Double-seal throttling stop valve

Abstract

This application discloses a dual-seal throttling valve, relating to the field of throttling valve technology, comprising: a valve body, a valve cover, a valve core, and a valve seat; wherein, a valve seat is disposed within the valve body, a valve cover is disposed at the top of the valve body, and the valve core is disposed within the valve body, with one end located on one side of the valve seat, and the other end sliding through the valve cover to extend to the outside of the valve body and connected to an external drive mechanism. This application employs a dual-seal structure of hard and soft seals, achieving functional complementarity and synergistic advantages, balancing sealing reliability and service life. During the opening and closing cycle of the throttling valve, the scouring effect of the medium mainly acts on the first hard seal, while the second soft seal remains in a non-scouring area, extending the service life of the soft seal. When the throttling valve is closed, the hard and soft seals are independent and do not affect each other, forming dual redundancy protection to ensure that the throttling valve does not leak medium, meeting the stringent sealing requirements in industrial production.

Description

Technical Field

[0001] This utility model relates to the field of throttling valve technology, specifically to a double-sealed throttling valve. Background Technology

[0002] Throttling valves are commonly used industrial valves that combine shut-off sealing and flow regulation functions. They are compact, reliably sealed, and offer excellent linear regulation. Internally, they often employ specialized throttling structures such as cones or plungers, providing superior resistance to erosion and cavitation compared to ordinary gate valves. When closed, the sealing surface of a throttling valve is forced into a tight seal with no leakage. When open, it allows for stable fine-tuning of operating parameters. Widely used in high-temperature and high-pressure pipeline systems in petroleum, chemical, power plant, and thermal industries, it is a core control valve integrating shut-off and throttling functions.

[0003] Existing throttling valves employ a single hard seal structure. In media containing solid particles, the sealing surface is easily eroded or damaged after long-term operation, or impurities may become embedded between the sealing surfaces, failing to achieve a good sealing effect. Furthermore, most existing double-seal throttling valves or double-seal regulating valves are fixed double seals with a rigid connection between the two seals. This means that both seals open or close simultaneously. If one seal fails to close properly due to impurities, the other seal will also fail to close properly, resulting in simultaneous failure of both seals. Moreover, during opening and closing, both seals are exposed to the erosion of the medium, with no mutual protection between them.

[0004] Therefore, a double-sealed throttling valve is needed to solve the above-mentioned technical problems. Utility Model Content

[0005] To achieve the above objectives, this utility model provides the following technical solution: a double-sealed throttling valve, comprising: a valve body, a valve cover, a valve core, and a valve seat;

[0006] The valve body contains a valve seat, the valve cover is located at the top of the valve body, and the valve core is located inside the valve body, with one end of the core located on one side of the valve seat and the other end sliding through the valve cover to extend to the outside of the valve body and connected to an external drive mechanism.

[0007] The valve core includes: a valve stem, a throttle valve head, a preload spring, a soft sealing seat, a first sealing ring, and a pressure ring;

[0008] Wherein, the end of the valve stem near the valve seat is connected to the throttle valve head through the pre-tightening spring, the outer wall of the valve stem is threaded to the inner wall of the top of the soft sealing seat, the outer wall of the throttle valve head is slidably connected to the inner wall of the bottom of the soft sealing seat, the outer wall of the bottom of the soft sealing seat is threaded to the pressure ring, and the pressure ring fixes the first sealing ring to the bottom of the soft sealing seat;

[0009] A hard seal is formed between the throttle valve head and the valve seat, and a soft seal is formed between the first sealing ring and the valve seat.

[0010] Furthermore, as a preferred embodiment, the inner wall of the soft sealing seat has an inner hole, and a second sealing ring is provided inside the inner hole.

[0011] Furthermore, as a preferred embodiment, the inner wall of the top end of the soft sealing seat is threaded to the outer wall of the valve stem via a first thread, and the outer wall of the bottom end of the soft sealing seat is threaded to the inner wall of the pressure ring via a second thread.

[0012] Furthermore, as a preferred embodiment, the outer wall of the valve seat top is provided with a first outer conical sealing surface, and the inner wall of the valve seat top is provided with a first inner conical sealing surface.

[0013] Furthermore, as a preferred embodiment, the bottom end of the first sealing ring is provided with a second inner conical sealing surface.

