A Sealed Automatic Compensation Type Ultra-Low Temperature Butterfly Valve

Abstract

A hermetically sealed automatic compensation type cryogenic butterfly valve provided by the present invention comprises: a valve body, a valve plate and a valve rod; a first installation groove penetrating the valve body horizontally is arranged on the valve body; the valve body is further provided with a longitudinal second installation groove, and the valve rod is inserted into the second installation groove; the valve plate is installed on the valve rod; one side of the valve plate is provided with an inclined surface; a retaining ring is installed on one side of the valve body; an annular PCTFE valve seat is arranged inside the retaining ring; the thickness of one side of the PCTFE valve seat close to the inclined surface is smaller than that of the other side. The present invention adopts a triple eccentric structure design and realizes sealing through torque; PCTFE is used as a sealing material to meet the stringent leakage requirements under cryogenic conditions; the structure can complete automatic compensation of the sealing surface to ensure a longer service life.

Description

Technical Field

[0001] The present invention relates to the field of butterfly valves, and particularly to a super-low temperature butterfly valve with automatic seal compensation. Background Art

[0002] Although double-eccentric butterfly valves have been widely introduced into the super-low temperature field due to their mature structure and relatively low manufacturing cost, they have some common problems due to their position-sealing design structure: there is a high risk of valve seat rupture at low temperatures, and in many cases, these ruptures are only discovered during use, which brings a lot of inconvenience to the user; leakage is unstable at low temperatures and once the leakage exceeds the standard, it cannot be adjusted, and only the new core parts can be disassembled and replaced, resulting in expensive maintenance costs. Summary of the Invention

[0003] (I) Technical Problems to be Solved

[0004] The purpose of the present invention is to provide a super-low temperature butterfly valve with automatic seal compensation, which solves the defects of the existing double-eccentric butterfly valve, such as high risk of valve seat rupture at low temperatures, and in many cases, these ruptures are only discovered during use, which brings a lot of inconvenience to the user; leakage is unstable at low temperatures and once the leakage exceeds the standard, it cannot be adjusted, and only the new core parts can be disassembled and replaced, resulting in expensive maintenance costs.

[0005] (II) Technical Solutions

[0006] In order to solve the above technical problems, the present invention provides a sealed automatic compensation type ultra-low temperature butterfly valve, comprising: a valve body, a valve plate and a valve stem; the valve body is provided with a first installation groove that runs through the valve body in a horizontal direction; the valve body is also provided with a second installation groove in a longitudinal direction, and the valve stem is inserted into the second installation groove; the valve plate is installed on the valve stem; a bevel is provided on one side of the valve plate; a retaining ring is provided on one side of the valve body; a ring-shaped PCTFE valve seat is provided on the inner side of the retaining ring; the thickness of the PCTFE valve seat on one side close to the bevel is smaller than that on the other side. The present invention adopts a three-eccentric structure design to achieve sealing through torque; PCTFE is used as a sealing material to meet the strict leakage requirements under ultra-low temperature; the structure can complete automatic sealing surface compensation to ensure a longer service life. The valve of the present invention achieves sealing through torque, so there is a larger fault tolerance space for parts and components, and the yield rate of the valve is significantly improved. The valve needs to load torque to achieve sealing, so when it is opened, the force loaded on the valve seat disappears, and the valve will immediately start to leak, so only a small force is required to open the valve. This allows a smaller execution structure to be equipped, reducing the overall pipeline cost. The three-eccentric design is adopted, and there is no friction during the opening and closing process, which can extend the service life to the maximum extent. The valve plate adopts a three-eccentric design, and the closing process is similar to a cam effect, which will become tighter and tighter. The integrated valve plate design is adopted to ensure that the structure can remain stable when working in a low-temperature environment, and the deformation is as small as possible after being loaded, so as to better complete the sealing; the wider sealing surface design, when the valve seat is worn after running for a period of time, and the sealing at this point fails, the valve plate will automatically continue to rotate to find a new sealing position because the valve adopts a torque sealing structure design, so as to realize automatic compensation for the wear of the valve seat. The present invention adopts a PCTFE sealing valve seat to achieve excellent sealing ability at low temperatures and meet the most stringent invention specification requirements in the industry. The valve seat with a cross-section approximately rectangular structure has a simple shape and is easy to process, which can greatly improve the yield rate of the manufacturing process. At the same time, the simple shape also provides more excellent mechanical properties, ensuring a longer service life of the invention.

