Special low-temperature ball valve for liquefied natural gas

Abstract

According to the special low-temperature ball valve for liquefied natural gas, the lower end of a ball body is radially positioned in an installation cavity of a left valve body, a left valve seat which is located on the left side of the ball body and is attached and matched with the outer spherical surface of the left side of the ball body is installed in the installation cavity of the left valve body in a sealed mode, and a right valve body and the left valve body are detachably connected into a whole in a sealed mode. The lower end of a valve rod arranged in a center hole of the lengthening rod in a penetrating mode penetrates out of a through hole in the upper end face of the left valve body and is connected with the upper end of the ball in a matched mode, and the valve rod is rotated through a handle arranged above the lengthening rod and connected with the valve rod in a matched mode. On-off control of a ball center channel and channels in the left valve body and the right valve body is achieved. The ball valve structure is optimized, the problem of leakage caused by uneven stress distribution is solved, under the action of the right valve seat elastically installed in the right valve body, sealing under reliable contact with the ball body is achieved, the leakage risk is eliminated, the ball body is accurately positioned, and the installation efficiency is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of pipeline accessories, and in particular relates to a special low-temperature ball valve for liquefied natural gas. Background Art

[0002] Faced with increasingly severe ecological and environmental pollution, people are turning to natural gas as a clean, efficient, and high-quality energy and fuel to optimize energy consumption and improve the atmospheric environment. Both industrial and civilian applications are increasingly reliant on natural gas. Liquefied natural gas (LNG), the liquid form of natural gas, offers advantages over its gaseous form in certain circumstances. Due to the characteristics of liquefied natural gas and gaseous natural gas, liquefied natural gas has a wider range of uses than gaseous natural gas. The ball of the ball valve is floating. Under the action of the medium pressure, the ball can produce a certain displacement and press tightly on the sealing surface of the outlet end. Liquefied natural gas is equipped with a special ball valve. The function of the ball valve is mainly used to cut off, distribute and change the flow direction of the medium on the pipeline. The ball of the ball valve is floating. Under the action of the medium pressure, the ball can produce a certain displacement and press tightly on the sealing surface of the outlet end. Since the ball is directly connected to the valve stem, the stress distribution is uneven during the process of rotating the lower floating ball to control the on and off of the ball valve, which can easily lead to leakage; at the same time, the valve body cavity is larger than the ball diameter. After the ball and valve seat are placed, the ball cannot be accurately positioned, which is not conducive to the rapid installation of the ball. Therefore, it is necessary to make improvements to the above problems. Utility Model Content

[0003] The technical problem solved by the present invention is as follows: a special low-temperature ball valve for liquefied natural gas is provided, by optimizing the ball valve structure, the lower end of the ball is positioned in the installation cavity of the left valve body, and when the valve stem connected to the upper end of the ball drives the ball to rotate, the positioning and support of the rotation center of the ball are achieved, ensuring uniform stress distribution, ensuring that the contact surfaces with the left valve seat and the right valve seat are uniformly stressed, solving the problem of leakage caused by uneven stress distribution, and optimizing the sealing installation structure of the left valve seat and the right valve seat in the left valve body and the right valve body respectively. Under the action of the right valve seat elastically installed in the right valve body, sealing is achieved under reliable contact with the ball, eliminating the risk of leakage, simple structure, novel design, precise ball positioning, no need to adjust the position of the ball in the left valve body, and improved installation efficiency.

[0004] The technical solution adopted by the present utility model is a special low-temperature ball valve for liquefied natural gas, comprising a left valve body, a right valve body, a ball, a valve stem and an extension rod, the lower end of the ball being radially positioned in the mounting cavity of the left valve body, and a left valve seat located on the left side of the ball and fittingly matched with the left outer spherical surface of the ball is sealed in the mounting cavity of the left valve body, the right valve body and the left valve body are detachably sealed and connected as one, and the right valve seat elastically positioned and installed at the left end of the inner hole of the right valve body fits closely with the right outer spherical surface of the ball, the lower end of the extension rod is adapted and fixedly connected to the upper end face of the left valve body, and the lower end of the valve stem arranged in the center hole of the extension rod passes through the through hole on the upper end face of the left valve body and is adapted and connected to the upper end of the ball, and the valve stem is rotated by a handle arranged above the extension rod and adapted and connected to the valve stem to realize on-off control of the center channel of the ball and the channels in the left valve body and the right valve body.

