 60 is formed having an outer circumferential surface 62a that can make surface contact with substantially the entire inner circumferential surface 21a of the cylindrical end portion 21, and tapered surfaces 62b and 62c at both ends. On the other hand, the inner circumferential surface 61 of the rotating bearing 60 is formed to have a constant inner diameter in the axial direction and is in surface contact with the bottom surface 42a of the annular groove 32.

[0040] Furthermore, the tapered surfaces 62b and 62c formed at both ends of the rotating bearing 60 are designed to gradually decrease in outer diameter towards the respective end faces 63 and 64 of the rotating bearing 60. The end faces 63 and 64 of the rotating bearing 60 are set to a thickness that allows them to contact the side faces 42b, 42b of the annular groove 32 of the stem 30, thereby restricting the axial movement of the rotating bearing 60.

[0041] The rotating bearing 60 has smoothly formed inner and outer surfaces 61 and 62a that make surface contact with the inner circumferential surface 21a of the cylindrical end portion 21 of the extension bonnet 20 and the outer circumferential surface 31 (bottom surface 32a) of the stem 30, respectively. More specifically, the rotating bearing 60 is surface-treated so that the surface roughness of the inner circumferential surface 61 and the outer circumferential surface 62a for surface contact is kept to a minimum. Furthermore, the outer circumferential surface 62 of the rotating bearing 60 may be smoothly formed over its entire surface, including not only the outer circumferential surface 62a for surface contact but also the tapered surfaces 62b and 62c at both ends. If the tapered surfaces 62b and 62c of the rotating bearing 60 are smoothed, the guiding function of the tapered surfaces 62b and 62c, described later, can be further improved.

[0042] In this way, by forming the inner circumferential surface 61 of the rotating bearing 60 smoothly, the inner circumferential surface 61 of the rotating bearing 60 and the bottom surface 42a of the annular groove portion 32, which is the outer circumferential surface of the stem 30, can be brought into closer contact, thereby reducing friction and allowing the stem 30 to rotate. Furthermore, by smoothly forming the outer circumferential surface 62a of the rotating bearing 60, the outer circumferential surface 62a of the rotating bearing 60 and the inner circumferential surface 21a of the cylindrical end 21 can be brought into closer contact, thereby reducing friction and allowing the stem 30 to rotate. In other words, the rotating bearing 60 not only has the basic function of a rotating bearing that rotatably supports the stem 30, but also functions as a sealing material that suppresses the inflow of fluid from the valve body 10 to the extension bonnet 20. Furthermore, it is preferable to surface-process not only the inner and outer surfaces 61 and 62 of the rotating bearing 60, but also the bottom surface 42a, which is the outer surface of the stem 30 that is in close contact with the rotating bearing 60, and the inner surface 21a of the cylindrical end 21, so that the arithmetic mean roughness (Ra) is 3.2 μm or less, thereby forming a smooth surface. Because the extension bonnet 20 is long, it is difficult to smoothly machine the inner surface on the far side away from the end, but the cylindrical end portion 21 can be easily machined smoothly.

[0043] Furthermore, as shown in Figure 4, the rotating bearing 60 has a slit-shaped fluid drainage channel 65 connecting both ends. In this embodiment 1, the fluid drainage channel 65 is formed in the shape of a slit that diagonally connects one end face and the other end face of the rotating bearing 60. More specifically, the fluid drainage channel 65 in this embodiment is a channel formed by a so-called bias cut. Here, a bias cut refers to a slit-shaped cut where, for example, one end face of a ring-shaped rotating bearing 60 and the other end face are connected at an angle (22 to 45 degrees with respect to the axis of the rotating bearing) and the cut surfaces face each other. When such a bias cut is applied to the fluid drainage channel 65, compared to a slit parallel to the axis of the rotating bearing 60, the distance between the opposing cut surfaces can be increased when attaching the rotating bearing 60 to the stem 30, making it less likely to break or be damaged, and improving the ease of installation and durability of the rotating bearing 60.

[0044] The fluid drainage channel 65 is designed to prevent the flow of low-temperature fluid from the valve body 10 into the extension bonnet 20 by the rotating bearing 60, but it also prevents the pressure inside the extension bonnet 20 from rising if low-temperature fluid does flow into the extension bonnet 20. The fluid venting passage 65 releases gas from the extension bonnet 20 into the valve body 10 when the pressure inside the extension bonnet 20 rises due to the vaporization of the low-temperature fluid that has flowed into the extension bonnet 20, thereby releasing the pressure inside the extension bonnet 20. Furthermore, the fluid drainage channel 65 allows both gas and liquid fluid to escape from inside the extension bonnet 20 into the valve body 10.

[0045] Furthermore, the fluid drainage channel 65 has a tapered surface 62b located on the inner side of the extension bonnet 20 of the rotating bearing 60, which converges the internal space of the extension bonnet 20 into a space that serves as the gas inlet side. Therefore, the rotating bearing 60 facilitates the guidance of gas within the extension bonnet 20 to the inlet of the fluid venting passage 65, and when the pressure inside the extension bonnet 20 rises, the gas can be efficiently released to the valve body 10.

