Valve working sealing assembly

Abstract

The invention relates to a valve working sealing assembly which comprises a valve body and a sealing unit installed in the valve body. The sealing unit comprises a left sealing cavity and a right sealing cavity; a left medium cavity and a right medium cavity are sequentially formed in the valve body from left to right. A left sealing cavity is formed between the sealing piece in the left sealing groove and the sealing piece in the middle sealing groove, and a right sealing cavity is formed between the sealing piece in the middle sealing groove and the sealing piece in the right sealing groove. The left sealing cavity and the right sealing cavity are matched with each other, when the sealing space on one side changes, rapid follow-up compensation can be achieved on the other side, then movable sealing is achieved, and the sealing performance is good.

Description

Technical Field

[0001] The present invention relates to the technical field related to valve sealing structures, and in particular to a valve working sealing component. Background Art

[0002] The valve is a control component in the fluid delivery system, which has the functions of shutoff, regulation, flow diversion, flow diversion, pressure relief, etc. Valves are widely used in the fields of oil, natural gas, mining, petrochemical, electric power, and smelting production. The valve structure in the prior art usually includes a valve body, which is provided with a fluid channel, and a valve core structure for blocking or conducting the fluid is provided in the fluid channel. The valve core structure is connected to the operating mechanism through the valve shaft, and the valve core structure is opened or closed by driving the operating mechanism. There is a sealing structure between the surface of the valve core structure and the inner wall of the fluid channel.

[0003] After massive searches, it was found that the Chinese patent announcement number is CN217029925U, which discloses a sealing ring and sealing structure for valves, which relates to the field of semiconductor valve sealing technology to solve the problem of poor sealing effect of existing sealing rings. The sealing ring for valves includes an upper ring portion, a middle ring portion and a lower ring portion distributed in sequence along the axial direction, and an annular protrusion is coaxially arranged on the upper ring portion and / or the lower ring portion, and the annular protrusion is used to seal with the base block metal. An elastic polygonal ring structure is coaxially arranged on the outer side of the middle ring portion, and the cross-section of the outer edge of the elastic polygonal ring structure is polygonal. When the sealing ring is matched with the base block, the outer edge of the elastic polygonal ring structure squeezes the base block along the radial direction of the sealing ring to seal with the base block through elastic deformation. The sealing structure for valves includes the sealing ring for valves mentioned in the above technical solution.

[0004] In summary, the existing sealing structure is generally carried out by means of a sealing ring, but the sealing ring made of rubber material has a relatively general strength, a relatively simple structure, and poor wear resistance;

[0005] In addition, long-term sliding or frequent start-stop operation will further aggravate the wear of the seal, thereby accelerating failure and shortening the service life.

[0006] In view of the above-mentioned defects, the designers have actively carried out research and innovation in order to create a valve working seal component to make it more valuable for industrial use. Summary of the invention

[0007] To solve any of the above technical problems, the purpose of the present invention is to provide a valve working sealing assembly.

[0008] To achieve the above object, the present invention adopts the following technical solution:

[0009] A valve working sealing assembly comprises a valve body and a sealing unit installed in the valve body;

[0010] The sealing unit comprises a left sealing cavity and a right sealing cavity;

[0011] A left medium cavity and a right medium cavity are sequentially opened on the valve body from left to right, the left medium cavity is connected with the left sealing cavity below, the right medium cavity is connected with the right sealing cavity below, a left sealing groove is opened in the valve body on the left side of the left medium cavity, a middle sealing groove is opened in the valve body between the left medium cavity and the right medium cavity, a right sealing groove is opened in the valve body on the right side of the right medium cavity, and sealing members are installed in the left sealing groove, the middle sealing groove and the right sealing groove;

[0012] A left sealing cavity is formed between the sealing element in the left sealing groove and the sealing element in the middle sealing groove, and a right sealing cavity is formed between the sealing element in the middle sealing groove and the sealing element in the right sealing groove;

[0013] The seal includes a sealing ring and an O-ring from top to bottom. The sealing ring includes a sealing ring body. An O-ring mounting groove for embedding the O-ring below is provided on the inner diameter surface at the bottom of the sealing ring body. At least two annular sealing ring protrusions are evenly distributed along the left and right directions on the outer diameter surface at the top of the sealing ring body. V-shaped sealing ring contact lips are provided on the left and right sides of the sealing ring body and at the contact point with the working surface.

[0014] As a further improvement of the present invention, a plurality of pressure balancing structures are evenly distributed on the front and back sides of the sealing ring body, and the pressure balancing structure includes a first pressure balancing groove and a second pressure balancing groove respectively located on both sides, and the first pressure balancing groove and the second pressure balancing groove are staggered.