[0007] Optionally, a limiting structure is provided at one end of the inner wall of the valve body away from the inclined surface.

[0008] Optionally, the limit structure is a flange protruding outward. The valve body of the present invention is designed with a mechanical position limit, which can ensure that the invention will not fail seriously and cause complete failure even in the event of an accident in which the limit of the driving mechanism fails or the valve stem breaks.

[0009] Optionally, a metal spare valve seat is also installed between the retaining ring and the valve body.

[0010] Optionally, the metal backup valve seat is annular. The present invention provides a backup metal backup valve seat to achieve a fire protection function. When the PCTFE valve seat fails partially or completely due to certain critical conditions, the valve can still control the leakage within the specification requirements through the metal backup valve seat.

[0011] (III) Beneficial effects

[0012] The sealed automatic compensation type ultra-low temperature butterfly valve provided by the present invention has the following advantages:

[0013] 1. The present invention adopts a three-eccentric structure design to achieve sealing through torque; PCTFE is used as a sealing material to meet the stringent leakage requirements under ultra-low temperatures; the structure can complete automatic sealing surface compensation to ensure a longer service life. The valve of the present invention achieves sealing through torque, so there is a larger fault tolerance space for components and components, which significantly improves the yield rate of the valve. The valve needs to be loaded with torque to achieve sealing, so when it is opened, the force loaded on the valve seat disappears and the valve will immediately start to leak, so only a small force is needed to open the valve. This allows for a smaller actuator structure and reduces the overall pipeline cost. The three-eccentric design is adopted, and there is no friction during the opening and closing process, which can extend the service life to the maximum extent possible. The valve plate adopts a three-eccentric design, and the closing process has a cam effect, which will become tighter and tighter. The integrated valve plate design ensures that the structure can remain stable when working in a low-temperature environment, and the deformation is minimized after being loaded, so as to better complete the sealing. The wider sealing surface design means that when the valve seat is worn after running for a period of time and the seal fails at this point, the valve plate will automatically continue to rotate to find a new sealing position due to the torque sealing structure design of the valve, thereby automatically compensating for the wear of the valve seat. The present invention adopts a PCTFE sealing valve seat to achieve excellent sealing ability at low temperatures and meet the most stringent invention specification requirements in the industry. The valve seat with a cross-section that is approximately rectangular has a simple shape and is easy to process, which can greatly improve the yield rate of the manufacturing process. At the same time, the simple shape also provides more excellent mechanical properties, ensuring a longer service life of the invention.

[0014] 2. The valve body of the present invention is designed with a mechanical position limit, which can ensure that the invention will not fail seriously and cause complete failure even in the event of an accident in which the driving mechanism limit fails or the valve stem breaks.

[0015] 3. Due to certain critical working conditions, even if the PCTFE valve seat fails partially or completely, the valve can still control the leakage within the specification requirements through the metal backup valve seat. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is a front view of the sealed automatic compensation type ultra-low temperature butterfly valve embodiment 1 of the present invention,

[0017] Figure 2 1 is a top view of a sectional view of a sealed automatic compensation type ultra-low temperature butterfly valve embodiment 1 of the present invention;

[0018] Figure 3 The sealed automatic compensation type ultra-low temperature butterfly valve embodiment 1 of the present invention Figure 2 A magnified structural diagram of part A;

[0019] Figure 4 It is the sectional structure diagram of the PCTFE valve seat of Embodiment 1 of the hermetically sealed automatic compensation type ultra-low temperature butterfly valve of the present invention.

[0020] 1. Valve body, 2. Valve plate, 3. Valve stem, 4. First installation groove, 5. Second installation groove, 6. Inclined surface, 7. Retaining ring, 8. PCTFE valve seat, 9. Limit structure, 10. Metal spare valve seat, 11. Bending piece, 12. Heat conduction cavity, 13. Electric heating wire, 14. Power supply, 15. Conducting wire, 17. Cylinder body, 18. Torsion spring, 19. Shape memory metal strip, 20. Metal ball. Specific implementation manners

[0021] The following will further describe in detail the specific implementation manners of the present invention in conjunction with the drawings and embodiments. The following examples are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0022] In the description of the present invention, unless otherwise specified, "a plurality of" means two or more; the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In the present invention, PCEFE is the abbreviation of polychlorotrifluoroethylene. Embodiment

