Packing sealing structure of floating ball valve

Abstract

The utility model discloses a packing sealing structure of a floating ball valve, and belongs to the technical field of floating ball valves. Comprising a valve body, a right body, a valve rod, a ball body, an upper packing assembly and lower packing. The right body is arranged on the right side of the valve body; the valve rod is vertically inserted into the upper end of the valve body and can rotate relative to the valve body; the ball body is arranged below the valve rod; the ball body is located in the valve body and can rotate relative to the valve body. An upper packing assembly is arranged close to the upper end of the valve rod and located in a contact surface gap between the valve body and the valve rod; the upper packing assembly is used for sealing a gap between the valve rod and the valve body; lower padding is arranged at the lower end of the valve rod and located on the valve body. And the lower packing is in inclined surface contact with the peripheral surface of the lower end of the valve rod. According to the floating ball valve, double-filler sealing is adopted, and the problem that when a valve rod is subjected to upward acting force, the filler sealing performance can be affected, and consequently material media can be leaked, of a vertically-contacted single-filler sealing mode of an existing floating ball valve is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of floating ball valves, and in particular relates to a packing sealing structure of a floating ball valve. Background Art

[0002] Floating ball valve is a commonly used valve type, widely used in industries such as petroleum, chemical, metallurgy and electric power. It has the characteristics of simple structure, good sealing performance and easy maintenance. It is one of the key equipment for achieving pipeline fluid control. The working principle of floating ball valve is to control the opening and closing of the valve by rotating the ball. Floating ball valve is mainly composed of valve body, valve cover, valve stem, ball, valve seat and other components. When the ball rotates to contact the valve seat, the valve is in the closed state; when the ball rotates away from the valve seat, the valve is in the open state. The opening and closing of the floating ball valve is achieved by the drive device driving the valve stem.

[0003] A packing is usually set between the valve stem and the valve body to seal the contact surface gap between the valve stem and the valve body to prevent the material medium from leaking from the contact surface gap between the two. Due to the structure and working principle of the floating ball valve, when the floating ball valve is working, the valve stem will be subjected to an upward force due to the action of the medium pressure, so that the packing follows the upward force between the valve stem and the valve body, which may cause the contact tightness between the packing and the valve body to be destroyed, resulting in leakage of the material medium. Utility Model Content

[0004] The utility model provides a packing sealing structure of a floating ball valve. In addition to a packing which is in vertical direct contact with the valve body and is arranged near the upper position of the valve stem, a lower packing is also arranged at the lower end of the valve stem. One side of the outer periphery of the lower end of the valve stem is arranged with an inclined surface. The cross section of the lower packing is a wedge-shaped surface, and the inclined surface of the wedge-shaped lower packing contacts the inclined surface of the outer periphery of the lower end of the valve stem, so that an inclined surface contact structure is formed between the two. In this way, when the valve stem is subjected to medium pressure and the valve stem is subjected to an upward force, the valve stem will fit more closely with the lower packing, and the sealing effect of the lower packing is enhanced. The utility model adopts a double packing seal, which solves the problem of the single packing seal with vertical direct contact in the current floating ball valve, in which the sealing performance of the packing will be affected when the valve stem is subjected to an upward force, which may cause leakage of the material medium.

[0005] In order to achieve the above technical objectives, the present invention is implemented through the following technical solutions:

[0006] A floating ball valve packing sealing structure, comprising: a valve body, a right body, a valve stem, a ball, an upper packing assembly, and a lower packing;

[0007] The right body is provided on the right side of the valve body;

[0008] The upper end of the valve body is vertically inserted into the valve stem, and the valve stem is rotatable relative to the valve body;

[0009] A sphere is provided at the lower end of the valve stem; the sphere is located inside the valve body and is rotatable relative to the valve body;

[0010] An upper packing assembly is provided near the upper end of the valve stem and in the gap between the contact surface of the valve body and the valve stem; the upper packing assembly is used to seal the gap between the valve stem and the valve body;

[0011] A lower packing is provided at the lower end of the valve stem and on the valve body;

[0012] The lower filler contacts the outer peripheral surface of the lower end of the valve stem through an inclined surface.

[0013] Preferably, the outer peripheral surface of the lower end of the valve stem is an inclined surface structure;

[0014] The cross section of the lower filler is a wedge-shaped structure, and the inclined surface of the lower filler is in contact with and fits the inclined outer peripheral surface of the lower end of the valve stem.

