Low-leakage double-gland plug valve

Abstract

The utility model relates to the technical field of plug valves, in particular to a low-leakage double-gland plug valve which comprises a valve body, a valve rod, a plug and a stuffing box, the valve rod and the plug are rotationally connected to the valve body, the valve rod is fixedly connected with the plug, the stuffing box is arranged on the valve rod in a sleeving mode, and the stuffing box is fixedly connected with the plug. A sealing bush used for sealing a gap between the valve body and the plug cock is arranged in the valve body, a packing gland used for pressing packing in the packing box is arranged on the valve rod, a sealing assembly is arranged between the valve body and the packing box, and by means of the arrangement of the sealing bush, the sealing bush can effectively seal the gap between the valve body and the plug cock. The gap between the stuffing box and the valve rod is filled with stuffing, and meanwhile the stuffing gland is used for pressing the stuffing in the stuffing box, so that the sealing performance between the valve body and the valve rod is enhanced; by means of the arrangement of the sealing assembly, the sealing performance between the valve body and the stuffing box is further improved, and therefore the risk of leakage of the plug valve is reduced.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of plug valves, in particular to a low-leakage double-gland plug valve. BACKGROUND

[0002] The plug valve is the earliest valve used, has the characteristics of simple structure, quick switching and small fluid resistance, and is widely applied to oilfield exploitation, petroleum chemical industry, coal gas, natural gas, liquefied petroleum gas, heating and ventilation industry and general industry. The plug valve is divided into soft sealing plug valves and hard sealing plug valves, wherein the soft sealing plug valve is often used in harsh environments such as corrosive, toxic and high-hazard media and places where leakage is strictly prohibited.

[0003] The plug valve is an important element in industrial and civil equipment, but the leakage of the medium in the plug valve has a great influence on the factory and the environment, and may seriously affect the underground water resources and the environment irreversibly. Therefore, the low-leakage plug valve is more and more concerned and demanded. The low-leakage valve can not only reduce the harm to the environment and health, but also help to reduce the waste of energy and resources. CONTENT OF THE INVENTION

[0004] In order to reduce the leakage of the medium in the plug valve, the application provides a low-leakage double-gland plug valve.

[0005] The application provides a low-leakage double-gland plug valve, which adopts the following technical scheme:

[0006] The low-leakage double-gland plug valve comprises a valve body, a valve rod, a plug and a packing gland, the valve rod and the plug are rotationally connected to the valve body, the valve rod is fixedly connected to the plug, the packing gland is sleeved on the valve rod, the valve body is internally provided with a sealing bush for sealing the gap between the valve body and the plug, the valve rod is provided with a packing gland for pressing the packing in the packing gland, and the valve body and the packing gland are provided with a sealing assembly.

[0007] By adopting the above technical scheme, the valve rod and the plug are rotationally connected to the valve body, so that the valve rod can drive the plug to control the on-off of the fluid by rotating the valve rod. The sealing bush is arranged to effectively seal the gap between the valve body and the plug. The gap between the packing gland and the valve rod is filled with packing, and the packing in the packing gland is pressed by the packing gland, which helps to enhance the sealing property between the valve body and the valve rod. The sealing assembly is arranged to further improve the sealing property between the valve body and the packing gland, thereby reducing the risk of leakage of the plug valve.

[0008] Preferably, the valve body is internally provided with a limiting groove, the sealing bush is provided with an opening groove for embedding cooperation with the plug, and the side of the sealing bush away from the opening groove is in embedding cooperation with the limiting groove.

[0009] By adopting the technical scheme, the plug is embedded and matched with the opening groove on the sealing bush, and the sealing bush is embedded in the limiting groove of the valve body, so that the sealing bush can be stably fixed in the valve body, and the sealing bush can form good sealing cooperation with the plug, thereby reducing the possibility of medium leakage of the plug valve.

[0010] Preferably, the sealing assembly comprises a first sealing ring, which is arranged between the valve body and the stuffing box.

[0011] By adopting the technical scheme, the arrangement of the first sealing ring improves the sealing performance between the valve body and the stuffing box, and reduces the risk of leakage of the gap between the valve body and the stuffing box.