[0023] As Figure 1 , Figure 2 and Figure 3 shown, a hermetically sealed automatic compensation type ultra-low temperature butterfly valve provided by the present invention includes: a valve body 1, a valve plate 2 and a valve stem 3; a first installation groove 4 penetrating the valve body horizontally is provided on the valve body; the valve body is also provided with a longitudinal second installation groove 5, and the valve stem is inserted into the second installation groove; the valve plate is installed on the valve stem; one side of the valve plate is provided with an inclined surface 6; a retaining ring 7 is installed on one side of the valve body; an annular PCTFE valve seat 8 is provided inside the retaining ring; the thickness of one side of the PCTFE valve seat close to the inclined surface is less than that of the other side. A limit structure 9 is provided at one end of the inner side wall of the valve body away from the inclined surface. The limit structure is a convex flange protruding outwards. An annular metal spare valve seat 10 is also installed between the retaining ring and the valve body.

[0024] During the implementation of this embodiment, when the valve seat is worn after running for a period of time and the sealing fails at this point, due to the torque sealing structure design of the valve, the valve plate will automatically continue to rotate to find a new sealing position, realizing automatic compensation for the wear of the valve seat. Embodiment

[0025] As Figure 4 shown, the difference between Embodiment 2 and Embodiment 1 is that a bending piece 11 made of a flexible high-temperature resistant material is provided on the contact surface between the PCTFE valve seat and the valve plate. A heat conduction cavity 12 in contact and sealed with the bending piece is provided inside the bending piece; an ethanol solution is provided in the heat conduction cavity; an electric heating wire 13 is further provided in the heat conduction cavity; the PCTFE valve seat is further equipped with a power supply 14; the power supply is connected to the electric heating wire through a wire 15, and a deformation device is provided on the wire. The deformation device includes a cylinder body 17. A torsion spring 18 is provided inside the cylinder body. One end of the torsion spring is fixed on the cylinder body, and the other end hangs in the cylinder body. A shape memory metal strip 19 is provided on the movable end of the torsion spring. The deformation temperature of the shape memory metal strip is 40°C; a metal ball 20 is provided in the cylinder body; when the shape memory metal strip is below 40°C, it naturally extends and returns to its original shape and contacts the metal ball, thereby enabling the power supply to conduct electricity to the electric heating wire and causing the electric heating wire to start heating. In the present invention, the electric heating wire heats up to vaporize or expand the liquid in the heating cavity, causing the bending piece to bulge outwards and tightly press against the valve plate; further improving the sealing performance with the valve plate.

[0026] The above embodiments are only used to illustrate the present invention. The mechanisms, connection methods, etc. of each component can be changed. Any equivalent transformation and improvement based on the technical solution of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A hermetically sealed automatic compensation type ultra-low temperature butterfly valve, characterized in that, Comprising: A valve body, a valve plate and a valve stem; a first installation groove penetrating the valve body horizontally is provided on the valve body; the valve body is also provided with a longitudinal second installation groove, and the valve stem is inserted into the second installation groove; the valve plate is installed on the valve stem; one side of the valve plate is provided with an inclined surface; a retaining ring is installed on one side of the valve body; an annular PCTFE valve seat is provided on the inner side of the retaining ring; the thickness of one side of the PCTFE valve seat close to the inclined surface is smaller than that of the other side; a limiting structure is provided at one end of the inner side wall of the valve body away from the inclined surface; the limiting structure is a flange protruding outwards; a metal spare valve seat is also installed between the retaining ring and the valve body; the metal spare valve seat is annular; a flexible bending piece is provided on the contact surface between the PCTFE valve seat and the valve plate, and a heat conduction cavity in contact and sealed with the bending piece is provided inside the bending piece; an ethanol solution is provided in the heat conduction cavity; an electric heating wire is also provided in the heat conduction cavity; the PCTFE valve seat is also provided with a power supply; the power supply is connected to the electric heating wire through a wire, and a deformation device is installed on the wire, the deformation device includes a cylinder body, a torsion spring is installed in the cylinder body, one end of the torsion spring is fixed on the cylinder body, the other end hangs in the cylinder body, a shape memory metal strip is installed on the movable end of the torsion spring, and the deformation temperature of the shape memory metal strip is 40 °C; a metal ball is installed in the cylinder body; when the shape memory metal strip is below 40 °C, it naturally stretches and returns to its original shape to contact the metal ball, thereby enabling the power supply to conduct electricity to the electric heating wire and causing the electric heating wire to start heating.

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