High-temperature pilot cage type regulating valve

Abstract

The high-temperature pilot cage type regulating valve comprises a valve body, an upper valve cover, a valve cage assembly and a valve element assembly, the valve body is detachably connected with the upper valve cover, the valve body is provided with a liquid inlet cavity and a liquid outlet cavity, the valve cage assembly is arranged between the valve body and the upper valve cover, and the valve cage assembly is connected with the valve element assembly used for controlling medium flow. A balance cavity is formed between the valve element assembly and the upper valve deck, and the valve element assembly comprises a large valve element, a small valve element, a valve rod, a pre-tightening spring and a limiting plate. The utility model mainly aims to balance the medium pressure on the upper side and the lower side of the large valve core through the action of firstly opening the small valve core, so that the valve is convenient to open, the requirement on the configuration of an actuator is reduced, and the manufacturing cost of the whole machine is reduced.

Description

Technical Field

[0001] This utility model relates to the technical field of valve bodies, and in particular to a high-temperature pilot-operated cage-type regulating valve. Background Technology

[0002] A control valve is a type of valve used to regulate process parameters such as flow rate, pressure, temperature, and liquid level in industrial automation process control. In industries such as petroleum, petrochemicals, power generation, new energy, coal chemicals, and fine chemicals, high pressure and high pressure differential conditions place extremely high demands on the leakage level of control valves.

[0003] Traditional pilot-operated cage control valves have certain shortcomings. Patent number CN201721257556.4 discloses a dual-core pilot-operated cage control valve, which uses a small valve core and a large valve core to work in sections, making full use of the pressure of the medium before the valve to increase the sealing force of the valve seat. The outer wall of the large valve core has a step, and the guide ring is set in the step and pressed on the large valve core by the limiting pressure plate. When the large valve core moves relative to the valve cage, the friction between the guide ring and the valve cage will act on the connection structure between the large valve core and the limiting pressure plate, which will cause the connection between the limiting pressure plate and the large valve core to loosen, affecting the service life of the control valve. Utility Model Content

[0004] To overcome the shortcomings of the prior art, the technical solution adopted by this utility model is as follows: a high-temperature pilot-operated cage-type regulating valve, including a valve body, an upper valve cover, a valve cage assembly, and a valve core assembly. The upper valve cover is detachably connected to the valve body. The valve body is provided with an inlet chamber and an outlet chamber. A valve cage assembly is provided between the valve body and the upper valve cover. The valve cage assembly is connected to a valve core assembly for controlling the flow rate of the medium. A balance chamber is formed between the valve core assembly and the upper valve cover. The valve core assembly includes a large valve core, a small valve core, a valve stem, a preload spring, and a limiting plate. A pilot hole is provided at the bottom of the large valve core. A small valve core is slidably connected to the large valve core and abuts against and seals against the pilot hole. One end of the small valve core is slidably connected to the upper valve cover through the valve stem. A preload spring is provided between the other end and the large valve core. A limiting plate for limiting the movement distance of the small valve core is threadedly connected to the inner side of the large valve core.

[0005] By adopting the above technical solution, the medium pressure on the upper and lower sides of the large valve core is balanced by opening the small valve core first, which facilitates valve opening and reduces the requirements for actuator configuration, thereby reducing the overall manufacturing cost. When the valve core assembly moves relative to the valve cage assembly, only the large valve core slides in contact with the valve cage assembly, without affecting the connection structure between the large valve core and the limit plate, thus extending the service life of the regulating valve.

[0006] The present invention is further configured such that the large valve core has an inner cavity coaxially distributed with the pilot hole, and a backflow hole for connecting the inner cavity and the liquid outlet cavity.

[0007] By adopting the above technical solution, after the valve is closed, the medium pressure P1 at the outlet chamber flows to the inner cavity of the large valve core through the backflow hole, so that the pressure P3 in the balance chamber is equal to P1, thereby increasing the sealing capacity between the valve core assembly and the valve cage assembly, thus achieving a high level of sealing effect.

