Double eccentric butterfly valve with long service life

Abstract

The scheme discloses a long-service-life double eccentric butterfly valve, which comprises a valve rod and a valve plate, and further comprises a first valve rod fixing part and a second valve rod fixing part; the first valve rod fixing part passes through the valve rod and is eccentrically positioned with the valve plate; the second valve rod fixing part is fixedly connected with the valve plate in a detachable mode. The second valve rod fixing part is at least two pairs, and is uniformly distributed in the length range of the valve rod corresponding to the valve plate. The second valve rod fixing part is a pin sleeve assembly. A thrust washer is arranged on the outer sleeve of the valve rod, and a matching groove is arranged at the corresponding position of the valve plate, and the matching groove is positioned by the thrust washer. The thrust washer is located at the exposed position of the valve rod. The beneficial effects of the scheme are as follows: 1, accurate positioning between the valve rod and the valve plate, the valve plate and the valve seat is realized; 2, parts can be quickly replaced on site, time and cost are saved; 3, the wear of the valve seat is reduced, and the service life is prolonged; 4, the optimization of the valve seat fixing structure can realize bidirectional zero leakage of the valve.

Description

Technical Field

[0001] This utility model relates to the field of valves, specifically a double eccentric butterfly valve with a long service life. Background Technology

[0002] Chinese patent document CN105179713A disclosed on December 23, 2015, a sealing structure for a marine bidirectional sealing double eccentric butterfly valve. By setting a valve body, a butterfly plate component, a valve stem component, a pair of sealing rings and a pair of sealing ring pressure plates, a pair of sealing rings are set between the valve body and the butterfly plate component, so that each sealing ring forms a sealing pair with the spherical sealing surface of the butterfly plate component and the sealing surface of the valve body, which can achieve a very good sealing effect.

[0003] Due to frequent use and poor operating conditions, the friction between the valve plate and seat of this type of double eccentric butterfly valve is quite severe, leading to easy wear and tear on some parts. Once the wear exceeds a critical point, the sealing effect is affected. However, traditional double eccentric butterfly valves are based on outdated structural designs, making it difficult to replace easily worn parts individually; instead, the entire valve must be replaced, which is unacceptable in terms of both economic and time costs. Summary of the Invention

[0004] Based on the above problems, this utility model provides a double eccentric butterfly valve with a long service life, which aims to effectively extend the service life and facilitate the replacement of easily worn parts instead of replacing the entire valve.

[0005] To achieve the purpose of this invention, the present invention adopts the following technical solution: A long-service-life double eccentric butterfly valve, comprising a valve stem and a valve plate. It also includes a first valve stem fixing component and a second valve stem fixing component; The first valve stem fixing component passes through the valve stem and is eccentrically positioned with respect to the valve plate; The second valve stem fixing component is detachably and fixedly connected to the valve plate.

[0006] Preferably, there are at least two second valve stem fixing parts, which are evenly distributed within the length range of the valve plate corresponding to the valve stem.

[0007] Preferably, the second valve stem fixing component is a pin sleeve assembly.

[0008] Preferably, the valve stem is fitted with a thrust washer, and the valve plate has a corresponding groove, which is positioned by the thrust washer.

[0009] Preferably, the thrust washer is located at the exposed position of the valve stem.

[0010] Preferably, the valve body, valve seat, and valve seat pressure plate are also included; the valve body and valve seat pressure plate form a clamping structure to hold the valve seat in the middle.

[0011] Preferably, the valve seat includes a valve seat end and a valve seat root; the valve seat root is clamped between the valve body and the valve seat pressure plate, and the valve seat end is enclosed into an annular shape.

[0012] Preferably, the clamping surfaces of the valve body and the valve seat pressure plate are mutually matched serrated surfaces.

[0013] Preferably, an O-ring is installed inside the valve seat end.

[0014] The beneficial effects of this plan are: 1. Achieve precise positioning between the valve stem and valve plate, and between the valve plate and valve seat; 2. Parts can be quickly replaced on-site, saving time and money; 3. Reduce valve seat wear and extend service life; 4. The optimization of the valve seat fixing structure can achieve bidirectional zero leakage of the valve. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 yes Figure 1 AA section view; Figure 3 yes Figure 1 BB section view; Figure 4 yes Figure 3 Enlarged view of part C; Figure 5 This is a cross-sectional schematic diagram of the valve seat.

