A six-eccentric bidirectional sealing butterfly valve

Abstract

The present invention discloses a six-eccentric bidirectional sealing butterfly valve, including a valve body, a butterfly plate, a valve stem, a main valve seat, an auxiliary valve seat, a main sealing ring, a pressure ring and an auxiliary sealing ring. A six-eccentric structure is adopted, and a double sealing pair works together to achieve a reverse seal of 1.1 times the nominal pressure, and there is no need to thicken the valve stem and the butterfly plate, and there is no need to increase the model of the actuator, so the cost is greatly reduced. A fixed valve seat is adopted instead of a movable valve seat, and there is no phenomenon of the movable valve seat being stuck, which fundamentally solves the problem of unstable reverse sealing performance. The internal structure does not have a rubber O-ring installed, and can withstand high temperatures above 425 degrees. Both the main sealing pair and the auxiliary sealing pair adopt conical surface sealing, and the sealing pair does not interfere when opening and closing, and the opening and closing torque is small.

Description

Technical Field

[0001] The present invention belongs to the field of valve technology, and in particular to a six-eccentric bidirectional sealing butterfly valve. It is used in sewage, petroleum, chemical, pharmaceutical, power industry and other pipeline systems for cutting off and regulating, and the medium is water, oil, steam, chemical medium, etc. It is widely used in pipelines with high temperature, low temperature, high pressure, high wear resistance, high corrosion, high vacuum and other harsh working conditions that require bidirectional sealing. Background Art

[0002] The defects of similar products on the market are as follows:

[0003] Question 1: A single fixed valve seat cannot achieve reverse sealing, especially for specifications above DN400, where the reverse leakage is greater. If the reverse sealing pressure is not high, it can be achieved by thickening the valve stem and butterfly plate and increasing the actuator, but the valve cost increases a lot, and the reverse sealing can only reach 0.6 times the nominal pressure.

[0004] Question 2: Conventional two-way sealing uses an independent movable valve seat. When reverse sealing is performed, the movable valve seat is pushed toward the butterfly plate seal ring to achieve reverse sealing. When the medium is not clean, it is easy to get stuck, resulting in unstable reverse sealing performance.

[0005] Question 3: Because the internal structure of the movable valve seat is installed with a rubber O-ring, this material can only be used below 250 degrees. Summary of the invention

[0006] The purpose of the present invention is to provide a six-eccentric bidirectional sealing butterfly valve in view of the deficiencies of the above-mentioned prior art.

[0007] To solve the above problems, the technical solution adopted by the present invention is:

[0008] A six-eccentric bidirectional sealing butterfly valve comprises a valve body, a butterfly plate, a valve stem, a main valve seat, an auxiliary valve seat, a main sealing ring, a pressure ring and an auxiliary sealing ring. The butterfly plate is located in the valve body, the valve stem is fixedly connected to the butterfly plate, both ends of the valve stem are rotatably matched with the valve body, the main valve seat and the auxiliary valve seat are located on both sides of the valve stem, an annular concave platform is provided on one side of the butterfly plate, the main sealing ring is arranged in the annular concave platform, the pressure ring is pressed on the main sealing ring and is installed on the butterfly plate by bolts, the main valve seat and the main sealing ring cooperate to form a main sealing pair, the auxiliary sealing ring is arranged between the butterfly plate and the auxiliary valve seat, and the auxiliary valve seat and the auxiliary sealing ring cooperate to form an auxiliary Sealing pair, the eccentric arrangement of the symmetric center line of the main sealing ring and the valve stem rotation center line constitutes a first eccentricity a, the eccentric arrangement of the flow channel center line of the valve body and the valve stem rotation center line constitutes a second eccentricity b, the eccentric arrangement of the cone center line formed by the sealing surface of the main sealing ring and the flow channel center line of the valve body constitutes a third eccentricity c, the eccentric arrangement of the center line of the butterfly plate on one side of the main sealing ring and the flow channel center line of the valve body constitutes a fourth eccentricity d, the eccentric arrangement of the valve stem rotation center line and the axis of the auxiliary sealing ring constitutes a fifth eccentricity e, and the eccentric arrangement of the symmetric center line of the auxiliary sealing ring and the valve stem rotation center line constitutes a sixth eccentricity f.

