Top-mounted low-temperature floating ball valve

Abstract

The utility model relates to a top-mounted low-temperature floating ball valve which comprises a valve body (5) and a lengthened valve cover (2) which are connected through a bolt, the valve body (5) adopts a top inlet design, a left valve seat (7), a ball body (8) and a right valve seat (9) are arranged in the valve body (5), a handle (1), a valve rod (4), a check ring (14), an electrostatic spring (13) and a valve rod sealing assembly are arranged on the lengthened valve cover (2), the bottom of the valve rod (4) is connected with the ball body (8), and the valve cover (2) is connected with the ball body (8). The ball body (8) can be driven to rotate by rotating the valve rod (4), and opening and closing of the valve are achieved. The electrostatic spring (13) is used for achieving communication between the valve rod (4) and the lengthened valve cover (2), friction static electricity generated in the opening and closing process of the valve is conducted to the outer surface of the valve, and electrostatic safety of the valve is achieved. The low-temperature floating ball valve has the advantages of being compact in structure, convenient to install and maintain, fireproof, anti-static, provided with disc spring sealing compensation and long in service life.

Description

TECHNICAL FIELD

[0001] The utility model belongs to ball valve technical field, concretely relates to a top-mounted low-temperature floating ball valve. BACKGROUND

[0002] In recent years, the LNG industry and the petrochemical industry in China have developed rapidly, and the low-temperature field has been continuously explored, and the requirements for low-temperature valves have been continuously improved. For small-diameter pipelines, low-temperature floating ball valves are often used as pipeline shut-off methods. The ball of the floating ball valve is floating, and the ball is pushed to the downstream side by the medium pressure, and the sealing is assisted by the medium pressure. The sealing effect is weak in a low-pressure environment. The floating ball valve is divided into a side-mounted structure and a top-mounted structure. The ball valve with a top-mounted structure is widely used in the low-temperature industry because its outer seal is not affected by the pipeline stress and can be disassembled and repaired online. At present, there are many types of low-temperature floating ball valve structures, but they all have problems such as complex structure, difficult installation, lack of safety structure, etc.

[0003] For example, the Chinese utility model patent with the authorization publication number CN216078382U discloses a top-mounted ultra-low-temperature floating ball valve, which adopts a top-mounted valve body, the left valve seat is pre-tightened by a spring, and the right valve seat is designed with a lip-shaped sealing ring + fireproof ring structure. However, this structure requires a special tool to compress the left valve seat by a large displacement during assembly to install the ball, which directly leads to a large stroke of the left valve seat spring and a complex installation and disassembly process.

[0004] For example, the Chinese invention patent application with the publication number CN114688286A discloses a top-mounted ultra-low-temperature floating ball valve. The bottom end of the valve body is provided with an annular protrusion, the inner side of the annular protrusion is provided with an annular groove, the annular groove is provided with a movable ring and a disc spring, the valve body is connected to the bottom end of the valve body, the upper end of the valve body is provided with a valve seat compression ring at the open end, the upper surface of the valve seat compression ring is connected to the lower surface of the annular protrusion and the disc spring on the lower surface of the movable ring, the valve body is symmetrically provided with a valve seat frame and a valve seat at both ends, the valve seat is arranged on the inner side of the valve seat frame and cooperates with the valve seat frame, the upper end of the valve seat is connected to the lower surface of the valve seat compression ring, and the sealing steel ring of the valve seat is provided with a plurality of concentric circles at one end in cooperation with the valve seat frame. The sealing steel ring is provided with an arc surface at the other end to cooperate with the ball valve. The structure is reasonable, the disc spring compensates the ring pressure to pre-tighten the valve seat compression ring, and the initial sealing is achieved. The contact position of the valve seat and the valve seat frame adopts a plurality of concentric circles, and the sealing performance is greatly improved. However, the floating ball valve adopts a top-mounted valve body, the left and right valve seats adopt a symmetrical wedge-shaped structure, the ball top is loaded with a disc spring to press downward, the wedge-shaped structure is used to realize the sealing of the valve seat and the ball, and the structure also has a fireproof structure. However, the wedge-shaped structure will cause the ball to continuously drop under the contraction characteristics of low temperature, and the ball cannot be moved back to the original position when the temperature returns to normal. The expansion of the valve seat and the ball will cause the friction between the ball and the valve seat to increase, and even the ball will be stuck.