[0015] As a further improvement of the present invention, the angle between two adjacent front pressure balancing structures and the back pressure balancing structure is 45 degrees.

[0016] As a further improvement of the present invention, a V-shaped groove with a V-shaped cross section is provided between two adjacent sealing ring protrusions, and the cross section of the sealing ring protrusion is an obtuse triangle.

[0017] As a further improvement of the present invention, two annular sealing ring protrusions are evenly distributed along the left-right direction on the outer diameter surface of the top of the sealing ring body, and the two sealing ring protrusions are symmetrical to each other.

[0018] As a further improvement of the present invention, the sealing ring is made of polyurethane ring material.

[0019] As a further improvement of the present invention, the sealing ring is composed of MDI type polyurethane prepolymer, polyester polyol and 1,4-butanediol, and the ratio of the MDI type polyurethane prepolymer, polyester polyol and 1,4-butanediol is 100:20:13.

[0020] As a further improvement of the present invention, the sealing ring is composed of MDI type polyurethane prepolymer, polyether polyol or polytetramethylene glycol and 1,4-butanediol, and the ratio of MDI type polyurethane prepolymer, polyether polyol or polytetramethylene glycol and 1,4-butanediol is 100:23:12.

[0021] As a further improvement of the present invention, the O-ring is made of nitrile rubber.

[0022] As a further improvement of the present invention, the diameter size of the sealing ring adopts a negative tolerance.

[0023] By means of the above scheme, the present invention has at least the following advantages:

[0024] The present invention realizes mutual adaptation of the left sealing cavity and the right sealing cavity. When the sealing space on one side changes, the other side can achieve rapid follow-up compensation, thereby realizing mobile sealing and achieving good sealing performance.

[0025] The present invention combines the sealing ring and the O-ring, so that the overall sealing structure has good static and dynamic sealing performance.

[0026] The invention supports and guides the sealing body through the multiple sealing ring protrusions on the sealing ring body, thereby improving the pressure resistance of the sealing ring, extending the service life of the sealing ring, and facilitating installation.

[0027] The invention has good wear resistance, tear resistance, stretch resistance and resilience after extreme stress through the design of the polyurethane ring material of the sealing ring.

[0028] The diameter size of the sealing ring of the present invention adopts a negative tolerance to ensure that the seal can hold the inner ring more tightly during installation. The larger holding force can resist a large part of the lateral force generated during extrusion, and the seal is not easy to turn over and twist.

[0029] The V-shaped sealing ring of the present invention contacts the lip, and has sufficient contact stress at the maximum opening angle of the lip to play a sealing role, thereby ensuring sealing while reducing the overall contact area of ​​the seal.

[0030] The present invention utilizes the working principle of O-ring compression sealing to provide good sealing in the groove bottom direction while giving the polyurethane ring more sufficient pre-tightening force to cope with working conditions with large gap changes.

[0031] The present invention opens asymmetric pressure balancing grooves on both sides, so that pressure can act on the O-ring quickly, generating a tightening force to push the M-ring and the groove to fit tightly, avoiding penetration leakage and ensuring the sealing effect.

[0032] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 It is a structural schematic diagram of a valve working sealing assembly of the present invention;

[0035] Figure 2 yes Figure 1 Schematic diagram of the structure of the middle seal;

[0036] Figure 3 yes Figure 2 Schematic diagram of the structure of the middle sealing ring;

[0037] Figure 4 It is a schematic diagram of the distribution structure of the first pressure balancing groove and the second pressure balancing groove on the sealing ring of the present invention.

[0038] The meanings of the various reference numerals in the figures are as follows.

[0039] Valve body 1, left medium cavity 2, right medium cavity 3, left sealing groove 4, sealing member 5, middle sealing groove 6, right sealing groove 7, sealing ring 8, O-ring 9, first pressure balancing groove 10, second pressure balancing groove 11;

[0040] Sealing ring body 81 , O-ring mounting groove 82 , sealing ring protrusion 83 , sealing ring contact lip 84 . DETAILED DESCRIPTION

[0041] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0042] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, rather than all the embodiments. The components of the embodiment of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiment of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiment of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0043] Example

[0044] like Figure 1 to Figure 4 As shown,

[0045] A valve working sealing assembly comprises a valve body 1 and a sealing unit installed in the valve body 1, wherein the sealing unit comprises a left sealing cavity and a right sealing cavity.

[0046] 1. Specific structure of the sealing unit:

[0047] A left medium cavity 2 and a right medium cavity 3 are sequentially provided on the valve body 1 from left to right. The left medium cavity 2 is connected to the left sealing cavity below, and the right medium cavity 3 is connected to the right sealing cavity below.