[0009] A further technical solution is that both the main sealing pair and the auxiliary sealing pair adopt conical surface sealing.

[0010] A further technical solution is that the main valve seat is built-up welded on the annular boss on the inner side of the valve body.

[0011] A further technical solution is that the auxiliary valve seat of the auxiliary sealing pair is welded to the valve body, and the auxiliary sealing ring adopts a self-machined sealing surface on the butterfly plate or is welded to the butterfly plate as an independent part.

[0012] A further technical solution is that the mating surfaces of the auxiliary valve seat and the auxiliary sealing ring are hardened by chrome plating or nitriding.

[0013] A further technical solution is that the valve stem includes an upper valve shaft and a lower valve shaft, the upper valve shaft is connected to the butterfly plate through a pin shaft, an upper shaft hole and a lower shaft hole are opened in the valve body, an upper shaft sleeve is provided in the upper shaft hole, a lower shaft sleeve is provided in the lower shaft hole, the upper valve shaft is inserted into the upper shaft sleeve, a stuffing box is provided at the upper end of the upper shaft hole, a stuffing and a stuffing gasket are provided in the stuffing box, a stuffing gland is provided above the stuffing box, the lower valve shaft is inserted into the lower shaft sleeve, the end of the lower shaft hole is sealed by an end cover, a gasket is provided between the end cover and the valve body, an adjustment gasket is provided between the end cover and the lower valve shaft, and a semi-open ring is provided between the lower valve shaft and the valve body.

[0014] A further technical solution is to further include a bracket, one end of which is connected to the valve body, and the other end of which is used to be connected to an external valve actuator.

[0015] The beneficial effects of the above technical solution are as follows: the six-eccentric bidirectional sealing butterfly valve of the present invention adopts a six-eccentric structure and a double sealing pair to achieve reverse sealing of 1.1 times the nominal pressure, without thickening the valve stem and the butterfly plate, and without increasing the model of the actuator, which greatly reduces the cost. A fixed valve seat is used instead of a movable valve seat, and there is no phenomenon of the movable valve seat getting stuck, which fundamentally solves the problem of unstable reverse sealing performance. The internal structure does not have a rubber O-ring installed, and can withstand high temperatures above 425 degrees. Both the main sealing pair and the auxiliary sealing pair use conical sealing. The sealing pair does not interfere when opening and closing, and the opening and closing torque is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a radial cross-sectional view of the present invention;

[0017] Figure 2 yes Figure 1 Enlarged view of part A in the middle;

[0018] Figure 3 is an axial cross-sectional view of the present invention;

[0019] Figure 4 yes Figure 3 A partial enlarged view of

[0020] Figure 5 yes Figure 3 A partial enlarged view of another part.

[0021] In the figure: 1. valve body; 2. main valve seat; 3. main sealing ring; 4. butterfly plate; 5. pressure ring; 6. adjustment pad; 7. end cover; 8. gasket; 9. semi-open ring; 10. pin shaft; 11. lower valve shaft; 12. upper valve shaft; 13. upper shaft sleeve; 14. packing pad; 15. packing; 16. bracket; 17. packing gland; 18. auxiliary valve seat; 19. auxiliary sealing ring; 20. lower shaft sleeve. DETAILED DESCRIPTION

