Bidirectional isobaric zero-leakage eccentric butterfly valve

Abstract

The utility model relates to the technical field of valves, in particular to a two-way isobaric zero-leakage eccentric butterfly valve, which solves the problem that the service life of a sealing ring of the existing butterfly valve product is not long due to the influence of the structure, and comprises a valve body, the valve rod is arranged in the valve body in a penetrating manner; the butterfly plate is mounted on the valve rod so as to be matched with the valve body to open and close the fluid channel; the valve body is provided with an opening and closing piece used for driving the valve rod to drive the butterfly plate to rotate. The valve rod deviates from the center of the butterfly plate, and the center of the valve rod deviates from the center of the fluid channel; when the butterfly valve is opened, the whole butterfly plate is not in contact with the valve body.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, specifically to a bidirectional equal pressure zero leakage eccentric butterfly valve. Background Technology

[0002] A butterfly valve, also known as a flap valve, is a simple regulating valve that can be used for on / off control of low-pressure pipeline media. A butterfly valve is a type of valve in which the closing element (valve disc or butterfly plate) is a disc that rotates around the valve shaft to achieve opening and closing.

[0003] In the prior art, there are butterfly valves with a linear design, i.e., butterfly valves without eccentricity, such as... Figure 1 As shown, this illustrates the structure in its closed state. Both the valve stem 1' and the butterfly plate 2' are located at the center of the pipeline. The movement path of the butterfly plate 2' is a circular motion trajectory 3' with the valve stem 1' as the center. For example... Figure 2 As shown, this is a commonly used single eccentric butterfly valve structure. The center position of the valve stem 1' is offset from the sealing surface of the valve, and a protrusion 3' is provided on the valve body (or valve seat) to cooperate with the sealing of the butterfly plate 2'.

[0004] However, in the above structure, such as Figure 3 , Figure 4 The diagram shows the state of a linear butterfly valve and a single eccentric butterfly valve when they are open. When this structure is open, the sealing ring on the butterfly plate 2' and the valve body (or valve seat) still have contact points a' and b' located near the two ends of the valve stem 1'. This makes these two points always in a state of friction. The negative effects are not only that it reduces the service life of the sealing ring on the butterfly plate 2', but also that it directly makes it very inconvenient to inspect or replace the sealing ring. Utility Model Content

[0005] Therefore, this utility model provides a bidirectional equal pressure zero leakage eccentric butterfly valve, which solves the problem that the sealing ring of current butterfly valve products has a short service life due to structural influence.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0007] A bidirectional isobaric zero-leakage eccentric butterfly valve includes:

[0008] The valve body has a fluid passage.

[0009] A valve stem, which passes through the valve body;

[0010] A butterfly plate, which is mounted on the valve stem to cooperate with the valve body to open and close the fluid passage;

[0011] The valve body is provided with an opening and closing component for driving the valve stem to rotate the butterfly plate;

[0012] The valve stem is positioned off-center from the center of the butterfly plate, and the center of the valve stem is offset from the center of the fluid passage.

[0013] When the butterfly valve is opened, the butterfly plate is not in contact with the valve body.

[0014] Preferably, the valve body is provided with a sealing surface that seals with the butterfly plate, and a sealing element for sealing with the sealing surface is installed on the butterfly plate by a sealing pressure plate. The cross-section of the sealing element has an embedded part that is embedded between the butterfly plate and the sealing pressure plate and an extension part that extends outward to contact the sealing surface.

[0015] When the butterfly valve is closed, the extension comes into contact with the sealing surface, and the side of the extension near the sealing plate forms a breathing chamber for fluid to enter.

[0016] Preferably, the sealing surface is provided with a copper alloy or a nickel-chromium alloy.

[0017] Preferably, the valve stem includes an upper valve stem located at the upper end of the butterfly plate and a lower valve stem located at the lower end of the butterfly plate.

[0018] Preferably, the butterfly plates are respectively inserted into the upper valve stem and the lower valve stem, and are fixedly connected by at least one locating pin.

[0019] Preferably, the opening and closing element is a worm gear assembly.

[0020] Preferably, the opening and closing element is connected to a handwheel that drives its transmission.

[0021] By adopting the aforementioned technical solution, the beneficial effects of this utility model are:

[0022] This technical solution designs a different eccentric structure, unlike traditional non-eccentric and eccentric butterfly valve designs. When the butterfly valve is opened, the entire butterfly plate does not contact the valve body at the sealing position. This allows the seals on the butterfly plate to be in a free state without force when the valve is opened, reducing the time the seals are under force and thus extending their service life. At the same time, during maintenance, the seals in the free state are easy to inspect and replace without disassembling the entire butterfly plate. This makes the valve flexible in use and facilitates maintenance and initial installation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a linear butterfly valve when it is closed (valve stem axial direction);

[0024] Figure 2 This is a schematic diagram of the structure of a linear butterfly valve when it is open (valve stem vertical direction);

[0025] Figure 3This is a schematic diagram of the existing eccentric butterfly valve in its closed state (valve stem axis).