[0014] Furthermore, as a preferred embodiment, the end of the throttling valve head away from the valve stem is provided with a throttling head, the end of the throttling valve head near the valve stem is provided with a first limiting step, and the outer wall of the throttling head is provided with a second outer conical sealing surface.

[0015] Furthermore, as a preferred embodiment, a soft seal is formed between the first outer conical sealing surface and the second inner conical sealing surface, and a hard seal is formed between the first inner conical sealing surface and the second outer conical sealing surface.

[0016] Furthermore, as a preferred embodiment, the soft sealing sleeve is provided with a pressure guiding hole, and the inner wall of the soft sealing sleeve is provided with a second limiting step that matches the shape of the first limiting step.

[0017] Furthermore, as a preferred option, the first sealing ring is made of a non-metallic material.

[0018] Compared with the prior art, this utility model provides a double-sealed throttling valve, which has the following beneficial effects:

[0019] Advantage 1: This application employs a dual-sealing structure of hard and soft seals, achieving complementary functions and synergistic advantages, balancing sealing reliability and service life. The hard seal, as the first layer, relies on its enhanced resistance to media erosion and wear after treatment, playing a primary sealing role during the dynamic opening and closing of the throttling valve, protecting it from damage caused by media erosion. The soft seal, as the second layer, leverages its excellent elastic fit to improve the sealing level of the throttling valve, achieving the requirement of zero media leakage and compensating for the shortcomings of the hard seal in terms of microscopic sealing precision.

[0020] Advantage 2: During the entire opening and closing cycle of the throttling valve, the main area affected by media erosion is concentrated in the first hard seal, while the second soft seal remains in the non-erosion zone, extending its service life. When the throttling valve is closed, the hard and soft seals operate independently, forming double redundancy protection. Even if one seal fails, the other can still function reliably, ensuring no media leakage and meeting the stringent sealing requirements of industrial production. This is particularly suitable for demanding conditions such as high pressure, high flow rate, and media containing solid particles. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a double-sealed throttling valve;

[0022] Figure 2 for Figure 1 Enlarged detail image of point A in the middle;

[0023] Figure 3 This is a schematic diagram of the opening process of a double-sealed throttling valve.

[0024] In the diagram: 1. Valve body; 2. Valve cover; 3. Valve core; 31. Valve stem; 32. Throttling valve head; 321. Second outer conical sealing surface; 322. First limiting step; 323. Throttling head; 33. Preload spring; 34. Soft sealing seat; 341. Pressure guide hole; 342. Second limiting step; 35. First sealing ring; 351. Second inner conical sealing surface; 36. Pressure ring; 37. Second sealing ring; 4. Valve seat; 41. First outer conical sealing surface; 42. First inner conical sealing surface; 5. First thread; 6. Second thread. Detailed Implementation

[0025] Please see Figures 1-3 This utility model provides a double-sealed throttling valve, comprising: valve body 1, valve cover 2, valve core 3 and valve seat 4;

[0026] The valve body 1 is provided with a valve seat 4, and a valve cover 2 is provided at the top of the valve body 1. The valve core 3 is provided inside the valve body 1, with one end located on one side of the valve seat 4 and the other end sliding through the valve cover 2 to extend to the outside of the valve body 1 and connected to the external drive mechanism.

[0027] In this embodiment, please refer to Figure 1As shown, the drive mechanism (not shown in the figure), as an external power output component, provides a stable linear driving force, driving the valve core 3 to reciprocate linearly in the vertical direction, thereby achieving the sealing and separation between the valve core 3 and the valve seat 4, and achieving the purpose of controlling the flow channel inside the valve body 1. The valve seat 4 is fixedly assembled at a key position in the flow channel inside the valve body 1. When the drive mechanism drives the valve core 3 to move downward until the valve core 3 and the valve seat 4 are tightly fitted, the valve core 3 blocks the valve seat 4. At this time, the flow channel inside the valve body 1 is in a completely cut-off state, and the flowing medium is blocked and cannot flow through the valve body 1. When the drive mechanism drives the valve core 3 to move upward, causing the valve core 3 to disengage from the valve seat 4, the valve core 3 cancels the blocking effect on the valve seat 4, and the flow channel inside the valve body 1 is in a completely open state. At this time, the medium smoothly enters from the inlet on the valve body 1 (e.g., Figure 1 (As shown by the solid arrow in the middle), after being guided through the internal flow channel of valve body 1, it is discharged from the outlet (as shown by the solid arrow in the middle). Figure 1 (As shown by the dashed arrow in the middle), to achieve normal transport of the medium.

