Leak-proof butterfly valve

Abstract

Aiming at the problems of poor sealing effect between a valve rod and a valve body of a butterfly valve in the prior art, easiness in leakage, higher cost and inconvenience in installation, the utility model provides the leak-proof butterfly valve, a filler between the valve rod and the valve body consists of a head filler part, a plurality of middle filler parts and a tail filler part, and the adjacent filler parts are connected in an inserting manner through a lug boss and a groove, so that the valve rod and the valve body are connected in a sealing manner. Due to the fact that the angle of the protruding part is larger than the angle of the groove where the protruding part is inserted, the middle packing piece and the tail packing piece can be opened under the atmospheric pressure, the sealing effect is good and the anti-leakage capacity is high under the scene that the butterfly valve is connected with a vacuum system, and compared with a traditional water seal structure, the water seal structure is more economical and convenient to install.

Description

Technical Field

[0001] This utility model belongs to the field of valve technology, and in particular relates to a leak-proof butterfly valve. Background Technology

[0002] Butterfly valves are a common type of valve, mainly used in pipelines to open or close or regulate the flow of media.

[0003] In existing technology, a butterfly valve consists of a valve body with an annular radial cross-section, a disc located in the flow channel of the valve body, a valve stem for rotating the disc under the drive of an actuator to open or close the flow channel, a valve seat for forming a sealing surface with the disc, and an insert for pressing the valve seat. In order to prevent leakage of the butterfly valve, a sealing medium is usually provided between the valve stem and the valve body, such as packing or a water seal. In scenarios where the butterfly valve is connected to a vacuum system (such as the condenser connected to the circulating cooling water system of a nuclear power plant), the sealing effect of packing is not good and leakage is easy. Although the sealing effect of water seal is better than that of packing, it is more expensive and inconvenient to install. Utility Model Content

[0004] Based on this, a leak-proof butterfly valve is provided to address the aforementioned technical problems.

[0005] The technical solution adopted in this utility model is as follows:

[0006] A leak-proof butterfly valve includes a valve body with an annular radial cross-section, a disc located within a flow channel of the valve body, a valve stem for rotating the disc under the drive of an actuator to open or close the flow channel, a valve seat for forming a sealing surface with the disc, and an insert for pressing the valve seat. The valve body has an upper channel and a lower channel opposite to each other. The lower end of the valve stem passes through the upper channel and the disc sequentially to the lower channel. A sealing medium is provided between the upper channel and the valve stem. The valve stem and the disc are fixed by a connecting pin passing through them. The sealing medium is packing material, which includes an upper packing structure and a lower packing structure. Both the upper and lower packing structures include a head packing element, multiple middle packing elements, and a tail packing element. The head packing element and the middle packing elements... Both the head and tail packing components are annular. The rear end face of the head packing component is flat, and the front end face forms a ring of triangular protrusions with an axial cross-section. The rear end face of the middle packing component forms a ring of triangular grooves with an axial cross-section, and the front end face forms a ring of triangular protrusions with an axial cross-section. The rear end face of the tail packing component forms a ring of triangular grooves with an axial cross-section, and the front end face is flat. The head packing component, multiple middle packing components, and tail packing components of the upper packing structure are arranged sequentially from top to bottom, with the front end face of each packing component facing downwards. The head packing component, multiple middle packing components, and tail packing components of the lower packing structure are arranged sequentially from bottom to top, with the front end face of each packing component facing upwards. Adjacent packing components are inserted through the protrusions and grooves, and the angle of the protrusion is greater than the angle of the corresponding groove.

[0007] The packing between the valve stem and the valve body of this utility model consists of a head packing element, multiple middle packing elements, and a tail packing element. Adjacent packing elements are connected by protrusions and grooves. Since the angle of the protrusion is greater than the angle of the groove into which it is inserted, the middle and tail packing elements will be pushed apart under atmospheric pressure. This results in a good sealing effect and strong leakage prevention capability in the scenario where the butterfly valve is connected to a vacuum system. Compared with the traditional water seal structure, it is more economical and easier to install. Attached Figure Description

[0008] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments:

[0009] Figure 1 An axial sectional view of a leak-proof butterfly valve provided in an embodiment of this utility model;

[0010] Figure 2 for Figure 1 A schematic diagram of the right-side view structure;