[0012] Preferably, the sealing assembly comprises a leakage-proof gasket, which is sleeved on the valve rod, and the upper surface of the leakage-proof gasket is in abutting cooperation with the stuffing box, and the lower surface of the leakage-proof gasket is in abutting cooperation with the valve body.

[0013] By adopting the technical scheme, the arrangement of the leakage-proof gasket improves the sealing performance between the valve body and the stuffing box, and effectively reduces the risk of leakage of the gap between the valve rod and the plug.

[0014] Preferably, the stuffing gland is provided with a fixing bolt, the fixing bolt is threaded through the stuffing gland and is in threaded connection with the stuffing box, a disc spring is sleeved on the threaded rod of the fixing bolt, the upper end of the disc spring is in abutting cooperation with the bolt head of the fixing bolt, and the lower end of the disc spring is in abutting cooperation with the stuffing gland.

[0015] By adopting the technical scheme, after the disc spring is pressed by the fixing bolt, the disc spring will rebound and press the stuffing gland tightly, and the elastic effect of the disc spring can keep the stuffing gland in the stuffing box under continuous pressure, so as to ensure that the stuffing in the stuffing box is always in a good sealing state.

[0016] Preferably, an adjusting pressure plate is sleeved on the valve rod, and the adjusting pressure plate is connected to the stuffing box by a screw.

[0017] By adopting the technical scheme, the arrangement of the adjusting pressure plate can control the tightness of the adjusting pressure plate by screwing the screw, so that the adjusting pressure plate can exert pressure on the sealing bush and the leakage-proof gasket on the valve rod, thereby enhancing the sealing performance between the valve body and the plug and between the valve body and the stuffing box, and further reducing the risk of internal medium leakage of the plug valve.

[0018] Preferably, a lip-shaped sealing ring is arranged on the sealing bush, and the inner wall of the lip-shaped sealing ring is in abutting cooperation with the outer wall of the plug.

[0019] By adopting the above technical scheme, the sealing effect between the sealing bushing and the plug is enhanced by the setting of the lip-shaped sealing ring, and the sealing performance of the valve is further improved.

[0020] Preferably, the valve stem is provided with a handle for facilitating the rotation of the valve stem by the staff.

[0021] By adopting the above technical scheme, the handle is provided to facilitate the staff to easily and quickly rotate the valve stem, so as to realize the opening and closing operation of the plug valve.

[0022] In summary, the present application has at least one of the following beneficial technical effects:

[0023] 1. The valve stem and the plug are both rotationally connected to the valve body, so that the plug can be driven to control the on-off of fluid by rotating the valve stem, the sealing bushing is provided to effectively seal the gap between the valve body and the plug, the filler is filled into the gap between the filler chamber and the valve stem, and the filler is pressed and held in the filler chamber by the filler gland, which helps to enhance the sealing between the valve body and the valve stem; the sealing assembly is provided to further improve the sealing between the valve body and the filler chamber, thereby reducing the risk of leakage of the plug valve;

[0024] 2. The plug is fitted in the opening groove on the sealing bushing, and the sealing bushing is fitted in the limiting groove on the valve body, so that the sealing bushing can be stably fixed in the valve body, and the sealing bushing can form a good sealing fit with the plug, thereby reducing the possibility of medium leakage of the plug valve;

[0025] 3. The setting of the adjusting pressure plate controls the compression degree of the adjusting pressure plate by screwing the screw, so that the adjusting pressure plate can exert pressure on the sealing bushing and the filler chamber, thereby enhancing the sealing between the valve body and the plug, the valve body and the filler chamber, and thereby reducing the risk of internal medium leakage of the plug valve. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a sectional view mainly embodying the overall structure in the embodiment of the present application;

[0027] Figure 2 is Figure 1 is a local enlarged view mainly embodying the structure of the sealing assembly in the embodiment of the present application.

