Double-knock seal trim control valve

Abstract

The utility model relates to a double corrugated pipe sealing regulating valve belongs to valve technical field, and the utility model discloses in order to solve the problem that the single layer corrugated pipe breakage leads to the sealing failure risk of existing regulating valve. Including valve body, the gland is established between valve cover and valve body, the upper end of lower valve stem passes through the gland and valve cover, and is connected with upper valve stem, the lower end of lower valve stem is connected with valve plug, and the bottom of lower valve stem is connected with the gland through inner bellows, and upper valve stem and valve cover are connected through outer bellows. The utility model discloses double sealing structure containing inner bellows and outer bellows, one is used for the sealing isolation between valve body inner chamber and lower valve stem, and the other is used for the sealing isolation between valve cover top export and outside, realizes zero leakage.

Description

Technical Field

[0001] This utility model belongs to the field of valve technology, and in particular relates to a double bellows sealing regulating valve. Background Technology

[0002] Control valves are commonly used fluid control devices. However, in fields such as nuclear power, metallurgy, and petrochemicals, when encountering special working environments and media, valves must strictly achieve zero leakage. Conventional control valves use stuffing box seals (such as graphite packing or PTFE packing), which are dynamic seals. Under high pressure differential conditions, they are prone to media leakage due to wear, and the friction between the packing and the valve stem can also increase the operating torque or thrust. While existing bellows control valves can improve leakage, there is a risk of seal failure due to the rupture of a single-layer bellows. In addition, the fatigue life of the bellows is limited under high-frequency opening and closing conditions. Utility Model Content

[0003] The purpose of this invention is to provide a double-bellows-sealed regulating valve to solve the problem of sealing failure caused by the rupture of a single-layer bellows in existing regulating valves. The technical solution adopted by this invention is as follows:

[0004] A double bellows-sealed regulating valve includes a valve body, which is a three-way component with a medium inlet, a medium outlet, and a shut-off control port. A partition is provided inside the valve body, which divides the inner cavity of the valve body into an upper valve cavity and a lower valve cavity. The medium outlet is connected to the lower valve cavity, and the medium inlet and the shut-off control port are respectively connected to the upper valve cavity. A valve seat is provided through the partition. The valve seat is cup-shaped and seals with the partition. A first sealing cone surface is provided on the upper edge of the inner circumference of the valve seat. A plurality of first throttling orifice groups are axially opened on the side wall of the valve seat in the lower valve cavity.

[0005] The valve cover is connected to the valve body, and a pressure cap is provided between the valve cover and the valve body. The pressure cap seals the shut-off control port. The shunting cover is a cylindrical component. The upper end of the shunting cover is sealed to the pressure cap, and the lower end of the shunting cover is fitted with the valve seat stop. Several second throttling hole groups are opened at the bottom of the shunting cover.

[0006] The valve plug includes a cylindrical part and a sleeve part that are coaxial. The outer diameter of the cylindrical part is larger than the outer diameter of the sleeve part. The outer circumferences of the cylindrical part and the sleeve part are connected by a second sealing cone surface. The outer circumference of the cylindrical part slides with the inner circumference of the fairing. The area of ​​the fairing with several first throttling orifice groups forms an annular gap with the valve plug. The outer circumference of the sleeve part slides with the inner circumference of the valve seat. Several third throttling orifice groups are opened along the axial direction on the upper part of the sleeve part. The first sealing cone surface and the second sealing cone surface abut against each other to seal or separate.

[0007] The actuator is supported on the valve cover by several columns. The upper end of the lower valve stem passes through the gland and the valve cover in sequence and is connected to the upper valve stem. The upper valve stem is connected to the output end of the actuator by a coupling. The coupling slides along any column. The lower end of the lower valve stem is connected to the valve plug. The bottom of the lower valve stem is sealed to the gland by an inner bellows. The valve cover and the upper valve stem are sealed to each other by an outer bellows.

[0008] Furthermore, the upper part of the gland is a circular plate structure, and the lower part of the gland is a tubular structure. The inner wall of the tubular structure slides with the lower valve stem. A guide groove is vertically provided on the tubular structure, and a guide pin is passed through the lower valve stem. The guide pin slides with the guide groove to prevent the inner bellows from twisting during expansion and contraction.

[0009] Furthermore, the valve cover and the gland are sealed by a gasket, the gland and the valve body are sealed by a gasket, and the valve seat and the partition are sealed by a gasket.

[0010] Furthermore, the valve cover is cylindrical, with a flange structure at the lower end that connects to the valve body, a support flange at the upper part of the valve cover, a column on the seat plate, the inner hole of the seat plate being threaded to the outer circumference of the valve cover, and the seat plate and the support flange abutting against each other vertically. A round nut is threaded to the valve cover and locks the seat plate.