[0015] Preferably, an elastic washer is provided at the outer edge of the lower bottom surface of the lower filler;

[0016] The lower bottom surface of the elastic washer contacts the horizontal upper surface of the connecting portion between the valve stem and the ball.

[0017] Preferably, a limiting insert is provided at a position on the outer side of the lower packing away from the valve stem;

[0018] The limiting insert is arranged on the valve body and is used to embed, fix and limit the lower filler.

[0019] Preferably, a convex ring is provided on the outer peripheral inclined surface of the lower end of the valve stem;

[0020] A groove ring matching the convex ring is provided on the inclined surface where the lower filler contacts the outer peripheral surface;

[0021] When the inclined surface of the lower filler contacts the outer peripheral surface of the lower end of the valve stem, the convex ring is located in the groove ring.

[0022] Preferably, the inclination angle of the inclined surface of the lower filler is 1 to 3 degrees greater than the inclination angle of the outer peripheral surface of the lower end of the valve stem.

[0023] Preferably, the upper packing assembly includes: a PTFE packing, a packing gland and a packing ring;

[0024] The PTFE filler is arranged between the valve stem and the valve body, and is filled in the filler groove provided on the valve body;

[0025] A packing pressure ring is provided above the PTFE packing, the lower portion of which is located in the valve body to compact the PTFE packing, and the upper portion of which is located outside the valve body;

[0026] A packing gland is provided above the packing pressure ring, and the packing gland is pressed onto the packing pressure ring.

[0027] Preferably, a limit block is provided near the upper end of the valve stem and on the outer periphery of the valve stem; the portion of the limit block away from the valve stem is embedded in the upper surface of the packing gland;

[0028] An elastic retaining ring for the shaft is provided on the upper surface of the limit block.

[0029] Preferably, valve seats are provided at the contact positions between the upper and lower ends of the sphere and the valve body;

[0030] The valve seat is embedded in the valve body.

[0031] The beneficial effects of the utility model are:

[0032] The utility model provides a packing seal structure of a floating ball valve, which is provided with a double packing seal assembly. In addition to the packing assembly close to the upper end of the valve stem, a lower packing with a wedge-shaped cross section is provided at the lower end of the valve stem, and the outer peripheral surface of the lower end of the valve stem is an inclined surface. The wedge-shaped inclined surface of the lower packing contacts the inclined outer peripheral surface of the lower end of the valve stem. The two are in inclined contact. When the valve stem is subjected to an upward force under the pressure of the medium, the contact between the valve stem and the lower packing is made tighter, so that the sealing performance is further enhanced, and leakage of the medium material is avoided when the valve stem is subjected to an upward force.

[0033] An elastic washer is provided near the outer edge of the lower bottom surface of the lower packing; when the valve stem is in contact with the lower packing, the elastic washer contacts the horizontal upper surface of the connection between the valve stem and the ball; when the valve stem is subjected to an upward force and contacts the lower packing, an extrusion contact is generated between the elastic washer and the connection part, which can also play a sealing role from the outer periphery of the lower packing, further improving the sealing effect.

[0034] A limit insert is provided on the side of the lower packing away from the valve stem. The limit insert is provided on the valve body and fills the gap between the lower packing and the valve body. What is important is that the limit insert can play a fixed limiting role on the lower packing so that the lower packing can maintain its own shape and avoid deformation as much as possible, which affects the tightness of the inclined contact surface with the valve stem and causes the sealing to be destroyed.

[0035] A convex ring is provided on the inclined outer peripheral surface of the lower end of the valve stem, and a groove ring is provided on the inclined surface of the lower packing to match the convex ring; when the inclined surface of the lower end of the valve stem contacts the lower packing, the convex ring is located in the groove ring, so that the lower end of the valve stem will not be displaced too much between the contact surface of the lower packing, affecting the sealing performance.

