An ultra-low temperature high-pressure triple offset butterfly valve

Abstract

The application relates to the technical field of butterfly valves, in particular to an ultralow-temperature high-pressure three-eccentric butterfly valve, which comprises a valve body, a valve rod and a butterfly plate, a circle of static sealing seats is fixedly installed on the inner side wall of the valve body, the valve rod penetrates through the valve body and is fixedly connected with the butterfly plate through a key groove structure, and a floating valve seat is arranged on the side of the static sealing seat close to the butterfly plate; the floating valve seat comprises a spring plate, a floating block and a first sealing ring, a sealing conical surface matched with the edge of the butterfly plate is arranged on the side of the floating block facing the butterfly plate, the side of the floating block away from the butterfly plate is fixedly installed with a first extrusion belt, an L-shaped channel is arranged in the floating block, a first push rod and a sealing block are respectively installed in the L-shaped channel, one end of the first push rod is fixedly connected with the first extrusion belt, and when reverse sealing is performed, pressure acts on the first extrusion belt, and the floating valve seat is automatically pushed to compensate the gap. No matter how the medium flows, the self-enhancing effect that the higher the pressure is, the tighter the sealing is can be realized.

Description

Technical Field

[0001] This invention relates to the field of butterfly valve technology, specifically to an ultra-low temperature high pressure triple eccentric butterfly valve. Background Technology

[0002] Traditional butterfly valves offer advantages such as compact structure, rapid opening and closing, and low cost under normal operating conditions, but they face significant challenges in ultra-low temperature and high pressure environments. While early soft-seal butterfly valves provided good sealing at room temperature, they were prone to hardening, cracking, or permanent deformation at ultra-low temperatures, leading to seal failure. Furthermore, soft-seal materials have limited pressure resistance, making them unsuitable for high pressure differential conditions.

[0003] To overcome the above problems, the industry is gradually shifting to metal hard-seal butterfly valves. Among them, the triple eccentric structure, due to its unique geometric design, achieves frictionless separation of the sealing pair and progressive wedge sealing during opening and closing through the double offset of the valve stem axis relative to the center of the butterfly plate and the inclined arrangement of the sealing cone surface, which significantly reduces wear and improves service life.

[0004] However, currently only soft-seal butterfly valves on the market achieve bidirectional sealing performance, while metal hard-seal butterfly valves cannot achieve bidirectional sealing performance due to their structure and traditional manufacturing processes, especially under long-term pulsating pressure of the medium in the pipeline, which can easily lead to sealing failure. Summary of the Invention

[0005] The purpose of this invention is to provide an ultra-low temperature high pressure triple eccentric butterfly valve to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An ultra-low temperature high pressure triple eccentric butterfly valve includes a valve body, a valve stem, and a butterfly plate. A static sealing seat is fixedly installed on the inner wall of the valve body. The valve stem passes through the valve body and is fixedly connected to the butterfly plate through a keyway structure. A floating valve seat is provided on the side of the static sealing seat near the butterfly plate. The floating valve seat includes a spring plate, a floating block, and a first sealing ring. A sealing cone surface adapted to the edge of the butterfly plate is provided on the side of the floating block facing the butterfly plate. A first extrusion band is fixedly installed on the side of the floating block away from the butterfly plate. An L-shaped channel is opened inside the floating block. A first push rod and a sealing block are respectively installed in the L-shaped channel. One end of the first push rod is fixedly connected to the first extrusion band.

[0008] Preferably, a first limiting plate is fixedly installed on the first push rod, a second limiting plate is fixedly installed on the inner wall of the L-shaped channel, and a first spring is sleeved on the first push rod, with the two ends of the first spring respectively fixed to the first limiting plate and the second limiting plate.

[0009] Preferably, the inner wall of the static sealing seat is provided with a guide groove, and the outer peripheral surface of the floating block is provided with a guide boss, and the guide boss and the guide groove are in clearance fit.

[0010] Preferably, the butterfly plate includes a plate body, a sealing ring, and a pressure ring. An annular groove is formed at the edge of the plate body surface, and a sealing gasket is installed in the annular groove. The pressure ring fixes the sealing ring to the plate body by bolts. An alloy layer is welded onto the conical surface of both the sealing block and the sealing ring, and the two cooperate to form a metal-to-metal sealing pair.

[0011] Preferably, the sealing ring has an installation groove on its conical surface, and a second sealing ring is embedded in the installation groove, the surface of the second sealing ring being flush with the conical surface of the sealing ring.