[0005] Among them, a positioning boss with a hemispherical lower end is fixed in the middle of the outer wall of the lower end of the sphere, and a long groove is made on the cavity wall of the lower end of the left valve body installation cavity, and the positioning boss is adapted to be positioned in the long groove to achieve radial positioning of the sphere in the left valve body installation cavity.

[0006] Furthermore, the width of the long groove is 0.5mm to 2mm larger than the diameter of the positioning boss ball head, and the left end groove wall of the long groove is a vertical surface while the right end groove wall is transitionally connected to the lower end inner wall of the left valve body cavity through an arc surface.

[0007] Furthermore, the positioning boss is symmetrically arranged with respect to a square groove provided in the middle of the outer wall of the upper end of the sphere and adapted to the lower end of the valve stem.

[0008] Furthermore, a square boss is integrally provided in the middle of the lower end surface of the valve stem, and the square boss is adapted to the square groove in the middle of the outer wall of the upper end of the sphere.

[0009] Furthermore, a sealing ring is provided between the right side wall of the left valve seat and the right side positioning groove wall of the left valve body installation cavity.

[0010] Furthermore, a graphite fireproof ring is provided in the annular groove arranged on the right end surface of the left valve body, which contacts the large step surface on the left end of the right valve body. The small diameter section on the left end of the right valve body is adapted to the center hole on the left end of the left valve body. The annular groove at the right end hole edge of the left valve body is adapted to the positioning ring on the left end outer wall of the right valve body, and a sealing ring is provided between the groove surface of the annular groove at the right end hole edge of the left valve body and the ring surface of the positioning ring on the left end outer wall of the right valve body.

[0011] Furthermore, the right valve seat is adapted in the inner hole of the large diameter section of the right valve body, and the spring adapted in the hole groove on the step surface of the inner hole of the right valve body is fixedly connected to the left end face of the right valve seat, and a sealing ring in contact with the outer wall of the right valve seat is provided in the annular groove on the wall of the inner hole of the large diameter section of the right valve body.

[0012] Furthermore, the extension rod adopts a hollow sleeve structure consisting of an equal diameter section, a flange provided at the lower end of the equal diameter section, and a large diameter section connected to the upper end of the equal diameter section through a tapered section. The flange at the lower end of the extension rod is detachably fixed to the upper end face of the left valve body by connecting screws. A graphite filler and a filler located at the upper end of the graphite filler are provided in the T-shaped stepped hole of the large diameter section of the extension rod. A filler pressure plate is fixed to the upper end of the extension rod by bolts, and the square hole on the horizontal plate at the lower end of the handle is adapted to be connected to the upper end of the valve stem passing through the filler pressure plate.

[0013] Furthermore, the upper horizontal section of the handle is covered with a leather cover.

[0014] The advantages of this utility model compared with the prior art are:

[0015] 1. This technical solution optimizes the ball valve structure and positions the lower end of the ball in the installation cavity of the left valve body. When the valve stem connected to the upper end of the ball drives the ball to rotate, the center of rotation of the ball is positioned and supported, ensuring uniform stress distribution and uniform force on the contact surfaces with the left and right valve seats, thus solving the problem of leakage caused by uneven stress distribution.

[0016] 2. This technical solution optimizes the sealing installation structure of the left and right valve seats in the left and right valve bodies respectively. Under the action of the right valve seat elastically installed in the right valve body, it achieves a seal with reliable contact with the ball, eliminating the risk of leakage;

[0017] 3. The horizontal section at the lower end of the handle of this technical solution is provided with a square hole which is adapted to connect with the square head at the upper end of the valve stem, making the handle easy and quick to disassemble and assemble. After the handle is disassembled, it can prevent the ball valve from being misoperated.