[0016] The components include: valve body 1, valve seat 2, valve seat end 2-1, valve seat root 2-2, O-ring 2-3, valve stem 3, valve plate 4, valve seat pressure plate 5, set screw 6, pin sleeve assembly 7, thrust washer 8, and bottom cover 9. Detailed Implementation

[0017] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0018] Example 1 Example 1 details a double eccentric butterfly valve with a long service life. This butterfly valve exhibits significant application advantages in the field of marine fluid control, primarily undertaking the task of precise control of various fluids in marine systems. Combined with... Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the core components of the double eccentric butterfly valve involved in this embodiment include a series of key parts or components such as valve body 1, valve seat 2, valve stem 3, valve plate 4, and bottom cover 9. The components work together to ensure the efficient and stable operation of the butterfly valve.

[0019] Among the many structural features, the connection method between the valve stem 3 and the valve plate 4 constitutes one of the main improvements of this double eccentric butterfly valve. Specifically, the first valve stem fixing component achieves eccentric positioning with the valve plate 4 by passing through the valve stem 3. This unique positioning mechanism lays the foundation for a stable connection thereafter. At the same time, the second valve stem fixing component adopts a detachable design concept, and is securely fixed to the valve plate 4. This detachable feature greatly improves the convenience of component replacement and maintenance.

[0020] In the actual installation process, strict operating procedures must be followed. First, the valve stem 3 is precisely positioned to ensure its accurate location within the system. Then, using the first valve stem fixing component, a specific point on the valve plate 4 is firmly fixed to the valve stem 3. This step aims to initially establish the relative positional relationship between the valve plate 4 and the valve stem 3. Next, the second valve stem fixing component is used to further fix other key points of the valve plate 4 to the valve stem 3, thereby enhancing the stability and reliability of the connection. In this embodiment, the first valve stem fixing component uses a set screw 6, which, with its high strength and precise positioning capability, effectively ensures the initial connection between the valve plate 4 and the valve stem 3. The second valve stem fixing component uses a pin sleeve assembly 7, with two sets. The pin sleeve assembly 7 achieves an interference fit through the tapered structure of the pin. This structure has three advantages: first, it strengthens the fit (making the structure more compact); second, the pin has threads for quick disassembly; and third, the hole between the valve plate 4 and the valve stem 3 is cylindrical, making it easy to machine. In this embodiment, the set screw 6 is centered, and a set of pin sleeve assemblies 7 are arranged above and below it, so that the fixing structure is evenly distributed within the length range of the valve plate 4 corresponding to the valve stem 3.

[0021] In actual operation, the operator first precisely fixes the relative positions of the valve plate 4 and the valve stem 3 using the set screw 6, ensuring their accurate spatial alignment. Then, a pin hole is machined between the valve plate 4 and the valve stem 3 using a matching drilling process. This process ensures the accuracy and coaxiality of the pin hole, providing favorable conditions for the subsequent installation of the pin sleeve assembly 7. Finally, the pin sleeve assembly 7 is accurately installed into the pin hole, thus completing the stable connection between the valve plate 4 and the valve stem 3. This connection method facilitates quick replacement of the valve plate 4 when needed, effectively shortening equipment maintenance time and improving the operational efficiency of the ship's system.

[0022] As a double eccentric butterfly valve, the positioning of the valve stem 3 and the valve plate 4 must strictly adhere to the eccentricity principle. The proper application of the eccentricity principle can optimize the hydrodynamic performance of the butterfly valve, reduce the impact force of the fluid on the valve plate 4, and thus extend the service life of the butterfly valve. The specific eccentricity dimension needs to be comprehensively considered and precisely set by those skilled in the art based on various factors such as the actual application scenario, fluid characteristics, and system requirements. Given that this part involves complex professional calculations and extensive practical experience, it will not be described in detail here.

[0023] This embodiment is the basic implementation of this solution. Subsequent solutions will continue to evolve and optimize based on this embodiment.

[0024] Example 2 Example 2 represents an innovative improvement upon existing technology. The core improvement lies in the ingenious addition of a thrust washer 8, a crucial component. The thrust washer 8 has a ring-shaped structure and is ingeniously designed to tightly wrap around the outside of the valve stem 3, forming a close and fitted relationship with it. Figure 4 Detailed observation reveals that a mating groove with an L-shaped opening is specifically designed at the lower edge of the inner side of the valve plate 4. The opening of this mating groove faces downward and inward, and its unique shape, precise dimensions, and specific position perfectly match the thrust washer 8. This fitting design lays a solid foundation for subsequent installation and functional realization.