[0008] The present invention is further configured such that the small valve core is provided with an upper cylindrical part, an outer ring part, a lower cylindrical part and a sealing part distributed from top to bottom, the outer ring part is slidably connected to the inner cavity and the outer ring part is provided with a flow groove distributed in a circle, the pre-tightening spring is sleeved on the lower cylindrical part and is provided between the outer ring part and the large valve core, and the sealing part is provided with a conical surface corresponding to the pilot hole.

[0009] By adopting the above technical solution, the sealing effect between the small valve core and the pilot hole is improved by forming a conical angle difference between the conical surface and the pilot hole. A flow groove is opened around the outer ring to avoid the pressure difference between the upper and lower sides of the outer ring while reducing the contact area between the small valve core and the large valve core, so that the small valve core moves more smoothly relative to the large valve core.

[0010] The present invention is further configured such that the large valve core is provided with a first threaded hole above the inner cavity, the limiting plate is connected to the large valve core through the first threaded hole, and the limiting plate is provided with flow holes in a circular pattern for connecting the balance cavity and the inner cavity.

[0011] Furthermore, the upper cylindrical portion extends outward through the limiting plate, and the upper cylindrical portion is provided with a second threaded hole, through which the valve stem is connected to the upper cylindrical portion.

[0012] Using the above technical solution, when installing the limiting plate, place the limiting plate at the first threaded hole, use calipers or other tools to insert it into the flow hole and rotate the limiting plate to achieve the installation of the limiting plate and the large valve core.

[0013] The present invention is further configured such that the valve cage assembly includes a guide valve cage, a pressure cage and a valve seat connected sequentially from top to bottom, and a sealing ring disposed between the guide valve cage and the pressure cage, wherein the large valve core is sealed to the pressure cage through the sealing ring.

[0014] Furthermore, the guide valve cage and the pressure cage are provided with inner holes adapted to the large valve core, the pressure cage is provided with side holes communicating with the inner holes, and a sealing groove with the opening direction facing inward is formed between the guide valve cage and the pressure cage, and the sealing ring is snapped into the sealing groove.

[0015] In the above technical solution, the guide ring is a high-temperature resistant metal ring that is snapped between the guide valve cage and the pressure cage, and mainly plays a guiding role.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] 1. By opening the small valve core first, the medium pressure on both sides of the large valve core is balanced, which facilitates valve opening, reduces the requirements for actuator configuration, and thus reduces the overall manufacturing cost;

[0018] 2. When the valve core assembly moves relative to the valve cage assembly, only the large valve core slides in contact with the valve cage assembly, without affecting the connection structure between the large valve core and the limit plate, thus extending the service life of the regulating valve.

[0019] The embodiments of this utility model will be further described below with reference to the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of the structure of this utility model;

[0021] Figure 2 This is a cross-sectional view of the valve core assembly of this utility model in the valve closed state;

[0022] Figure 3 This is a cross-sectional view of the valve core assembly of this utility model in the valve open state;

[0023] Figure 4 For the present utility model Figure 1 A magnified view of the central A-direction view;

[0024] Wherein: 1-valve body, 2-upper valve cover, 3-valve cage assembly, 4-valve core assembly, 11-inlet chamber, 12-outlet chamber, 13-balance chamber, 31-guide valve cage, 32-pressure cage, 33-valve seat, 34-guide ring, 321-inner hole, 322-side hole, 323-sealing groove, 41-large valve core, 42-small valve core, 43-valve stem, 44-preload spring, 45-limiting plate, 411-pilot hole, 412-inner cavity, 413-backflow hole, 414-first threaded hole, 421-upper cylindrical part, 422-outer ring part, 423-lower cylindrical part, 424-sealing part, 425-flow groove, 426-conical surface, 427-second threaded hole, 451-flow hole; Detailed Implementation