[0026] Figure 4 This is a schematic diagram of the existing eccentric butterfly valve in its open state (valve stem vertical direction);

[0027] Figure 5 This is a schematic diagram of the butterfly valve in an embodiment of the present invention;

[0028] Figure 6 for Figure 5 A magnified schematic diagram of the local structure at point A;

[0029] Figure 7 This is a schematic diagram of the butterfly valve's closed state in an embodiment of this utility model;

[0030] Figure 8 This is a schematic diagram of the butterfly valve's state when it is open, according to an embodiment of this utility model.

[0031] Reference numerals: 1. Valve stem; 11. Bottom cover; 12. Gland; 13. Locating pin; 2. Butterfly plate; 21. Sealing pressure plate; 22. Sealing element; 221. Embedded part; 222. Extension part; 223. Breathing chamber; 3. Valve body; 31. Sealing surface; 4. Opening and closing element; 41. Handwheel. Detailed Implementation

[0032] The following will describe the implementation of this utility model in detail with reference to specific embodiments, so that the process of how this utility model uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0033] Example

[0034] refer to Figures 5 to 8 A bidirectional isobaric zero-leakage eccentric butterfly valve, comprising:

[0035] Valve body 3, wherein a fluid passage is formed inside the valve body 3;

[0036] A valve stem 1 is inserted into the valve body 3. The valve stem 1 includes an upper valve stem 1 located at the upper end of the butterfly plate 2 and a lower valve stem 1 located at the lower end of the butterfly plate 2. The split structure of the valve stem 1 facilitates installation. The lower valve stem 1 is inserted through an opening at the bottom and fixed by a bottom cover 11. The upper valve stem 1 is fixed by a pressure cover 12, and the upper end of the upper valve stem 1 continues to extend upward. Specifically, the butterfly plate 2 is respectively inserted into the upper valve stem 1 and the lower valve stem 1, and fixedly connected by at least one positioning pin 13. The upper valve stem 1 adopts a structure with two positioning pins 13 to achieve a double positioning and fixing structure, ensuring installation accuracy.

[0037] The butterfly plate 2 is mounted on the valve stem 1 to cooperate with the valve body 3 to open and close the fluid passage; specifically, the valve body 3 is provided with a sealing surface 31 that seals with the butterfly plate 2, and a sealing element 22 for sealing with the sealing surface 31 is installed on the butterfly plate 2 by a sealing pressure plate 21. The cross-section of the sealing element 22 has an embedded portion 221 that is embedded between the butterfly plate 2 and the sealing pressure plate 21 and an extension portion 222 that extends outward to contact the sealing surface 31.

[0038] The valve body 3 is provided with an opening and closing component 4 for driving the valve stem 1 to rotate the butterfly plate 2; wherein, the opening and closing component 4 is a worm gear assembly; the worm gear assembly is connected to a handwheel 41 for driving its transmission, and the valve is opened and closed by rotating the handwheel 41; this embodiment shows the most basic structure of the valve, and the above structure can also be replaced with corresponding known structures, using electric control opening and closing or other transmission structures, etc.

[0039] Structurally, the valve stem 1 is offset from the center of the butterfly plate 2, and the center of the valve stem 1 is offset from the center of the fluid passage; with this design, when the butterfly valve is opened, the butterfly plate 2 as a whole does not contact the valve body 3; this non-contact means, for example... Figure 7 , Figure 8 As shown, when the butterfly plate 2 rotates, it deviates from the traditional eccentric butterfly valve's movement trajectory 3'. After opening, the butterfly plate 2 moves as a whole away from the sealing surface 31 to achieve a structure in which the whole does not contact the valve body 3. Fluid can also pass through the upper and lower ends of the butterfly plate 2. This structure adopts an optimized double eccentric structure design. When the opening angle is very small, the butterfly plate 2 has already separated from the valve body 3, and the sealing element 22 is no longer under force and relaxes, reducing the friction of the sealing element 22 and extending the service life of the valve.

[0040] The structure of the seal 22 and the installation structure of the butterfly plate 2 are designed such that when the butterfly valve is closed, the extension 222 contacts the sealing surface 31, and the side of the extension 222 near the sealing pressure plate 21 forms a breathing chamber 223 for fluid to enter; in actual use, a bidirectional pressure bearing design is formed: the design of the seal 22 ensures bidirectional 1:1 equal pressure bearing when the valve plate is closed;

[0041] In principle:

[0042] Forward sealing relies on the worm gear assembly to drive the valve stem 1 to rotate, and the sealing element 22 on the transmission butterfly plate 2 gradually comes into contact with the sealing surface 31 of the valve body 3. Finally, under the action of the medium pressure, the butterfly plate 2 is pushed and the rubber expands until it is completely in contact, thus achieving a complete seal.