[0046] Furthermore, the shape of the pressure relief channel 65 of the rotating bearing 60 is not limited to a slit shape that diagonally connects one end face and the other end face of the rotating bearing 60. For example, the fluid relief channel may be formed in a curved shape.

[0047] Such a rotating bearing 60 is positioned at the connection point between the extension bonnet 20 and the valve body 10, rotatably supporting the end of the stem 30 on the side connected to the valve body 40, while its inner and outer circumferential surfaces 61 and 62a are in surface contact with the bottom surface 42a of the annular groove 32, which is the outer circumferential surface of the stem 30, and the inner circumferential surface 21a of the extension bonnet 20. Therefore, the rotary bearing 60 prevents the elongated stem 30 from tilting relative to the axis of the extension bonnet 20, even when the extension bonnet type rotary valve 1 is used in vertical piping, as shown in Figure 2(b). Furthermore, the rotating bearing 60 is positioned at the connection point between the extension bonnet 20 and the valve body 10, that is, in the boundary region where the inside of the valve body 10 and the inside of the extension bonnet 20 communicate. The inner and outer surfaces 61 and 62a are in surface contact with the bottom surface 42a of the annular groove 32, which is the outer surface of the stem 30, and the inner surface 21a of the extension bonnet 20, respectively, so as to eliminate the clearances between the stem 30 and the outer surface 31, which would cause low-temperature fluid to flow in, and between the stem 30 and the inner surface 21a of the extension bonnet 20.

[0048] <Assembly procedure for extension bonnet type rotary valve 1> The assembly procedure for the extension bonnet type rotary valve 1 will be explained below with reference to Figures 5-7. Figures 5 and 6 are diagrams illustrating the assembly procedure of the extension bonnet type rotary valve 1 according to Embodiment 1 of the present invention. Figure 7 is a cross-sectional view of the extension bonnet type rotary valve 1 in the process of assembly shown in Figure 6(e). In this assembly procedure, the valve body 10 is shown in a separated state before the outlet body 10B is connected to the inlet body 10A, and the annular ball seats 51 and 52 and the valve body 40 are not set inside the inlet body 10A. In this state, first attach the rotating bearing 60 to the stem 30 (see Figures 5(a) and 5(b)). In this assembly process, the assembler fits the rotating bearing 60 into the annular groove 32 of the stem 30. Since the rotating bearing 60 has a fluid drainage channel 65 formed in the shape of a slit, the assembler can easily fit the rotating bearing 60 into the annular groove 32 while slightly adjusting the inner diameter using the fluid drainage channel 65. In other words, the rotating bearing 60 is fitted into the annular groove 32 of the stem 30 while utilizing the elastic force of the rotating bearing in the radial direction. The rotating bearing 60 may be fitted into the annular groove 32 so that its inner circumferential surface 61 makes surface contact with the bottom surface 42a of the annular groove 32 with radially inward elastic force, or the stem may be positioned in the completed mounting position so that the outer circumferential surface 62a for surface contact makes surface contact with the inner circumferential surface 21a of the cylindrical end 21 with radially outward elastic force, and the inner circumferential surface 61 makes surface contact with the bottom surface 42a of the annular groove 32.

[0049] Next, the stem 30 with the rotating bearing 60 attached is inserted into the extension bonnet 20 through the upper end opening 20a of the extension bonnet 20 (see Figure 5(c)). In this assembly process, as the tip portion 30a of the stem 30 passes through the reduced diameter cylindrical end portion 21 of the extension bonnet 20, the rotating bearing 60 begins to contact the inner circumferential surface 21a of the cylindrical end portion 21 with its lower tapered surface 62c, and this tapered surface 62c guides the stem to a position where the outer circumferential surface 62a for surface contact and the inner circumferential surface 21a of the cylindrical end portion 21 make surface contact. By being guided by the lower tapered surface 62c in this way, the rotating bearing 60 can pass through the cylindrical end 21 without getting caught on the reduced diameter cylindrical end 21.

[0050] Then, insert the stem 30 further into the extension bonnet 20 until the pin hole 45 near the tip of the stem 30 is exposed to the valve chamber 14 of the valve body 10 (see Figure 6(d)). During this assembly process, the stem 30 is inserted into the extension bonnet 20 while the outer circumferential surface 62a of the rotating bearing 60 and the inner circumferential surface 21a of the cylindrical end portion 21 are in sliding contact with each other. In this embodiment 1, the tapered surface 62c on the lower side of the rotating bearing 60 also contacts the inner circumferential surface of the locking annular projection 13a of the valve body 10 below the cylindrical end portion 21, thereby guiding the downward movement of the stem 30. When the stem 30 is moved downward to a position where the pin hole 45 is exposed to the valve chamber 14 of the valve body 10, the upper tapered surface 62b of the rotating bearing 60 is positioned below the cylindrical end 21.

