Valve sealing structure and ball valve

Abstract

A valve sealing structure and a ball valve. The valve sealing structure is applied and connected to a communicating position of an inner cavity (11) of a valve body (1) and a channel (21) of a valve cover (2), and comprises a C-shaped ball body (3) and a PTFE sealing ring (41), the C-shaped ball body (3) is rotatably connected in the inner cavity (11) of the valve body (1), and a first metal sealing ring (31) is arranged on the outer surface of the C-shaped ball body (3); the PTFE sealing ring (41) is mounted at a liquid outlet of the inner cavity (11) of the valve body (1), and the PTFE sealing ring (41) and the liquid outlet of the inner cavity (11) are concentrically arranged; a second metal sealing ring (42) is concentrically arranged on the end surface of the PTFE sealing ring (41) facing away from the C-shaped ball body (3) in the axial direction; an elastic pressing component is provided on the end surface of the second metal sealing ring (42) facing away from the PTFE sealing ring (41), and the elastic pressing component is used for applying to the second metal sealing ring (42) a pre-tightening force in the axial direction toward the PTFE sealing ring (41); and when the C-shaped ball body (3) is in a closed state, the first metal sealing ring (31) and the PTFE sealing ring (41) are concentrically arranged. The valve sealing structure can ensure that reliable sealing performance is always kept at different operating temperatures.

Description

Valve sealing structure and ball valve

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on January 26, 2024, with application number 202410116242.0 and invention name “A valve sealing structure and ball valve”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of valve manufacturing technology, and in particular to a valve sealing structure and a ball valve. Background Art

[0004] Ball valve is one of the most widely used valves. It has a simple structure, reliable sealing, easy maintenance, and the sealing surface and the ball are often in a closed state, which is not easily eroded by the medium. It is widely used in petroleum, chemical industry, metallurgy, light industry, food, atomic energy, aviation and other fields.

[0005] A ball valve generally comprises a valve body and a valve cover connected by bolts. An inner cavity is provided in the valve body, and a channel is provided in the valve cover. The liquid inlet of the channel is connected to the liquid outlet of the inner cavity, thereby enabling the circulation of the medium in the ball valve. A ball is rotatably connected in the inner cavity and driven to rotate by a valve stem. When the ball valve needs to be shut off, the ball is driven by the valve stem to rotate along the axis of the valve stem to the connection point between the liquid inlet of the channel and the liquid outlet of the inner cavity, thereby closing the ball valve. In order to ensure the sealing performance of the ball valve when it is closed, a sealing structure is required to be in contact with the metal outer surface of the ball for sealing. Most existing sealing structures generally use sealing materials (such as O-rings, packings, lip-type sealing rings, etc.) in contact with the metal outer surface of the ball to form a non-metallic soft sealing pair to achieve soft sealing. However, the sealing performance of this sealing method is poor in reliability under sudden high temperature conditions (such as above 250°C), and the sealing effect is not ideal.

[0006] Summary of the Invention

[0007] Therefore, the technical problem to be solved by this application is to overcome the defect in the existing technology that the sealing structure adopts a non-metallic soft sealing pair and the metal outer surface of the sphere to achieve soft sealing, and cannot maintain reliable sealing when the operating temperature exceeds the critical value due to an emergency, thereby providing a valve sealing structure and a ball valve.

[0008] According to a first aspect of the present application, a valve sealing structure is provided, which is applied to the connection between the inner cavity of the valve body and the channel of the valve cover, and the valve sealing structure includes:

[0009] A C-shaped ball, adapted to be rotatably connected to the inner cavity of the valve body, wherein the C-shaped ball has a closed state in which the passage between the inner cavity of the valve body and the valve cover is blocked, and an open state in which the passage between the inner cavity of the valve body and the valve cover is connected;

[0010] a first metal sealing ring, disposed on the outer surface of the C-shaped sphere;

[0011] The PTFE sealing ring is used to be installed at the liquid outlet of the inner cavity of the valve body and is arranged concentrically with the liquid outlet of the inner cavity;

[0012] a second metal sealing ring, arranged on the end surface of the PTFE sealing ring axially away from the C-shaped sphere;

[0013] an elastic pressing assembly, provided on an end surface of the second metal sealing ring axially away from the PTFE sealing ring, and used for applying a pre-tightening pressure axially toward the PTFE sealing ring to the second metal sealing ring;

[0014] When the C-shaped sphere is in a closed state, the first metal sealing ring and the PTFE sealing ring are arranged concentrically.