[0025] The thrust washer 8 plays several crucial roles. First, it provides critical height positioning for the valve plate 4. During the operation of the double eccentric butterfly valve, the valve plate 4 needs to operate precisely at a specific height to ensure smooth fluid flow and effective control. The thrust washer 8, through its interaction with the mating groove on the inner side of the valve plate 4, provides stable height support for the valve plate 4, ensuring its accurate position in the height direction and thus guaranteeing the overall stability of the butterfly valve's performance. Second, the thrust washer 8 effectively prevents the valve plate 4 from excessively compressing the valve seat 2 below. During the opening and closing of the butterfly valve, the valve plate 4 moves relative to the valve seat 2. Without the buffering and restraint of the thrust washer 8, the valve plate 4 may exert excessive pressure on the valve seat 2 due to various factors (such as fluid pressure changes, mechanical vibration, etc.), leading to wear and deformation on the surface of the valve seat 2, which in turn affects the sealing performance and service life of the valve seat 2. The thrust washer 8 acts like a buffer, dispersing the pressure of the valve plate 4 on the valve seat 2, preventing excessive compression, and effectively protecting the valve seat 2 from damage.

[0026] During installation, operators must follow strict procedures to ensure the thrust washer 8 performs optimally. First, the thrust washer 8 must be accurately fitted onto the preset position of the valve stem 3. This step requires precise control of the thrust washer 8's position to ensure a perfect fit with the mating groove of the valve plate 4. Next, a trial installation of the valve plate 4 is performed, carefully checking its height. If the valve plate 4 is found to be too high, the operator can lower the thrust washer 8 as needed. This lowering process requires precise measurement and meticulous operation to ensure the lowered height allows the valve plate 4 to reach the appropriate position. Once the valve plate 4 height is adjusted appropriately, its position is fixed. At this point, due to the precise matching relationship between the thrust washer 8 and the mating groove, the position between the lower edge of the valve plate 4 and the valve seat 2 below is relatively fixed. This fixed relationship effectively prevents excessive compression of the valve seat 2 during butterfly valve operation, fundamentally solving the problem of reduced service life caused by excessive wear of the valve seat 2, and greatly improving the reliability and durability of the butterfly valve.

[0027] Furthermore, considering the structural layout of the valve stem 3, both its upper and lower parts extend into the valve body 1. This design enhances the connection stability between the valve stem 3 and the valve body 1, allowing the valve stem 3 to remain stable under various external forces. The middle part of the valve stem 3 passes through the valve plate 4, with only the upper and lower edges of the corresponding valve plate 4 exposed. Considering the marine fluid control field in which this embodiment is applied, the medium passing through the valve is usually corrosive. These corrosive media may erode the exposed parts of the valve stem 3, leading to corrosion and wear on the surface of the valve stem 3 after long-term use, affecting its strength and sealing performance, and consequently impacting the normal operation of the entire butterfly valve. The thrust washer 8 cleverly solves this problem by covering the exposed parts of the valve stem 3, forming an effective protective barrier and reducing direct contact between the corrosive medium and the valve stem 3, thereby significantly reducing the damage caused by corrosion. Even after a period of use, when the thrust washer 8 needs replacement due to prolonged exposure to corrosive media, its simple structure and convenient installation make replacement time and cost economical, minimizing disruption to the ship's normal operation and maintenance. In summary, Example 2, through the addition of the thrust washer 8, achieves significant improvements in valve plate positioning, valve seat protection, and valve stem corrosion prevention, effectively enhancing the performance and reliability of the double eccentric butterfly valve in marine fluid control.

[0028] Same as Example 1.

[0029] Example 3 Based on the technical achievements of Example 2, Example 3 has undergone more in-depth and comprehensive optimization and improvement. The core improvements of this example are mainly reflected in two aspects: first, the valve seat pressure plate 5 is carefully configured; second, the structural design of the valve seat 2 is optimized. Through the synergistic effect of these two aspects, the overall performance and reliability of the double eccentric butterfly valve are significantly improved.

[0030] Specific combination Figure 5 A detailed analysis reveals that the valve seat 2 in this embodiment is designed as a ring structure precisely adapted to the size of the valve plate 4. This design ensures a tight and efficient fit between the valve seat 2 and the valve plate 4, effectively guaranteeing the sealing performance of the butterfly valve. The valve seat 2 is manufactured using a one-piece molding process and consists of two key parts: the valve seat end 2-1 and the valve seat root 2-2. The valve seat end 2-1 is in a ring-shaped enclosure, with its two sides closing together and extending to the right, naturally forming the valve seat root 2-2. Functionally, the valve seat root 2-2 bears the responsibility of fixation, ensuring that the valve seat 2 is securely mounted on the valve body 1, preventing displacement or loosening during butterfly valve operation. The valve seat end 2-1, on the other hand, is a free part, capable of elastic deformation within a certain range to better adapt to the opening and closing actions of the valve plate 4, while maintaining a sealing effect.

