A double eccentric butterfly valve of monolithic forging

Abstract

The utility model relates to a kind of integral forging type double eccentric butterfly valves, it includes valve body, sealing ring and pressure ring, butterfly plate and valve rod, the valve body is the integral forging structure without weld joint, radial self-tightening structure is equipped between the butterfly plate and sealing ring, sealing ring is fixed in valve body export side by pressure ring, the edge of sealing ring side towards butterfly plate is equipped with pressure receiving bevel, the edge of butterfly plate side towards sealing ring is equipped with pressure exerting bevel;When butterfly plate is closed to sealing ring, the pressure exerting bevel extrudes pressure receiving bevel, forces sealing ring to produce radial expansion deformation, so that sealing ring outer wall is tightly attached to valve body inner cavity.This integral forging type double eccentric butterfly valve is designed by valve body integral forging structure and radial self-tightening structure, and valve rod support and stuffing box assembly design, significantly improve the reliability, sealing performance and service life of butterfly valve under high pressure, severe working condition, and reduce maintenance requirement.

Description

Technical Field

[0001] This utility model relates to the field of fluid control equipment technology, specifically to an integral forged double eccentric butterfly valve suitable for high pressure differential conditions. Background Technology

[0002] Butterfly valves are widely used in industrial pipelines due to their simple structure, rapid opening and closing, and low flow resistance. Among them, the double eccentric butterfly valve, with its unique eccentric structure, allows the valve plate and seat to quickly separate or press together during opening and closing, effectively reducing friction and wear on the sealing surface. However, existing double eccentric butterfly valves have the following problems when facing complex operating conditions such as high pressure differentials and harsh media:

[0003] (1) Insufficient valve body reliability: Traditional butterfly valve bodies are mostly manufactured using casting or welding processes. Cast valve bodies are prone to defects such as sand holes, air holes, and shrinkage, which affect the strength and sealing performance of the valve body. Welded valve bodies may have weld defects, which pose leakage risks and safety hazards under high pressure, making it difficult to meet the reliability requirements of high-pressure working conditions.

[0004] (2) Limitations in sealing performance: Under high pressure, the sealing components of traditional butterfly valves are prone to deformation or failure, making it difficult to achieve reliable zero leakage. Furthermore, the sealing rings are easily eroded and worn, which reduces the overall sealing performance and lifespan of the valve.

[0005] (3) Valve stem eccentricity and wear: Under the impact of high pressure differential medium, the valve plate is easily subjected to unbalanced torque, which causes the valve stem to bear eccentricity. Long-term operation will cause the wear of the valve stem and supporting components to intensify, affecting the stability of the valve plate and the centering of the seal, thereby shortening the service life of the valve.

[0006] (4) Short life of packing seal: As an important dynamic sealing component, the valve stem packing gland is subjected to uneven stress and wears quickly in the existing design, which leads to seal failure and requires frequent maintenance, increasing operating costs. Utility Model Content

[0007] The technical problem to be solved by this invention is: the invention aims to overcome the problems of insufficient valve body reliability, limited sealing performance, valve stem eccentric wear, and short packing seal life in the existing high-pressure butterfly valve, and to provide an integral forged double eccentric butterfly valve with more reliable structure, better sealing performance, longer service life and easy maintenance.

[0008] This integral forged double eccentric butterfly valve includes a valve body with an inner cavity forming the main flow channel, a sealing ring and a pressure ring disposed on the outlet side of the valve body, a butterfly plate disposed within the valve body for sealing the sealing ring, and a valve stem for driving the butterfly plate. The valve body is an integral forged structure without welds. A radial self-tightening structure is provided between the butterfly plate and the sealing ring. The sealing ring is fixed to the outlet side of the valve body by the pressure ring. The edge of the sealing ring facing the butterfly plate has a pressure-receiving slope, and the edge of the butterfly plate facing the sealing ring has a pressure-applying slope. When the butterfly plate closes towards the sealing ring, the pressure-applying slope compresses the pressure-receiving slope, forcing the sealing ring to undergo radial expansion deformation, so that the outer wall of the sealing ring is tightly attached to the inner cavity of the valve body, achieving radial self-tightening sealing.

[0009] Furthermore, the angles of both the pressure-applying inclined plane and the pressure-receiving inclined plane are 15±1°.

[0010] In the optimized configuration, the valve stem is supported within the valve body by two valve stem bushings, which are respectively located on the upper and lower sides of the butterfly plate. The line connecting the centers of the two valve stem bushings intersects perpendicularly with the axis of the valve body flow channel.