[0025] like Figure 1 , 2As shown, this embodiment provides a high-temperature pilot-operated cage-type regulating valve, including a valve body 1, an upper valve cover 2, a valve cage assembly 3, and a valve core assembly 4. The upper valve cover 2 is detachably connected to the valve body 1. The valve body 1 has an inlet chamber 11 and an outlet chamber 12. The valve cage assembly 3 is provided between the valve body 1 and the upper valve cover 2. The valve cage assembly 3 is connected to the valve core assembly 4 for controlling the flow rate of the medium. A balance chamber 13 is formed between the valve core assembly 4 and the upper valve cover 2. The valve core assembly 4 includes a large valve core 4. 1. A small valve core 42, a valve stem 43, a preload spring 44, and a limiting plate 45. A pilot hole 411 is provided at the bottom of the large valve core 41, and a small valve core 42 is slidably connected to the large valve core 41 and abuts against and seals against the pilot hole 411. One end of the small valve core 42 is slidably connected to the upper valve cover 2 through the valve stem 43, and a preload spring 44 is provided between the other end and the large valve core 41. A limiting plate 45 for limiting the movement distance of the small valve core 42 is threadedly connected to the inner side of the large valve core 41.

[0026] In this embodiment, the large valve core 41 is provided with an inner cavity 412 coaxially distributed with the pilot hole 411, and a backflow hole 413 for connecting the inner cavity 412 and the liquid outlet cavity 12. After the valve is closed, the medium pressure P1 at the liquid outlet cavity 12 flows to the inner cavity 412 of the large valve core 41 through the backflow hole 413, so that the pressure P3 in the balance cavity 13 is equal to P1, thereby increasing the sealing capacity between the valve core assembly 4 and the valve cage assembly 3, thereby achieving a high level of sealing effect.

[0027] In this embodiment, the small valve core 42 is provided with an upper cylindrical portion 421, an outer ring portion 422, a lower cylindrical portion 423, and a sealing portion 424 from top to bottom. The outer ring portion 422 is slidably connected to the inner cavity 412 and is provided with a circumferentially distributed flow groove 425. The preload spring 44 is sleeved on the lower cylindrical portion 423 and is located between the outer ring portion 422 and the large valve core 41. The sealing portion 424 is provided with a conical surface 426 corresponding to the pilot hole 411. The conical surface 426 and the pilot hole 411 form an angle difference, which improves the sealing effect between the small valve core 42 and the pilot hole 411. The flow groove 425 is provided around the outer ring portion 422 to avoid the pressure difference between the upper and lower sides of the outer ring portion 422 and reduce the contact area between the small valve core 42 and the large valve core 41, so that the small valve core 42 moves more smoothly relative to the large valve core 41.

[0028] In this embodiment, the large valve core 41 is provided with a first threaded hole 414 above the inner cavity 412. The limiting plate 45 is connected to the large valve core 41 through the first threaded hole 414, and the limiting plate 45 is circumferentially distributed with flow holes 451 for connecting the balance cavity 13 and the inner cavity 412. The upper cylindrical part 421 extends outward through the limiting plate 45, and the upper cylindrical part 421 is provided with a second threaded hole 427. The valve stem 43 is connected to the upper cylindrical part 421 through the second threaded hole 427. When installing the limiting plate 45, the limiting plate 45 is placed at the first threaded hole 414, and tools such as calipers are used to insert it into the flow hole 451 and rotate the limiting plate 45 to realize the installation of the limiting plate 45 and the large valve core 41.

[0029] Combination Figure 4 As shown, in this embodiment, the valve cage assembly 3 includes a guide valve cage 31, a pressure cage 32, and a valve seat 33 connected sequentially from top to bottom, and a guide ring 34 disposed between the guide valve cage 31 and the pressure cage 32. The large valve core 41 is sealed to the pressure cage 32 through the guide ring 34. The guide valve cage 31 and the pressure cage 32 are provided with an inner hole 321 adapted to the large valve core 41. The pressure cage 32 is provided with a side hole 322 communicating with the inner hole 321. A sealing groove 323 with the opening direction facing inward is formed between the guide valve cage 31 and the pressure cage 32. The guide ring 34 is snapped into the sealing groove 323. The guide ring 34 is a high-temperature resistant metal ring, which mainly plays a guiding role between the guide valve cage 31 and the pressure cage 32.