[0028] Label: 1, valve body; 11, limiting groove; 12, sealing bush; 121, open slot; 122, lip seal ring; 2, valve stem; 21, sealing assembly; 211, first sealing ring; 212, leak-proof gasket; 22, packing gland; 221, fixing bolt; 222, disc spring; 23, connecting gasket; 24, adjusting pressure plate; 25, stepped surface; 26, handle; 3, plug; 31, through hole; 4, packing box; 41, second sealing ring; 42, third sealing ring. DETAILED DESCRIPTION

[0029] The following will be described in detail below with reference to the accompanying drawings Figure 1 - the accompanying drawings Figure 2 The application is further described in detail.

[0030] The application discloses a low-leakage double-gland plug valve.

[0031] Referring to Figure 1 A low-leakage double-gland plug valve comprises a valve body 1, a valve stem 2, a plug 3 and a packing box 4, the valve body 1 is hollow inside, the valve stem 2 is rotationally connected to the valve body 1, the valve stem 2 is fixedly connected to the plug 3, and the plug 3 is arranged inside the valve body 1. In this embodiment, the valve stem 2 is threadedly connected to the plug 3, the plug 3 is in a cylindrical shape, and the plug 3 is provided with a through hole 31, so that the valve stem 2 can drive the through hole 31 of the plug 3 to rotate in the valve body 1 to control the on-off of fluid.

[0032] Referring to Figure 1 The packing box 4 is sleeved on the valve stem 2, and an annular chamber for packing sealing is formed between the packing box 4 and the valve stem 2. Packing the annular chamber helps to enhance the sealing performance between the valve body 1 and the valve stem 2. The packing box 4 is threadedly connected to the valve body 1 by a bolt.

[0033] Referring to Figure 1 The valve body 1 is internally provided with a limiting groove 11 and a sealing bush 12 for sealing the gap between the valve body 1 and the plug 3. The sealing bush 12 is made of corrosion-resistant material. In this embodiment, the sealing bush 12 is made of PTFE material. The sealing bush 12 is embeddedly matched with the limiting groove 11. The sealing bush 12 is provided with an open slot 121 with an opening facing upward. The open slot 121 of the sealing bush 12 is embeddedly matched with the bottom of the plug 3, so that the sealing bush 12 can be stably fixed in the valve body 1, and the sealing bush 12 can be well matched with the plug 3 to enhance the stability and sealing performance of the sealing bush 12.

[0034] Referring to Figure 1At the same time, the sealing bush 12 is mounted on the valve body 1 through the connecting rib, preventing the sealing bush 12 from rotating when the valve stem 2 drives the plug 3 to rotate. In actual use, the plug 3 can scrape the surface of the sealing bush 12 when rotating, thereby providing a self-cleaning function for the sealing bush 12. Therefore, the plug valve is suitable for controlling the flow of viscous and fouling media.

[0035] Referring to Figure 1 , the sealing bush 12 is sleeved with a lip-shaped sealing ring 122 near the opening groove 121. The outer wall of the lip-shaped sealing ring 122 is in abutting cooperation with the inner wall of the limiting groove 11 of the valve body 1, and the inner wall of the lip-shaped sealing ring 122 is in abutting cooperation with the outer wall of the plug 3, thereby enhancing the sealing effect between the sealing bush 12 and the plug 3. Since the lip-shaped sealing ring 122 is sleeved on the sealing bush 12, it can not only achieve sealing but also prevent the medium from directly washing the sealing bush 12, thereby protecting the sealing bush 12.

[0036] Referring to Figure 1 and Figure 2 , a sealing assembly 21 is arranged between the valve body 1 and the stuffing box 4. The sealing assembly 21 includes a first sealing ring 211 and a leak-proof gasket 212. The first sealing ring 211 is arranged in an O-shaped manner and is sleeved in the gap between the valve body 1 and the stuffing box 4. In this embodiment, two first sealing rings 211 are arranged. The arrangement of the first sealing ring 211 improves the sealing performance between the valve body 1 and the stuffing box 4 and reduces the possibility of leakage of the medium from the gap between the valve body 1 and the stuffing box 4.