[0005] For example, the Chinese patent application with the publication number CN106122510A discloses an upper-mounted low-temperature floating ball valve, which comprises a valve body, a ball body and a valve seat assembly, the ball body is arranged in the valve body, the valve seat assembly is arranged between the ball body and the valve body, and the upstream and downstream of the ball body are both provided with the valve seat assembly; the valve seat assembly comprises a valve seat inner ring, a valve seat and a valve seat support, the valve seat is sleeved on the valve seat inner ring, and the valve seat support is sleeved on the valve seat. The valve seat support and the valve seat inner ring play a protective role on the valve seat, prevent the valve seat from being deformed under the pressure of the medium, improve the sealing reliability of the valve and prolong the service life of the valve. The upper-mounted low-temperature floating ball valve adopts an upper-mounted valve body, and the lower end of the ball body is provided with a lower valve rod, so that the support on the ball body is increased, and the problem of the ball body falling under low temperature is effectively avoided. However, the valve seat does not add a sealing compensation device, and effective sealing cannot be formed when the medium pressure is low, and the valve seat lacks a fireproof structure, so that the valve seat cannot be sealed and compensated after a fire, and effective sealing of the valve cannot be formed after the fire. SUMMARY

[0006] In view of the problems in the prior art, the utility model provides an upper-mounted low-temperature floating ball valve, which can be used in low-temperature medium environments such as liquid nitrogen, LNG and ethylene by changing the shell material, has the characteristics of compact structure, convenient installation and maintenance, fireproof and anti-static functions, disc spring sealing compensation and long service life.

[0007] The utility model discloses an upper-mounted low-temperature floating ball valve, which comprises a valve body and an elongated valve cover connected by bolts, the valve body adopts a top inlet design, and is internally provided with a left valve seat, a ball body and a right valve seat, the elongated valve cover is provided with a handle, a valve rod, a check ring, an electrostatic spring and a valve rod sealing assembly, the bottom of the valve rod is connected with the ball body, and rotating the valve rod can drive the ball body to rotate, thereby realizing the opening and closing of the valve; the electrostatic spring is used to realize the conduction between the valve rod and the elongated valve cover, and the frictional static electricity generated during the opening and closing of the valve is conducted to the outer surface of the valve, thereby realizing the electrostatic safety of the valve.

[0008] The valve cover of the utility model is designed to be elongated, and a drip tray is arranged in the middle part, which is helpful for heat dissipation of the valve cover and condensate water dripping, and can prevent low temperature in the valve cavity from being transmitted to the valve rod sealing, thereby affecting the operation of the valve.

[0009] Preferably, a double sealing structure composed of a flexible graphite gasket and a first lip-shaped sealing ring is adopted between the valve body and the elongated valve cover, which has good sealing effect and fire safety performance.

[0010] In any of the above schemes, preferably, the left valve seat and the right valve seat are metal parts; the left valve seat, the right valve seat and the contact part of the ball are inlaid with non-metallic sealing rings, thereby achieving support of the ball and sealing between the valve seat and the ball. When the non-metallic sealing ring is damaged in a fire, the metal valve seat and the ball can be directly sealed by relying on the medium pressure and the pre-tightening force of the disc spring, and the valve seat has fire safety.

[0011] In any of the above schemes, preferably, the front end of the left valve seat is provided with a group of transverse disc springs to provide pre-tightening force for sealing, and after the non-metallic sealing ring is damaged in a fire, the left valve seat can be pushed to move to the right, and the metal valve seat directly forms secondary sealing with the ball; the right end of the right valve seat is inlaid with a non-metallic sealing ring to achieve sealing between the right valve seat and the valve body 1; the right end of the right valve seat is provided with a fireproof graphite ring to achieve sealing between the right valve seat and the valve body after the non-metallic sealing ring is damaged in a fire.