[0011] Figure 3 This is a radial sectional view of the valve body according to an embodiment of the present utility model;

[0012] Figure 4 for Figure 1 A magnified view of a portion at point A;

[0013] Figure 5 This is a three-dimensional structural diagram of the disc plate according to an embodiment of the present utility model;

[0014] Figure 6 for Figure 1 A transverse sectional view showing the valve stem and disc tubes fixed by connecting pins;

[0015] Figure 7 for Figure 1 A magnified view of a section at point B. Detailed Implementation

[0016] The embodiments of this utility model will be described below with reference to the accompanying drawings. It should be noted that the embodiments described in this specification are not exhaustive and do not represent the only embodiments of this utility model. The following corresponding embodiments are only for clearly illustrating the utility model content of this patent and are not intended to limit its implementation. For those skilled in the art, different variations and modifications can be made based on the described embodiments. Any obvious variations or modifications that fall within the technical concept and utility model content of this utility model are also within the protection scope of this utility model.

[0017] like Figure 1 As shown in the figure, this application provides a leak-proof butterfly valve, including a valve body 110, a disc 120, a valve stem 130, a valve seat 140, and an insert 150.

[0018] The valve body 110 has an annular radial cross-section, with an internal flow channel 111, and flanges on both the front and back sides. Figure 1 The flow direction of the medium in the flow channel 111 is shown, where "front" refers to the side of the valve body 110 from which the medium is output. Figure 1 The right side of the valve body 110 refers to the opposite side (in the middle). Figure 1 (Left side of the middle).

[0019] like Figure 3 As shown, the valve body 110 has an upper channel 112 and a lower channel 113 that are opposite each other. The upper channel 112 is formed on the seat 114 and is passed through by the valve stem 130. The lower channel 113 is a blind hole, which can reduce leakage points compared with the through hole in the prior art.

[0020] like Figure 3 As shown, the upper channel 112 has a step, dividing it into an upper section 112a and a lower section 112b. The upper section 112a is wider than the lower section 112b. Packing 160 is provided between the upper section 112a and the valve stem 130. (See also...) Figure 1 ,like Figure 2 and Figure 4As shown, the packing 160 is pressed onto the step of the upper channel 112 by the packing cover 115. The packing cover 115 is passed through by the valve stem 130 and is fixed to the seat 114 by two left and right fixing bolts 116. Figure 2 As shown, multiple elastic washers 116b are provided between the packing cover 115 and the nut 116a of the fixing bolt 116. The elastic washers 116b are pre-compressed by the nut 116a. When the internal and external pressure difference changes, the elastic washers 116b can adaptively rebound to compensate, ensuring that the packing cover 115 presses down on the packing 160.

[0021] The packing 160 is divided into an upper packing structure and a lower packing structure. In this embodiment, as shown... Figure 4 As shown, both the upper and lower packing structures include one head packing element 161, three middle packing elements 162, and one tail packing element 163. The head packing element 161, middle packing elements 162, and tail packing element 163 are all annular. The rear end face of the head packing element 161 and the front end face of the tail packing element 163 are both planar. The front end face of the head packing element 161 and the front end face of the middle packing element 162 each form a ring of protrusions 164 with an axial cross-section of an equilateral triangle. The top angle of the protrusion 164 is 90 degrees. The rear end face of the middle packing element 162 and the rear end face of the tail packing element 163 each form a ring of grooves with an axial cross-section of an equilateral triangle. The bottom angle of the groove is 70 degrees.

[0022] Based on the above structure, the upper packing structure has one head packing element 161, three middle packing elements 162 and one tail packing element 163 arranged from top to bottom, with the front end face of each packing element facing down. The lower packing structure has one head packing element 161, three middle packing elements 162 and one tail packing element 163 arranged from bottom to top, with the front end face of each packing element facing up. Adjacent packing elements are connected by protrusions 164 and grooves.

[0023] For the upper packing structure, since the angle of the protrusion 164 is greater than the angle of the groove into which it is inserted, the three middle packing pieces 162 and one tail packing piece 163 will be pushed open under atmospheric pressure, resulting in a good sealing effect. Compared with the traditional water seal structure, it is more economical and easier to install.

[0024] The lower packing structure is the opposite of the upper packing structure. This is to facilitate the installation of the packing. If all the packing adopts the upper packing structure, the lower packing pieces will be tighter to the upper passage 112 and valve stem 130, making it difficult to complete the packing.