[0036] The inclination angle of the inclined surface of the lower packing is 1 to 3 degrees greater than the inclination angle of the outer peripheral surface of the lower end of the valve stem. In this way, when the valve stem is subjected to an upward force and contacts the lower packing, the inclined surface of the lower packing has more compensation margin, which can ensure that the contact between the lower packing and the valve stem is sufficiently tight and ensures good sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 This is a schematic diagram of the side cross-sectional structure of the floating ball valve of the utility model;

[0039] Figure 2 This is a front view of the floating ball valve of the utility model;

[0040] Figure 3 This is a partial enlarged schematic diagram A of the present invention; specifically, it is a schematic diagram of the contact between the lower packing and the inclined surface of the lower end of the valve stem;

[0041] Figure 4 This is a schematic diagram of the structure of the utility model in which an elastic washer is provided at the outer edge of the lower bottom surface of the lower filler;

[0042] Figure 5 This is a schematic diagram of the structure of the limiting insert provided on the side of the lower filler of the utility model;

[0043] Figure 6 The utility model is a schematic diagram of a structure in which a convex ring is provided on the outer peripheral surface of the lower end of the valve stem, a groove ring is provided on the inclined surface of the lower packing, and the convex ring and the groove ring are matched.

[0044] In the accompanying drawings, the structural names represented by the reference numerals are:

[0045] 1-valve body, 2-right body, 3-ball, 4-valve seat, 5-valve stem, 6-PTFE packing, 7-packing gland, 8-packing ring, 9-limit block, 10-lower packing, 1001-elastic washer, 1002-limit insert, 1003-convex ring, 11-elastic ring for shaft, 12-bolt, 13-nut, 14-stud stud, 15-hexagonal nut, 16-washer. DETAILED DESCRIPTION

[0046] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] Example 1

[0048] A floating ball valve packing seal structure, comprising: a valve body 1, a right body 2, a valve stem 5, a ball 3, an upper packing assembly, and a lower packing 10;

[0049] like Figure 1 As shown, the right side of the valve body 1 is connected to the right body 2, and the valve body 1 and the right body 2 are connected by a stud 14, and then tightened by a hexagonal nut 15 to keep the connection between the valve body 1 and the right body 2 fixed;

[0050] A valve opening is provided at the upper end of the valve body 1, and a valve stem 5 is inserted into the valve body 1 from the valve body opening, and the valve stem 5 is rotatable relative to the valve body 1; a ball 3 is provided at the lower end of the valve stem 5, and the rotation of the ball 3 is controlled by the valve stem 5 to realize the opening or closing of the floating ball valve; the ball 3 is located inside the valve body 1, and is located at the inlet end and the outlet end of the valve body 1, and the inlet end and the outlet end of the floating ball valve can be blocked by the ball 3; valve seats 4 are provided at the contact positions of the upper and lower ends of the ball 3 with the valve body 1, and the valve seats 4 are respectively provided at the inlet end and the outlet end of the valve body 1 by embedded fixings; when the ball 3 closes the floating ball valve, the ball 3 and the valve seat 4 are squeezed and contacted with each other, and the valve seat 4 plays a sealing role between the ball 3 and the valve body 1 to prevent the medium material from leaking at the outlet end or the inlet end of the valve body 1.

[0051] An upper packing assembly is provided in the upper opening of the valve body 1 and between the valve stem 5 and the inner wall of the valve body 1. Figure 1 As shown, the upper packing assembly includes: PTFE packing 6, packing gland 7 and packing ring 8;

[0052] The PTFE packing 6 is arranged between the valve stem 5 and the valve body 1 and is filled in the packing groove provided on the valve body 1. A packing pressing ring 8 is arranged above the PTFE packing 6. The lower portion of the packing pressing ring 8 is located inside the valve body 1, compacting the PTFE packing 6. The upper portion is located outside the valve body 1. The packing pressing ring 8 tightly compresses the PTFE packing 6 to ensure its sealing effect. A packing gland 7 is arranged above the packing pressing ring 8. The packing gland 7 is pressed onto the packing pressing ring 8 and further compresses and secures the packing pressing ring 8 and the PTFE packing 6. The packing gland 7 is connected to the upper portion of the valve body 1 via stud bolts. Nuts are provided on the stud bolts. By screwing the nuts, the packing gland 7 can be gradually tightened to the valve body 1 and gradually pressed downward.

[0053] A limit block 9 is sleeved near the upper end of the valve stem 5 and located on the outer periphery of the valve stem 5; the part of the limit block 9 away from the valve stem 5 is embedded in the upper surface of the packing gland 7; and a shaft elastic circlip 11 is provided on the upper surface of the limit block 9.

[0054] The above-mentioned upper packing assembly will seal the gap between the upper part of the valve stem 5 and the valve body 1 to prevent the medium material from leaking out of the gap between the upper part of the valve stem 5 and the valve body 1; however, due to the structure and working principle of the floating ball valve, when the ball 3 is working, under the action of the medium pressure, the ball 3 and the valve stem 5 will receive an upward force, which may cause the packing to follow the valve stem 5 and the valve body 1 to be affected by the upward force; resulting in the destruction of the contact tightness between the packing and the valve body 1, causing material leakage.