[0037] Referring to Figure 1 and Figure 2 , the leak-proof gasket 212 is sleeved on the valve stem 2. The upper surface of the leak-proof gasket 212 is in abutting cooperation with the lower surface of the stuffing box 4, and the lower surface of the leak-proof gasket 212 is in abutting cooperation with the valve body 1 and the top of the plug 3, thereby improving the sealing performance between the valve body 1 and the stuffing box 4. The double sealing of the first sealing ring 211 and the leak-proof gasket 212 enhances the overall sealing effect between the valve body 1 and the valve stem 2.

[0038] Referring to Figure 1 and Figure 2 , a packing gland 22 for pressing the packing in the stuffing box 4 is sleeved on the valve stem 2. The packing gland 22 is provided with fixing bolts 221 for connecting the packing gland 22 and the stuffing box 4. The fixing bolts 221 are arranged in multiple numbers, and in this embodiment, two fixing bolts 221 are symmetrically arranged. Since the structure and connection mode of the two fixing bolts 221 are the same, one of the fixing bolts 221 will be described as an example.

[0039] Referring to Figure 1The fixed bolt 221 is arranged through the packing gland 22 and is screwed with the packing box 4, a disc spring 222 is sleeved on the threaded rod of the fixed bolt 221, the upper end of the disc spring 222 is in abutting cooperation with the lower surface of the bolt head of the fixed bolt 221, and the lower end of the disc spring 222 is in abutting cooperation with the upper surface of the packing gland 22.

[0040] With reference to Figure 1 and Figure 2 , by arranging the disc spring 222, the disc spring 222 is elastically pressed against the packing gland 22 under the pressure of the fixed bolt 221, the elastic effect of the disc spring 222 can keep the packing gland 22 continuously pressing the packing in the packing box 4, so that the packing in the packing box 4 is always in a good sealing state, the sealing stability and durability between the valve stem 2 and the packing box 4 are improved, and the risk of medium leakage caused by loose packing is reduced.

[0041] With reference to Figure 1 and Figure 2 , the second sealing ring 41 is arranged between the packing gland 22 and the packing box 4, and the third sealing ring 42 is arranged between the packing gland 22 and the valve stem 2, both the second sealing ring 41 and the third sealing ring 42 are arranged in an O-shaped manner, and by arranging the second sealing ring 41 and the third sealing ring 42 and the packing in the packing box 4, the triple sealing between the valve stem 2 and the packing box 4 is realized, thereby improving the sealing performance between the valve stem 2 and the valve body 1.

[0042] With reference to Figure 1 , the connecting gasket 23 and the adjusting pressure plate 24 are sleeved on the valve stem 2, the valve stem 2 is provided with a stepped surface 25, the upper surface of the connecting gasket 23 is in abutting cooperation with the lower surface of the adjusting pressure plate 24, the lower surface of the connecting gasket 23 is in abutting cooperation with the stepped surface 25 of the valve stem 2, and the adjusting pressure plate 24 is connected to the packing box 4 by screws.

[0043] With reference to Figure 1 , by arranging the connecting gasket 23 and the adjusting pressure plate 24, the staff can control the pressing degree of the adjusting pressure plate 24 on the packing box 4 by screwing the screws, the adjusting pressure plate 24 can also exert pressure on the valve stem 2 through the connecting gasket 23, so as to press and hold the sealing bush 12, and at the same time, the packing gland 22 can also provide pressure to the packing box 4 as a whole, so as to also provide pressure to the sealing bush 12 and the leak-proof gasket 212, thereby enhancing the sealing between the valve body 1 and the plug 3 and between the valve body 1 and the valve stem 2, and reducing the risk of medium leakage in the plug valve.

[0044] With reference to Figure 1 , the handle 26 is arranged on the valve stem 2 to facilitate the staff to rotate the valve stem 2, so as to easily and quickly rotate the valve stem 2 through the handle 26, thereby realizing the opening and closing operation of the plug valve.