[0048] A left sealing groove 4 is opened in the valve body 1 on the left side of the left medium cavity 2, a middle sealing groove 6 is opened in the valve body 1 between the left medium cavity 2 and the right medium cavity 3, a right sealing groove 7 is opened in the valve body 1 on the right side of the right medium cavity 3, and sealing members 5 are installed in the left sealing groove 4, the middle sealing groove 6 and the right sealing groove 7.

[0049] A left sealing cavity is formed between the sealing member 5 in the left sealing groove 4 and the sealing member 5 in the middle sealing groove 6 , and a right sealing cavity is formed between the sealing member 5 in the middle sealing groove 6 and the sealing member 5 in the right sealing groove 7 .

[0050] 2. Specific structure of the sealing member 5:

[0051] The sealing member 5 includes a sealing ring 8 and an O-ring 9 from top to bottom. The sealing ring 8 includes a sealing ring body 81. An O-ring mounting groove 82 for embedding the O-ring 9 below is provided on the inner diameter surface at the bottom of the sealing ring body 81. At least two annular sealing ring protrusions 83 are evenly distributed along the left and right directions on the outer diameter surface at the top of the sealing ring body 81. V-shaped sealing ring contact lips 84 are provided on the left and right sides of the sealing ring body 81 and at the contact point with the working surface.

[0052] A plurality of pressure balancing structures are evenly distributed on the front and back of the sealing ring body 81. The pressure balancing structures include a first pressure balancing groove 10 and a second pressure balancing groove 11 located on both sides, and the first pressure balancing groove 10 and the second pressure balancing groove 11 are staggered. The angle between two adjacent pressure balancing structures on the front and the pressure balancing structure on the back is 45 degrees.

[0053] A V-shaped groove with a V-shaped cross section is provided between two adjacent sealing ring protrusions 83 , and the cross section of the sealing ring protrusion 83 is an obtuse triangle.

[0054] Two annular sealing ring protrusions 83 are evenly distributed along the left-right direction on the outer diameter surface of the top of the sealing ring body 81, and the two sealing ring protrusions 83 are symmetrical to each other.

[0055] 3.Material of seal 5:

[0056] The sealing ring 8 is made of polyurethane.

[0057] The reaction formula of the polyurethane ring is:

[0058]

[0059] Polyurethane sealing products are made by mixing three materials: ABC:

[0060] Material A (prepolymer): MDI type polyurethane prepolymer:

[0061]

[0062] NCO mass fraction is 13%.

[0063] Material B (cross-linking agent): polyester polyol:

[0064]

[0065] Material C (chain extender): 1,4-butanediol (BDO)

[0066]

[0067] In addition, material B can be replaced with polyether polyols and polytetramethylene glycol.

[0068] There are two specific situations:

[0069] 1) The sealing ring 8 is composed of MDI type polyurethane prepolymer, polyester polyol and 1,4-butanediol, and the ratio of the MDI type polyurethane prepolymer, polyester polyol and 1,4-butanediol is 100:20:13.

[0070] 2) The sealing ring 8 is composed of MDI type polyurethane prepolymer, polyether polyol or polytetramethylene glycol and 1,4-butanediol, and the ratio of MDI type polyurethane prepolymer, polyether polyol or polytetramethylene glycol and 1,4-butanediol is 100:23:12.

[0071] The O-ring 9 is made of nitrile rubber.

[0072] The working process of the present invention is briefly described as follows:

[0073] A left medium cavity 2 and a right medium cavity 3 are sequentially opened on the valve body 1 from left to right. The left medium cavity 2 is connected with the left sealing cavity below, and the right medium cavity 3 is connected with the right sealing cavity below. A left sealing groove 4 is opened in the valve body 1 on the left side of the left medium cavity 2, a middle sealing groove 6 is opened in the valve body 1 between the left medium cavity 2 and the right medium cavity 3, and a right sealing groove 7 is opened in the valve body 1 on the right side of the right medium cavity 3. Seals 5 are installed in the left sealing groove 4, the middle sealing groove 6 and the right sealing groove 7.

[0074] A left sealing cavity is formed between the sealing member 5 in the left sealing groove 4 and the sealing member 5 in the middle sealing groove 6 , and a right sealing cavity is formed between the sealing member 5 in the middle sealing groove 6 and the sealing member 5 in the right sealing groove 7 .

[0075] By introducing liquid medium into the left medium cavity 2 and the right medium cavity 3, a relatively sealed space is formed, and kinetic energy conversion is performed through the transmission of the liquid medium.