[0051] Next, insert the retaining pin 44 into the pin hole 45 of the stem 30 to attach the retaining pin 44 to the stem 30 (see Figure 6(d)). In this assembly process, the assembler can use the valve chamber 14 as a workspace for inserting the retaining pin 44, allowing them to easily insert the retaining pin 44 into the pin hole 45.

[0052] Next, lift the stem 30 and position it in the completed mounting position within the extension bonnet 20 (see Figure 6(e)). In this assembly process, the assembler pulls up the stem 30, which has been inserted below the completed mounting position in order to install the retaining pin 44, to a position where the outer circumferential surface 62a of the rotating bearing 60, which is the completed mounting position, and the inner circumferential surface 21a of the cylindrical end 21 make surface contact. When the stem 30 is pulled up, the upper tapered surface 62b of the stem 30 begins to come into contact with the inner circumferential surface 21a of the cylindrical end 21, and this tapered surface 62b guides the movement of the stem 30 to a position where the outer circumferential surface 62a for surface contact and the inner circumferential surface 21a of the cylindrical end 21 come into surface contact. In other words, when the stem 30 is pulled back upward, the rotating bearing 60 is guided by the upper tapered surface 62b and positioned within the cylindrical end 21 without getting caught on the reduced diameter cylindrical end 21. Thus, the tapered surfaces 62b and 62c formed at both the upper and lower ends of the rotating bearing 60 facilitate the setting of the retaining pin 44 and also serve to guide the reciprocating vertical movement of the stem 30 relative to the extension bonnet 20, allowing the stem 30 to be easily moved and positioned so that the outer surface 62 of the rotating bearing 60 makes surface contact with the inner surface 21a of the cylindrical end 21.

[0053] As a result of these steps, the stem 30 with the retaining pin 44 attached is positioned in the completed installation location. As shown in Figure 7, the stem 30 is prevented from popping out of the upper end opening 20a of the extension bonnet 20 by restricting its upward movement with the retaining pin 44. Furthermore, the stem 30 is guided by the tapered surfaces 62b and 62c formed at both the upper and lower ends of the rotating bearing 60, and after insertion and withdrawal movements of the stem 30 for the installation of the retaining pin 44, it is finally moved to a position where the outer circumferential surface 62 of the rotating bearing 60 is in surface contact with the inner circumferential surface 21a of the cylindrical end 21 of the extension bonnet 20. As described above, by positioning the stem 30 in the completed mounting position, the outer surface 62a for surface contact may be brought into surface contact with the inner surface 21a of the cylindrical end portion 21, and the inner surface 61 of the rotating bearing 60 may be brought into surface contact with the bottom surface 42a of the annular groove portion 32.

[0054] Then, by assembling various parts such as the annular ball seats 51 and 52 and the valve body 40, and connecting the outlet body 10B to the inlet body 10A, the extension bonnet type rotary valve 1 is completed.

[0055] In the above-described explanation of the assembly procedure for the extension bonnet type rotary valve 1, Figure 5 shows the procedure of inserting the stem 30 into the extension bonnet 20 while the extension bonnet 20 and the inlet-side body 10A are connected. However, it is also acceptable to insert the stem 30 into the extension bonnet 20 first, and then connect the extension bonnet 20 and the inlet-side body 10A.

[0056] <Regarding the valve opening and closing operation of the extension bonnet type rotary valve 1> The extension bonnet type rotary valve 1 is applicable to both vertical and horizontal piping, and while there are no problems when used in horizontal piping, it resolves the problems that arise when used in vertical piping. Therefore, the valve opening and closing operation of the extension bonnet type rotary valve 1 when used in vertical piping will be explained below.

[0057] The extension bonnet type rotary valve 1 rotates in the valve opening and closing direction by rotating an operating handle (not shown).

[0058] The stem 30 is rotatably supported near the end connected to the valve body 40 by a rotating bearing 60, and rotates in the valve opening and closing direction while preventing the flow of low-temperature fluid from the valve body 10 into the extension bonnet 20.

[0059] In the extension bonnet type rotary valve 1, the rotary bearing 60 is positioned at the connecting portion between the extension bonnet 20 and the valve body 10, that is, in the region where the inside of the valve body 10 and the inside of the extension bonnet 20 are in communication, and is provided to eliminate the clearance between the outer circumferential surface 41 of the stem 30, which is a gap through which the low-temperature fluid passes, and the inner circumferential surface 21a of the extension bonnet 20. Therefore, as shown in Figure 2(b), when used in vertical piping, the axis of the extension bonnet 20 becomes horizontal, making it easier for the low-temperature fluid flowing from the inlet side passage 11 to the outlet side passage 12 of the valve body 10 to flow into the extension bonnet 20. However, the rotating bearing 60 prevents the low-temperature fluid from flowing into the extension bonnet 20, thus preventing the low-temperature fluid from circulating inside the extension bonnet 20.