[0025] like Figure 2As shown, the base 114 has a support frame 114a for fixing the actuator 2. The support frame 114a is formed by bending a horizontal steel plate along the left and right direction of the valve body 110, so that its radial cross section along the valve body 110 is a trapezoid with a narrow top and a wide bottom, which improves the shock resistance and better meets the safety requirements of nuclear power scenarios. The two ends of the steel plate are fixed to the top of the base 114 by bolts. The top of the base 114 forms extensions on the left and right sides for fixing to the two ends of the steel plate.

[0026] Of course, the support frame 114a can also be designed as a trapezoid with a narrower top and a wider bottom in both the left-right and front-back directions.

[0027] The top surface of the support frame 114a has an opening through which the output shaft 21 of the actuator 2 passes. In this embodiment, the actuator 2 is a cylinder actuator.

[0028] like Figure 1 As shown, the disc 120 is disc-shaped and is located within the flow channel 111 of the valve body 110. Figure 1 and Figure 5 As shown, a tube 121 is formed on the back side of the disc 120. The tube 121 is vertical and concentric with the upper channel 112 and lower channel 113 of the valve body 110, and passes through the center of the back side of the disc 120.

[0029] The valve stem 130 is used to drive the disc 120 to rotate under the drive of the actuator 2, thereby opening or closing the flow channel 111.

[0030] like Figure 1 and Figure 2 As shown, the upper end of the valve stem 130 is located above the upper channel 112, and it passes upward through the packing cover 115 to connect to the output shaft 21 of the actuator 2. The lower end of the valve stem 130 passes through the tube body 121 of the upper channel 112 and the disc 120 in sequence to the lower channel 113. A bushing is provided between the valve stem 130 and the upper channel 112 and the lower channel 113 respectively.

[0031] like Figure 1 As shown, the valve stem 130 and the disc 120 are fixed by three connecting pins 170 that pass vertically through them. The connecting pins 170 are in the form of saddle pins, such as... Figure 1 and Figure 6 As shown, the connecting pin 170 is arranged along the axial direction of the valve body 110, and its center line is located at the joint between the valve stem 130 and the pipe body 121. That is, it can be understood that the center line of the connecting pin 170 is tangent to the valve stem 130. The pin hole corresponding to the connecting pin 170 is partially formed on the valve stem 130 and partially formed on the pipe body 121.

[0032] Compared to the prior art where the connecting pin passes through the center line of the valve stem, in the above structure, since the center line of the connecting pin 170 is offset from the center line of the valve stem 130, the contact area between the valve stem 130 and the connecting pin 170 is reduced, resulting in less stress on the valve stem 130 and making it less prone to breakage.

[0033] Of course, the connecting pin 170 can also be arranged along the left and right direction of the valve body 110, such as... Figure 5 As shown, of the three pin holes 180 corresponding to the three connecting pins 170, two are located at the upper part of the tube body 121 and one is located at the lower part of the tube body 121; the center line of the connecting pin 170 may not be tangent to the valve stem 130, and the connecting pin 170 may also pass obliquely through the valve stem 130 and the tube body 121.

[0034] To prevent the valve stem 130 from flying out, a stop step 131 is formed at the top of its packing position. The stop step 131 is located below the packing cover 115. See [reference needed]. Figure 4 .

[0035] like Figure 1 As shown, the valve seat 140 is used to form a sealing surface with the disc 120. The valve seat 140 is generally annular and has a lip-shaped radial section. It is pressed by the insert 150 onto the step on the inner wall of the flow channel 111.

[0036] The insert 150 has an annular radial cross-section and is disposed within the front flow channel orifice of the valve body 110. Its outer diameter is adapted to the inner diameter of the front flow channel orifice, such as... Figure 1 As shown, the insert 150 has a flange 151 on its front side, which is embedded in a corresponding notch formed on the front side of the valve body 110 and fixed by bolts. The side of the insert 150 that contacts the valve seat 140 has a structure corresponding to the lip structure.

[0037] To further prevent leakage, an O-ring 152 is provided between the insert 150 and the inner wall of the flow channel 111, located at the corner between the flange 151 and the outer wall of the insert 150. See [reference needed]. Figure 7 .

