Plug valve

Abstract

The plug valve comprises a valve body, a valve cover, a valve rod and a plug cock, the valve cover is installed at an opening in the upper end of the valve body, the valve rod penetrates through the valve cover and extends into the valve body to be connected with the plug cock, a flow channel and a plug cock cavity are arranged in the valve body, the plug cock is arranged in the plug cock cavity, and an overflowing hole corresponding to the flow channel is formed in the plug cock. The rotary plug further comprises a lining, the lining comprises an upper sealing ring, a lower sealing ring and at least two sealing strips arranged between the upper sealing ring and the lower sealing ring, the outer circumferential face of the rotary plug is tightly attached to the inner circumferential face of the rotary plug cavity, the upper sealing ring and the lower sealing ring are arranged at the positions, corresponding to the upper end and the lower end of the flow channel, of the rotary plug cavity respectively, and the sealing strips are arranged on the inner wall of the rotary plug cavity. The upper sealing ring, the lower sealing ring and the sealing strip are tightly attached to the outer wall of the rotary plug. The plug cock can be prevented from inclining when the valve is used, the bush is limited in the circumferential direction, the bush is prevented from rotating under the action of the plug cock, and the valve has the advantages of being long in service life and stable and reliable in structure.

Description

Technical Field

[0001] The utility model relates to the technical field of valves, in particular to a plug valve. Background Art

[0002] The plug valve is a rotary valve in the shape of a closing piece or a plunger. It is a valve that can be opened or closed by rotating 90 degrees to connect or separate the channel opening on the valve plug with the channel opening on the valve body. The shape of its valve plug can be cylindrical or conical. In a cylindrical valve plug, the channel is generally rectangular; while in a conical valve plug, the channel is trapezoidal. These shapes make the structure of the plug valve light and compact. It is most suitable for cutting off and connecting media and for diversion, but it can sometimes be used for throttling depending on the applicable properties and the erosion resistance of the sealing surface.

[0003] The Chinese utility model patent with application number CN201621155715.5 discloses a soft-sealed plug valve, which includes a valve body, a plug and a bushing; a flow channel hole is opened in the valve body, and the plug is installed in the valve body to open and close the flow channel hole; the bushing is fixed on the hole wall of the flow channel hole; a bushing hole is opened in the bushing, and the plug is pressed into the bushing hole, and the plug and the bushing hole are interference fit. In this structure, since the bushing is soft, when the valve stem operates the plug to rotate, the plug will tilt to a certain extent, causing uneven force, which is easy to cause poor sealing after frequent use, reducing the service life of the valve. In addition, since the bushing and the plug fit closely, the plug can easily drive the bushing to rotate, causing the bushing hole on the bushing to be misaligned with the flow channel hole on the valve body, affecting the opening and closing performance of the valve. Utility Model Content

[0004] The purpose of the utility model is to provide a plug valve, which can not only prevent the plug from tilting when the valve is in use, but also limit the bushing circumferentially to prevent it from rotating under the action of the plug, and has the advantages of long service life and stable and reliable structure.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a plug valve, comprising a valve body, a valve cover, a valve stem and a plug, the valve cover is installed at the opening of the upper end of the valve body, the valve stem passes through the valve cover and extends into the interior of the valve body to be connected with the plug, the valve body is provided with a flow channel and a plug cavity, the plug is arranged in the plug cavity, and the plug is provided with a flow hole corresponding to the flow channel; it also includes a sleeve, the sleeve comprises an upper sealing ring, a lower sealing ring and at least two sealing strips arranged between the upper sealing ring and the lower sealing ring, the outer circumferential surface of the plug is tightly fitted with the inner circumferential surface of the plug cavity, the upper sealing ring and the lower sealing ring are respectively arranged at the upper and lower ends of the flow channel of the plug cavity corresponding to the upper and lower ends, the sealing strip is arranged on the inner wall of the plug cavity, and the upper sealing ring, the lower sealing ring and the sealing strip are all tightly fitted with the outer wall of the plug.

[0006] By adopting the above technical solution, the plug is composed of an upper sealing ring, a lower sealing ring and a sealing strip, which is used to form a seal with the plug. The plug is mainly supported by the inner wall of the plug cavity, that is, the inner wall of the valve body, so that the plug will not tilt during use, and the good sealing performance of the valve can be ensured.

[0007] The present utility model is further configured such that a plurality of positioning grooves equal in number to the sealing strips are provided on the inner wall of the plug cavity of the valve body, and the sealing strips are embedded in the corresponding positioning grooves.