[0055] So, if Figure 1 and Figure 3 As shown, in this embodiment, a lower packing 10 is also provided at the lower end of the valve stem 5. The lower packing 10 is provided at the lower end of the valve stem 5 and is provided on the valve body 1. The lower packing 10 is provided with an annular structure. From the cross section of the annular lower packing 10, the cross section of the lower packing 10 is a wedge-shaped structure, one of the surfaces of which is an inclined surface; and the outer peripheral surface of the lower end of the valve stem 5 is also provided with an inclined surface; in this way, the wedge-shaped inclined surface of the lower packing 10 and the inclined surface of the lower end of the valve stem 5 fit in contact with each other; when the valve stem 5 is subjected to an upward force, due to the inclined surface contact between the lower end of the valve stem 5 and the lower packing 10, the lower packing 10 plays a sealing role at the lower end of the valve stem 5, thereby preventing the medium material from leaking upward along the valve stem 5; and the greater the upward force applied to the valve stem 5, the greater the contact force between the lower end of the valve stem 5 and the lower packing 10, and the better the sealing effect.

[0056] Example 2

[0057] Based on Example 1, when the lower filler 10 is usually made of PTFE material, it itself has a certain elasticity; Figure 3As shown, the valve stem 5 and the ball 3 are connected by a connecting portion, and there is a gap between the lower bottom surface of the lower packing 10 and the platform of the connecting portion. Therefore, when the valve stem 5 is subjected to an excessively large upward force, the lower packing 10 may be deformed and extend to the gap between the lower bottom surface of the lower packing 10 and the platform of the connecting portion. Such a large deformation of the lower packing 10 will affect the sealing effect of the lower packing 10.

[0058] So, if Figure 4 As shown, in this embodiment, an elastic washer 1001 is provided at the outer edge of the lower bottom surface of the lower packing 10; the lower bottom surface of the elastic washer 1001 contacts the horizontal upper surface of the connection between the valve stem 5 and the ball 3. When the valve stem 5 is subjected to a large upward force and contacts the lower packing 10, the elastic washer 1001 and the connection portion are in compression contact, which can support the lower packing 10 and prevent the lower packing 10 from experiencing large compression and tensile deformation, which would also affect the sealing effect of the lower packing 10. In addition, the elastic washer 1001 can also seal the outer periphery of the lower packing 10, further improving the sealing effect.

[0059] Example 3

[0060] Based on Example 2, Figure 4 As shown, the lower packing 10 is directly connected to the valve body 1 through the upper surface, and there is no connection structure between the side of the lower packing 10 away from the valve stem 5 and the valve body 1, and there is a gap between the two; when the lower packing 10 contacts the valve stem 5 and is subjected to the upward force of the valve stem 5, it will also be squeezed and deformed toward the above-mentioned gap, affecting the overall structure of the lower packing 10, which may cause its inclined contact surface with the lower part of the valve stem 5 to be affected, thereby affecting the sealing effect.

[0061] like Figure 5 As shown, in this embodiment, a limiting insert 1002 is provided on the outer side of the lower packing 10 away from the lower end of the valve stem 5. The limiting insert 1002 is provided on the valve body 1 to insert and fix the lower packing 10. It also prevents the lower packing 10 from having excess space for extension and deformation when it is squeezed upward.

[0062] Example 4

[0063] Based on Example 1, in Example 1, the wedge-shaped inclined surface of the lower packing 10 contacts the outer peripheral inclined surface of the outer side surface of the lower end of the valve stem 5. Under the action of the inclined surface, the valve stem 5 can be subjected to an upward force, and the contact between the lower packing 10 and the valve stem 5 can play a sealing role; and the greater the upward force, the tighter the contact between the two inclined surfaces, and the better the sealing effect;

[0064] In this embodiment, the angle of the inclined surface of the lower packing 10 is 1-3 degrees greater than the angle of the outer peripheral surface of the lower end of the valve stem 5. This allows the outer peripheral inclined surface of the valve stem 5 to contact the inclined surface of the lower packing 10, and the two are squeezed. This allows the lower packing 10 to have more squeeze compensation margin, ensuring a tighter squeeze contact between the lower packing 10 and the valve stem 5, minimizing gaps and achieving a better sealing effect.