[0045] The implementation principle of the embodiment of the application is as follows: in actual operation, the staff first installs the sealing bush 12 in the valve body 1, then embeds the plug 3 fixed on the valve rod 2 on the sealing bush 12, the sealing bush 12 can form a good sealing fit with the plug 3, then the staff successively sets the leak-proof gasket 212 and the packing gland 4 with the first sealing ring 211 on the valve rod 2, the first sealing ring 211 and the leak-proof gasket 212 perform double sealing between the valve body 1 and the packing gland 4; then the staff fills the packing in the annular chamber between the packing gland 4 and the valve rod 2, and uses the packing gland 22 and the disc spring 222 to continuously press and seal the packing.

[0046] The staff then fixes the adjusting pressure plate 24 on the packing gland 4 through the screw, and uses the adjusting pressure plate 24 to apply a pressing force to the valve rod 2 and the packing gland 4, and the packing gland 22 also applies a pressing force to the packing gland 4, the leak-proof gasket 212 located below the packing gland 4 and the sealing bush 12 at the bottom of the valve rod 2 are pressed to realize self-sealing with the valve body 1, thereby enhancing the sealing between the valve body 1 and the plug 3 and between the valve body 1 and the valve rod 2, and further reducing the risk of medium leakage in the plug valve.

[0047] Finally, the staff operates the valve rod 2 through the handle 26, so that the valve rod 2 can drive the through hole 31 of the plug 3 to rotate in the valve body 1 to control the on-off of the fluid.

[0048] The above are preferred embodiments of the application, and do not limit the protection scope of the application, so: any equivalent changes made according to the structure, shape, principle of the application should be covered in the protection scope of the application.

Claims

1. A low-leakage double-gland globe valve characterized by: The utility model provides a valve, including valve body (1), valve stem (2), plug (3) and stuffing box (4), valve stem (2) with plug (3) are all rotationally connected on valve body (1), valve stem (2) with plug (3) fixed connection, stuffing box (4) is set on valve stem (2), valve body (1) inside is provided with the sealing bushing (12) for sealing the gap between valve body (1) and plug (3), valve stem (2) is provided with the packing gland (22) for pressing the packing in stuffing box (4), and sealing assembly (21) is arranged between valve body (1) and stuffing box (4).

2. A low-leakage double-gland globe valve according to claim 1, characterized in that: The valve body (1) is internally provided with a limiting groove (11), and the sealing bushing (12) is provided with an opening groove (121) for forming an embedded cooperation with the plug (3), and the side of the sealing bushing (12) away from the opening groove (121) forms an embedded cooperation with the limiting groove (11).

3. A low-leakage double-gland globe valve according to claim 1, characterized in that: The sealing assembly (21) includes a first sealing ring (211), and the first sealing ring (211) is arranged between the valve body (1) and the stuffing box (4).

4. A low-leakage double-gland globe valve according to claim 1, characterized in that: The sealing assembly (21) includes a leak-proof gasket (212), the leak-proof gasket (212) is sleeved on the valve stem (2), the upper surface of the leak-proof gasket (212) forms an abutting cooperation with the stuffing box (4), and the lower surface of the leak-proof gasket (212) forms an abutting cooperation with the valve body (1).

5. A low-leakage double-gland globe valve according to claim 1, wherein: The packing gland (22) is provided with a fixing bolt (221), the fixing bolt (221) penetrates the packing gland (22) and is threadedly connected with the stuffing box (4), a disc spring (222) is sleeved on the threaded rod of the fixing bolt (221), the upper end of the disc spring (222) forms an abutting cooperation with the bolt head of the fixing bolt (221), and the lower end of the disc spring (222) forms an abutting cooperation with the packing gland (22).

6. A low-leakage double-gland globe valve according to claim 4, characterized in that: The valve stem (2) is sleeved with an adjusting pressing plate (24), and the adjusting pressing plate (24) is connected to the stuffing box (4) through a screw.

7. A low-leakage double-gland globe valve according to claim 1, wherein: The sealing bushing (12) is provided with a lip-shaped sealing ring (122), and the inner wall of the lip-shaped sealing ring (122) forms an abutting cooperation with the outer wall of the plug (3).

8. A low-leakage double-gland globe valve according to claim 1, wherein: The valve stem (2) is provided with a handle (26) for facilitating the rotation of the valve stem (2) by the staff.

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