[0011] In an optimized configuration, a stuffing box assembly is provided between the valve stem and the valve body. The stuffing box assembly includes a stuffing plate, a stuffing pad, and multiple layers of packing disposed between the stuffing plate and the stuffing pad. A pressure dispersion groove is provided between the multiple layers of packing and the stuffing plate.

[0012] Furthermore, the multilayer packing is a three-layer PTFE packing with thicknesses of 4mm, 3.5mm, and 3mm from top to bottom, respectively.

[0013] Specifically, the radial offset between the valve stem axis and the valve body flow channel axis is 8%-10% of the flow channel diameter; the axial offset between the butterfly plate and the valve stem axis is 15%-20% of the valve plate thickness.

[0014] This utility model discloses an integral forged double eccentric butterfly valve, which significantly improves the reliability, sealing performance and service life of the butterfly valve under high pressure and harsh working conditions, and reduces maintenance requirements, through the design of the integral forged valve body structure and radial self-tightening structure, as well as the design of valve stem support and stuffing box assembly. Attached Figure Description

[0015] The following description, in conjunction with the accompanying drawings, further illustrates an integral forged double eccentric butterfly valve of this utility model:

[0016] Figure 1 This is a schematic diagram of the main plan view of this integral forged double eccentric butterfly valve;

[0017] Figure 2 yes Figure 1 A schematic diagram of the longitudinal section structure;

[0018] Figure 3This is a partial structural diagram of the radial self-tightening structure of the integral forged double eccentric butterfly valve.

[0019] Figure 4 yes Figure 2 Enlarged view of the local structure of part A in the middle.

[0020] In the picture:

[0021] 1-Valve body;

[0022] 2-Sealing ring; 21-Pressure slope;

[0023] 3-Pressure ring;

[0024] 4-Butterfly plate; 41-Pressure slope;

[0025] 5-Valve stem; 51-Valve stem sleeve; 52-Stuffing box assembly; 521-Stuffing plate; 522-Stuffing pad; 523-Multi-layer packing; 524-Pressure dispersion groove. Detailed Implementation

[0026] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0027] In the description of this utility model, it should be understood that the terms "left", "right", "front", "rear", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0028] The present invention will be further described below with specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments.

[0029] Implementation method 1: such as Figures 1 to 3As shown, this integral forged double eccentric butterfly valve includes a valve body 1 with an inner cavity forming the main flow channel, a sealing ring 2 and a pressure ring 3 disposed on the outlet side of the valve body 1, a butterfly plate 4 disposed inside the valve body 1 for sealing the sealing ring 2, and a valve stem 5 for driving the butterfly plate 4. The valve body 1 is an integral forged structure without welds. A radial self-tightening structure is provided between the butterfly plate 4 and the sealing ring 2. The sealing ring 2 is fixed to the outlet side of the valve body 1 by the pressure ring 3. The edge of the sealing ring 2 facing the butterfly plate 4 is provided with a pressure-receiving slope 21, and the edge of the butterfly plate 4 facing the sealing ring 2 is provided with a pressure-applying slope 41. When the butterfly plate 4 closes to the sealing ring 2, the pressure-applying slope 41 squeezes the pressure-receiving slope 21, forcing the sealing ring 2 to undergo radial expansion deformation, so that the outer wall of the sealing ring 2 is tightly attached to the inner cavity of the valve body 1, thereby achieving radial self-tightening sealing. Unlike traditional cast or welded valve bodies, the integral forged valve body 1 is formed in one piece through a forging process. Its internal grain structure is denser and more uniform, eliminating casting defects (such as sand holes and porosity) and welding stress concentration, thus significantly improving the valve body's strength, toughness, and pressure resistance. The integral forging structure design allows the valve body 1 to withstand higher pipeline medium pressures, making operation safer and more reliable under high-pressure conditions and greatly reducing the risk of leakage. The radial self-tightening structure formed between the top edges of the butterfly plate 4 and the sealing ring 2, when the butterfly plate 4 closes towards the sealing ring 2, causes the pressure-applying inclined surface 41 to compress the pressure-receiving inclined surface 21, forcing the sealing ring 2 to undergo radial expansion deformation, making its outer wall tightly fit against the inner cavity of the valve body 1, thereby achieving a radial self-tightening seal. This radial self-tightening structure design also utilizes the effect of medium pressure; the higher the pressure, the greater the clamping force between the sealing ring 2 and the inner cavity of the valve body 1, resulting in a more reliable sealing effect. This effectively solves the problem of easy leakage under high pressure with traditional seals and improves the overall sealing performance of the valve. The angles of the pressure-applying inclined surface 41 and the pressure-receiving inclined surface 21 are both 15±1°. The optimally designed 15°±1° angle ensures radial self-tightening while minimizing friction between the butterfly plate 4 and the sealing ring 2 during closure. It also optimizes the efficiency of radial expansion deformation of the sealing ring 2, achieving the best balance between sealing force and operating force. This further enhances the reliability and durability of the seal, reduces resistance during operation, and extends the service life of the sealing surface.