[0065] Example 5

[0066] Based on Example 1, in Example 1, the inclined surface of the lower packing 10 is in direct contact with the inclined surface of the outer periphery of the valve stem 5; when the floating ball valve is used for lubricants, oils and other slippery media materials, when the lower end of the valve stem 5 is subjected to an upward force and contacts the inclined surface of the lower packing 10, due to the slippery medium material, the contact friction between the lower end of the valve stem 5 and the lower packing 10 may decrease, and the two may be significantly displaced; the displacement of the two will affect the sealing effect.

[0067] like Figure 6 As shown, a raised ring 1003 is provided on the outer circumferential inclined surface at the lower end of the valve stem 5. A groove ring that matches the raised ring 1003 is provided on the inclined surface where the lower packing 10 contacts the outer circumferential surface. When the inclined surface of the lower packing 10 contacts the outer circumferential surface at the lower end of the valve stem 5, the raised ring 1003 is located within the groove ring. The cooperation between the raised ring 1003 and the groove ring prevents large displacement errors between the two, which could affect the sealing effect of the lower packing.

[0068] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0069] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, numerous modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A floating ball valve packing seal structure, characterized in that: include: Valve body, right body, valve stem, ball, upper packing assembly, lower packing; The right body is provided on the right side of the valve body; The upper end of the valve body is vertically inserted into the valve stem, and the valve stem is rotatable relative to the valve body; A sphere is provided at the lower end of the valve stem; the sphere is located inside the valve body and is rotatable relative to the valve body; An upper packing assembly is provided near the upper end of the valve stem and in the gap between the contact surface of the valve body and the valve stem; the upper packing assembly is used to seal the gap between the valve stem and the valve body; A lower packing is provided at the lower end of the valve stem and on the valve body; The lower filler contacts the outer peripheral surface of the lower end of the valve stem through an inclined surface.

2. A floating ball valve packing seal structure according to claim 1, characterized in that: The outer peripheral surface of the lower end of the valve stem is an inclined surface structure; The cross section of the lower filler is a wedge-shaped structure, and the inclined surface of the lower filler is in contact with and fits the inclined outer peripheral surface of the lower end of the valve stem.

3. The floating ball valve packing seal structure according to claim 1, characterized in that: An elastic washer is provided at the outer edge of the lower bottom surface of the lower filler; The lower bottom surface of the elastic washer contacts the horizontal upper surface of the connecting portion between the valve stem and the ball.

4. A floating ball valve packing seal structure according to claim 3, characterized in that: A limiting insert is provided at the outer side of the lower packing away from the valve stem; The limiting insert is arranged on the valve body and is used to embed, fix and limit the lower filler.

5. The floating ball valve packing seal structure according to claim 1, characterized in that: A convex ring is provided on the outer peripheral inclined surface of the lower end of the valve stem; A groove ring matching the convex ring is provided on the inclined surface where the lower filler contacts the outer peripheral surface; When the inclined surface of the lower filler contacts the outer peripheral surface of the lower end of the valve stem, the convex ring is located in the groove ring.

6. The floating ball valve packing seal structure according to claim 1, characterized in that: The inclination angle of the inclined surface of the lower filler is 1 to 3 degrees greater than the inclination angle of the outer peripheral surface of the lower end of the valve stem.

7. The floating ball valve packing seal structure according to claim 1, characterized in that: The upper packing assembly includes: a PTFE packing, a packing gland and a packing ring; The PTFE filler is arranged between the valve stem and the valve body, and is filled in the filler groove provided on the valve body; A packing pressure ring is provided above the PTFE packing, the lower portion of which is located in the valve body to compact the PTFE packing, and the upper portion of which is located outside the valve body; A packing gland is provided above the packing pressure ring, and the packing gland is pressed onto the packing pressure ring.

8. The floating ball valve packing seal structure according to claim 7, characterized in that: A limit block is provided near the upper end of the valve stem and on the outer periphery of the valve stem; a portion of the limit block away from the valve stem is embedded in the upper surface of the packing gland; An elastic retaining ring for the shaft is provided on the upper surface of the limit block.

9. The floating ball valve packing seal structure according to claim 1, characterized in that: Valve seats are provided at the contact positions between the upper and lower ends of the sphere and the valve body; The valve seat is embedded in the valve body.

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