[0028] Valve core 3 includes: valve stem 31, throttle valve head 32, preload spring 33, soft sealing seat 34, first sealing ring 35, and pressure ring 36;

[0029] Among them, the valve stem 31 is connected to the throttle valve head 32 via a pre-tightening spring 33 at one end near the valve seat 4. The outer wall of the valve stem 31 is threaded to the inner wall of the top of the soft sealing seat 34. The outer wall of the throttle valve head 32 is slidably connected to the inner wall of the bottom of the soft sealing seat 34. The outer wall of the bottom of the soft sealing seat 34 is threaded to the pressure ring 36. The pressure ring 36 fixes the first sealing ring 35 to the bottom of the soft sealing seat 34.

[0030] A hard seal is formed between the throttle valve head 32 and the valve seat 4, and a soft seal is formed between the first sealing ring 35 and the valve seat 4.

[0031] Furthermore, the inner wall of the soft sealing sleeve 34 has an inner hole, and a second sealing ring 37 is provided inside the inner hole.

[0032] In this embodiment, please refer to Figure 2 As shown, the second sealing ring 37 is an O-ring. O-rings are commonly used sealing elements in industrial fields due to their simple structure, convenient installation, high sealing reliability, and strong versatility. They are well-known existing technologies in this field, and their specific molding process, material formulation, standard parameters, and sealing function will not be elaborated here. The core function of the second sealing ring 37 is to achieve a dynamic seal between the soft sealing seat 34 and the throttle valve head 32, effectively preventing leakage of the medium at the mating gap between the two.

[0033] Furthermore, the inner wall of the top end of the soft sealing seat 34 is threaded to the outer wall of the valve stem 31 via the first thread 5, and the outer wall of the bottom end of the soft sealing seat 34 is threaded to the inner wall of the pressure ring 36 via the second thread 6.

[0034] Furthermore, a first outer conical sealing surface 41 is provided on the outer wall of the top end of the valve seat 4, and a first inner conical sealing surface 42 is provided on the inner wall of the top end of the valve seat 4.

[0035] Furthermore, a second inner conical sealing surface 351 is provided at the bottom end of the first sealing ring 35.

[0036] Furthermore, a throttling head 323 is provided at the end of the throttling valve head 32 away from the valve stem 31, a first limiting step 322 is provided at the end of the throttling valve head 32 near the valve stem 31, and a second outer conical sealing surface 321 is provided on the outer wall of the throttling head 323.

[0037] In this embodiment, please refer to Figure 2 and Figure 3 As shown, the throttle head 32, as the core component for flow regulation, can be manufactured into different structural forms according to the actual working conditions and flow characteristics requirements. These include, but are not limited to, linear, equal percentage, and quick-opening types. Throttling heads 323 with different outer contour structures can achieve precise adjustment of different flow characteristics by changing the correspondence between the flow area and the opening degree of the medium. This adapts to the flow control requirements of different pipeline systems, improves the flow regulation flexibility and adaptability of the throttle valve, and meets the diverse flow control scenarios in industrial production.

[0038] It should be noted that the surfaces of the second outer conical sealing surface 321, the first outer conical sealing surface 41, and the first inner conical sealing surface 42 are all reinforced using a hard alloy welding process. Hard alloy materials possess the characteristics of high hardness, strong wear resistance, excellent resistance to media corrosion, and excellent erosion resistance. By bonding them to the surfaces of the second outer conical sealing surface 321, the first outer conical sealing surface 41, and the first inner conical sealing surface 42 through a welding process, the surface hardness and structural strength can be significantly improved, service life can be extended, and their resistance to media erosion and wear can be enhanced.

[0039] Furthermore, a soft seal is formed between the first outer conical sealing surface 41 and the second inner conical sealing surface 351, and a hard seal is formed between the first inner conical sealing surface 42 and the second outer conical sealing surface 321.

[0040] In this embodiment, please refer to Figure 1 , Figure 2 and Figure 3As shown, when the throttling valve is closed, this application can form two independent and non-interfering seals to achieve reliable sealing. Specifically, the first inner conical sealing surface 42 on the valve seat 4 precisely fits with the second outer conical sealing surface 321 on the throttling valve head 32, forming the first hard seal. The first outer conical sealing surface 41 on the valve seat 4 tightly fits with the second inner conical sealing surface 351 on the first sealing ring 35, forming the second soft seal. The first hard seal and the second soft seal work simultaneously, and their sealing functions are independent of each other, possessing good redundancy protection characteristics. When the first hard seal fails due to wear, erosion, or other factors, the second soft seal can maintain its original sealing performance, effectively preventing media leakage. Similarly, when the second soft seal malfunctions, the first hard seal can still function normally, ensuring that the entire throttling valve is always in a good sealing state, significantly improving the reliability and safety of the throttling valve seal, and making it suitable for industrial pipeline systems with stringent sealing requirements.