[0008] By adopting the above technical solution, the sealing strips are embedded in the positioning grooves, which is not only convenient for installation, but also has good firmness and will not rotate due to the friction of the plug. Thus, it can ensure that the fluid in the flow channel can pass through smoothly when the valve is opened, and has the advantages of stable and reliable structure.

[0009] The present utility model is further configured such that the cross-section of the positioning groove is in a tapered shape with a larger inner diameter and a smaller outer diameter, and the shape of the sealing strip is adapted to the shape of the positioning groove.

[0010] By adopting the above technical solution, when the sealing strip is subjected to the extrusion force of the plug and the extrusion forces of the upper sealing ring and the lower sealing ring, it can have a tension fit with the positioning groove, not only with better sealing performance, but also stronger structural stability.

[0011] The present utility model is further configured such that the number of the sealing strips is four. Two of the sealing strips are connected to the upper sealing ring and the lower sealing ring to enclose an upstream sealing portion, and the other two sealing strips are connected to the upper sealing ring and the lower sealing ring to enclose a downstream sealing portion.

[0012] By adopting the above technical solution, the upstream sealing portion and the downstream sealing portion act as valve seats. When the valve is closed, it can prevent the medium from leaking from the upstream to the downstream.

[0013] The present utility model is further configured such that the upper and lower ends of the sealing strip are respectively in close contact with the upper sealing ring and the lower sealing ring.

[0014] By adopting the above technical solution, the sealing performance between the sealing strip and the upper sealing ring and the lower sealing ring can be ensured, and it can prevent the medium from leaking from the gap between the sealing strip and the upper sealing ring or from the gap between the sealing strip and the lower sealing ring when the valve is closed.

[0015] The present utility model is further configured such that the upper sealing ring, the lower sealing ring and the sealing strip are of an integral structure.

[0016] By adopting the above technical solution, it not only has high structural strength and long service life, but also has more reliable sealing performance.

[0017] The present utility model is further configured such that the plug is cylindrical or conical in shape, and the shape of the plug cavity is adapted to the outer shape of the plug.

[0018] By adopting the above technical solution, this bushing structure can be matched with both a cylindrical plug and a conical plug, having structural diversity.

[0019] The present utility model is further configured such that upper and lower mounting grooves are respectively provided at positions corresponding to the upper and lower ends of the plug cavity in the valve body, and the upper sealing ring and the lower sealing ring are respectively embedded in the upper and lower mounting grooves.

[0020] By adopting the above technical solution, the positioning installation of the upper sealing ring and the lower sealing ring can be achieved.

[0021] The present utility model is further configured such that the lower end of the valve body is open, and a bottom cover is installed at the opening of the lower end of the valve body. The valve cover presses the upper sealing ring in the upper mounting groove, and the bottom cover presses the lower sealing ring in the lower mounting groove. The outer peripheral surface of the plug is provided with an upper conical surface of the plug and a lower conical surface of the plug. The upper sealing ring and the lower sealing ring are respectively provided with an upper sealing surface that cooperates with the upper conical surface of the plug and a lower sealing surface that cooperates with the lower conical surface of the plug.

[0022] By adopting the above technical solution, the disassembly and assembly operations of the bushing are greatly facilitated, and at the same time, the sealing performance between the bushing and the plug is also significantly improved. Description of the Drawings

[0023] Figure 1 is a schematic structural diagram of the whole of the present utility model;

[0024] Figure 2 is a schematic structural diagram of the bushing of the present utility model;

[0025] Figure 3 A transverse cross-sectional view of the valve body of the present utility model;

[0026] Figure 4 is a longitudinal cross-sectional view of the valve body of the present utility model;

[0027] Figure 5 is a schematic assembly structural diagram of the bushing and the valve body of the present utility model;

[0028] Figure 6 is a schematic structural diagram of the plug of the present utility model.

[0029] In the figure: 1. Valve body; 2. Valve cover; 3. Valve stem; 4. Plug; 5. Flow channel; 6. Plug cavity; 7. Flow-through hole; 8. Bushing; 9. Upper sealing ring; 10. Lower sealing ring; 11. Sealing strip; 12. Positioning groove; 13. Upstream sealing part; 14. Downstream sealing part; 15. Upper mounting groove; 16. Lower mounting groove; 17. Bottom cover; 18. Upper conical surface of the plug; 19. Lower conical surface of the plug; 20. Upper sealing surface; 21. Lower sealing surface. Detailed implementation mode