[0015] The valve sealing structure of the present application has at least the following technical effects:

[0016] A second metal sealing ring is concentrically arranged at one end of the PTFE sealing ring axially away from the C-shaped sphere, and a pre-tightening pressure is applied axially toward the PTFE sealing ring to the second metal sealing ring through an elastic pressing component. On the one hand, when the operating temperature of the ball valve equipped with the valve sealing structure does not exceed the critical melting temperature of PTFE, the pre-tightening pressure applied by the elastic pressing component on the second metal sealing ring is transmitted to the PTFE sealing ring, so that the PTFE sealing ring and the first metal sealing ring fit tightly to achieve reliable sealing; on the other hand, when the working environment of the ball valve equipped with the valve sealing structure is abnormal (for example, a fire occurs), the operating temperature exceeds the critical melting temperature of PTFE, and the PTFE sealing ring gradually melts and disappears. At this time, the second metal sealing ring moves axially toward the C-shaped sphere under the action of the pre-tightening pressure applied by the elastic pressing component to enter the position where the original PTFE sealing ring was located, so that the second metal sealing ring and the first metal sealing ring fit tightly to ensure reliable sealing under abnormally high temperature working conditions. The valve sealing structure forms two layers of seals through the PTFE sealing ring and the second metal sealing ring, ensuring that the ball valve equipped with this valve sealing structure can simultaneously be compatible with the advantages of using non-metallic soft sealing pairs for sealing and the advantages of using metal hard sealing pairs for sealing, thereby ensuring that the ball valve equipped with this valve sealing structure always maintains reliable sealing performance under different operating temperatures.

[0017] Optionally, the elastic clamping assembly includes a plurality of connecting columns, which are used to be connected to the end face of the valve body axially facing the valve cover and are arranged at intervals along the circumference of the PTFE sealing ring; a sealing pressure ring is axially slidingly provided on the connecting column, and the second metal sealing ring is connected to the end face of the sealing pressure ring facing the PTFE sealing ring, and a limiting portion is provided at one end of the connecting column axially away from the C-shaped sphere, and an elastic member is sleeved on the connecting column, and both ends of the elastic member are respectively connected to the limiting portion and the two end faces of the sealing pressure ring axially facing each other, and the elastic member has an initial state of being compressed and storing force.

[0018] Optionally, the elastic pressing assembly further includes a plurality of connecting bolts and threaded holes corresponding to the connecting bolts one by one, the threaded holes being arranged on the end surface of the valve body axially facing the valve cover, the connecting bolts being threadedly connected in the threaded holes; the screw portions of the connecting bolts forming the connecting columns, and the screw heads of the connecting bolts forming the limiting portions;

[0019] And / or, the elastic member is configured as a coil spring or a butterfly spring.

[0020] Optionally, the cross-sectional shape of the second metal sealing ring is set to be wedge-shaped, and the end surface of the PTFE sealing ring facing the second metal sealing ring is concavely provided with a circle of wedge-shaped grooves.

[0021] Optionally, the outer circumferential surface of the first metal sealing ring is set as a first spherical surface, and the inner circumferential surface of the PTFE sealing ring is set as a second spherical surface, and the second spherical surface matches the first spherical surface;

[0022] And / or, the outer circumferential surface of the first metal sealing ring is set as a first spherical surface, and the inner circumferential surface of the second metal sealing ring is set as a third spherical surface, and the third spherical surface matches the first spherical surface;

[0023] And / or, a positioning groove is concavely provided on the outer surface of the C-shaped sphere, the first metal sealing ring is embedded in the positioning groove, and the first metal sealing ring is detachably connected to the C-shaped sphere by a fastening screw.

[0024] According to the second aspect of the present application, a ball valve is provided, including a valve body, a valve cover and a valve sealing structure, wherein an inner cavity is provided in the valve body, a channel is provided in the valve cover, the valve cover is connected to the liquid outlet end of the valve body by bolts, and the inner cavity is connected to the channel; the valve sealing structure adopts the valve sealing structure provided by the first aspect above.