[0038] As can be seen from the above, the anti-leakage butterfly valve provided in this application embodiment has a packing between the valve stem and the valve body consisting of a head packing element, multiple middle packing elements, and a tail packing element. Adjacent packing elements are connected by protrusions and grooves. Since the angle of the protrusion is greater than the angle of the groove into which it is inserted, the middle packing elements and the tail packing elements will be pushed open under atmospheric pressure. This results in a good sealing effect and strong anti-leakage capability in scenarios where the butterfly valve is connected to a vacuum system. Moreover, compared with the traditional water seal structure, it is more economical and easier to install.

[0039] Meanwhile, the centerline of the connecting pin is offset from the centerline of the valve stem, which reduces the stress on the valve stem during rotation, making it less prone to breakage, thus improving the lifespan of the butterfly valve and reducing maintenance costs.

[0040] In addition, a support frame that is narrow at the top and wide at the bottom is designed on the valve body to fix the actuator, which improves the shock resistance and better meets the safety requirements of nuclear power scenarios.

[0041] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A leak-proof butterfly valve, comprising a valve body with an annular radial cross-section, a disc located within a flow channel of the valve body, a valve stem for rotating the disc under the drive of an actuator to open or close the flow channel, a valve seat for forming a sealing surface with the disc, and an insert for pressing the valve seat, wherein the valve body has an upper channel and a lower channel opposite to each other, the lower end of the valve stem passes sequentially through the upper channel and the disc to the lower channel, a sealing medium is provided between the upper channel and the valve stem, and the valve stem and the disc are fixed by a connecting pin passing through both, characterized in that, The sealing medium is packing material, which includes an upper packing structure and a lower packing structure. Both the upper and lower packing structures include a head packing element, multiple middle packing elements, and a tail packing element. The head, middle, and tail packing elements are all annular. The rear end face of the head packing element is flat, and the front end face forms a ring of protrusions with a triangular axial cross-section. The rear end face of the middle packing element forms a ring of grooves with a triangular axial cross-section, and the front end face forms a ring of protrusions with a triangular axial cross-section. The rear end face of the tail packing element forms a ring of grooves with a triangular axial cross-section, and the front end face is flat. The head packing element, multiple middle packing elements, and tail packing elements of the upper packing structure are arranged sequentially from top to bottom, with the front end face of each packing element facing downwards. The head packing element, multiple middle packing elements, and tail packing elements of the lower packing structure are arranged sequentially from bottom to top, with the front end face of each packing element facing upwards. Adjacent packing elements are inserted through the protrusions and grooves, and the angle of the protrusion is greater than the angle of the corresponding groove.

2. The anti-leakage butterfly valve according to claim 1, characterized in that, The centerline of the connecting pin is offset from the centerline of the valve stem.

3. The anti-leakage butterfly valve according to claim 2, characterized in that, The connecting pin passes vertically through the disc and the valve stem.

4. The anti-leakage butterfly valve according to claim 2, characterized in that, The centerline of the connecting pin is tangent to the valve stem.

5. A leak-proof butterfly valve according to any one of claims 2-4, characterized in that, The back of the disc is formed with a tube through which the valve stem passes vertically. The tube and the valve stem are fixed by a connecting pin passing through both. The tube passes through the center of the back of the disc.

6. The anti-leakage butterfly valve according to claim 1, characterized in that, The valve body has a seat, the upper channel is formed on the seat, and the seat has a support frame for fixing the actuator. The support frame is trapezoidal, narrow at the top and wide at the bottom.

7. A leak-proof butterfly valve according to claim 6, characterized in that, The support frame is made by bending a steel plate.

8. A leak-proof butterfly valve according to claim 1, characterized in that, The upper channel has a step, dividing it into an upper section and a lower section. The upper section is wider than the lower section. The packing material is disposed between the upper section and the valve stem. The packing material is pressed onto the step by a packing cap. The packing cap is passed through by the valve stem and fixed to the valve body by fixing bolts.

9. A leak-proof butterfly valve according to claim 8, characterized in that, An elastic washer is provided between the packing cover and the nut of the fixing bolt.

10. A leak-proof butterfly valve according to claim 1, characterized in that, A sealing ring is provided between the insert and the inner wall of the flow channel of the valve body, and the lower channel is a blind hole.

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