[0031] To improve the elasticity of the valve seat end 2-1, enabling it to quickly return to its original shape and maintain good sealing under repeated action of the valve plate 4, an O-ring 2-3 is carefully installed inside the valve seat end 2-1. The O-ring 2-3, with its unique circular cross-section structure, can produce uniform elastic deformation when compressed, thereby filling the tiny gap between the valve seat end 2-1 and the valve plate 4, effectively preventing fluid leakage. In this embodiment, the valve seat end 2-1 and the valve seat root 2-2 are made of RPTFE material, i.e., polytetrafluoroethylene glass fiber. This material has many excellent properties, such as excellent corrosion resistance, resisting the erosion of various strong acids, strong alkalis, and other corrosive media; good high-temperature resistance, maintaining stable physical and chemical properties at high temperatures; and a low coefficient of friction, reducing frictional resistance between the valve seat 2 and the valve plate 4, reducing wear, and extending service life. The O-ring 2-3 is made of FKM material, i.e., fluororubber. Fluororubber also possesses excellent corrosion resistance and high temperature resistance, as well as superior sealing performance and anti-aging properties. It can maintain good elasticity and sealing effect during long-term use, ensuring the reliable operation of the butterfly valve.

[0032] The design of the valve seat pressure plate 5 is another major highlight of this embodiment. The valve seat pressure plate 5 and the valve body 1 are fitted together to form a stable clamping structure, tightly holding the valve seat root 2-2 of the valve seat 2 in the middle. This clamping structure not only provides strong fixing force for the valve seat 2, preventing displacement or deformation under fluid pressure, but also facilitates the installation and disassembly of the valve seat 2, making subsequent maintenance and replacement easier. To further optimize the clamping effect and ensure a tight and secure connection between the valve seat 2, the valve body 1, and the valve seat pressure plate 5, the clamping surfaces of the valve body 1 and the valve seat pressure plate 5 are designed with matching serrated surfaces. See [link to details]. Figure 4 The serrated surface design increases the friction and contact area between the clamping surfaces, making the valve seat 2 less prone to loosening under external force, thereby greatly improving the installation stability and sealing reliability of the valve seat 2.

[0033] In summary, Example 3, through the addition of the valve seat pressure plate 5 and structural optimization of the valve seat 2, achieved significant technological breakthroughs in valve seat fixation, improved sealing performance, and enhanced corrosion resistance. These improvements enable the double eccentric butterfly valve to operate more stably and reliably in the field of marine fluid control, effectively reducing equipment failure rates and maintenance costs, and providing strong support for the safe navigation and efficient operation of ships.

[0034] Same as Example 2.

Claims

1. A long-service-life double eccentric butterfly valve, comprising a valve stem (3) and a valve plate (4), characterized in that, It also includes a first valve stem fixing component and a second valve stem fixing component; The first valve stem fixing member passes through the valve stem (3) and is eccentrically positioned with respect to the valve plate (4); The second valve stem fixing component is detachably and fixedly connected to the valve plate (4).

2. The long-service-life double eccentric butterfly valve according to claim 1, characterized in that, There are at least two second valve stem fixing parts, which are evenly distributed within the length range of the valve stem (3) corresponding to the valve plate (4).

3. The long-service-life double eccentric butterfly valve according to claim 2, characterized in that, The second valve stem fixing component is a pin sleeve assembly (7).

4. A long-service-life double eccentric butterfly valve according to claim 1, 2, or 3, characterized in that, The valve stem (3) is fitted with a thrust washer (8), and the valve plate (4) is fitted with a groove at the corresponding position. The groove is positioned by the thrust washer (8).

5. A long-service-life double eccentric butterfly valve according to claim 4, characterized in that, The thrust washer (8) is located at the exposed position of the valve stem (3).

6. A long-service-life double eccentric butterfly valve according to claim 1, 2, or 3, characterized in that, It also includes a valve body (1), a valve seat (2) and a valve seat pressure plate (5); the valve body (1) and the valve seat pressure plate (5) form a clamping structure to hold the valve seat (2) in the middle.

7. A long-service-life double eccentric butterfly valve according to claim 6, characterized in that, The valve seat (2) includes a valve seat end (2-1) and a valve seat root (2-2); the valve seat root (2-2) is held between the valve body (1) and the valve seat pressure plate (5), and the valve seat end (2-1) is enclosed in an annular shape.

8. A long-service-life double eccentric butterfly valve according to claim 7, characterized in that, The clamping surfaces of the valve body (1) and the valve seat pressure plate (5) are mutually matched sawtooth surfaces.

9. A long-service-life double eccentric butterfly valve according to claim 7, characterized in that, An O-ring (2-3) is installed inside the valve seat end (2-1).

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