[0025] The ball valve according to this application has at least the following technical effects:

[0026] A second metal sealing ring is concentrically arranged at one end of the PTFE sealing ring in the valve sealing structure axially away from the C-shaped sphere, and a pre-tightening pressure is applied axially toward the PTFE sealing ring to the second metal sealing ring through an elastic compression assembly. On the one hand, when the operating temperature of the ball valve does not exceed the critical melting temperature of PTFE, the pre-tightening pressure applied by the elastic compression assembly on the second metal sealing ring is transmitted to the PTFE sealing ring, so that the PTFE sealing ring and the first metal sealing ring fit tightly to achieve reliable sealing; on the other hand, when the working environment of the ball valve is abnormal (for example, a fire occurs), the operating temperature exceeds the critical melting temperature of PTFE, and the PTFE sealing ring gradually melts and disappears. At this time, the second metal sealing ring moves axially toward the C-shaped sphere under the action of the pre-tightening pressure applied by the elastic compression assembly to enter the position where the original PTFE sealing ring was located, so that the second metal sealing ring and the first metal sealing ring fit tightly to ensure reliable sealing under abnormally high temperature conditions. The valve sealing structure forms a double seal through the PTFE sealing ring and the second metal sealing ring, ensuring that the ball valve can simultaneously take advantage of both non-metallic soft sealing pairs and metal hard sealing pairs for sealing, thereby ensuring that the ball valve always maintains reliable sealing performance under different operating temperatures.

[0027] Optionally, a mounting hole is formed on the valve body along the rotation axis direction of the C-shaped sphere, the mounting hole is connected to the inner cavity, the C-shaped sphere is connected to the valve stem via a first limit screw, the valve stem is rotatably connected in the mounting hole, and one end of the valve stem extends out of the valve body through the mounting hole; sealing filler is filled between the side surface of the valve stem and the inner wall of the mounting hole.

[0028] Optionally, the mounting hole is configured as a stepped hole, the large diameter portion of the mounting hole is located at the end of the small diameter portion of the mounting hole away from the inner cavity, and the sealing filler is filled between the inner wall of the large diameter portion of the mounting hole and the side surface of the valve stem; the end of the sealing filler away from the small diameter portion of the mounting hole is abutted against a packing pressure ring, and the packing pressure ring is fixedly connected to the valve body.

[0029] Optionally, a bearing ring is provided between the inner wall of the small diameter portion of the mounting hole and the side surface of the valve stem.

[0030] Optionally, one end of the C-shaped sphere facing away from the valve stem is connected to a support rod via a second limit screw, the support rod is concentrically arranged with the valve stem, and the support rod is rotatably connected to the surrounding wall of the inner cavity.

[0031] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] FIG1 is a schematic structural diagram of a ball valve equipped with a valve sealing structure according to an embodiment of the present invention;

[0034] FIG2 is an enlarged schematic diagram of point A in FIG1 ;

[0035] FIG3 is a schematic structural diagram of the PTFE sealing ring in FIG2 after it melts and disappears and the second metal sealing ring moves into the position of the original PTFE sealing ring;

[0036] FIG4 is a schematic structural diagram of a valve sealing structure according to the present embodiment in which the elastic member is configured as a butterfly spring.

[0037] Description of reference numerals:

[0038] 1-valve body, 11-inner cavity;

[0039] 2-valve cover, 21-channel;

[0040] 3-C-shaped sphere, 31-first metal sealing ring, 311-first spherical surface, 32-fastening screw, 33-first limiting screw, 34-second limiting screw, 35-support rod;

[0041] 41-PTFE sealing ring, 411-wedge groove, 42-second metal sealing ring, 421-third spherical surface;

[0042] 51-sealing pressure ring, 511-sliding hole, 52-connecting bolt, 53-coil spring, 54-butterfly spring;

[0043] 6-valve stem;

[0044] 71-sealing packing, 72-packing pressure ring, 73-bearing ring, 74-fastening bolt. DETAILED DESCRIPTION

[0045] The following will clearly and completely describe the technical solution of this application in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0046] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not 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 limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0048] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0049] Example 1

[0050] As shown in Figures 1 to 3, a valve sealing structure and a ball valve provided in this embodiment are applied to the connection point between the inner cavity 11 of the valve body 1 and the channel 21 of the valve cover 2. The valve sealing structure includes a C-type ball 3 and a PTFE sealing ring 41. The C-type ball 3 is used to be rotatably connected in the inner cavity 11 of the valve body 1. The C-type ball 3 has a closed state that blocks the inner cavity 11 of the valve body 1 and the channel 21 of the valve cover 2, and has an open state that connects the inner cavity 11 of the valve body 1 and the channel 21 of the valve cover 2; a first metal sealing ring 31 is provided on the outer surface of the C-type ball 3; the PTFE sealing ring 41 is used to be installed at the liquid outlet of the inner cavity 11 of the valve body 1, and is concentrically arranged with the liquid outlet of the inner cavity 11; the PTFE sealing ring 41 A second metal sealing ring 42 is concentrically arranged on the end face axially away from the C-shaped sphere 3; an elastic pressing assembly is provided on the end face axially away from the PTFE sealing ring 41 of the second metal sealing ring 42, and the elastic pressing assembly is used to apply a pre-tightening pressure axially toward the PTFE sealing ring 41 to the second metal sealing ring 42; when the C-shaped sphere 3 is in the closed state, the first metal sealing ring 31 and the PTFE sealing ring 41 are concentrically arranged, and when the PTFE sealing ring 41 is not melted, the first metal sealing ring 31 and the PTFE sealing ring 41 abut against each other for sealing; when the PTFE sealing ring 41 melts and disappears, the first metal sealing ring 31 and the second metal sealing ring 42 abut against each other for sealing. It can be understood that the axial direction described in this embodiment refers to the axial direction in Figure 1.