[0060] Furthermore, the rotating bearing 60 rotatably supports the end of the stem 30 that is connected to the valve body 40, with its inner and outer circumferential surfaces 61 and 62a in surface contact with the bottom surface 42a of the annular groove 32, which is the outer circumferential surface of the stem 30, and the inner circumferential surface 21a of the extension bonnet 20, without any clearance between them. Therefore, when the extension bonnet type rotary valve 1 is used in vertical piping, it prevents the elongated stem 30 from tilting relative to the axis of the extension bonnet 20, stably maintaining a state where the stem 30 and the axis of the extension bonnet 20 are aligned, and as a result, prevents the stem 30 from contacting a member that supports the stem 30, such as the gland packing P, in an inclined state. In other words, the extension bonnet type rotary valve 1 is designed to allow valve opening and closing while suppressing an increase in operating torque, even in vertical piping.

[0061] Next, using Table 1, we will explain the results of the valve seat leakage evaluation performed on the extension bonnet type rotary valve 1 of this embodiment 1. In the comparative product, the extension bonnet type rotary valve 100 (hereinafter referred to as the "comparative product"), which is used to compare with the extension bonnet type rotary valve 1 of this embodiment 1, is arranged with a clearance between the rotary bearing 160, which does not form a tapered surface, and the inner circumferential surface 121a of the cylindrical end portion 121 of the extension bonnet 120, as shown in Figure 12. In other words, the comparison product 100 is constructed using a general rotary bearing 160 that is positioned with a clearance between it and the inner circumferential surface 121a of the extension bonnet 120.

[0062] <Evaluation Criteria> The evaluation criteria are as follows. The pipe size is 40A, and the temperature of the cryogenic fluid is -50°C. Furthermore, the test differential pressure (the differential pressure between the inlet and outlet flow paths) was set to 0.2 MPa, 0.6 MPa, and 1.96 MPa.

[0063] [Table 1]

[0064] Table 1 shows the valve seat leakage amount for both horizontal and vertical piping for the comparative product 100, while for the extension bonnet type rotary valve 1 of this embodiment 1, it shows the valve seat leakage amount for vertical piping only.

[0065] <Evaluation results of valve seat leakage amount> As shown in Table 1, the extension bonnet type rotary valve 1 of this embodiment 1 exhibits a valve seat leakage amount similar to that of the vertical piping of the comparative product 100 under the test differential pressure condition of 0.2 (MPa), but under the test differential pressure conditions of 0.6 (MPa) and 1.96 (MPa), it exhibits a valve seat leakage amount similar to that of the horizontal piping of the comparative product 100. In other words, it can be seen that the extension bonnet type rotary valve 1 of this embodiment 1 can reduce the amount of valve seat leakage even when used in vertical piping, compared to a general extension bonnet type rotary valve that is positioned with clearance around the rotary bearing.

[0066] Next, using Table 2, we will explain the results of the evaluation of the operating torque performed on the extension bonnet type rotary valve 1 of this embodiment 1. In evaluating the operating torque, the comparison product used for comparison with the extension bonnet type rotary valve 1 of this embodiment 1 is the same as the comparison product 100 described above.

[0067] <Evaluation Criteria> The evaluation criteria are as follows. The evaluation conditions are the same as those for the valve seat leakage evaluation described above: the pipe size is 40A, and the temperature of the low-temperature fluid is -50°C. Furthermore, the test differential pressure (the differential pressure between the inlet and outlet flow paths) was set to 0.2 MPa, 0.6 MPa, and 1.96 MPa.

[0068] [Table 2]

[0069] Table 2 shows the operating torque for both horizontal and vertical piping when the valve is opened and closed for the comparative product 100, while for the extension bonnet type rotary valve 1 of this embodiment 1, it shows the operating torque when the valve is opened and closed only in vertical piping. Furthermore, the operating torque values ​​shown represent the measurement results for the valve body in the closed, open, and intermediate positions between the closed and open states.

[0070] <Evaluation results of operating torque> As shown in Table 2, the extension bonnet type rotary valve 1 of this embodiment 1 exhibits a significantly lower operating torque compared to the comparative product 100 at all test differential pressures. In other words, it can be seen that the extension bonnet type rotary valve 1 of this embodiment 1 can reduce the operating torque even in vertical piping compared to a typical extension bonnet type rotary valve 100 that has clearance and a rotary bearing 160.