[0011] Furthermore, the valve body and valve cover are connected by fastening bolts and fastening nuts.

[0012] Furthermore, the top of the fairing is provided with several pressure balancing holes.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0014] The inner bellows is a double-layered, thin-walled cylindrical shell with multiple transverse corrugations. Its lower end is welded to the valve stem frustum, and its upper end is welded to the gland boss, sealing the gap between the lower valve stem and the valve cover. The outer bellows has a similar structure to the inner bellows; its lower end is welded to the boss on the top of the valve cover, and its upper end is welded to the lower part of the upper valve stem, sealing the gap between the lower valve stem and the valve cover. The upper valve stem is connected to the actuator's push rod via a thread on its upper part. This invention includes a double-sealing structure with inner and outer bellows: one for sealing and isolating the valve body cavity from the lower valve stem, and the other for sealing and isolating the valve cover's top outlet from the outside, achieving zero leakage. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the valve body structure;

[0017] Figure 3 This is a schematic diagram of the valve seat structure;

[0018] Figure 4 This is a schematic diagram of the valve plug structure;

[0019] Figure 5 This is a schematic diagram of the lower valve stem.

[0020] Figure 6 This is a schematic diagram of the gland structure;

[0021] Figure 7 This is a schematic diagram of the fairing structure;

[0022] Figure 8 This is a schematic diagram of the valve cover structure.

[0023] In the diagram, 1. Valve body, 2. Valve seat, 3. Valve plug, 4. Regulator, 5. Lower valve stem, 6. Guide pin, 7. Inner bellows, 8. Gland, 9. Valve cover, 10. Seat plate, 11. Round nut, 12. Outer bellows, 13. Upper valve stem, 14. Fastening bolt, 15. Fastening nut, 16. Sealing gasket, 17. Upper valve chamber, 18. Medium inlet, 19. Lower valve chamber, 20. Medium outlet, 21. Cut-off control port, 22. First sealing cone, 23. First throttling orifice group, 24. Cylindrical part, 25. Second sealing cone, 26. Third throttling orifice group, 27. Threaded hole, 28. Circular sleeve, 29. Pin hole, 30. Lower valve stem frustum, 31. Tubular structure, 32. Guide groove, 33. 34. Second throttling orifice group, 35. Air pressure balance hole, 36. Support flange, 37. Column, 38. Actuator, 39. Coupling. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the present utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the present utility model.

[0025] The connections mentioned in this utility model are divided into fixed connections and detachable connections. Fixed connections, also known as non-detachable connections, include but are not limited to conventional fixed connection methods such as folded connections, riveted connections, adhesive connections, and welded connections. Detachable connections include but are not limited to conventional disassembly methods such as bolt connections, snap-fit ​​connections, pin connections, and hinge connections. When a specific connection method is not explicitly defined, it is assumed that at least one existing connection method can be found to achieve this function, and those skilled in the art can choose according to their needs. For example, a welded connection can be chosen for a fixed connection, and a bolted connection can be chosen for a detachable connection.

[0026] The present invention will be further described in detail below with reference to the accompanying drawings. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0027] Example: Figures 1 to 8 As shown, a double bellows-sealed regulating valve includes a valve body 1, which is a three-way component with a medium inlet 18, a medium outlet 20, and a shut-off control port 21. A partition is provided inside the valve body 1, which divides the inner cavity of the valve body 1 into an upper valve cavity 17 and a lower valve cavity 19. The medium outlet 20 is connected to the lower valve cavity 19, and the medium inlet 18 and the shut-off control port 21 are respectively connected to the upper valve cavity 17. A valve seat 2 is provided through the partition. The valve seat 2 is cup-shaped and seals with the partition. A first sealing cone surface 22 is provided on the upper edge of the inner circumference of the valve seat 2. A plurality of first throttling orifice groups 23 are axially opened on the side wall of the valve seat 2 in the lower valve cavity 19.

[0028] The valve cover 9 is connected to the valve body 1. A pressure cap 8 is provided between the valve cover 9 and the valve body 1. The pressure cap 8 closes the shut-off control port 21. The rectifier 4 is a cylindrical component. The upper end of the rectifier 4 is sealed to the pressure cap 8. The lower end of the rectifier 4 is matched with the stop of the valve seat 2. Several second throttling hole groups 33 are opened at the bottom of the rectifier 4.