[0051] The valve sealing structure of this embodiment is provided with a second metal sealing ring 42 concentrically at one end of the PTFE sealing ring 41 axially away from the C-shaped sphere 3, and a pre-tightening pressure is applied to the second metal sealing ring 42 axially toward the PTFE sealing ring 41 by an elastic pressing component. On the one hand, when the operating temperature of the ball valve equipped with the valve sealing structure of this embodiment does not exceed the critical melting temperature of PTFE (as shown in FIG. 2 ), the pre-tightening pressure applied by the elastic pressing component to the second metal sealing ring 42 is transmitted to the PTFE sealing ring 41, so that the PTFE sealing ring 41 is tightly fitted with the first metal sealing ring 31 to achieve reliable sealing; on the other hand, when the ball valve equipped with the valve sealing structure of this embodiment is The working environment of the ball valve of the valve sealing structure of the embodiment is abnormal (for example, a fire occurs), so that the working temperature (specifically, 250°C) exceeds the critical melting temperature of PTFE, and the PTFE sealing ring 41 gradually melts and disappears. At this time, the second metal sealing ring 42 moves axially toward the C-shaped sphere 3 under the action of the pre-tightening pressure applied by the elastic pressing assembly to enter the position where the PTFE sealing ring 41 was originally located (as shown in Figure 3), so that the second metal sealing ring 42 and the first metal sealing ring 31 are tightly fitted, ensuring reliable sealing under abnormally high temperature conditions. The valve sealing structure of this embodiment forms two layers of sealing by the PTFE sealing ring 41 and the second metal sealing ring 42, ensuring that the ball valve equipped with the valve sealing structure of this embodiment can simultaneously compatibly use the advantages of sealing with a non-metallic soft sealing pair and the advantages of sealing with a metal hard sealing pair, thereby ensuring that the ball valve equipped with the valve sealing structure of this embodiment always maintains reliable sealing performance under different working temperatures; in particular, it plays a fire prevention role, ensuring that the ball valve equipped with the valve sealing structure of this embodiment can maintain reliable sealing performance when in a closed state even in the event of a fire.

[0052] As shown in Figures 1 to 3, in some embodiments of the present application, the elastic clamping assembly includes a plurality of connecting columns, four of which may be optionally provided here, and the four connecting columns are used to be connected to the end face of the valve body 1 axially facing the valve cover 2, and are arranged at intervals along the circumference of the PTFE sealing ring 41; a sealing pressure ring 51 is axially slidingly provided on the connecting column, and the second metal sealing ring 42 is connected to the end face of the sealing pressure ring 51 facing the PTFE sealing ring 41, and a limiting portion is provided at one end of the connecting column axially away from the C-shaped sphere 3, and an elastic member is sleeved on the connecting column, and both ends of the elastic member are respectively connected to the limiting portion and the two end faces of the sealing pressure ring 51 axially facing each other, and the elastic member has an initial state of being compressed and storing force. Because the elastic member is initially compressed and force-accumulating in its initial state after assembly, the elastic member always applies a pre-tightening pressure to the sealing pressure ring 51 to drive the sealing pressure ring 51 to maintain a tendency to move axially toward the C-shaped sphere 3, so that after the PTFE sealing ring 41 gradually melts and disappears, and under the sliding cooperation of the connecting column and the sealing pressure ring 51, the pre-tightening pressure applied by the elastic member can drive the second metal sealing ring 42 to move axially in a straight line along with the sealing pressure ring 51 until the second metal sealing ring 42 enters the position where the PTFE sealing ring 41 was originally located, thereby ensuring that the operating temperature of the ball valve equipped with the valve sealing structure of this embodiment can still maintain reliable sealing performance after the PTFE sealing ring 41 gradually melts and disappears due to sudden situations such as fire.