[0030] Combination Figure 1 , 2 As shown in Figure 3, the working principle of this utility model is as follows: When the valve is closed, the large valve core 41 first forms a preliminary seal with the valve cage assembly 3, while the small valve core 42 quickly closes. At this time, the pre-tightening spring 44 is compressed, and the medium pressure P1 at the outlet chamber 12 flows to the balance chamber 13 through the backflow hole 413, so that the pressure P3 in the balance chamber 13 is equal to P1, thereby increasing the sealing force between the valve core assembly 4 and the valve cage assembly 3. When the valve is open, the force of the pre-tightening spring 44 first lifts the small valve core 42, so that the liquid medium in the inlet chamber 11 flows to the large valve core 41 through the side hole 322 and the backflow hole 413, and reduces the pressure difference between the inlet chamber 11 and the balance chamber 13. After depressurization, the pressure difference P3-P2 on the upper and lower sides of the valve core assembly 4 approaches "zero", making it easier to open the valve.

[0031] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high-temperature pilot-operated cage-type regulating valve, comprising a valve body (1), an upper valve cover (2), a valve cage assembly (3), and a valve core assembly (4), wherein the upper valve cover (2) is detachably connected to the valve body (1), the valve body (1) is provided with an inlet chamber (11) and an outlet chamber (12), and a valve cage assembly (3) is provided between the valve body (1) and the upper valve cover (2), the valve cage assembly (3) is connected to a valve core assembly (4) for controlling the flow rate of the medium, and a balance chamber (13) is formed between the valve core assembly (4) and the upper valve cover (2), characterized in that, The valve core assembly (4) includes a large valve core (41), a small valve core (42), a valve stem (43), a preload spring (44), and a limiting plate (45). The large valve core (41) has a pilot hole (411) at its bottom, and the large valve core (41) is slidably connected to a small valve core (42) that abuts against and seals with the pilot hole (411). One end of the small valve core (42) is slidably connected to the upper valve cover (2) through the valve stem (43), and the other end is provided with a preload spring (44) between it and the large valve core (41). The inner side of the large valve core (41) is threaded with a limiting plate (45) for limiting the movement distance of the small valve core (42). The large valve core (41) is provided with an inner cavity (412) coaxially distributed with the pilot hole (411), and a backflow hole (413) for connecting the inner cavity (412) and the liquid outlet cavity (12); The small valve core (42) has an upper cylindrical part (421), an outer ring part (422), a lower cylindrical part (423), and a sealing part (424) arranged from top to bottom. The outer ring part (422) is slidably connected to the inner cavity (412), and the outer ring part (422) is provided with a circumferentially distributed flow groove (425). The preload spring (44) is sleeved on the lower cylindrical part (423) and is located between the outer ring part (422) and the large valve core (41). The sealing part (424) is provided with a conical surface (426) corresponding to the pilot hole (411).

2. The high-temperature pilot-operated cage-type regulating valve according to claim 1, characterized in that: The large valve core (41) is provided with a first threaded hole (414) above the inner cavity (412). The limiting plate (45) is connected to the large valve core (41) through the first threaded hole (414), and the limiting plate (45) has flow holes (451) distributed in a circumferential manner to connect the balance cavity (13) and the inner cavity (412).

3. A high-temperature pilot-operated cage-type regulating valve according to claim 2, characterized in that: The upper cylindrical portion (421) extends outward through the limiting plate (45), and the upper cylindrical portion (421) is provided with a second threaded hole (427), and the valve stem (43) is connected to the upper cylindrical portion (421) through the second threaded hole (427).

4. A high-temperature pilot-operated cage-type regulating valve according to claim 1, characterized in that: The valve cage assembly (3) includes a guide valve cage (31), a pressure cage (32) and a valve seat (33) connected sequentially from top to bottom, and a guide ring (34) disposed between the guide valve cage (31) and the pressure cage (32). The large valve core (41) is sealed to the pressure cage (32) through the guide ring (34).

5. A high-temperature pilot-operated cage-type regulating valve according to claim 4, characterized in that: The guide valve cage (31) and the pressure cage (32) are provided with an inner hole (321) that is compatible with the large valve core (41). The pressure cage (32) is provided with a side hole (322) that communicates with the inner hole (321). A sealing groove (323) with the opening direction facing inward is formed between the guide valve cage (31) and the pressure cage (32). The guide ring (34) is engaged in the sealing groove (323).

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