[0012] Preferably, a second extrusion belt is fixedly installed on the side of the plate away from the pressure ring. An extrusion groove is formed inside the plate. An extrusion rod is slidably installed in the extrusion groove. One end of the extrusion rod is fixed to the second extrusion belt. A second spring is fixedly connected between the other end of the extrusion rod and the bottom surface of the extrusion groove. An air passage is formed inside the plate. One end of the air passage is connected to the extrusion groove. An air pipe is fixedly connected to the other end of the air passage. The air pipe is connected to the second sealing ring.

[0013] Preferably, a guide cylinder is fixedly installed on the plate, and the extrusion rod is slidably installed inside the guide cylinder.

[0014] Preferably, one end of the valve stem extends to the outside of the valve body and is connected to a drive mechanism, and an extension neck is provided between the valve body and the drive mechanism, the extension neck being filled with packing material.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. During forward sealing, the medium pressure acts on the second extrusion band, activating the expansion of the auxiliary sealing ring; during reverse sealing, the pressure acts on the first extrusion band, pushing the floating valve seat to automatically compensate for the gap. Regardless of the direction of medium flow, it can achieve a self-reinforcing effect of the higher the pressure, the tighter the seal.

[0017] 2. The second compression band absorbs some of the fluid impact energy during the pressure indentation process. Combined with the elastic buffering effect of the second spring, it significantly reduces the instantaneous impact of water hammer or pressure fluctuations on the sealing pair, thereby improving the sealing stability and structural safety of the valve under high pressure fluctuation conditions. Attached Figure Description

[0018] Figure 1 This is a plan view of the present invention;

[0019] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0020] Figure 3 This is a schematic diagram of the conical surface of the sealing ring of the present invention;

[0021] Figure 4 This is a schematic diagram of the butterfly plate, floating valve seat, and static sealing seat of the present invention;

[0022] Figure 5 This is a schematic diagram of the internal structure of the static sealing seat of the present invention;

[0023] Figure 6 for Figure 5 Enlarged view of the A-structure;

[0024] Figure 7 This is a schematic diagram of the internal structure of the floating block of the present invention;

[0025] Figure 8 for Figure 7 Enlarged view of the B-structure.

[0026] The attached diagram lists the components represented by each number as follows:

[0027] 10. Valve body; 11. Extended neck; 12. Packing; 20. Valve stem; 30. Butterfly plate; 31. Plate body; 311. Annular groove; 312. Sealing gasket; 313. Second spring; 314. Air passage; 315. Air pipe; 316. Extrusion groove; 317. Extrusion rod; 318. Guide cylinder; 32. Sealing ring; 321. Mounting groove; 33. Pressure ring; 34. Second sealing ring; 35. Second extrusion band; 40. Static sealing seat; 41. Guide groove; 50. Floating valve seat; 51. Spring plate; 52. Floating block; 521. Sealing cone surface; 522. L-shaped channel; 523. Second limiting plate; 524. Guide boss; 53. First sealing ring; 54. First extrusion band; 55. First push rod; 551. First limiting plate; 552. First spring; 56. Sealing block; 60. Drive mechanism. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example: Refer to Figure 1 - Figure 8A cryogenic high-pressure triple eccentric butterfly valve is disclosed for regulating flow and cutting off media. It includes a valve body 10, a valve stem 20, and a butterfly plate 30. A static sealing seat 40 is fixedly installed on the inner wall of the valve body 10. The valve stem 20 passes through the valve body 10 and is fixedly connected to the butterfly plate 30 via a keyway structure. Specifically, the valve body 10 is an integral forged structure. The valve stem 20 passes through the valve body 10 perpendicular to the media flow direction. One end of the valve stem 20 extends to the outside of the valve body 10 and is connected to a drive mechanism 60. The drive mechanism 60 can be a manual worm gear box, a pneumatic actuator, or an electric actuator, flexibly configured according to on-site control requirements. Notably, an extension neck is provided between the valve body 10 and the drive mechanism 60. 11. The extended neck 11 extends axially along the valve stem 20. The extended neck 11 is filled with packing 12. The packing 12 is pressed from above by a packing 12 gland to form a dynamic sealing structure for the valve stem 20. This prevents the leakage of high-pressure and low-temperature medium in the valve cavity without affecting the smooth rotation of the valve stem 20 during opening and closing. During valve operation, the heat of the medium inside the valve body 10 is conducted upward through the valve stem 20. However, due to the thermal resistance effect of the extended neck 11 and the low thermal conductivity of the packing 12, the heat transfer is significantly weakened. This effectively isolates the heat conduction effect of the medium inside the valve body 10 on the drive mechanism 60, ensuring the normal working life and operational reliability of the drive mechanism 60. The valve stem 20 is fixedly connected to the butterfly plate 30 via a keyway structure, ensuring reliable torque transmission. The butterfly plate 30 is located within the valve body 10 cavity and features a streamlined design to reduce flow resistance. Its edges are machined with a high-precision sealing cone surface 521. One end of the valve stem 20 extends to the outside of the valve body 10 and is connected to a drive mechanism 60. In this embodiment, the drive mechanism 60 is a manual worm gear mechanism with a self-locking function, providing a large output torque. Crucially, a floating valve seat 50 is provided on the side of the static sealing seat 40 closest to the butterfly plate 30. This is used to achieve bidirectional sealing and adaptive compensation functions, such as… Figures 5 to 8As shown, the floating valve seat 50 includes a spring plate 51, a floating block 52, and a first sealing ring 53. The spring plate 51 is an annular elastic element disposed between the static sealing seat 40 and the floating block 52, evenly distributed along the circumference of the static sealing seat 40, to provide axial preload, ensuring that the floating block 52 always has an initial pressing tendency towards the butterfly plate 30. The first sealing ring 53 is embedded at the mating surface of the static sealing seat 40 and the floating block 52, forming a secondary sealing barrier to prevent media leakage from the gap between them. Furthermore, a first compression band 5 is fixedly installed on the side of the floating block 52 facing away from the butterfly plate 30. 4. An L-shaped channel 522 is provided inside the floating block 52. A first push rod 55 and a sealing block 56 are respectively installed in the L-shaped channel 522. The extension lines of the first push rod 55 and the sealing block 56 are perpendicular to each other. The first push rod 55 is slidably installed in the sealing block 56 and makes inclined contact with the inner wall of the sealing block 56. One end of the first push rod 55 is fixedly connected to the first extrusion band 54. When the medium pressure acts on the first extrusion band 54, the pressure is transmitted to the sealing block 56 through the first push rod 55, pushing it to fit more tightly against the sealing ring 32 of the butterfly plate 30, thereby achieving a pressure self-reinforcing sealing effect.

[0030] This butterfly valve adopts a triple eccentric structure design. When the medium flows in from the inlet end, the pressure pushes the butterfly plate 30 to press against the sealing cone surface 521. At the same time, the triple eccentric structure generates a wedge effect, which enhances the sealing pressure. When the medium flows in the reverse direction, the pressure of the medium in the pipeline acts on the outside of the first extrusion band 54, pushing it to move slightly towards the butterfly plate 30. The gap is automatically compensated by the first push rod 55 and the sealing block 56 to achieve reliable reverse sealing.

[0031] During operation, the butterfly plate 30 disengages from the valve seat sealing surface at the initial opening stage, resulting in frictionless opening and closing. During closing, the butterfly plate 30 presses against the floating valve seat 50 at a progressive angle, forming a sealing process of first contact and then compression, which significantly reduces wear and scratches on the sealing surface and extends service life.

[0032] Furthermore, a first limiting plate 551 is fixedly installed on the first push rod 55, and a second limiting plate 523 is fixedly installed on the inner wall of the L-shaped channel 522. A first spring 552 is sleeved on the first push rod 55, and the two ends of the first spring 552 are fixed to the first limiting plate 551 and the second limiting plate 523 respectively, thereby limiting the maximum extension stroke of the first push rod 55, preventing damage to the floating block 52 due to excessive movement, and providing a restoring force for the sealing block 56.

[0033] To ensure that the floating block 52 moves smoothly only radially when under pressure, avoiding deflection or jamming, refer to Figure 6The inner wall of the static sealing seat 40 is provided with a guide groove 41, and the outer peripheral surface of the floating block 52 is provided with a guide boss 524. The guide boss 524 and the guide groove 41 are fitted with a clearance, which not only ensures that the floating block 52 can move freely in the radial direction under the action of medium pressure, but also effectively restricts its circumferential rotation and axial movement, ensuring that the sealing cone surface 521 is accurately aligned and uniformly stressed.