[0071] <Effects of Embodiment 1> As described above, the extension bonnet type rotary valve 1 according to Embodiment 1 includes an extension bonnet 20 with a cylindrical end 21 connected to the valve body 10, a stem 30 rotatably housed within the extension bonnet 20 and having a tip 30a inserted into the valve body 10 through the cylindrical end 21 connected to the valve body 40, and a ring-shaped rotary bearing 60 that rotatably supports the stem such that the inner and outer surfaces 61 and 62a of the inner and outer surfaces 61 and 62a of the stem 30 make surface contact with the inner circumferential surface 21a of the cylindrical end 21 and the outer circumferential surface 62a of the stem 30, respectively. With this configuration, even in vertical piping, the flow of low-temperature fluid from the valve body 10 to the extension bonnet 20 is suppressed by a rotating bearing 60 in which the inner and outer surfaces 61 and 62a of the cylindrical end 21 and the outer surface 62a of the stem 30, respectively, are in surface contact with each other, without the need for a sealing member at the connection between the extension bonnet 20 and the valve body 10. Furthermore, even in the case of vertical piping, the long stem 30 tilts relative to the axis of the extension bonnet 20. To prevent this, a rotating bearing 60 is provided on the cylindrical end 21 side, where the amplitude of oscillation relative to the axis of the extension bonnet 20 is larger. This bearing eliminates the clearance between the inner circumferential surface 21a of the cylindrical end 21 and the stem 30, thereby rotatably supporting the stem 30 so that it aligns with the axis of the extension bonnet 20. Therefore, according to the extension bonnet type rotary valve 1 of Embodiment 1, even with a simple configuration, it is possible to prevent fluid from flowing from the valve body 10 to the extension bonnet 20 and to prevent the operating torque from becoming excessive, even in vertical piping, and it can be applied to both vertical and horizontal piping.

[0072] Furthermore, according to the extension bonnet type rotary valve 1 of Embodiment 1, the rotary bearing 60 has a thickness such that it is in close contact with the stem 30 and the inner circumferential surface 21a, that is, a thickness slightly greater than the dimension between the stem 30 and the inner circumferential surface 21a, and the rotary bearing 60 has a thickness such that it is in close contact without hindering the rotation function. Due to this thickness, the elastic force of the rotary bearing 60 acts in the inner and outer diameter directions of the rotary bearing 60. As a result, the rotary bearing 60 is tightly sealed between the stem 30 and the inner circumferential surface 21a, suppressing fluid leakage and ensuring sealing performance. Therefore, by making the rotary bearing 60 tightly contact the outer circumferential surface 62a of the stem 30 for surface contact, it is possible to reduce the operating torque and achieve a tight seal.

[0073] Furthermore, according to the extension bonnet type rotary valve 1 of Embodiment 1, the rotary bearing 60 has smoothly formed inner and outer surfaces 61 and 62 that come into surface contact with the inner circumferential surface 21a of the cylindrical end 21 and the outer circumferential surface 62a of the stem 30, respectively. As a result, the rotary bearing 60 can rotate the stem 30 while maintaining close contact with the inner circumferential surface 21a of the cylindrical end 21 and the outer circumferential surface 62a of the stem 30, thereby reducing frictional resistance. This improves the sealing performance of the rotary bearing 60 and further reduces the operating torque.

[0074] Furthermore, according to the extension bonnet type rotary valve 1 of Embodiment 1, the cylindrical end portion 21 has an inner circumferential surface 21a that is smaller in diameter than the other end portion of the extension bonnet 20, and the rotary bearing 60 is attached to the stem with tapered surfaces 62b and 62c formed at both ends of the extension bonnet 20, and the axial movement of the stem 30 is restricted. When the stem 30 with the rotary bearing 60 attached is inserted into the extension bonnet 20 through the upper end opening 20a and assembled to the extension bonnet 20, as the rotary bearing 60 passes through the smaller diameter cylindrical end portion 21 of the extension bonnet 20, each tapered surface 62b and 62c begins to come into contact with the inner circumferential surface 21a of the cylindrical end portion 21, and each tapered surface 62b and 62c guides the outer circumferential surface 62a of the rotary bearing 60 to a position where it makes surface contact with the inner circumferential surface 21a of the cylindrical end portion 21. Therefore, when inserting the stem 30 with the rotating bearing 60 attached through the upper end opening 20a of the extension bonnet 20 and assembling it to the extension bonnet 20, the rotating bearing 60 can pass through the cylindrical end 21 without getting caught on the reduced diameter cylindrical end 21, and the stem 30 can be easily moved to a position where the outer circumferential surface 62a of the rotating bearing 60 makes surface contact with the inner circumferential surface 21a of the cylindrical end 21. As a result, the stem 30 with the rotating bearing 60 attached can be easily assembled to the extension bonnet 20.

[0075] Furthermore, according to the extension bonnet type rotary valve 1 of Embodiment 1, the rotary bearing 60 has a slit-shaped fluid venting passage 65 connecting both ends. Therefore, even if fluid flows into the extension bonnet 20 and vaporizes, causing the pressure inside the extension bonnet 20 to rise, the gas is released from the extension bonnet 20 into the valve body 10 through the fluid venting passage 65, thereby suppressing the pressure rise inside the extension bonnet 20. Furthermore, if a tapered surface 62b is formed at the end of the rotating bearing 60 located on the inner side of the extension bonnet 20, the space converged by the tapered surface 62b within the extension bonnet 20 becomes the gas inlet side. This makes it easier to guide the gas inside the extension bonnet 20 to the inlet, and allows the gas to be efficiently released to the valve body 10 when the pressure inside the extension bonnet 20 rises.