[0041] In this embodiment, during the initial opening of the throttling valve, the drive mechanism outputs power to move the valve stem 31 vertically upwards. Simultaneously, the valve stem 31 drives the soft sealing seat 34, the second sealing ring 37, the first sealing ring 35, and the pressure ring 36 upwards as a whole. During this process, the second soft seal first releases its contact, thus opening the soft seal. At this time, under the combined action of the medium sealing force and the pre-tightening force of the pre-tightening spring 33, the throttling valve head 32 maintains a tight fit between its second outer conical sealing surface 321 and the first inner conical sealing surface 42 of the valve seat 4, and the first hard seal remains closed. As the soft sealing seat 34 continues to rise, its second limiting step 342 gradually contacts and forms a limiting fit with the first limiting step 322 on the throttling valve head 32. Subsequently, the upward driving force of the valve stem 31 is transmitted to the throttling valve head 32, causing the throttling valve head 32 to move upwards synchronously, releasing the first hard seal and opening the hard seal. Since the first sealing ring 35 has moved upward a certain distance along with the soft sealing seat 34, the second inner conical sealing surface 351 on it has been removed from the mainstream media scouring area. This effectively prevents the medium containing solid particles from directly scouring the second inner conical sealing surface 351, thus providing reliable protection for it. When the throttling valve is fully open, the medium flows smoothly along the preset flow channel and will not directly scour the second inner conical sealing surface 351. This ensures that after long-term operation, the second soft seal can still maintain good sealing performance and is not affected by media scouring.

[0042] In this embodiment, when the throttling valve is closed, the valve stem 31 moves downward under the drive of the driving mechanism. First, the second outer conical sealing surface 321 on the throttling valve head 32 contacts and adheres to the first inner conical sealing surface 42 on the valve seat 4. Under the pre-tightening force of the pre-tightening spring 33, the first hard seal is completely closed, achieving initial sealing of the medium. At this time, the valve stem 31 continues to drive the soft sealing seat 34, the second sealing ring 37, the first sealing ring 35, and the pressure ring 36 downward. Since the first hard seal is completely closed, the area where the second soft seal is located is essentially in a static state without medium flow, effectively preventing the medium from eroding the second inner conical sealing surface 351 and the first outer conical sealing surface 41 during the closing process of the second soft seal. In this application, the second soft seal always operates under static medium conditions, effectively avoiding wear and erosion caused by medium erosion, ensuring long-term stable sealing performance of the second soft seal, and further improving the overall sealing reliability of the throttling valve.

[0043] In a preferred embodiment, this application employs a dual-sealing structure of hard and soft seals, achieving complementary functions and synergistic advantages, while balancing sealing reliability and service life. The hard seal, as the first layer of sealing, relies on its enhanced resistance to media erosion and wear after strengthening treatment, playing a primary sealing role during the dynamic opening and closing of the throttling valve, resisting damage caused by media erosion. The soft seal, as the second layer of sealing, leverages its excellent elastic fit to improve the sealing level of the throttling valve, achieving the requirement of zero media leakage and compensating for the shortcomings of the hard seal in microscopic sealing precision. Throughout the entire opening and closing cycle of the throttling valve, the main area affected by media erosion is concentrated at the first hard seal, while the second soft seal remains in the non-erosion zone, extending the service life of the soft seal. When the throttling valve is closed, the hard seal and soft seal are independent of each other and do not affect each other, forming a double redundancy protection. Even if one seal fails, the other seal can still play a stable sealing role, ensuring that the throttling valve does not leak media, meeting the stringent requirements for sealing performance in industrial production, and is especially suitable for harsh working conditions such as high pressure, high flow rate, and media containing solid particles.

[0044] Furthermore, the soft sealing sleeve 34 is provided with a pressure guiding hole 341, and the inner wall of the soft sealing sleeve 34 is provided with a second limiting step 342 that matches the shape of the first limiting step 322.