[0030] Implementation method 2: such as Figure 2As shown, in this integral forged double eccentric butterfly valve, the valve stem 5 is supported within the valve body 1 by two valve stem bushings 51. The two valve stem bushings 51 are respectively located on the upper and lower sides of the butterfly plate 4, and the line connecting the centers of the two valve stem bushings 51 intersects perpendicularly with the flow channel axis of the valve body 1. By directly placing the two valve stem bushings 51 on the upper and lower sides of the butterfly plate 4, making them as close as possible to the center of gravity and stress point of the butterfly plate 4, a more direct and stable support for the valve stem 5 is provided. The compact and balanced support layout minimizes the deflection and sway of the valve stem 5 under high-speed fluid or high pressure differential, ensuring the concentricity of the valve stem 5, greatly enhancing the operational stability of the valve under complex working conditions, and further reducing the wear of the valve stem 5, bushings 51, and seals, thereby significantly extending the service life and reliability of the entire valve.

[0031] Implementation method 3: such as Figure 2 As shown, this integral forged double eccentric butterfly valve has a stuffing box assembly 52 between the valve stem 5 and the valve body 1. The stuffing box assembly includes a stuffing plate 521, a stuffing pad 522, and multi-layer packing 523 disposed between the stuffing plate and the stuffing pad. A pressure dispersion groove 524 is provided between the multi-layer packing 523 and the stuffing plate 521. The stuffing box assembly 52 serves as a dynamic seal between the valve stem 5 and the external environment. By setting up multi-layer packing 523, a longer sealing path and better media barrier capability are provided. The pressure dispersion groove 524 at the bottom of the stuffing plate 521 ensures that the clamping force can be more evenly distributed on the multi-layer packing 523, avoiding local overpressure or underpressure, thereby significantly improving the sealing efficiency and durability of the packing 523, effectively preventing leakage at the valve stem 5, and greatly extending the replacement cycle of the packing 523, reducing maintenance costs. The multi-layer packing 523 is a three-layer PTFE packing with thicknesses of 4mm, 3.5mm, and 3mm from top to bottom. PTFE (polytetrafluoroethylene) is used as a packing material, exhibiting excellent corrosion resistance, high-temperature resistance, and a low coefficient of friction. Using three layers of PTFE packing 523 of varying thicknesses, decreasing in thickness from top to bottom, creates a gradient sealing structure. This structure better accommodates the minute deformations of the valve stem 5 during compression, providing superior elastic recovery and more durable sealing performance. The optimized combination of thicknesses allows the packing 523 to maintain a highly efficient seal under high pressure differentials, further enhancing the reliability and lifespan of the valve operation.

[0032] Implementation method 4: such as Figure 1As shown, in this integral forged double eccentric butterfly valve, the radial offset between the valve stem 5 axis and the flow channel axis of the valve body 1 is 8%-10% of the flow channel diameter; the axial offset between the butterfly plate 4 and the valve stem 5 axis is 15%-20% of the valve plate thickness. This is a common structural design for double eccentric butterfly valves. The radial offset of 8%-10% ensures that the butterfly plate 4 can quickly and completely disengage from the sealing ring 2 when opening, reducing friction; the axial offset of 15%-20% ensures that the butterfly plate 4 can accurately press the sealing ring 2 when closing, forming a reliable seal, while further reducing the wear of the sealing surface during opening and closing. The eccentricity design is the result of experiments during the development of this butterfly valve. Under this value, the butterfly valve achieves an optimal balance between opening and closing torque, sealing performance, and service life, improving the overall performance of the valve.

[0033] In use: Turn the handwheel or activate the actuator (not shown, connected to...) Figure 1 , 2 The actuator drives the valve stem 5 to rotate. With the stable support of the valve stem sleeve 51, the valve stem 5 drives the butterfly plate 4 to rotate. Due to its double eccentric design, the butterfly plate 4 can quickly disengage from the sealing ring 2 upon opening, reducing friction. During closing, the butterfly plate 4 smoothly presses against the sealing ring 2. When the butterfly plate 4 closes towards the sealing ring 2, the pressure-applying inclined surface 41 on the butterfly plate 4 squeezes the pressure-receiving inclined surface 21 on the sealing ring 2, forcing the sealing ring 2 to undergo radial expansion deformation, causing its outer wall to tightly fit against the inner cavity of the valve body 1, achieving radial self-tightening sealing and ensuring zero leakage. Simultaneously, the multi-layer packing 523 within the stuffing box provides a uniform and reliable dynamic seal under the action of the pressure dispersion groove 524, ensuring the sealing performance when the valve stem 5 rotates. The integral forging structure of the entire valve body 1 ensures the structural integrity and long-term reliable operation of the valve under high pressure.