[0043] Reverse sealing relies on the medium to achieve the sealing effect. When the medium pressure acts on the breathing chamber 223 formed between the outer extension 222 of the sealing surface 31 and the valve body 3, the extension 222 expands under the medium pressure, gradually fitting with the valve body 3 until it is completely sealed. The greater the reverse pressure, the better the reverse sealing effect, the more reliable the sealing, the less torque, and the easier the opening and closing.

[0044] Meanwhile, a structural design was also implemented for the sealing surface 31: a copper alloy or nickel-chromium alloy was provided on the sealing surface 31. During production, a welding process was used to configure the copper alloy or nickel-chromium alloy, which greatly reduced the coefficient of friction between the sealing element 22 and the sealing surface 31, reduced friction on the sealing surface 31, improved the service life of the sealing element 22, extended the service life of the valve, and reduced torque.

[0045] This technical solution designs a different eccentric structure, unlike traditional non-eccentric and eccentric butterfly valve designs. When the butterfly valve is opened, the entire butterfly plate 2 does not contact the valve body 3 at the sealing position. This makes the sealing element 22 on the butterfly plate 2 in a free state without force when it is opened. The sealing element 22 is reduced in the time it is under force, thereby extending its service life. At the same time, during maintenance, the sealing element 22 in the free state is easy to maintain and replace without disassembling the entire butterfly plate 2. It is flexible in use and easy to maintain and use in the initial installation.

[0046] This technical solution does not describe other necessary components of the valve, such as bearings and bushings for rotating the valve stem 1, as these are not the main improvement points of this technology. However, in production, in order to further improve the service life, all valve fasteners can be made of stainless steel during material selection, which avoids corrosion of the fasteners due to oxidation reaction with air, thus preventing them from becoming a factor affecting the valve's service life.

[0047] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. A bidirectional isobaric zero-leakage eccentric butterfly valve, comprising: A valve body (3) has a fluid passage inside it; Valve stem (1), which passes through the valve body (3); A butterfly plate (2) is mounted on the valve stem (1) to cooperate with the valve body (3) to open and close the fluid passage; The valve body (3) is provided with a sealing surface (31) that seals with the butterfly plate (2), and the valve body (3) is provided with an opening and closing element (4) for driving the valve stem (1) to drive the butterfly plate (2) to rotate; Its features are: The valve stem (1) is positioned off-center from the center of the butterfly plate (2), and the center of the valve stem (1) is offset from the center of the fluid channel; When the butterfly valve is opened, the butterfly plate (2) is not in contact with the valve body (3).

2. The bidirectional isobaric zero-leakage eccentric butterfly valve according to claim 1, characterized in that: The valve body (3) is provided with a sealing surface (31) that seals with the butterfly plate (2). A sealing element (22) for sealing with the sealing surface (31) is installed on the butterfly plate (2) by a sealing pressure plate (21). The cross section of the sealing element (22) has an embedded part (221) that is embedded between the butterfly plate (2) and the sealing pressure plate (21) and an extension part (222) that extends outward to contact the sealing surface (31). When the butterfly valve is closed, the extension (222) contacts the sealing surface (31), and the side of the extension (222) near the sealing plate (21) forms a breathing chamber (223) for fluid to enter.

3. The bidirectional isobaric zero-leakage eccentric butterfly valve according to claim 2, characterized in that: The sealing surface (31) is provided with a copper alloy or a nickel-chromium alloy.

4. The bidirectional isobaric zero-leakage eccentric butterfly valve according to claim 1, characterized in that: The valve stem (1) includes an upper valve stem (1) located at the upper end of the butterfly plate (2) and a lower valve stem (1) located at the lower end of the butterfly plate (2).

5. A bidirectional isobaric zero-leakage eccentric butterfly valve according to claim 4, characterized in that: The butterfly plate (2) is respectively inserted and installed on the upper valve stem (1) and the lower valve stem (1), and is fixedly connected by at least one positioning pin (13).

6. A bidirectional isobaric zero-leakage eccentric butterfly valve according to any one of claims 1-5, characterized in that: The opening and closing component (4) is a worm gear assembly.

7. A bidirectional isobaric zero-leakage eccentric butterfly valve according to any one of claims 1-5, characterized in that: The opening and closing component (4) is connected to a handwheel (41) that drives its transmission.

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