[0034] Reference Figure 5 - Figure 8 The butterfly plate 30 includes an arc-shaped plate 31, a sealing ring 32, and a pressure ring 33. The arc-shaped plate 31 is the main load-bearing component, and its overall shape is streamlined to reduce flow resistance and weight. An annular groove 311 is provided at the edge of the surface. A sealing gasket 312 is installed in the annular groove 311. The sealing gasket 312 acts as a primary sealing barrier, which can effectively prevent the medium from seeping in through the tiny gap between the arc-shaped plate 31 and the sealing ring 32, thereby improving the overall sealing reliability. The pressure ring 33 fixes the sealing ring 32 to the arc-shaped plate 31 with bolts. Preferably, an anti-loosening gasket is provided between the pressure ring 33 and the arc-shaped plate 31 to prevent the bolts from loosening due to vibration. An alloy layer is welded onto the conical surface of both the sealing block 56 and the sealing ring 32, and the two work together to form a metal-to-metal hard seal pair.

[0035] The sealing ring 32 is a key sealing element. Its outer edge is machined with a high-precision conical sealing surface, which forms a metal-to-metal hard seal with the sealing conical surface 521 of the floating block 52 in the floating valve seat 50. To enhance sealing adaptability, an installation groove 321 is provided on the conical surface of the sealing ring 32. A second sealing ring 34 is embedded in the installation groove 321. The surface of the second sealing ring 34 is flush with the conical surface of the sealing ring 32, avoiding scratching or stress concentration during opening and closing, and realizing a composite sealing mechanism with hard sealing as the main method and soft sealing as the auxiliary method.

[0036] When the valve is closed, the drive mechanism 60 rotates the valve stem 20, causing the butterfly plate 30 to rotate to a position perpendicular to the flow channel. Thanks to the triple eccentric structure design, the butterfly plate 30 generates a slight axial wedging motion at the end of the closing phase. The conical surface of its sealing ring 32 gradually comes into contact with and presses against the sealing conical surface 521 of the floating valve seat 50. At this time, the first-stage seal is achieved by the sealing gasket 312, preventing the medium from penetrating along the interface between the arc-shaped plate 31 and the sealing ring 32. The second-stage main seal is provided by the metal conical surface pair of hard alloy overlay, forming a high-pressure seal under the pressure of the medium or the preload of the spring plate 51. The third-stage auxiliary seal is provided by the second sealing ring 34, reducing the risk of leakage.

[0037] Reference Figures 5 to 8A second extrusion band 35 is fixedly installed on the side of the plate 31 opposite to the pressure ring 33. An extrusion groove 316 is opened inside the plate 31. An extrusion rod 317 is slidably installed in the extrusion groove 316. One end of the extrusion rod 317 is fixed to the second extrusion band 35. A second spring 313 is fixedly connected between the other end of the extrusion rod 317 and the bottom surface of the groove of the extrusion groove 316. When there is no external pressure, the second spring 313 provides a pre-tightening force to the extrusion rod 317, so that the second extrusion band 35 maintains a certain initial compression state. When subjected to medium pressure, the second spring 313 can absorb part of the impact energy. An air passage 314 is opened inside the plate 31. One end of the air passage 314 is connected to the extrusion groove 316. The other end of the air passage 314 is fixedly connected to an air pipe 315. The air pipe 315 is connected to the second sealing ring 34, so that the working state of the second sealing ring 34 can be indirectly adjusted by controlling the gas pressure in the air passage 314.

[0038] Furthermore, a guide cylinder 318 is fixedly installed on the plate 31, and the extrusion rod 317 is slidably installed inside the guide cylinder 318 to ensure that the extrusion rod 317 moves smoothly only along the axial direction and avoids the occurrence of deviation or jamming.

[0039] When the valve is closed, the pressure of the medium in the pipeline acts on the second extrusion band 35, causing it to indent inward, pushing the extrusion rod 317 to compress the second spring 313, and forcing the gas in the extrusion groove 316 into the auxiliary second sealing ring 34 through the air passage 314 and the air pipe 315, causing the auxiliary second sealing ring 34 to expand radially to enhance the sealing effect. At the same time, the indentation deformation of the second extrusion band 35 plays a buffering role against the impact of the medium.