[0034] This integral forged double eccentric butterfly valve significantly improves its reliability, sealing performance, and service life under high pressure and harsh conditions, while reducing maintenance requirements, through its integral forged valve body structure, radial self-tightening structure design, and valve stem support and stuffing box assembly design. Specifically:

[0035] (1) By adopting a seamless integral forged valve body structure, casting or welding defects are effectively avoided, significantly improving the strength, pressure resistance and overall reliability of the valve body, making it suitable for more demanding high-pressure conditions.

[0036] (2) Through the radial self-tightening structure between the butterfly plate and the sealing ring, the sealing ring expands radially when closed and under pressure, and fits tightly against the valve body cavity, thus achieving the effect of tighter sealing with higher pressure, effectively improving the sealing reliability of the valve and the service life of the sealing components.

[0037] (3) The valve stem is stably supported on the two valve stem bushings and positioned perpendicular to the flow channel axis. The valve stem bushings are set on the upper and lower sides of the butterfly plate, which effectively resists the eccentric load of the medium fluid on the valve stem, ensures the stability of valve stem operation, reduces the wear of valve stem and bushing, and extends service life.

[0038] (4) Through the multi-layer packing design and the pressure dispersion groove at the bottom of the packing plate, the packing is subjected to uniform force and has a better sealing effect, which significantly extends the service life and maintenance cycle of the packing and reduces the operating cost.

[0039] The above description illustrates the main features, basic principles, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments or examples described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the above embodiments or examples should be considered exemplary and not restrictive. The scope of this utility model is defined by the appended claims rather than the foregoing description, and therefore all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0040] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An integral forged double eccentric butterfly valve, comprising a valve body (1) with an inner cavity forming a main flow channel, a sealing ring (2) and a pressure ring (3) disposed on the outlet side of the valve body (1), a butterfly plate (4) disposed within the valve body (1) for sealing the sealing ring (2), and a valve stem (5) for driving the butterfly plate (4), characterized in that: The valve body (1) is a seamless integral forging structure, and a radial self-tightening structure is provided between the butterfly plate (4) and the sealing ring (2); The sealing ring (2) is fixed to the outlet side of the valve body (1) by the pressure ring (3). The edge of the sealing ring (2) facing the butterfly plate (4) is provided with a pressure-receiving slope (21), and the edge of the butterfly plate (4) facing the sealing ring (2) is provided with a pressure-applying slope (41). When the butterfly plate (4) closes to the sealing ring (2), the pressure-applying slope (41) squeezes the pressure-receiving slope (21), forcing the sealing ring (2) to undergo radial expansion deformation, so that the outer wall of the sealing ring (2) is tightly attached to the inner cavity of the valve body (1), thereby achieving radial self-tightening sealing.

2. The integral forged double eccentric butterfly valve according to claim 1, characterized in that: The angles of the pressure-applying inclined plane (41) and the pressure-receiving inclined plane (21) are both 15±1°.

3. The integral forged double eccentric butterfly valve according to claim 2, characterized in that: The valve stem (5) is supported in the valve body (1) by two valve stem bushings (51). The two valve stem bushings (51) are respectively set on the upper and lower sides of the butterfly plate (4), and the line connecting the centers of the two valve stem bushings (51) intersects perpendicularly with the flow channel axis of the valve body (1).

4. The monoblock double eccentric butterfly valve according to claim 3, characterized in that: A stuffing box assembly (52) is provided between the valve stem (5) and the valve body (1). The stuffing box assembly includes a stuffing plate (521), a stuffing pad (522), and a multi-layer packing (523) disposed between the stuffing plate and the stuffing pad. A pressure dispersion groove (524) is provided between the multi-layer packing (523) and the stuffing plate (521).

5. The integral forged double eccentric butterfly valve according to claim 4, characterized in that: The multilayer packing (523) is a three-layer PTFE packing with thicknesses of 4mm, 3.5mm and 3mm from top to bottom.

6. The monoblock double eccentric butterfly valve according to any one of claims 1 to 5, characterized in that: The radial offset between the axis of the valve stem (5) and the axis of the flow channel of the valve body (1) is 8%-10% of the flow channel diameter; the axial offset between the butterfly plate (4) and the axis of the valve stem (5) is 15%-20% of the valve plate thickness.

Images