[0053] As shown in Figures 2 and 3, the sealing pressure ring 51 is specifically provided with sliding holes 511 corresponding to the connecting posts. The sliding holes 511 axially penetrate the sealing pressure ring 51, and the connecting posts are axially slidably connected within the sliding holes 511. The sliding connection between the sliding holes 511 and the connecting posts ensures that after the PTFE sealing ring 41 gradually melts and disappears, the second metal sealing ring 42 is driven by the preload pressure applied by the elastic member to move linearly in the axial direction, thereby ensuring that the second metal sealing ring 42 is accurately pushed into the position originally occupied by the PTFE sealing ring 41.

[0054] In specific applications, the number of the connecting columns can be reasonably increased or decreased according to the cross-sectional size of the liquid outlet of the inner cavity 11 perpendicular to the axial direction. For example, in other embodiments, the connecting columns are provided with two, three, five or other numbers.

[0055] As shown in Figures 1 to 3, in some embodiments of the present application, the elastic compression assembly further includes a plurality of connecting bolts 52 and threaded holes corresponding to the connecting bolts 52. The threaded holes are provided on the end surface of the valve body 1 axially facing the valve cover 2, and the connecting bolts 52 are threadedly connected within the threaded holes. The screw portion of the connecting bolt 52 forms the connecting column, and the screw head of the connecting bolt 52 forms the limiting portion. By integrally forming the connecting column and the limiting portion to form the connecting bolt 52, and providing a threaded hole at a position corresponding to the connecting bolt 52 on the end surface of the valve body 1 axially facing the valve cover 2, the pre-compression amount of the elastic member in the initial state can be flexibly adjusted by controlling the depth of the threaded connection of the connecting bolt 52 within the threaded hole, that is, adjusting the axial distance between the screw head of the connecting bolt 52 and the sealing pressure ring 51, thereby conveniently achieving fine-tuning of the sealing pressure ratio between the PTFE sealing ring 41 and the first metal sealing ring 31.

[0056] As shown in Figures 2 and 3, specifically, the elastic member is configured as a coil spring 53, which provides pre-tightening pressure to drive the second metal sealing ring 42 to maintain an axial movement trend toward the PTFE sealing ring 41. This can ensure that the PTFE sealing ring 41 and the first metal sealing ring 31 are tightly fitted to achieve a reliable seal, and can also ensure that after the PTFE sealing ring 41 melts and disappears, the second metal sealing ring 42 is driven to move into the original position of the PTFE sealing ring 41, achieving a tight fit and reliable seal between the second metal sealing ring 42 and the first metal sealing ring 31. As an alternative to the above technical solution, as shown in Figure 4, the elastic member is configured as a butterfly spring 54.

[0057] As shown in FIG2 , in some embodiments of the present application, the cross-section of the second metal sealing ring 42 is configured to be wedge-shaped, and the end surface of the PTFE sealing ring 41 facing the second metal sealing ring 42 is recessed with a circle of wedge-shaped grooves 411. By inserting the second metal sealing ring 42 into the wedge-shaped grooves 411 with the end surface facing the PTFE sealing ring 41, the second metal sealing ring 42 is subjected to pre-tightening pressure applied by the elastic member, which enables the PTFE sealing ring 41 to fit more tightly with the first metal sealing ring 31, thereby achieving a more reliable seal.

[0058] As shown in FIG2 , in some embodiments of the present application, the outer circumferential surface of the first metal sealing ring 31 is configured as a first spherical surface 311, and the inner circumferential surface of the PTFE sealing ring 41 is configured as a second spherical surface, which matches the first spherical surface 311. The cooperation between the first spherical surface 311 and the second spherical surface creates spherical contact between the first metal sealing ring 31 and the PTFE sealing ring 41. This allows the preload pressure generated by the elastic member to be evenly applied to the PTFE sealing ring 41 and the first metal sealing ring 31, preventing uneven friction from reducing the service life of the valve sealing structure of this embodiment. Furthermore, the contact area is increased, resulting in a more reliable seal.

[0059] As shown in Figures 2 and 3, in some embodiments of the present application, the inner circumferential surface of the second metal sealing ring 42 is configured as a third spherical surface 421, which matches the first spherical surface 311. After the PTFE sealing ring 41 melts and disappears and the second metal sealing ring 42 moves into the position originally occupied by the PTFE sealing ring 41, the cooperation between the third spherical surface 421 and the first spherical surface 311 results in spherical contact between the second metal sealing ring 42 and the first metal sealing ring 31. On the one hand, this allows the preload pressure generated by the elastic member to act evenly on the second metal sealing ring 42 and the first metal sealing ring 31, preventing uneven friction from reducing the service life of the valve sealing structure of this embodiment; on the other hand, it increases the contact area, making the seal more reliable.