[0022] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0023] like Figure 1-5A six-eccentric bidirectional sealing butterfly valve shown in the figure comprises a valve body 1, a butterfly plate 4, a valve stem, a main valve seat 2, an auxiliary valve seat 18, a main sealing ring 3, a pressure ring 5 and an auxiliary sealing ring 19, wherein the butterfly plate 4 is located in the valve body 1, the valve stem is fixedly connected to the butterfly plate 4, both ends of the valve stem are rotatably matched with the valve body 1, the main valve seat 2 and the auxiliary valve seat 18 are located on both sides of the valve stem, an annular recess is provided on one side of the butterfly plate 4, the main sealing ring 3 is arranged in the annular recess, the pressure ring 5 is pressed on the main sealing ring 3 and is installed on the butterfly plate 4 by bolts, the main valve seat 2 cooperates with the main sealing ring 3 to form a main sealing pair, the auxiliary sealing ring 19 is arranged between the butterfly plate 4 and the auxiliary valve seat 18, the auxiliary valve seat 18 cooperates with the auxiliary sealing ring 19 to form an auxiliary sealing pair, and the symmetrical center line of the main sealing ring 3 is eccentrically arranged with the valve stem rotation center line to form a second sealing pair. An eccentricity a can eliminate the interference between the end faces of the two shaft heads of the butterfly plate and the valve seat. The eccentric setting of the flow channel center line of the valve body 1 and the valve stem rotation center line constitutes a second eccentricity b. When the valve is opened, the sealing pair disengages quickly, reducing the opening and closing torque. The cone center line formed by the sealing surface of the main sealing ring 3 and the eccentric setting of the flow channel center line of the valve body 1 constitute a third eccentricity c. The sealing pair can disengage quickly during opening and closing. The center line of the butterfly plate 4 on one side of the main sealing ring 3 and the eccentric setting of the flow channel center line of the valve body 1 constitute a fourth eccentricity d, which improves the processing efficiency of the butterfly plate. The eccentric setting of the valve stem rotation center line and the axis of the auxiliary sealing ring 19 constitutes a fifth eccentricity e, which improves the reverse sealing performance. The symmetrical center line of the auxiliary sealing ring 19 and the eccentric setting of the valve stem rotation center line constitute a sixth eccentricity f, which solves the problem of interference between the auxiliary sealing pair.

[0024] Wherein, the main sealing pair and the auxiliary sealing pair both adopt conical surface sealing, the sealing pair does not interfere with each other during opening and closing, and the opening and closing torque is small.

[0025] The main valve seat 2 is welded on the annular boss inside the valve body 1. Specifically, when the main sealing ring 3 is a multi-layer stainless steel sandwich structure, D507Mo can be welded. When the sealing pair is all metal, STL hard alloy can be welded. It can also be made according to customer requirements.

[0026] The auxiliary valve seat 18 of the auxiliary sealing pair is welded on the valve body 1, and the auxiliary sealing ring 19 adopts the self-machined sealing surface on the butterfly plate 4 or is welded on the butterfly plate 4 as an independent part. The mating surfaces of the auxiliary valve seat 18 and the auxiliary sealing ring 19 are hardened by chrome plating or nitriding treatment to ensure the long-term stable performance of the bidirectional seal.

[0027] The valve stem includes an upper valve shaft 12 and a lower valve shaft 11, the upper valve shaft 12 is connected to the butterfly plate 4 through a pin shaft 10, an upper shaft hole and a lower shaft hole are opened in the valve body 1, an upper shaft sleeve 13 is arranged in the upper shaft hole, a lower shaft sleeve 20 is arranged in the lower shaft hole, the upper valve shaft 12 is inserted into the upper shaft sleeve 13, a stuffing box is arranged at the upper end of the upper shaft hole, a stuffing 15 and a stuffing gasket 14 are arranged in the stuffing box, a stuffing gland 17 is arranged above the stuffing box, the lower valve shaft 11 is inserted into the lower shaft sleeve 20, the end of the lower shaft hole is blocked by an end cover 7, a gasket 8 is arranged between the end cover 7 and the valve body 1, an adjustment gasket 6 is arranged between the end cover 7 and the lower valve shaft 11, and a semi-open ring 9 is arranged between the lower valve shaft 11 and the valve body 1.