[0029] The valve plug 3 includes a cylindrical part 24 and a sleeve part 28 that are coaxial. The outer diameter of the cylindrical part 24 is larger than the outer diameter of the sleeve part 28. The outer peripheries of the cylindrical part 24 and the sleeve part 28 are connected by a second sealing cone surface 25. The outer periphery of the cylindrical part 24 slides with the inner periphery of the rectifier 4. The area of ​​the rectifier 4 where a plurality of first throttling orifice groups 23 are provided forms an annular gap with the valve plug 3. The outer periphery of the sleeve part 28 slides with the inner periphery of the valve seat 2. The upper part of the sleeve part 28 is provided with a plurality of third throttling orifice groups 26 along the axial direction. The first sealing cone surface 22 and the second sealing cone surface 25 abut against each other to seal or separate.

[0030] The actuator 37 is supported on the valve cover 9 by several columns 36. The upper end of the lower valve stem 5 passes through the gland 8 and the valve cover 9 in sequence and is connected to the upper valve stem 13. The upper valve stem 13 is connected to the output end of the actuator 37 through a coupling 37. The coupling 37 slides along any column 36. The lower end of the lower valve stem 5 is connected to the valve plug 3. The bottom of the lower valve stem 5 is sealed to the gland 8 through an inner bellows 7. The valve cover 9 and the upper valve stem 13 are sealed to each other through an outer bellows 12.

[0031] The upper part of the pressure cap 8 is a circular plate structure, and the lower part of the pressure cap 8 is a tubular structure 31. The inner wall of the tubular structure 31 is slidably fitted with the lower valve stem 5. A guide groove 32 is vertically provided on the tubular structure 31. A pin hole 29 is provided on the lower valve stem 5. A guide pin 6 passes through the pin hole 29. The guide pin 6 is slidably fitted with the guide groove 32 to prevent the inner bellows 7 from twisting during expansion and contraction.

[0032] The valve cover 9 and the pressure plate 8 are sealed by a sealing gasket 16, the pressure plate 8 and the valve body 1 are sealed by a sealing gasket 16, and the valve seat 2 and the partition are sealed by a sealing gasket 16.

[0033] The valve cover 9 is cylindrical. The lower end of the valve cover 9 is provided with a flange structure that connects to the valve body 1. The upper part of the valve cover 9 is provided with a support flange 35. The column 36 is set on the seat plate 10. The inner hole of the seat plate 10 is threadedly connected to the outer circumference of the valve cover 9. The seat plate 10 and the support flange 35 abut against each other. The round nut 11 is threadedly connected to the valve cover 9 and locks the seat plate 10.

[0034] The valve body 1 and the valve cover 9 are connected by fastening bolts 14 and fastening nuts 15.

[0035] The top of the fairing 4 is provided with several pressure balancing holes 34 to balance the internal and external pressures of the fairing 4.

[0036] The bottom end of the lower valve stem 5 is provided with a threaded section. The lower valve stem 5 is connected to the threaded hole 27 on the top of the valve plug 3 through the threaded section. A protruding valve stem frustum 30 is provided above the threaded section. The inner bellows 7 is a double-layer thin-walled cylindrical shell with multiple transverse corrugations. Its lower end is welded to the valve stem frustum 30, and its upper end is welded to the boss of the pressure cover 8 to seal the gap between the lower valve stem 5 and the valve cover 9.

[0037] The outer bellows 12 has a similar structure to the inner bellows 7. Its lower end is welded to the boss on the top of the valve cover 9, and its upper end is welded to the lower part of the upper valve stem 13, sealing the gap between the lower valve stem 5 and the valve cover 9. The upper valve stem 13 is connected to the push rod of the actuator 37 through its upper thread.

[0038] Both the inner bellows 7 and the outer bellows 12 are sleeved on the outside of the lower valve stem 5. This utility model includes a double sealing structure of the inner bellows 7 and the outer bellows 12. One is used for sealing and isolating the inner cavity of the valve body 1 and the lower valve stem 5, and the other is used for sealing and isolating the top outlet of the valve cover 9 from the outside, so as to achieve zero leakage.

[0039] When the valve is in the fully closed position, the valve plug 3 is pressed against the first sealing cone 22 of the valve seat 2 through the second sealing cone 25, and the regulating valve is closed, blocking the flow of the working fluid. This can be regarded as the original state of the inner bellows 7 and the outer bellows 12.

[0040] As the valve gradually opens, the second sealing cone 25 disengages from the first sealing cone 22, and several third throttling orifice groups 26 are positioned above several first throttling orifice groups 23. The working fluid flows into the upper valve chamber 17 from the medium inlet 18, passing sequentially through several second throttling orifice groups 33, several third throttling orifice groups 26, and several first throttling orifice groups 23, thereby regulating the flow rate of the working fluid. It then flows out through the lower valve chamber 19 and the medium outlet 20. At this time, the inner bellows 7 is gradually compressed as the lower valve stem 5 moves upward, while the outer bellows 12 is gradually stretched. Conversely, as the valve gradually closes, the inner bellows 7 is gradually stretched as the lower valve stem 5 moves downward, while the outer bellows 12 is gradually compressed. Both work together to ensure the working fluid remains sealed and does not leak.