[0076] Furthermore, according to the extension bonnet type rotary valve 1 of Embodiment 1, the rotary bearing 60 is made of a resin material, which allows the application of a resin material with high heat resistance, chemical resistance, and a low coefficient of friction. This allows for durability even against low or high temperature fluids, and enables the rotation of the stem 30 while suppressing frictional resistance even when the inner circumferential surface 21a of the cylindrical end 21 and the outer circumferential surface 62a of the stem 30 are in surface contact with each other.

[0077] Furthermore, according to the assembly method of the extension bonnet type rotary valve according to Embodiment 1, the rotary bearing 60 is attached to the outer peripheral surface 62a of the stem 30 for surface contact, with movement restricted in the axial direction of the stem 30, and the stem insertion step is to insert the stem 30 with the rotary bearing 60 attached from the upper end opening 20a of the end opposite to the cylindrical end 21 of the extension bonnet 20 toward the cylindrical end 21, and push out the tip 30a of the stem 30 so that it is exposed to the valve chamber 14 in the valve body 10 while the lower tapered surface 62c of the rotary bearing 60 slides against the inner peripheral surface 21a of the cylindrical end 21, and the rotary bearing The process includes: a stem retaining member installation step in which a retaining pin 44 is attached to the tip 30a of the stem 30 using the space in the valve chamber 14, with a portion of the stem 30 to which the bearing 60 is attached inserted into the extension bonnet 20, and the tip 30a of the stem 30 exposed in the valve chamber 14 of the valve body 10; and a surface contact position movement guiding step in which the stem 30, with its tip 30a exposed in the valve chamber 14, is pulled back by sliding the upper tapered surface 62b against the inner surface 21a until the inner and outer surfaces 61 and 62a of the rotating bearing 60, other than the tapered surface, are in surface contact with the inner surface 21a of the cylindrical end 21 and the outer surface 62a of the stem 30 for surface contact. By including this process, in order to attach the retaining pin 44 that prevents the stem from coming out to the tip 30a of the stem 30, when the stem 30 is inserted from the upper end opening 20a of the extension bonnet 20 on the side opposite to the cylindrical end 21 and then pulled back, the rotating bearing 60 is returned to a position where it makes surface contact with the inner circumferential surface 21a of the cylindrical end 21 without getting caught on the cylindrical end 21, thanks to the tapered surfaces 62b and 62c formed on both ends of the rotating bearing 60. Therefore, the rotating bearing 60 does not get caught on the reduced diameter cylindrical end 21, and the retaining pin 44 can be attached to the tip 30a of the stem 30, allowing the stem 30 to be easily moved to a position where the outer surface 62a of the rotating bearing 60 makes surface contact with the inner surface 21a of the cylindrical end 21. As a result, the stem 30 with the rotating bearing 60 attached can be easily assembled to the extension bonnet 20 so that the rotating bearing 60 makes surface contact with the inner surface 21a of the cylindrical end 21 and the bottom surface 42a of the annular groove 32, which is the outer surface 41 of the stem 30, with the inner and outer surfaces 61 and 62a, respectively, other than the tapered surfaces 62b and 62c.

[0078] (Embodiment 2) Next, the extension bonnet type rotary valve 2 according to Embodiment 2 will be described with reference to Figures 8 and 9. Figure 8 is a perspective view of an extension bonnet type rotary valve 2 according to Embodiment 2 of the present invention. Figure 9 is a perspective view of the rotary bearing shown in Figure 8. In Embodiment 2, the same reference numerals are used for the same parts as in Embodiment 1, thereby omitting redundant explanations. The extension bonnet type rotary valve 2 of this embodiment 2 differs from the extension bonnet type rotary valve 1 of embodiment 1 in that a tapered surface 162b is provided only at one end of the rotary bearing 160, and the assembly method also differs from the assembly method of the extension bonnet type rotary valve of embodiment 1.

[0079] The extension bonnet type rotary valve 2 according to this second embodiment includes a valve body 10, an extension bonnet 20 connected to the valve body 10, a stem 30 rotatably inserted into the extension bonnet 20, a valve body 40 connected to the tip 30a of the stem 30 and rotating together with the stem 30, and an operating handle (not shown) detachably provided on the end of the stem 30 that protrudes from the upper end opening 20a of the extension bonnet 20.

[0080] <About Rotary Bearing 160> The rotating bearing 160 serves both to support the rotation of the stem 30 and as a sealing material to prevent the intrusion of low-temperature fluid from the valve body 10 into the extension bonnet 20.

[0081] The rotating bearing 70 is, for example, a substantially cylindrical member made of fluororesin, and in this second embodiment, a tapered surface 62b is formed only at one end. The rotating bearing 70 is mounted on the stem 30 such that its inner and outer surfaces 71 and 72a are in surface contact with the inner circumferential surface 21a of the cylindrical end 21 of the extension bonnet 20 and the bottom surface 42a of the annular groove 32 which is the outer circumferential surface 41 of the stem 30, and in a manner that restricts the axial movement of the stem 30.