[0028] It also includes a bracket 16, one end of which is connected to the valve body 1, and the other end of which is used to be connected to an external valve actuator.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A six-eccentric bidirectional sealing butterfly valve, characterized in that: The valve comprises a valve body (1), a butterfly plate (4), a valve stem, a main valve seat (2), an auxiliary valve seat (18), a main sealing ring (3), a pressure ring (5) and an auxiliary sealing ring (19), wherein the butterfly plate (4) is located in the valve body (1), the valve stem is fixedly connected to the butterfly plate (4), both ends of the valve stem are rotatably matched with the valve body (1), the main valve seat (2) and the auxiliary valve seat (18) are located on both sides of the valve stem, an annular concave platform is provided on one side of the butterfly plate (4), the main sealing ring (3) is arranged in the annular concave platform, the pressure ring (5) is pressed on the main sealing ring (3) and is installed on the butterfly plate (4) by bolts, the main valve seat (2) and the main sealing ring (3) cooperate to form a main sealing pair, the auxiliary sealing ring (19) is arranged between the butterfly plate (4) and the auxiliary valve seat (18), and the auxiliary sealing ring (19) is arranged between the butterfly plate (4) and the auxiliary valve seat (18). The valve seat (18) and the auxiliary sealing ring (19) cooperate to form an auxiliary sealing pair, the symmetric center line of the main sealing ring (3) and the valve stem rotation center line are eccentrically arranged to form a first eccentricity a, the flow channel center line of the valve body (1) and the valve stem rotation center line are eccentrically arranged to form a second eccentricity b, the cone center line formed by the sealing surface of the main sealing ring (3) and the flow channel center line of the valve body (1) are eccentrically arranged to form a third eccentricity c, the center line of the butterfly plate (4) on one side of the main sealing ring (3) and the flow channel center line of the valve body (1) are eccentrically arranged to form a fourth eccentricity d, the valve stem rotation center line and the axis of the auxiliary sealing ring (19) are eccentrically arranged to form a fifth eccentricity e, and the symmetric center line of the auxiliary sealing ring (19) and the valve stem rotation center line are eccentrically arranged to form a sixth eccentricity f.

2. A six-eccentric bidirectional sealing butterfly valve according to claim 1, characterized in that: The main sealing pair and the auxiliary sealing pair both adopt conical surface sealing.

3. A six-eccentric bidirectional sealing butterfly valve according to claim 1, characterized in that: The main valve seat (2) is welded onto the annular boss on the inner side of the valve body (1).

4. The six-eccentric bidirectional sealing butterfly valve according to claim 1, characterized in that: The auxiliary valve seat (18) of the auxiliary sealing pair is welded to the valve body (1), and the auxiliary sealing ring (19) adopts a self-machined sealing surface on the butterfly plate (4) or adopts an independent part welded to the butterfly plate (4).

5. A six-eccentric bidirectional sealing butterfly valve according to claim 4, characterized in that: The matching surfaces of the auxiliary valve seat (18) and the auxiliary sealing ring (19) are hardened by chrome plating or nitriding.

6. The six-eccentric bidirectional sealing butterfly valve according to claim 1, characterized in that: The valve stem comprises an upper valve shaft (12) and a lower valve shaft (11), the upper valve shaft (12) being connected to the butterfly plate (4) via a pin shaft (10), an upper shaft hole and a lower shaft hole being provided in the valve body (1), an upper shaft hole being provided with an upper shaft sleeve (13), and a lower shaft hole being provided with a lower shaft sleeve (20), the upper valve shaft (12) being inserted into the upper shaft sleeve (13), a stuffing box being provided at the upper end of the upper shaft hole, a stuffing box being provided with a stuffing (15) and a stuffing gasket (14), a stuffing gland (17) being provided above the stuffing box, the lower valve shaft (11) being inserted into the lower shaft sleeve (20), the end of the lower shaft hole being blocked by an end cover (7), a gasket (8) being provided between the end cover (7) and the valve body (1), an adjustment gasket (6) being provided between the end cover (7) and the lower valve shaft (11), and a semi-open ring (9) being provided between the lower valve shaft (11) and the valve body (1).

7. The six-eccentric bidirectional sealing butterfly valve according to claim 1, characterized in that: It also comprises a bracket (16), one end of which is connected to the valve body (1), and the other end of which is used to be connected to an external valve actuator.

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