[0060] As shown in FIG1 , in some embodiments of the present application, a positioning groove is recessed on the outer surface of the C-shaped sphere 3, and the first metal sealing ring 31 is embedded in the positioning groove. The first metal sealing ring 31 is detachably connected to the C-shaped sphere 3 via a fastening screw 32. The positioning function of the positioning groove facilitates more precise assembly of the first metal sealing ring 31 on the C-shaped sphere 3, further improving the sealing reliability of the valve sealing structure of this embodiment. At the same time, the first metal sealing ring 31 is connected to the C-shaped sphere 3 via the fastening screw 32. This not only facilitates the installation and connection of the first metal sealing ring 31 to the C-shaped sphere 3 to form an integral body, but also facilitates the removal of the first metal sealing ring 31 from the C-shaped sphere 3 for maintenance and replacement.

[0061] Specifically, the sealing connection surface of the first metal sealing ring 31 is sprayed with a chromium carbide coating, which increases the hardness of the sealing connection surface of the first metal sealing ring 31 and the wear resistance of the first metal sealing ring 31; and ensures reliable sealing with the second metal sealing ring 42 under an operating temperature environment exceeding the critical melting temperature of PTFE.

[0062] Example 2

[0063] As shown in Figures 1 to 4, a ball valve is provided in this embodiment, including a valve body 1, a valve cover 2 and a valve sealing structure. The valve body 1 is provided with an inner cavity 11, the valve cover 2 is provided with a channel 21, the valve cover 2 is connected to the liquid outlet end of the valve body 1 by bolts, and the inner cavity 11 is connected to the channel 21; the valve sealing structure adopts the valve sealing structure described in Example 1.

[0064] The ball valve of this embodiment is provided with a second metal sealing ring 42 concentrically at one end of the PTFE sealing ring 41 in the valve sealing structure axially away from the C-shaped sphere 3, and a pre-tightening pressure is applied to the second metal sealing ring 42 axially toward the PTFE sealing ring 41 by an elastic pressing component. On the one hand, when the operating temperature of the ball valve of this embodiment does not exceed the critical melting temperature of PTFE (as shown in FIG. 2 ), the pre-tightening pressure applied by the elastic pressing component to the second metal sealing ring 42 is transmitted to the PTFE sealing ring 41, so that the PTFE sealing ring 41 is tightly fitted with the first metal sealing ring 31 , achieving reliable sealing; on the other hand, when the working environment of the ball valve of this embodiment is abnormal (for example, a fire occurs), the working temperature (specifically, 250°C) exceeds the critical melting temperature of PTFE, and the PTFE sealing ring 41 gradually melts and disappears. At this time, the second metal sealing ring 42 moves axially toward the C-shaped sphere 3 under the action of the pre-tightening pressure applied by the elastic pressing assembly to enter the position where the original PTFE sealing ring 41 is located (as shown in Figure 3), so that the second metal sealing ring 42 and the first metal sealing ring 31 are tightly fitted, ensuring reliable sealing under abnormally high temperature working conditions. The valve sealing structure forms two layers of sealing through the PTFE sealing ring 41 and the second metal sealing ring 42, ensuring that the ball valve of this embodiment can simultaneously be compatible with the advantages of sealing using a non-metallic soft sealing pair and the advantages of sealing using a metal hard sealing pair, thereby ensuring that the ball valve of this embodiment always maintains reliable sealing performance under different working temperatures, especially playing a fire prevention role, ensuring that the ball valve of this embodiment can maintain reliable sealing performance when it is in a closed state even in the event of a fire.

[0065] As shown in Figure 1, specifically, the channel 21 is set as a stepped hole, and the large diameter portion of the channel 21 is located at one end of the small diameter portion of the channel 21 axially toward the inner cavity 11, so as to avoid the connecting column and the sealing pressure ring 51 when assembling the valve cover 2 and the valve body 1, thereby avoiding interference.