[0018] 4. This technical solution has a simple structure, novel design, and precise ball positioning. There is no need to adjust the position of the ball in the left valve body, which improves installation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the utility model. DETAILED DESCRIPTION

[0020] The following is a combination of the embodiments of the present invention Figure 1 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0021] It should be noted that, in this document, unless otherwise stated, it should be understood that the terms "center," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate positions or relationships based on those shown in the accompanying drawings. These are intended only to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] As used herein, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the elements.

[0023] Special cryogenic ball valves for liquefied natural gas, such as Figure 1 As shown, it includes a left valve body 2, a right valve body 1, a ball 7, a valve stem 8 and an extension rod 12. The lower end of the ball 7 is radially positioned in the mounting cavity of the left valve body 2, and a left valve seat 6 is sealed and installed in the mounting cavity of the left valve body 2, which is located on the left side of the ball 7 and fits closely with the left outer spherical surface of the ball 7. The right valve body 1 and the left valve body 2 are detachably sealed and connected as a whole, and the right valve seat 18 elastically positioned and installed at the left end of the inner hole of the right valve body 1 fits closely with the right outer spherical surface of the ball 7. The lower end of the extension rod 12 is adapted and fixedly connected to the upper end face of the left valve body 2, and the lower end of the valve stem 8 arranged in the center hole of the extension rod 12 passes through the upper end face of the left valve body 2 The through hole on the end face is adapted to be connected with the upper end of the ball 7, and the valve stem 8 is rotated by the handle 17 provided above the extension rod 12 and adapted to be connected with the valve stem 8, thereby realizing on-off control of the central channel of the ball 7 and the channels in the left valve body 2 and the right valve body 1. In the above structure, by optimizing the ball valve structure, the lower end of the ball 7 is positioned in the installation cavity of the left valve body 2. When the valve stem 8 connected to the upper end of the ball 7 drives the ball to rotate, the rotation center position of the ball 7 is positioned and supported, ensuring uniform stress distribution and uniform force on the contact surface with the left valve seat 2 and the right valve seat 1, thereby solving the problem of leakage caused by uneven stress distribution.

[0024] The radial positioning connection structure of the lower end of the spherical body 7 and the left valve body 2 is as follows: a positioning boss 19 with a hemispherical structure at the lower end is fixed in the middle of the outer wall of the lower end of the spherical body 7, and a long groove 4 is formed on the wall of the lower end of the installation cavity of the left valve body 2, and the positioning boss 19 is adapted to be positioned in the long groove 4, so as to realize the radial positioning of the spherical body 7 in the installation cavity of the left valve body 2; specifically, the groove width of the long groove 4 is 0.5mm to 2mm larger than the diameter of the ball head position of the positioning boss 19, and the left end groove wall of the long groove 4 is a vertical surface, while the right end groove wall is connected to the inner wall of the left valve body 2 through an arc surface. The inner wall of the lower end of the cavity is transitionally connected; specifically, the positioning boss 19 is symmetrically arranged with a square groove provided in the middle of the outer wall of the upper end of the sphere 7 and adapted to the lower end of the valve stem 8; specifically, the radial positioning structure of the lower end of the valve stem 8 and the sphere 7 is as follows: a square boss is integrally provided in the middle of the lower end surface of the valve stem 8, and the square boss is adapted to the square groove in the middle of the outer wall of the upper end of the sphere 7; the positioning boss 19 and the valve stem 8 are respectively positioned and connected to the sphere 7, so that the sphere 7 is stable and reliable during rotation, and the force is evenly applied during the rotation process, providing conditions for ensuring good sealing;

[0025] The sealing positioning and installation structure of the left valve seat 6 in the left valve body 2 is as follows: a sealing ring 5 is provided between the right side wall of the left valve seat 6 and the right side positioning groove wall of the installation cavity of the left valve body 2. Under the action of the spring 15, a reliable seal between the left valve seat 6 and the left valve body 2 is effectively ensured.