[0045] In this embodiment, please refer to Figure 3 As shown, the pressure guide hole 341 is used to balance the pressure inside and outside the soft seal sleeve 34. The first limiting step 322 and the second limiting step 342 can assist in completing the sequential opening operation of the second soft seal and the first hard seal, and can limit the maximum downward displacement of the throttle valve head 32.

[0046] Furthermore, the first sealing ring 35 is made of a non-metallic material.

[0047] In this embodiment, please refer to Figure 2 As shown, the first sealing ring 35 can be made of high-performance non-metallic materials such as RPTFE (reinforced polytetrafluoroethylene) and PEEK (polyether ether ketone), and can work under high pressure and strong corrosion conditions. The first sealing ring 35 made of non-metallic materials has a certain degree of elasticity, which effectively improves the sealing performance.

[0048] In practice, the drive mechanism drives the valve stem 31 to move vertically. In the closed state, the hard seal and soft seal seal synchronously and independently. The failure of one does not affect the operation of the other. In the initial opening stage, the soft seal opens first, followed by the hard seal, to prevent the medium from eroding the soft seal. In the initial closing stage, the hard seal closes first, followed by the soft seal, and always operates in a state where the medium is stationary. Overall, it meets the requirements of high sealing level, erosion resistance, and long service life, and is suitable for harsh working conditions such as high pressure, strong corrosion, and solid particles.

[0049] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A double-sealed throttling valve, characterized in that: include: Valve body (1), valve cover (2), valve core (3) and valve seat (4); The valve body (1) is provided with the valve seat (4), the valve cover (2) is provided at the top of the valve body (1), and the valve core (3) is provided in the valve body (1). One end of the core is located on one side of the valve seat (4), and the other end slides through the valve cover (2) to extend to the outside of the valve body (1) and is connected to the external drive mechanism. The valve core (3) includes: valve stem (31), throttle valve head (32), preload spring (33), soft sealing seat (34), first sealing ring (35), and pressure ring (36); Wherein, the valve stem (31) is connected to the throttle valve head (32) at one end near the valve seat (4) through the preload spring (33), the outer wall of the valve stem (31) is threaded to the inner wall of the top of the soft sealing seat (34), the outer wall of the throttle valve head (32) is slidably connected to the inner wall of the bottom of the soft sealing seat (34), the outer wall of the bottom of the soft sealing seat (34) is threaded to the pressure ring (36), and the pressure ring (36) fixes the first sealing ring (35) to the bottom of the soft sealing seat (34); A hard seal is formed between the throttle valve head (32) and the valve seat (4), and a soft seal is formed between the first sealing ring (35) and the valve seat (4).

2. The double-sealed throttling valve according to claim 1, characterized in that: The inner wall of the soft sealing seat (34) has an inner hole, and a second sealing ring (37) is provided inside the inner hole.

3. The double-sealed throttling valve according to claim 1, characterized in that: The inner wall of the top end of the soft sealing seat (34) is threaded to the outer wall of the valve stem (31) through the first thread (5), and the outer wall of the bottom end of the soft sealing seat (34) is threaded to the inner wall of the pressure ring (36) through the second thread (6).

4. The double-sealed throttling valve according to claim 1, characterized in that: The valve seat (4) has a first outer conical sealing surface (41) on the outer wall of the top end and a first inner conical sealing surface (42) on the inner wall of the top end.

5. A double-sealed throttling valve according to claim 4, characterized in that: The bottom end of the first sealing ring (35) is provided with a second inner conical sealing surface (351).

6. A double-sealed throttling valve according to claim 5, characterized in that: The throttle valve head (32) is provided with a throttle head (323) at the end away from the valve stem (31), and a first limiting step (322) is provided at the end of the throttle valve head (32) close to the valve stem (31). The outer wall of the throttle head (323) is provided with a second outer conical sealing surface (321).

7. A double-sealed throttling valve according to claim 6, characterized in that: The soft seal is formed between the first outer conical sealing surface (41) and the second inner conical sealing surface (351), and the hard seal is formed between the first inner conical sealing surface (42) and the second outer conical sealing surface (321).

8. A double-sealed throttling valve according to claim 6, characterized in that: The soft sealing seat (34) is provided with a pressure guiding hole (341), and the inner wall of the soft sealing seat (34) is provided with a second limiting step (342) that matches the shape of the first limiting step (322).

9. A double-sealed throttling valve according to claim 1, characterized in that: The first sealing ring (35) is made of non-metallic material.

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