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0031] Embodiment: As shown in the attached Figures 1 to 6 A plug valve, including a valve body 1, a valve cover 2, a valve stem 3 and a plug 4. The valve cover 2 is installed at the upper opening of the valve body 1, and can be connected by bolts or threads. The valve stem 3 penetrates through the valve cover 2 and extends into the valve body 1 to be connected with the plug 4. Specifically, a rectangular groove can be provided at the upper end of the plug 4, and a rectangular protrusion is provided at the lower end of the valve stem 3. The rectangular protrusion cooperates with the rectangular groove to realize the circumferential linkage between the valve stem 3 and the plug 4. A flow channel 5 and a plug cavity 6 are provided in the valve body 1. The plug 4 is arranged in the plug cavity 6, and a flow-through hole 7 corresponding to the flow channel 5 is provided on the plug 4. The plug valve further includes a bushing 8, and the bushing 8 includes an upper sealing ring 9, a lower sealing ring 10 and at least two sealing strips 11 arranged between the upper sealing ring 9 and the lower sealing ring 10. The outer peripheral surface of the plug 4 is closely attached to the inner peripheral surface of the plug cavity 6. The upper sealing ring 9 and the lower sealing ring 10 are respectively arranged at the upper and lower ends of the plug cavity 6 corresponding to the flow channel 5. The sealing strip 11 is arranged on the inner wall of the plug cavity 6. The upper sealing ring 9, the lower sealing ring 10 and the sealing strip 11 are all closely attached to the outer wall of the plug 4. The plug 4 is composed of the upper sealing ring 9, the lower sealing ring 10 and the sealing strip 11 for sealing with the plug 4, and the plug 4 is mainly supported by the inner wall of the plug cavity 6, that is, the inner wall of the valve body 1, so that the plug 4 will not tilt during use, and good sealing performance of the valve can be ensured.

[0032] As shown in the attached Figures 3 to 5As shown, on the inner wall of the plug cavity 6 of the valve body 1, there are a plurality of positioning grooves 12 with the same number as the sealing strips 11, and the sealing strips 11 are embedded in the corresponding positioning grooves 12. Embedding the sealing strips 11 in the positioning grooves 12 is not only convenient for installation but also has good firmness and will not rotate due to the frictional effect of the plug 4. Thus, it can ensure that the fluid in the flow channel 5 can pass through smoothly when the valve is opened, having the advantages of stable and reliable structure.

[0033] Among them, the cross-section of the positioning groove 12 is in a tapered shape with a larger inner diameter and a smaller outer diameter, such as a dovetail shape, and the shape of the sealing strip 11 is adapted to the shape of the positioning groove 12. When the sealing strip 11 is subjected to the extrusion force of the plug 4 and the extrusion forces of the upper sealing ring 9 and the lower sealing ring 10, it can have a tension fit with the positioning groove 12, not only having better sealing performance but also stronger structural stability.

[0034] As shown in the appendix Figure 2 In this embodiment, as shown, the number of the sealing strips 11 is four. Two of the sealing strips 11 are connected to the upper sealing ring 9 and the lower sealing ring 10 to form a closed-loop upstream sealing part 13, and the other two sealing strips 11 are connected to the upper sealing ring 9 and the lower sealing ring 10 to form a closed-loop downstream sealing part 14. The upstream sealing part 13 and the downstream sealing part 14 have the function of a valve seat. When the valve is closed, it can prevent the medium from leaking from the upstream to the downstream.

[0035] The upper and lower ends of the sealing strip 11 are respectively in close contact with the upper sealing ring 9 and the lower sealing ring 10. This design can ensure the sealing performance between the sealing strip 11 and the upper sealing ring 9 and the lower sealing ring 10, and prevent the medium from leaking through the gap between the sealing strip 11 and the upper sealing ring 9 or the gap between the sealing strip 11 and the lower sealing ring 10 when the valve is closed.

[0036] Furthermore, there are two ways to set the upper sealing ring 9, the lower sealing ring 10 and the sealing strip 11:

[0037] One way is: after installing the upper sealing ring 9, the lower sealing ring 10 and the sealing strip 11 in their corresponding positions, press the three together into an integral structure by a press.

[0038] The other way is: the upper sealing ring 9, the lower sealing ring 10 and the sealing strip 11 are directly of an integral structure. This design not only has high structural strength and long service life but also has more reliable sealing performance.

[0039] Among them, the plug 4 is in a cylindrical or conical shape, and the shape of the plug cavity 6 is adapted to the outer shape of the plug 4. This bushing 8 structure can cooperate with both the cylindrical plug 4 and the conical plug 4, having structural diversity.

[0040] As shown in the appendix Figure 1 and in the appendix Figure 5As shown, upper mounting groove 15 and lower mounting groove 16 are respectively provided at positions corresponding to the upper and lower ends of the plug cavity 6 in the valve body 1, and the upper sealing ring 9 and the lower sealing ring 10 are respectively embedded in the upper mounting groove 15 and the lower mounting groove 16, so as to realize the positioning and installation of the upper sealing ring 9 and the lower sealing ring 10.