[0026] The sealing connection structure of the left valve body 2 and the right valve body 1 is as follows: a graphite fireproof ring 3 in contact with the large step surface on the left end of the right valve body 1 is provided in the annular groove arranged on the right end face of the left valve body 2, and the small diameter section on the left end of the right valve body 1 is adapted to the center hole on the left end of the left valve body 2, and the annular groove at the right end hole edge position of the left valve body 2 is adapted to the positioning ring on the left end outer wall of the right valve body 1, and a sealing ring 9 is provided between the groove surface of the annular groove at the right end hole edge position of the left valve body 2 and the ring surface of the positioning ring on the left end outer wall of the right valve body 1 to improve the sealing effect.

[0027] The sealing installation structure of the right valve seat 18 in the valve body 1 is as follows: the right valve seat 18 is adapted to the inner hole of the large diameter section of the right valve body 1, and the spring 15 adapted in the hole groove on the step surface of the inner hole of the right valve body 1 is fixedly connected to the left end face of the right valve seat 18, and a sealing ring 5 in contact with the outer wall of the right valve seat 18 is provided in the annular groove on the wall of the inner hole of the large diameter section of the right valve body 1.

[0028] By optimizing the sealing installation structure of the left valve seat 6 and the right valve seat 18 in the left valve body 2 and the right valve body 1 respectively, the right valve seat 18 elastically installed in the right valve body 1 achieves a seal with reliable contact with the ball 7, eliminating the risk of leakage;

[0029] The specific structure of the extension rod 12 is as follows: the extension rod 12 adopts a hollow sleeve structure composed of an equal diameter section, a flange provided at the lower end of the equal diameter section, and a large diameter section connected to the upper end of the equal diameter section through a tapered section. The flange at the lower end of the extension rod 12 is detachably fixed to the upper end surface of the left valve body 2 by a connecting screw 10. A graphite filler 13 and a filler 14 located at the upper end of the graphite filler 13 are provided in the T-shaped stepped hole of the large diameter section of the extension rod 12. A filler pressure plate 16 is fixed to the upper end of the extension rod 12 by a bolt 11, and the square hole on the horizontal plate at the lower end of the handle 17 is adapted to be connected with the upper end of the valve stem 8 passing through the filler pressure plate 16; specifically, the upper horizontal section of the handle 17 is covered with a leather cover; in the above structure, the horizontal section at the lower end of the handle 17 is provided with a square hole adapted to be connected with the square head at the upper end of the valve stem, so that the handle 17 is easy and quick to disassemble and assemble, and after the handle 17 is disassembled, it plays a role in preventing misoperation of the ball valve;

[0030] This technical solution has a simple structure, novel design, and precise ball positioning. There is no need to adjust the position of the ball in the left valve body, which improves installation efficiency.

[0031] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present invention. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0032] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A special cryogenic ball valve for liquefied natural gas, comprising a left valve body (2), a right valve body (1), a ball (7), a valve stem (8) and an extension rod (12), characterized in that: The lower end of the ball (7) is radially positioned in the installation cavity of the left valve body (2), and a left valve seat (6) is sealed and installed in the installation cavity of the left valve body (2), which is located on the left side of the ball (7) and fits closely with the outer spherical surface of the left side of the ball (7). The right valve body (1) and the left valve body (2) are detachably sealed and connected as a whole, and the right valve seat (18) elastically positioned and installed at the left end of the inner hole of the right valve body (1) fits closely with the outer spherical surface of the right side of the ball (7). The lower end of the rod (12) is adapted and fixedly connected to the upper end face of the left valve body (2), and the lower end of the valve stem (8) arranged in the center hole of the extended rod (12) passes through the through hole on the upper end face of the left valve body (2) and is adapted and connected to the upper end of the sphere (7), and the valve stem (8) is rotated by a handle (17) arranged above the extended rod (12) and adapted and connected to the valve stem (8) to realize the on-off control of the central channel of the sphere (7) and the channels in the left valve body (2) and the right valve body (1).