[0040] Working principle: In the initial stage of valve closure, the butterfly plate 30 disengages from the valve seat sealing surface, resulting in frictionless opening and closing. During closure, the butterfly plate 30 gradually presses against the floating valve seat 50 at an angle, forming a sealing process of contact followed by compression, reducing wear on the sealing surface and extending service life. When the valve is closed, under positive sealing conditions, the medium pressure in the pipeline acts on the second compression band 35, causing it to indent inward, pushing the compression rod 317 to compress the second spring 313, and forcing gas through the air passage 314 and air pipe 315 into the auxiliary second sealing ring 34, causing the auxiliary second sealing ring 34 to expand radially, enhancing the sealing effect, and simultaneously buffering the impact of the medium. In addition, the guide cylinder 318 ensures that the compression rod 317 moves smoothly only along the axial direction, avoiding deviation or jamming. The first limiting plate 551 on the first push rod 55 and the second limiting plate 523 in the L-shaped channel 522 limit the maximum extension stroke of the first push rod 55, preventing damage to the floating block 52 due to excessive movement, and providing a reset force for the sealing block 56. In the reverse sealing state, the pressure of the medium in the pipeline acts on the outside of the first extrusion band 54, pushing it to move slightly towards the butterfly plate 30, and automatically compensates for the gap through the first push rod 55 and the sealing block 56, achieving a pressure-reinforced sealing effect.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cryogenic high-pressure triple eccentric butterfly valve, comprising a valve body (10), a valve stem (20), and a butterfly plate (30), wherein a ring of static sealing seats (40) is fixedly installed on the inner wall of the valve body (10), characterized in that: The valve stem (20) passes through the valve body (10) and is fixedly connected to the butterfly plate (30) through a keyway structure. A floating valve seat (50) is provided on the side of the static sealing seat (40) near the butterfly plate (30). The floating valve seat (50) includes a spring plate (51), a floating block (52) and a first sealing ring (53). The floating block (52) has a sealing cone surface (521) adapted to the edge of the butterfly plate (30) on the side facing the butterfly plate (30). The floating block (52) has a first extrusion band (54) fixedly installed on the side facing away from the butterfly plate (30). The floating block (52) has an L-shaped channel (522) inside. The L-shaped channel (522) has a first push rod (55) and a sealing block (56) installed in it respectively. One end of the first push rod (55) is fixedly connected to the first extrusion band (54). A first limiting plate (551) is fixedly installed on the first push rod (55), and a second limiting plate (523) is fixedly installed on the inner wall of the L-shaped channel (522). A first spring (552) is sleeved on the first push rod (55), and the two ends of the first spring (552) are respectively fixed to the first limiting plate (551) and the second limiting plate (523). The butterfly plate (30) includes a plate body (31), a sealing ring (32) and a pressure ring (33). An annular groove (311) is provided at the edge of the surface of the plate body (31). A sealing gasket (312) is installed in the annular groove (311). The pressure ring (33) fixes the sealing ring (32) to the plate body (31) by bolts. An alloy layer is welded on the conical surface of the sealing block (56) and the sealing ring (32). The two cooperate to form a metal-to-metal sealing pair. The sealing ring (32) has an installation groove (321) on its conical surface, and a second sealing ring (34) is embedded in the installation groove (321). The surface of the second sealing ring (34) is flush with the conical surface of the sealing ring (32). A second extrusion band (35) is fixedly installed on the side of the plate (31) away from the pressure ring (33). An extrusion groove (316) is provided inside the plate (31). An extrusion rod (317) is slidably installed in the extrusion groove (316). One end of the extrusion rod (317) is fixed to the second extrusion band (35). A second spring (313) is fixedly connected between the other end of the extrusion rod (317) and the bottom surface of the groove (316). An air passage (314) is provided inside the plate (31). One end of the air passage (314) is connected to the extrusion groove (316). An air pipe (315) is fixedly connected to the other end of the air passage (314). The air pipe (315) is connected to the second sealing ring (34).

2. The cryogenic high-pressure triple eccentric butterfly valve according to claim 1, characterized in that: The inner wall of the static sealing seat (40) is provided with a guide groove (41), and the outer peripheral surface of the floating block (52) is provided with a guide boss (524), and the guide boss (524) and the guide groove (41) are in clearance fit.

3. The cryogenic high-pressure triple eccentric butterfly valve according to claim 1, characterized in that: A guide cylinder (318) is fixedly installed on the plate (31), and the extrusion rod (317) is slidably installed inside the guide cylinder (318).

4. The cryogenic high-pressure triple eccentric butterfly valve according to claim 1, characterized in that: One end of the valve stem (20) extends to the outside of the valve body (10) and is connected to a drive mechanism (60). An extension neck (11) is provided between the valve body (10) and the drive mechanism (60), and the extension neck (11) is filled with packing material (12).

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