[0082] Furthermore, as shown in Figure 9, the rotating bearing 70, like the rotating bearing 60 in Embodiment 1, has a slit-shaped fluid drainage channel 75 connecting both ends.

[0083] <Assembly procedure for extension bonnet type rotary valve 2> The assembly procedure for the extension bonnet type rotary valve 2 will be explained below with reference to Figure 10. Figures 10 and 11 are diagrams illustrating the assembly procedure of the extension bonnet type rotary valve 2 according to Embodiment 2 of the present invention. In this assembly procedure, the valve body 10 is shown in a separated state before the outlet body 10B is connected to the inlet body 10A, and the annular ball seats 51 and 52 and the valve body 40 are not set inside the inlet body 10A. In this state, first attach the rotating bearing 70 to the stem 30 (see Figures 10(a) and 10(b)). In this assembly process, the assembler fits the rotating bearing 70 into the annular groove 32 of the stem 30.

[0084] Next, the stem 30 with the rotating bearing 70 attached is inserted into the extension bonnet 20 from the cylindrical end 21 at the lower end of the extension bonnet 20 (see Figure 10(c)).

[0085] Next, the extension bonnet 20 is connected to the inlet-side body 10A so that the pin hole 45 near the tip of the stem 30 is exposed to the valve chamber 14 of the valve body 10, and the retaining pin 44 is then inserted into the pin hole 45 to attach the retaining pin 44 to the stem 30 (see Figure 10(d)). In this assembly process, the assembler can easily insert the retaining pin 44 into the pin hole 45 by utilizing the space in the valve chamber 14.

[0086] Next, lift the stem 30 and position it in the completed mounting position within the extension bonnet 20 (see Figure 5(e)). In this assembly process, the assembler pulls up the stem 30, which is located below the completed mounting position, to a position where the outer circumferential surface 72a of the rotating bearing 70, which is the completed mounting position, and the inner circumferential surface 21a of the cylindrical end 21 make surface contact. When the stem 30 is pulled up, the tapered surface 62b of the rotating bearing 70 begins to come into contact with the inner circumferential surface 21a of the cylindrical end 21, and this tapered surface 62b guides the movement of the stem 30 to a position where the surface contact outer circumferential surface 72a and the inner circumferential surface 21a of the cylindrical end 21 make surface contact. In other words, when the stem 30 is pulled upward, the rotating bearing 70 can be positioned inside the reduced-diameter cylindrical end 21 without getting caught on it. Through the assembly work performed up to this point, the retaining pin 44 is set in the stem 30, and the stem 30 is positioned in the completed mounting position where the rotating bearing 70 makes surface contact with the inner circumferential surface 21a of the cylindrical end 21.

[0087] Then, various parts such as the annular ball seats 51 and 52 and the valve body 40 are assembled, and the outlet body 10B is connected to the inlet body 10A to complete the extension bonnet type rotary valve 2. In the extension bonnet type rotary valve 2, if the stem 30 moves upward, a retaining pin 44 attached to the stem 30 catches on a locking annular projection 13a of the valve body 10, preventing it from moving upward.

[0088] <Effects of Embodiment 2> As described above, the extension bonnet type rotary valve 2 according to Embodiment 2 provides the same effects as the extension bonnet type rotary valve 1 according to Embodiment 1.

[0089] Furthermore, according to the assembly method of the extension bonnet type rotary valve 2 according to Embodiment 2, the rotary bearing mounting step involves attaching the rotary bearing 70 to the annular groove portion 32 of the stem 30 in a state where movement of the stem 30 is restricted in the axial direction of the stem 30, and inserting a part of the stem 30 to which the rotary bearing 160 is attached into the extension bonnet 20, and with the tip portion 30a of the stem 30 exposed in the valve chamber 14 of the valve body 10, the space of the valve chamber 14 is The process includes a stem retaining member attachment step, which involves using the stem 30 to attach a retaining pin 44 to the tip 30a of the stem 30, and a surface contact position movement guiding step, which involves moving the stem 30, with its tip 30a exposed in the valve chamber 14, by sliding the tapered surface 62b against the inner surface 21a until the inner and outer surfaces 71 and 72a of the rotating bearing 70, other than the tapered surface 62b, are in surface contact with the inner surface 21a of the cylindrical end 21 and the bottom surface 42a of the annular groove portion 32, which is the outer surface 41 of the stem 30. By including this process, in order to attach a retaining pin 44 to the tip 30a of the stem 30 to prevent the stem 30 from coming loose, when the stem 30 with the rotating bearing 70 attached is inserted into the extension bonnet 20 from the reduced diameter cylindrical end 21 at the lower end of the extension bonnet 20 and assembled to the extension bonnet 20, the rotating bearing 70 begins to come into contact with the inner circumferential surface 21a of the cylindrical end 21 with its tapered surface 62b, and this tapered surface 62b guides the outer circumferential surface 72a of the rotating bearing 70 to a position where it makes surface contact with the inner circumferential surface 21a of the cylindrical end 21. Therefore, the rotating bearing 70 can be positioned inside the reduced-diameter cylindrical end 21 without getting caught on it, and the stem 30 can be easily moved to a position where the outer surface 72a of the rotating bearing 70 makes surface contact with the inner surface 21a of the cylindrical end 21. As a result, the stem 30 with the rotating bearing 70 attached can be easily assembled to the extension bonnet 20 so that the rotating bearing 70 makes surface contact with the inner surface 21a of the cylindrical end 21 and the bottom surface 42a of the annular groove portion 32, which is the outer surface of the stem 30, with all surfaces except the tapered surface 62b in contact.