2. The special cryogenic ball valve for liquefied natural gas according to claim 1, characterized in that: A positioning boss (19) with a hemispherical lower end is fixed in the middle of the outer wall of the lower end of the sphere (7), and a long groove (4) is formed on the wall of the lower end of the installation cavity of the left valve body (2), and the positioning boss (19) is adapted to be positioned in the long groove (4), thereby realizing radial positioning of the sphere (7) in the installation cavity of the left valve body (2).

3. The special cryogenic ball valve for liquefied natural gas according to claim 2, characterized in that: The width of the long groove (4) is 0.5 mm to 2 mm larger than the diameter of the ball head of the positioning boss (19), and the left end groove wall of the long groove (4) is a vertical surface, while the right end groove wall is transitionally connected to the inner wall of the lower end of the inner cavity of the left valve body (2) through an arc surface.

4. The special cryogenic ball valve for liquefied natural gas according to claim 3, characterized in that: The positioning boss (19) is symmetrically arranged with a square groove provided in the middle of the outer wall of the upper end of the sphere (7) and adapted to the lower end of the valve stem (8).

5. The special cryogenic ball valve for liquefied natural gas according to claim 4, characterized in that: A square convex column is integrally provided in the middle of the lower end surface of the valve stem (8), and the square convex column is adapted to the square groove in the middle of the outer wall of the upper end of the sphere (7).

6. The special cryogenic ball valve for liquefied natural gas according to claim 1, characterized in that: A sealing ring (5) is provided between the right side wall of the left valve seat (6) and the right side positioning groove wall of the installation cavity of the left valve body (2).

7. The special cryogenic ball valve for liquefied natural gas according to claim 1, characterized in that: A graphite fireproof ring (3) is provided in the annular groove provided on the right end surface of the left valve body (2) and contacts the large step surface on the left end of the right valve body (1); the small diameter section on the left end of the right valve body (1) is adapted to the center hole on the left end of the left valve body (2); the annular groove at the right end hole edge of the left valve body (2) is adapted to the positioning ring on the left end outer wall of the right valve body (1); and a sealing ring (9) is provided between the groove surface of the annular groove at the right end hole edge of the left valve body (2) and the ring surface of the positioning ring on the left end outer wall of the right valve body (1).

8. The special cryogenic ball valve for liquefied natural gas according to claim 1, characterized in that: The right valve seat (18) is adapted to the inner hole of the large diameter section of the right valve body (1), and the spring (15) adapted to the hole groove on the step surface of the inner hole of the right valve body (1) is fixedly connected to the left end face of the right valve seat (18), and a sealing ring (5) in contact with the outer wall of the right valve seat (18) is provided in the annular groove on the wall of the inner hole of the large diameter section of the right valve body (1).

9. The special cryogenic ball valve for liquefied natural gas according to claim 1, characterized in that: The extension rod (12) adopts a hollow sleeve structure consisting of a constant diameter section, a flange provided at the lower end of the constant diameter section, and a large diameter section connected to the upper end of the constant diameter section through a tapered section. The flange at the lower end of the extension rod (12) is detachably fixed to the upper end face of the left valve body (2) by a connecting screw (10). A graphite filler (13) and a filler (14) located at the upper end of the graphite filler (13) are provided in the T-shaped stepped hole of the large diameter section of the extension rod (12). A filler pressure plate (16) is fixed to the upper end of the extension rod (12) by a bolt (11), and the square hole on the horizontal plate at the lower end of the handle (17) is adapted to be connected to the upper end of the valve stem (8) passing through the filler pressure plate (16).

10. The special cryogenic ball valve for liquefied natural gas according to any one of claims 1 to 9, characterized in that: The upper horizontal section of the handle (17) is sheathed with a leather cover.

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