[0041] More specifically, as shown in the appendix Figure 1 As shown, the lower end of the valve body 1 is open, and a bottom cover 17 is installed at the opening of the lower end of the valve body 1. The bottom cover 17 can be installed at the opening of the lower end of the valve body 1 by means of bolt connection or threaded connection. The valve cover 2 presses the upper sealing ring 9 into the upper mounting groove 15, and the bottom cover 17 presses the lower sealing ring 10 into the lower sealing ring 10. An upper conical surface 18 and a lower conical surface 19 of the plug are provided on the outer peripheral surface of the plug 4, and an upper sealing surface 20 matching the upper conical surface 18 of the plug and a lower sealing surface 21 matching the lower conical surface 19 of the plug are respectively provided on the upper sealing ring 9 and the lower sealing ring 10. This design greatly facilitates the disassembly and assembly operation of the bushing 8, and also significantly improves the sealing performance between the bushing 8 and the plug 4.

Claims

1. A plug valve, comprising a valve body (1), a valve cover (2), a valve stem (3) and a plug (4), wherein the valve cover (2) is mounted at an opening at the upper end of the valve body (1), the valve stem (3) penetrates the valve cover (2) and extends into the interior of the valve body (1) to be connected with the plug (4), a flow channel (5) and a plug cavity (6) are provided in the valve body (1), the plug (4) is arranged in the plug cavity (6), and a flow hole (7) corresponding to the flow channel (5) is provided on the plug (4); characterized in that: The invention also comprises a bushing (8), wherein the bushing (8) comprises an upper sealing ring (9), a lower sealing ring (10) and at least two sealing strips (11) arranged between the upper sealing ring (9) and the lower sealing ring (10); the outer peripheral surface of the plug (4) is tightly fitted with the inner peripheral surface of the plug cavity (6); the upper sealing ring (9) and the lower sealing ring (10) are respectively arranged at the upper and lower ends of the flow channel (5) corresponding to the plug cavity (6); the sealing strip (11) is arranged on the inner wall of the plug cavity (6); and the upper sealing ring (9), the lower sealing ring (10) and the sealing strip (11) are all tightly fitted with the outer wall of the plug (4).

2. A plug valve according to claim 1, characterized in that: A plurality of positioning grooves (12) whose number is equal to the number of the sealing strips (11) are provided on the inner wall of the plug cavity (6) of the valve body (1), and the sealing strips (11) are embedded in the corresponding positioning grooves (12).

3. A plug valve according to claim 2, characterized in that: The cross section of the positioning groove (12) is in a conical shape with a larger inner portion and a smaller outer portion, and the shape of the sealing strip (11) is adapted to the shape of the positioning groove (12).

4. A plug valve according to claim 1, characterized in that: The number of the sealing strips (11) is four, of which two sealing strips (11) are connected to the upper sealing ring (9) and the lower sealing ring (10) to form an upstream sealing portion (13), and the other two sealing strips (11) are connected to the lower upper sealing ring (9) and the lower sealing ring (10) to form a downstream sealing portion (14).

5. A plug valve according to claim 1, characterized in that: The upper and lower ends of the sealing strip (11) are tightly pressed against the upper sealing ring (9) and the lower sealing ring (10) respectively.

6. A plug valve according to claim 1, characterized in that: The upper sealing ring (9), the lower sealing ring (10) and the sealing strip (11) are an integrated structure.

7. A plug valve according to claim 1, characterized in that: The plug (4) is cylindrical or conical in shape, and the shape of the plug cavity (6) is compatible with the outer shape of the plug (4).

8. A plug valve according to claim 1, characterized in that: An upper mounting groove (15) and a lower mounting groove (16) are respectively provided at positions corresponding to the upper and lower ends of the plug cavity (6) in the valve body (1), and the upper sealing ring (9) and the lower sealing ring (10) are respectively embedded in the upper mounting groove (15) and the lower mounting groove (16).

9. A plug valve according to claim 8, characterized in that: The lower end of the valve body (1) is open, and a bottom cover (17) is installed at the lower end opening of the valve body (1); the valve cover (2) presses the upper sealing ring (9) into the upper mounting groove (15); the bottom cover (17) presses the lower sealing ring (10) into the lower sealing ring (10); the outer peripheral surface of the plug (4) is provided with an upper plug conical surface (18) and a lower plug conical surface (19); the upper sealing ring (9) and the lower sealing ring (10) are respectively provided with an upper sealing surface (20) matching with the upper plug conical surface (18) and a lower sealing surface (21) matching with the lower plug conical surface (19).

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