[0090] While embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above, and various modifications are possible without departing from its spirit.

[0091] In embodiments 1 and 2 described above, a ball valve, in which the valve body is a ball, was used as the extension bonnet type rotary valve. However, the extension bonnet type rotary valve is not limited to a ball valve; other types of rotary valves may also be used. For example, a butterfly valve may be used as the extension bonnet type rotary valve.

[0092] Furthermore, while embodiments 1 and 2 described above illustrate the use of low-temperature fluids through extension bonnet-type rotary valves 1 and 2, extension bonnet-type rotary valves can also be applied to systems through which high-temperature fluids flow. [Explanation of Symbols]

[0093] 1, 2 Extension Bonnet Type Rotary Valve 10 Valve Body 14 valve chambers 20 Extension Bonnet 21 Cylindrical end 21a Inner surface 30 Stem 30a Tip 31 Outer surface 32a Bottom surface (outer surface) 44 Retaining pin (retaining component) 40 valve body 60, 70 rotational bearings 61, 71 Inner surface 62, 72 outer surface 62a, 72a Outer surface for surface contact 62b, 62c Tapered surface 65, 75 Fluid drainage channel

Claims

1. An extension bonnet type rotary valve having an extension bonnet with a cylindrical end connected to the valve body, and a stem rotatably housed within the extension bonnet, with its tip inserted into the valve chamber of the valve body through the cylindrical end and connected to the valve body, An extension bonnet type rotary valve characterized by having a ring-shaped rotary bearing that rotatably supports the stem such that its inner and outer surfaces make surface contact with the inner surface of the cylindrical end and the outer surface of the stem, respectively.

2. The extension bonnet type rotary valve according to claim 1, wherein the rotary bearing has smoothly formed inner and outer surfaces that make surface contact with the inner surface of the cylindrical end and the outer surface of the stem, respectively.

3. The cylindrical end has an inner circumferential surface that is smaller in diameter than the other end of the extension bonnet. The extension bonnet type rotary valve according to claim 1 or 2, wherein the rotary bearing has a tapered surface formed at least at the end located on the inner side of the extension bonnet, and is attached to the stem in a manner that restricts the axial movement of the stem.

4. The extension bonnet type rotary valve according to claim 1 or 2, wherein the rotary bearing has a slit-shaped fluid drainage channel connecting both ends.

5. The extension bonnet type rotary valve according to claim 1, wherein the rotary bearing is made of a resin material.

6. A method for assembling an extension bonnet type rotary valve, comprising: an extension bonnet with a cylindrical end connected to the valve body, the other end of which is reduced in diameter; a stem rotatably mounted within the extension bonnet, the tip of which is inserted into the valve body through the cylindrical end and connected to a valve body; and a rotary bearing attached to the stem in a state in which at least the inner end of the extension bonnet has a tapered surface, the inner and outer surfaces other than the tapered surface are in surface contact with the inner surface of the cylindrical end and the outer surface of the stem, and the axial movement of the stem is restricted. A rotating bearing mounting step involves mounting the rotating bearing to the outer circumferential surface of the stem in a state where its movement in the axial direction of the stem is restricted. A stem retaining member installation step involves inserting a portion of the stem to which the rotating bearing is attached into the extension bonnet, and with the tip of the stem exposed in the valve chamber of the valve body, and using the space in the valve chamber to attach the stem retaining member to the tip of the stem, A method for assembling an extension bonnet type rotary valve, comprising a surface contact position movement guide step, which involves moving the stem, with its tip exposed in the valve chamber, by sliding the tapered surface against the inner surface until the inner and outer surfaces of the rotary bearing other than the tapered surface make surface contact with the inner surface of the cylindrical end and the outer surface of the stem.

7. The process includes inserting the stem to which the rotating bearing is attached into the extension bonnet from the end opposite to the cylindrical end toward the cylindrical end, and pushing the tip of the stem into the valve chamber of the valve body while the tapered surface on the stem insertion side of the rotating bearing slides against the inner circumferential surface of the cylindrical end, The method for assembling an extension bonnet type rotary valve according to claim 6, wherein the surface contact position movement guiding step involves pushing the tip of the stem into the valve chamber, exposing the tip of the stem to the valve chamber, and then pulling the stem back by sliding the tapered surface on the side opposite to the tapered surface on the stem insertion side against the inner surface until the inner and outer surfaces of the rotating bearing other than the tapered surface make surface contact with the inner surface of the cylindrical end and the outer surface of the stem.

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