[0066] As shown in Figure 1, in some embodiments of the present application, a mounting hole is formed on the valve body 1 along the direction of the rotation axis of the C-shaped sphere 3, the mounting hole is connected to the inner cavity 11, the C-shaped sphere 3 is connected to the valve stem 6 through a first limit screw 33, the valve stem 6 is rotatably connected in the mounting hole, and one end of the valve stem 6 extends through the mounting hole to the outside of the valve body 1; a sealing filler 71 is filled between the side surface of the valve stem 6 and the inner wall of the mounting hole. The valve stem 6, which extends outside the valve body 1, drives the C-shaped ball 3 to rotate within the inner cavity 11, thereby adjusting the C-shaped ball 3 to switch between the closed state and the open state. A sealing filler 71 is filled between the side surface of the valve stem 6 and the inner wall of the mounting hole to ensure the sealing between the radial side surface of the valve stem 6 and the inner wall of the mounting hole, preventing particles in the medium flowing through the inner cavity 11 and the channel 21 from entering the upper portion of the valve stem 6, thereby protecting the valve stem 6 from wear and extending the service life of the ball valve of this embodiment. The valve stem 6 and the C-shaped ball 3 are also connected as a whole by a first limit screw 33. Compared with the valve stem 6 being connected as a whole by inserting it into the insertion groove of the C-shaped ball 3 through an interference fit, the valve stem 6 of the ball valve of this embodiment has an anti-extrusion function, preventing the valve stem 6 from separating from the C-shaped ball 3 and being pushed out of the inner cavity 11 when the inner cavity 11 is pressurized. It can be understood that the rotation axis direction of the C-shaped ball 3 described in this embodiment refers to the first direction in Figure 1.

[0067] Specifically, the sealing packing 71 includes a PTFE packing piece and a graphite packing piece. The graphite packing piece is arranged at the end of the PTFE packing piece away from the inner cavity 11 to form two sealing lines, further improving the sealing between the radial side surface of the valve stem 6 and the inner wall of the mounting hole; of course, only the material of the sealing packing 71 is selected here. In actual applications, the sealing packing 71 can be other types of packing in the prior art.

[0068] As shown in FIG1 , in some embodiments of the present application, the mounting hole is configured as a stepped hole. The larger diameter portion of the mounting hole is located at the end of the smaller diameter portion of the mounting hole facing away from the inner cavity 11. The sealing packing 71 is filled between the inner wall of the larger diameter portion of the mounting hole and the side surface of the valve stem 6. A packing press ring 72 abuts against the end of the sealing packing 71 facing away from the smaller diameter portion of the mounting hole. The packing press ring 72 is fixedly connected to the valve body 1. The packing press ring 72 restricts the freedom of movement of the sealing packing 71 away from the inner cavity 11, thereby ensuring that the sealing packing 71 is tightly packed within the larger diameter portion of the mounting hole, thereby effectively sealing the gap between the radial side surface of the valve stem 6 and the inner wall of the larger diameter portion of the mounting hole. Specifically, the packing press ring 72 is connected to the valve body 1 via a fastening bolt 74.

[0069] Specifically, a bearing ring 73 is provided between the inner wall of the small-diameter portion of the mounting hole and the side surface of the valve stem 6. The bearing ring 73 can reduce the friction between the radial side surface of the valve stem 6 and the inner wall of the small-diameter portion of the mounting hole, thereby facilitating the rotation of the valve stem 6 and extending the service life of the valve stem 6.

[0070] As shown in FIG1 , in some embodiments of the present application, the end of the C-shaped sphere 3 facing away from the valve stem 6 is connected to a support rod 35 via a second stop screw 34. The support rod 35 is concentrically arranged with the valve stem 6 and is rotatably connected to the wall surrounding the inner cavity 11. The support rod 35 increases the rotational connection area between the C-shaped sphere 3 and the wall surrounding the inner cavity 11, allowing the C-shaped sphere 3 to rotate smoothly and steadily under the drive of the valve stem 6, thereby accurately adjusting the C-shaped sphere 3 between the closed and open states. The second stop screw 34 also facilitates the installation and removal of the support rod 35 from the C-shaped sphere 3.

[0071] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of this application.

Claims

1. A valve sealing structure is applied to the connection at the communication between the inner cavity (11) of the valve body (1) and the passage (21) of the valve cover (2), and is characterized in that, The valve sealing structure comprises: A C-shaped ball (3) is used for being rotatably connected in the inner cavity (11) of the valve body (1), wherein the C-shaped ball (3) has a closed state in which the inner cavity (11) of the valve body (1) and the passage (21) of the valve cover (2) are blocked, and an open state in which the inner cavity (11) of the valve body (1) and the passage (21) of the valve cover (2) are connected; a first metal sealing ring (31), arranged on the outer surface of the C-shaped sphere (3); A PTFE sealing ring (41) is used for being installed at the liquid outlet of the inner cavity (11) of the valve body (1) and is arranged concentrically with the liquid outlet of the inner cavity (11); A second metal sealing ring (42) is concentrically arranged on the end surface of the PTFE sealing ring (41) axially facing away from the C-shaped sphere (3); an elastic pressing assembly, arranged on an end surface of the second metal sealing ring (42) axially away from the PTFE sealing ring (41), and used for applying a pre-tightening pressure axially toward the PTFE sealing ring (41) to the second metal sealing ring (42); When the C-shaped sphere (3) is in a closed state, the first metal sealing ring (31) and the PTFE sealing ring (41) are arranged concentrically.