[0076] When the liquid medium introduced into the left medium cavity 2 increases and the liquid medium introduced into the right medium cavity 32 decreases, the sealing ring will move toward the right; when the liquid medium introduced into the left medium cavity 2 decreases and the liquid medium introduced into the right medium cavity 32 increases, the sealing ring will move toward the left. The opening and closing of the sealing channel is realized through the above-mentioned left and right movement process. In addition, the distance of left and right movement can also be controlled by the flow rate of the liquid medium.

[0077] The key improvements of the present invention are:

[0078] 1. The sealing member 5 includes a sealing ring 8 and an O-ring 9 from top to bottom. The sealing ring 8 includes a sealing ring body 81. An O-ring mounting groove 82 for embedding the O-ring 9 below is provided on the inner diameter surface of the bottom of the sealing ring body 81. At least two annular sealing ring protrusions 83 are evenly distributed along the left and right directions on the outer diameter surface of the top of the sealing ring body 81. V-shaped sealing ring contact lips 84 are provided on the left and right sides of the sealing ring body 81 and at the contact point with the working surface.

[0079] The seal 5 of the combined seal is composed of a sealing ring 8 of polyurethane with an M-shaped cross-section and an O-ring 9 of nitrile rubber. An O-ring installation groove 82 for embedding the O-ring is provided on the inner diameter surface where the sealing ring 8 and the O-ring 9 contact. At least two annular continuous sealing ring protrusions 83 are provided on the outer diameter surface of the sealing ring 8. The two sealing ring protrusions 83 are axially symmetrically arranged, and the top angle of the cross section formed between adjacent sealing ring protrusions 83 is a V-shaped groove. The sealing ring protrusion 83 is a protrusion with an obtuse triangle cross-section, which supports and guides the sealing ring body 81, thereby improving the pressure resistance of the sealing ring, extending the service life of the sealing ring, and being easy to install. The combined seal is designed to have a compression amount of 5mm, and the overall structure has excellent static and dynamic sealing performance.

[0080] 2. Material of sealing ring 8:

[0081] The sealing ring 8 is composed of MDI type polyurethane prepolymer, polyester polyol and 1,4-butanediol, and the ratio of the MDI type polyurethane prepolymer, polyester polyol and 1,4-butanediol is 100:20:13.

[0082] Or,

[0083] The sealing ring 8 is composed of MDI type polyurethane prepolymer, polyether polyol or polytetramethylene glycol and 1,4-butanediol, and the ratio of the MDI type polyurethane prepolymer, polyether polyol or polytetramethylene glycol and 1,4-butanediol is 100:23:12.

[0084] The polyurethane ring material has good wear resistance, tear resistance, tensile strength, and rebound ability after extreme stress:

[0085] 1) Elastic modulus (DIN 53504): ≥15N / mm 2 ;

[0086] 2) Elongation at break (DIN 53504): ≥330%;

[0087] 3) Tensile strength (DIN 53504): ≥45N / mm 2 ;

[0088] 4) Hardness (Shore A) (DIN 53505): 95±2;

[0089] 5) Tear strength (DIN ISO 34-1): ≥80N / mm 2 ;

[0090] 6) Abrasion (DIN ISO 4649): ≤21mm 3 ;

[0091] 7) Pressure bearing: ≥20MPa.

[0092] Based on the good elongation of the material, the diameter design and production tolerance of the sealing ring 8 adopts a negative tolerance to ensure that the seal can hold the O-ring 9 more tightly during installation. The larger holding force can resist a large part of the lateral force generated during extrusion, and the seal is not easy to flip and twist. With the technology of integrated molding of the whole circle, the pressure-bearing performance of the seal can be better ensured.

[0093] 3. The combined seal wear-resistant seal ring is made of polyurethane material and is in an M-shaped ring shape. A V-shaped symmetrical seal ring contact lip 84 is provided at the contact position with the working surface. By utilizing the working principle of the seal lip, there is sufficient contact stress at the maximum position of the lip opening angle to play a sealing role, thereby ensuring sealing while reducing the overall contact area of ​​the seal.

[0094] 4. The O-ring 9 is made of nitrile rubber.

[0095] The combined sealing elastomer adopts an O-ring 9 formed by processing nitrile rubber material, which fully utilizes the working principle of O-ring compression sealing, and provides a more sufficient pre-tightening force to the polyurethane ring while doing a good job of sealing in the groove bottom direction, so as to cope with the working conditions of large gap changes.