[0041] The above embodiments are merely illustrative examples of the present utility model and do not limit its scope of protection. Those skilled in the art can make partial changes to it, as long as they do not exceed the spirit and essence of the present utility model, they are all within the scope of protection of the present utility model.

Claims

1. A double-bellows sealed regulating valve, characterized in that: The valve body (1) is a three-way component with a medium inlet (18), a medium outlet (20) and a shut-off control port (21). A partition is provided inside the valve body (1), which divides the inner cavity of the valve body (1) into an upper valve cavity (17) and a lower valve cavity (19). The medium outlet (20) is connected to the lower valve cavity (19), and the medium inlet (18) and the shut-off control port (21) are connected to the upper valve cavity (17) respectively. A valve seat (2) is provided through the partition. The valve seat (2) is cup-shaped and is sealed with the partition. A first sealing cone surface (22) is provided on the upper edge of the inner circumference of the valve seat (2). Several first throttling hole groups (23) are opened axially on the side wall of the valve seat (2) inside the lower valve cavity (19). The valve cover (9) is connected to the valve body (1). A pressure cap (8) is provided between the valve cover (9) and the valve body (1). The pressure cap (8) closes the shut-off control port (21). The shunting shield (4) is a cylindrical component. The upper end of the shunting shield (4) is sealed to the pressure cap (8). The lower end of the shunting shield (4) is fitted with the stop of the valve seat (2). Several second throttling hole groups (33) are opened at the bottom of the shunting shield (4). The valve plug (3) includes a cylindrical part (24) and a sleeve part (28) that are coaxial. The outer diameter of the cylindrical part (24) is larger than the outer diameter of the sleeve part (28). The outer peripheries of the cylindrical part (24) and the sleeve part (28) are connected by a second sealing cone surface (25). The outer periphery of the cylindrical part (24) slides with the inner periphery of the fairing (4). The area of ​​the fairing (4) with a number of first throttling hole groups (23) forms an annular gap with the valve plug (3). The outer periphery of the sleeve part (28) slides with the inner periphery of the valve seat (2). The upper part of the sleeve part (28) is provided with a number of third throttling hole groups (26) along the axial direction. The first sealing cone surface (22) and the second sealing cone surface (25) abut against each other to seal or separate. The actuator (37) is supported on the valve cover (9) by several columns (36). The upper end of the lower valve stem (5) passes through the gland (8) and the valve cover (9) in sequence and is connected to the upper valve stem (13). The upper valve stem (13) is connected to the output end of the actuator (37) through a coupling (38). The coupling (38) slides along any column (36). The lower end of the lower valve stem (5) is connected to the valve plug (3). The bottom of the lower valve stem (5) is sealed to the gland (8) through an inner bellows (7). The valve cover (9) and the upper valve stem (13) are sealed to each other through an outer bellows (12).

2. The double bellows-sealed regulating valve according to claim 1, characterized in that: The upper part of the pressure cap (8) is a circular plate structure, and the lower part of the pressure cap (8) is a tubular structure (31). The inner wall of the tubular structure (31) is in sliding fit with the lower valve stem (5). A guide groove (32) is vertically provided on the tubular structure (31). A guide pin (6) is provided on the lower valve stem (5). The guide pin (6) is in sliding fit with the guide groove (32) to prevent the inner bellows (7) from twisting during expansion and contraction.

3. The double bellows-sealed regulating valve according to claim 1, characterized in that: The valve cover (9) and the pressure plate (8) are sealed by a sealing gasket (16), the pressure plate (8) and the valve body (1) are sealed by a sealing gasket (16), and the valve seat (2) and the partition are sealed by a sealing gasket (16).

4. The double bellows-sealed regulating valve according to claim 1, characterized in that: The valve cover (9) is cylindrical. The lower end of the valve cover (9) is provided with a flange structure that connects to the valve body (1). The upper part of the valve cover (9) is provided with a support flange (35). The column (36) is set on the seat plate (10). The inner hole of the seat plate (10) is threadedly connected to the outer circumference of the valve cover (9). The seat plate (10) and the support flange (35) abut against each other. The round nut (11) is threadedly connected to the valve cover (9) and locks the seat plate (10).

5. A double bellows-sealed regulating valve according to claim 1, characterized in that: The valve body (1) and the valve cover (9) are connected by fastening bolts (14) and fastening nuts (15).

6. A double bellows-sealed regulating valve according to any one of claims 1-5, characterized in that: The top of the fairing (4) is provided with several pressure balancing holes (34).

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