2. The valve sealing structure according to claim 1, wherein, The elastic pressing assembly includes a plurality of connecting columns, which are used to be connected to the end face of the valve body (1) axially facing the valve cover (2) and are arranged at intervals along the circumference of the PTFE sealing ring (41); a sealing pressure ring (51) is axially slidably provided on the connecting column, and the second metal sealing ring (42) is connected to the end face of the sealing pressure ring (51) facing the PTFE sealing ring (41); a limiting portion is provided at one end of the connecting column axially away from the C-shaped sphere (3); an elastic member is sleeved on the connecting column, and both ends of the elastic member are respectively connected to the limiting portion and the two end faces of the sealing pressure ring (51) axially facing each other, and the elastic member has an initial state of being compressed and storing force.

3. The valve sealing structure according to claim 2, characterized in that, The elastic pressing assembly further comprises a plurality of connecting bolts (52) and threaded holes corresponding to the connecting bolts (52), the threaded holes being arranged on the end surface of the valve body (1) axially facing the valve cover (2), the connecting bolts (52) being threadedly connected in the threaded holes; the screw rod portion of the connecting bolt (52) forming the connecting column, and the screw head of the connecting bolt (52) forming the limiting portion; And / or, the elastic member is configured as a coil spring (53) or a butterfly spring (54).

4. The valve sealing structure according to claim 1, characterized in that, The cross-sectional shape of the second metal sealing ring (42) is set to be wedge-shaped, and the end surface of the PTFE sealing ring (41) facing the second metal sealing ring (42) is concavely provided with a circle of wedge-shaped grooves (411).

5. The valve sealing structure according to claim 1, characterized in that, The outer peripheral surface of the first metal sealing ring (31) is set as a first spherical surface (311), and the inner peripheral surface of the PTFE sealing ring (41) is set as a second spherical surface, and the second spherical surface matches the first spherical surface (311); And / or, the outer peripheral surface of the first metal sealing ring (31) is provided as a first spherical surface (311), the inner peripheral surface of the second metal sealing ring (42) is provided as a third spherical surface (421), and the third spherical surface (421) matches the first spherical surface (311); And / or, a positioning groove is concavely provided on the outer surface of the C-shaped sphere (3), the first metal sealing ring (31) is fitted in the positioning groove, and the first metal sealing ring (31) is detachably connected to the C-shaped sphere (3) by fastening screws (32).

6. A ball valve, characterized in that, It includes a valve body (1), a valve cover (2) and a valve sealing structure. An inner cavity (11) is provided in the valve body (1), a channel (21) is provided in the valve cover (2), the valve cover (2) is connected to the liquid outlet end of the valve body (1) by bolts, and the inner cavity (11) communicates with the channel (21); the valve sealing structure adopts the valve sealing structure according to any one of claims 1 to 5.

7. The ball valve according to claim 6, wherein, An installation hole is formed through the valve body (1) along the rotation axis direction of the C-shaped sphere (3), the installation hole communicates with the inner cavity (11), the C-shaped sphere (3) is connected to a valve rod (6) by a first limit screw (33), the valve rod (6) is rotatably connected in the installation hole, and one end of the valve rod (6) extends out of the valve body (1) through the installation hole; a sealing packing (71) is filled between the side surface of the valve rod (6) and the inner wall of the installation hole.

8. The ball valve according to claim 7, wherein, The installation hole is provided as a stepped hole, the large-diameter part of the installation hole is located at one end of the small-diameter part of the installation hole away from the inner cavity (11), and the sealing packing (71) is filled between the inner wall of the large-diameter part of the installation hole and the side surface of the valve rod (6); one end of the sealing packing (71) away from the small-diameter part of the installation hole abuts against a packing gland (72), and the packing gland (72) is fixedly connected to the valve body (1).

9. The ball valve according to claim 8, wherein, A bearing ring (73) is provided between the inner wall of the small-diameter part of the installation hole and the side surface of the valve rod (6).

10. The ball valve according to claim 7, characterized in that, One end of the C-shaped sphere (3) away from the valve rod (6) is connected to a support rod (35) by a second limit screw (34), the support rod (35) is concentric with the valve rod (6), and the support rod (35) is rotatably connected to the surrounding wall of the inner cavity (11).

Images