[0012] In any of the above schemes, preferably, the ball adopts a flattened design and is an internal hollow structural part; round holes are formed on both sides of the ball to communicate with the hollow cavity; a rectangular hole is formed on the top of the ball; a pressure relief hole is formed on the left side of the side wall of the ball, and the hollow cavity in the ball is directly communicated with the left side of the valve body after the valve is closed; the low-temperature medium in the valve cavity can be heated and gasified to achieve pressure communication after the valve is closed.

[0013] When the ball is installed, the ball body is vertically inserted, then rotated by 90 degrees for sealing, and in the rotating process, the left valve seat is pushed to the left side to extrude the disc spring and form sealing pre-tightening. During the installation of the ball, the valve seat does not need to be additionally compressed, and the ball is easy to assemble and disassemble.

[0014] In any of the above schemes, preferably, the lower end of the valve stem is provided with a boss, and the boss is provided with a gasket; the lower end of the lengthened valve cover is provided with an elastic retainer, which limits the downward movement of the valve stem and prevents the upper end of the valve stem from moving downward when impacted, thereby increasing the reliability of the valve. When the valve stem is assembled, it is inserted from the bottom end of the lengthened valve cover, which can achieve a safety design of preventing the valve stem from being blown out, and the gasket installed on the boss reduces friction when the valve is opened and closed, thereby reducing the operating torque.

[0015] In any of the above schemes, preferably, the valve stem sealing assembly comprises a second lip-shaped sealing ring, a low-leakage graphite packing group, an O-ring, a packing pressing sleeve, a packing pressing plate, a disc spring and a pressing bolt.

[0016] The valve stem and the lengthened valve cover are sealed by a triple combination of a lip-shaped sealing ring, a low-leakage graphite packing group and an O-ring. The low-leakage graphite packing group is compressed by the packing pressing sleeve and the packing pressing plate, the bolt is fastened on the packing pressing plate, and the disc spring is arranged on the bolt to compensate for the compression force, thereby achieving good sealing effect and prolonging the service life of the seal.

[0017] In any of the above embodiments, it is preferred that the extended valve cover has a drip tray in the middle, and the drip tray adopts an edge bending design to prevent condensate from entering the cold insulation layer along the edge of the drip tray due to surface tension.

[0018] In summary, the top-mounted cryogenic floating ball valve of this utility model has the following advantages: The flattened ball design significantly reduces the difficulty of assembling and disassembling the top-mounted cryogenic floating ball valve; a disc spring on the left valve seat provides sealing pre-tightening and sealing compensation, offering effective sealing pre-tightening when the medium pressure is low, improving the valve's sealing effect in low-pressure environments; simultaneously, the valve can effectively push the valve seat for sealing compensation after prolonged use and in the event of a fire; a double seal is provided between the valve body and the valve cover, achieving sealing between the valve body and the valve cover and ensuring fire safety; a triple seal is provided between the valve stem and the valve cover, achieving sealing between the valve cover and the valve stem and ensuring fire safety; a sealing bevel is provided at the point where the valve seat and the ball are close together, a disc spring is provided on the left valve seat, and a fireproof sealing ring is provided on the right valve seat, achieving sealing between the valve seat and the ball, and between the valve seat and the valve body, ensuring fire safety and giving the valve as a whole excellent sealing and fire safety functions.

[0019] Handle 1, Extended valve cover 2, Drip tray 3, Valve stem 4, Valve body 5, Horizontal disc spring 6, Left valve seat 7, Ball 8, Rectangular hole 81, Cavity 82, Round hole 83, Pressure relief hole 84, Right valve seat 9, Fireproof sealing ring 10, Flexible graphite gasket 11, First lip seal 12, Static spring 13, Elastic retaining ring 14, Disc spring 21, Packing pressure plate 22, Packing sleeve 23, O-ring 24, Low leakage graphite packing assembly 25, Second lip seal 26. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a preferred embodiment of the top-mounted cryogenic floating ball valve according to the present invention.

[0021] Figure 2 In accordance with the present invention, the top-mounted cryogenic floating ball valve Figure 1 Enlarged view of point A in the preferred embodiment shown.