[0096] 5. A plurality of pressure balancing structures are evenly distributed on the front and back sides of the sealing ring body 81. The pressure balancing structures include a first pressure balancing groove 10 and a second pressure balancing groove 11 respectively located on both sides, and the first pressure balancing groove 10 and the second pressure balancing groove 11 are staggered.

[0097] Asymmetric pressure balancing grooves (i.e., the first pressure balancing groove 10 and the second pressure balancing groove 11) are opened on both sides, through which pressure is quickly introduced so that pressure can quickly act on the O-ring, generating a tightening force to push the sealing ring 8 to fit the groove, avoiding through leakage and ensuring the sealing effect.

[0098] The present invention realizes mutual adaptation of the left sealing cavity and the right sealing cavity. When the sealing space on one side changes, the other side can achieve rapid follow-up compensation, thereby realizing mobile sealing and achieving good sealing performance.

[0099] The present invention combines the sealing ring and the O-ring, so that the overall sealing structure has good static and dynamic sealing performance.

[0100] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implying the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0101] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A valve working seal assembly, comprising a valve body (1) and a sealing unit installed in the valve body (1); Features: The sealing unit comprises a left sealing cavity and a right sealing cavity; A left medium cavity (2) and a right medium cavity (3) are sequentially provided on the valve body (1) from left to right. The left medium cavity (2) is connected to a left sealing cavity below, and the right medium cavity (3) is connected to a right sealing cavity below. A left sealing groove (4) is provided in the valve body (1) on the left side of the left medium cavity (2), a middle sealing groove (6) is provided in the valve body (1) between the left medium cavity (2) and the right medium cavity (3), and a right sealing groove (7) is provided in the valve body (1) on the right side of the right medium cavity (3). Sealing elements (5) are installed in the left sealing groove (4), the middle sealing groove (6) and the right sealing groove (7); A left sealing cavity is formed between the sealing member (5) in the left sealing groove (4) and the sealing member (5) in the middle sealing groove (6), and a right sealing cavity is formed between the sealing member (5) in the middle sealing groove (6) and the sealing member (5) in the right sealing groove (7); The sealing member (5) comprises a sealing ring (8) and an O-ring (9) in order from top to bottom. The sealing ring (8) comprises a sealing ring body (81). An O-ring mounting groove (82) for embedding the O-ring (9) below is provided on the inner diameter surface at the bottom of the sealing ring body (81). At least two annular sealing ring protrusions (83) are evenly distributed along the left and right directions on the outer diameter surface at the top of the sealing ring body (81). V-shaped sealing ring contact lips (84) are provided on both left and right sides of the sealing ring body (81) and at the contact point with the working surface.

2. A valve working seal assembly according to claim 1, characterized in that: A plurality of pressure balancing structures are evenly distributed on the front and back sides of the sealing ring body (81), wherein the pressure balancing structures include a first pressure balancing groove (10) and a second pressure balancing groove (11) respectively located on both sides, and the first pressure balancing groove (10) and the second pressure balancing groove (11) are staggered.

3. A valve working seal assembly as claimed in claim 2, characterized in that: The angle between two adjacent front pressure balancing structures and the back pressure balancing structure is 45 degrees.

4. A valve working seal assembly according to claim 1, characterized in that: A V-shaped groove with a V-shaped cross section is provided between two adjacent sealing ring protrusions (83), and the cross section of the sealing ring protrusion (83) is an obtuse triangle.

5. A valve working seal assembly according to claim 1, characterized in that: Two annular sealing ring protrusions (83) are evenly distributed along the left-right direction on the outer diameter surface of the top of the sealing ring body (81), and the two sealing ring protrusions (83) are symmetrical to each other.

6. A valve working seal assembly according to claim 1, characterized in that: The sealing ring (8) is made of polyurethane ring material.

7. A valve working seal assembly as claimed in claim 6, characterized in that: The sealing ring (8) is composed of MDI type polyurethane prepolymer, polyester polyol and 1,4-butanediol, and the ratio of the MDI type polyurethane prepolymer, polyester polyol and 1,4-butanediol is 100:20:

13.

8. A valve working seal assembly as claimed in claim 6, characterized in that: The sealing ring (8) is composed of MDI type polyurethane prepolymer, polyether polyol or polytetramethylene glycol and 1,4-butanediol, and the ratio of the MDI type polyurethane prepolymer, polyether polyol or polytetramethylene glycol and 1,4-butanediol is 100:23:

12.

9. A valve working seal assembly as claimed in claim 1, characterized in that: The O-ring (9) is made of nitrile rubber.

10. A valve working seal assembly according to claim 1, characterized in that: The diameter dimension of the sealing ring (8) adopts a negative tolerance.

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