[0022] Figure 3 In accordance with the present invention, the top-mounted cryogenic floating ball valve Figure 1 Enlarged view of point B in the preferred embodiment shown.

[0023] Figure 4 For the top-mounted cryogenic floating ball valve according to this utility model Figure 1 A schematic diagram of the structure of the sphere in the preferred embodiment is shown. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] As Figure 1 The utility model discloses a kind of upper-mounted low-temperature floating ball valves, it includes valve body 5 and lengthened bonnet 2 connected by bolt, valve body 5 adopts top inlet design, left valve seat 7, ball 8 and right valve seat 9 are equipped in its inside, handle 1, valve stem 4, retaining ring 14, electrostatic spring 13 and valve stem sealing assembly are equipped on the lengthened bonnet 2, the bottom of valve stem 4 is connected with ball 8, rotating valve stem 4 can drive ball 8 to rotate, realize the opening and closing of valve;Electrostatic spring 13 is used to realize the conduction of valve stem 4 and lengthened bonnet 2, the friction electrostatic generated in the process of valve opening and closing is conducted to the outer surface of valve, realize valve electrostatic safety.

[0026] The utility model discloses the bonnet of valve adopts lengthened design, and drip tray is set in middle part, it is helpful to the heat dissipation of bonnet and the drop of condensate, prevent low temperature in valve cavity from being transmitted to valve stem seal, influence valve operation.

[0027] In the embodiment, the drip tray adopts edge bending design, prevent condensate from entering cold preservation layer along drip tray edge due to surface tension.

[0028] In the embodiment, the left valve seat 7 and right valve seat 9 are metal parts;Non-metallic sealing ring is embedded in the contact part of left valve seat 7, right valve seat 9 and ball 8, to realize the support of ball and the sealing between valve seat and ball. When non-metallic sealing ring is damaged in fire, direct sealing of metal valve seat and ball can be realized by relying on medium pressure and disc spring pre-tightening force, with valve seat sealing fire safety.

[0029] In the embodiment, the front end of left valve seat 7 is provided with a set of transverse disc spring 6, which provides pre-tightening force for sealing, and can push left valve seat 7 to move to the right after non-metallic sealing ring is damaged in fire, so that metal valve seat forms secondary sealing with ball directly;Right end of right valve seat 9 is embedded with non-metallic sealing ring, to realize the sealing between right valve seat 9 and valve body 1;Fireproof graphite ring 10 is installed at the right end of right valve seat 9, to realize the sealing between right valve seat 9 and valve body 1 after non-metallic sealing ring is damaged in fire.

[0030] Referring to Figure 2 The preferred embodiment of the upper-mounted low-temperature floating ball valve according to the utility model is shown in the enlarged view of A in the figure. Figure 1

[0031] In the embodiment, double sealing structure composed of flexible graphite pad 11 and first lip-shaped sealing ring 12 is used between valve body 5 and lengthened bonnet 2, which has good sealing effect and fireproof safety performance.

[0032] ​In the embodiment, the lower end of the valve stem 4 is provided with a boss, and the boss is provided with a gasket; the lower end of the lengthened valve cover 2 is provided with an elastic check ring 14, which limits the downward movement of the valve stem 4 and prevents the upper end of the valve stem 4 from moving downward when impacted, thereby increasing the reliability of the valve. The valve stem 4 is assembled from the bottom end of the lengthened valve cover 2, and the safety design of preventing the valve stem from being blown out can be realized. The gasket is installed on the boss to reduce friction when the valve is opened and closed, thereby reducing the operation torque.

[0033] As shown in Figure 3 the upper-mounted low-temperature floating ball valve of the present application, as shown in the preferred embodiment of Figure 1 the enlarged view of B.

[0034] In the embodiment, the valve stem sealing assembly comprises a second lip-shaped sealing ring 26, a low-leakage graphite packing group 25, an O-shaped ring 24, a packing pressing sleeve 23, a packing pressing plate 22, a disc spring 21 and a pressing bolt.

[0035] The triple combination sealing mode of the second lip-shaped sealing ring 26 plus the low-leakage graphite packing group 25 plus the O-shaped ring 24 is adopted between the valve stem 4 and the lengthened valve cover 2. The low-leakage graphite packing group 25 is compressed by the packing pressing sleeve 23 and the packing pressing plate 22. The bolt is fastened on the packing pressing plate 22, and the disc spring 21 is arranged on the bolt to compensate the compression force. The good sealing effect is realized, and the service life of the sealing is prolonged.

[0036] Finally, referring to Figure 4 the upper-mounted low-temperature floating ball valve of the present application, as shown in the preferred embodiment of Figure 1 the structure diagram of the ball body.

[0037] In the embodiment, the ball body 8 adopts a flattened design, and the inside is a structure with a cavity 82. Round holes 83 are opened on both sides of the ball body 8 and are in communication with the cavity 82. A rectangular hole 81 is opened on the top of the ball body 8. A pressure relief hole 84 is opened on the left side wall of the ball body 8. After the valve is closed, the cavity in the ball body 8 is directly communicated with the left side of the valve body 5. When the valve is closed, the low-temperature medium in the valve cavity is heated and gasified to realize pressure communication.

[0038] When the ball body 8 is installed, the ball body is vertically entered and then rotated by 90 degrees for sealing. In the rotating process, the left valve seat 7 is pushed to the left side to extrude the disc spring 6 to form a sealing pre-tightening. During the installation process of the ball body, the valve seat does not need to be additionally compressed, and the ball body is simple to assemble and disassemble.

[0039] It is not difficult for those skilled in the art to understand that the upper-mounted low-temperature floating ball valve of the present application comprises any combination of the parts in the specification. Due to the limited length and in order to make the specification brief, these combinations are not introduced in detail here, but after reading the specification, it is self-evident that the scope of the present application formed by any combination of the parts in the specification.

Claims

1. A top-mounted cryogenic floating ball valve, comprising a valve body (5) and an extended valve cover (2) connected by bolts, the valve body (5) adopting a top inlet design, and having a left valve seat (7), a ball (8) and a right valve seat (9) inside, characterized in that: The extended valve cover (2) is equipped with a handle (1), valve stem (4), retaining ring (14), electrostatic spring (13) and valve stem sealing assembly. The bottom of the valve stem (4) is connected to the ball (8).

2. The top-mounted cryogenic floating ball valve as described in claim 1, characterized in that: The valve body (5) and the extended valve cover (2) are connected by a double sealing structure consisting of a flexible graphite pad (11) and a first lip seal ring (12).

3. The top-mounted cryogenic floating ball valve as described in claim 1, characterized in that: The left valve seat (7) and the right valve seat (9) are metal parts; non-metallic sealing rings are inlaid at the contact parts of the left valve seat (7), the right valve seat (9) and the ball (8).

4. The top-mounted cryogenic floating ball valve as described in claim 1, characterized in that: A set of transverse disc springs (6) is installed at the front end of the left valve seat (7); a non-metallic sealing ring is inlaid at the right end of the right valve seat (9); a fireproof graphite ring (10) is installed at the right end of the right valve seat (9).

5. The top-mounted cryogenic floating ball valve as described in claim 1 or 3, characterized in that: The sphere (8) adopts a flat design and has a cavity (82) inside. There are round holes (83) on both sides of the sphere (8) that are connected to the cavity (82). There is a rectangular hole (81) on the top of the sphere (8). There is a pressure relief hole (84) on the left side of the side wall of the sphere (8).

6. The top-mounted cryogenic floating ball valve as described in claim 1, characterized in that: The lower end of the valve stem (4) is provided with a boss, and a gasket is provided on the boss; the lower end of the extended valve cover (2) is provided with an elastic retaining ring (14).

7. The top-mounted cryogenic floating ball valve as described in claim 1, characterized in that: The valve stem sealing assembly includes a second lip seal (26), a low-leakage graphite packing assembly (25), an O-ring (24), a packing sleeve (23), a packing plate (22), a disc spring (21), and a clamping bolt.

8. The top-mounted cryogenic floating ball valve as described in claim 1 or 2, characterized in that: The extended valve cover has a drip tray in the middle, and the drip tray has an edge bending design.

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