Y-shaped low-temperature stop valve

Abstract

The Y-shaped low-temperature stop valve comprises a valve body assembly and a movable valve rod assembly, a valve clack assembly installed at one end of the valve rod assembly is arranged in the valve body assembly, the Y-shaped low-temperature stop valve further comprises a valve deck assembly installed at the end, away from the valve clack assembly, of the valve body assembly in the axial direction of the valve rod assembly, and a pressure balance cavity and a pressure guiding channel are formed in the valve deck assembly. The piston is used for communicating the pressure balance cavity with the valve body assembly, and the piston is installed in the pressure balance cavity and moves synchronously with the valve rod assembly. Force output to the valve rod assembly for sealing is reduced through the pressure balance cavity, strong convective heat exchange between a low-temperature liquid medium in the pressure guide channel and a channel material is avoided through the design of the pressure guide channel, and the situation that cold energy generated by the pressure guide medium is transmitted to the pressure balance cavity is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of valves, and in particular relates to a Y-type low-temperature stop valve. Background Art

[0002] The stop valve is widely used and is the most direct and reliable type of valve in sealing among all valves. The industries such as petroleum, chemical industry, metallurgy, electric power, water treatment, etc. all use the pressure of the pump to realize pipeline medium transportation. In their transportation pipelines, there will also be a stop valve for opening and closing the transportation pipeline. The sealing principle of the stop valve is to rely on the transmission mechanism to transfer the force to the valve disc sealing surface through the valve stem. The valve disc sealing surface and the valve seat sealing surface form a forced seal through the principle of extrusion elastic deformation. There is no friction on the sealing surface and the seal is reliable.

[0003] In order to improve the sealing performance of the existing Y-type pneumatic low-temperature stop valve, when using the cylinder seal, especially under large-caliber or high-pressure working, the cylinder needs a large output force, and the unbalanced force on the valve stem is large, which seriously affects the service life of the cylinder and the sealing life of the valve body. At the same time, for the large-caliber low-temperature Y-type stop valve, the internal blind cavity is large in volume, and the low-temperature medium in the valve body or the evaporating gas and the valve stem metal material produce strong convection heat exchange, the medium transfers a large amount of cold, and under certain working conditions, it will be gasified and accumulated over a large area. The gas enters the downstream pipeline along the valve outlet and damages the downstream equipment. The overall heat leakage of the valve is also large.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art. The purpose is to provide a Y-type low-temperature stop valve structure to reduce the cylinder output force requirements and, at the same time, reduce the cold transfer generated by the medium to prevent the low-temperature medium from gasifying and accumulating over a large area in the valve body cavity. The gas will enter the downstream pipeline along the valve outlet and damage the downstream equipment, thereby reducing the overall heat leakage of the valve.

[0006] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is: A Y-type low-temperature stop valve comprises a valve body assembly, a movable valve stem assembly, a valve flap assembly installed at one end of the valve stem assembly, and a A valve cover assembly is installed at one end of the valve body assembly axially away from the valve disc assembly along the valve stem assembly, and a pressure balance chamber is provided in the valve cover assembly; A pressure-introducing channel, used to connect the pressure-balancing chamber to the valve body assembly; The piston is installed in the pressure balance chamber and moves synchronously with the valve stem assembly.

[0007] Furthermore, the pressure-inducing channel is arranged on the valve stem assembly, one end of which is communicated with the pressure balance chamber, and the other end of which is communicated with the valve body assembly.

[0008] Furthermore, the pressure-inducing channel extends to the pressure balance chamber at the axis or deviates from the axis along the axis direction; Preferably, the pressure-introducing channel extends along the axis to the portion of the valve stem assembly in the pressure-balancing chamber, and then extends radially to communicate with the pressure-balancing chamber; More preferably, the pressure-inducing channel is an annular channel disposed close to the outer periphery of the valve stem assembly, and extends axially to communicate with the pressure balance chamber.

[0009] Furthermore, the pressure balance chamber is divided into a variable first chamber and a second chamber by a piston, and the pressure-inducing channel includes a first channel and a second channel; In a sealed state, the first chamber is communicated with the valve body inlet through a first passage, and the second chamber is communicated with the valve body assembly through a second passage; In the open state, the first chamber and the second chamber are in communication with the valve body assembly.

[0010] Furthermore, the valve stem assembly includes an inner valve stem and an outer valve stem disposed in at least a partial gap around the inner valve stem, and the gap portion constitutes the first channel.

[0011] Furthermore, the valve cover assembly includes a support rod, and the support rod is sleeved on the outer circumference of the outer valve stem and is provided with a gap, and the gap constitutes the second channel.

[0012] Furthermore, a heat-insulating chamber is provided on the periphery of the pressure-inducing channel, and the heat-insulating chamber is used to reduce the amount of cold transferred to the outside of the valve cover assembly.

[0013] Furthermore, the valve cover assembly comprises a valve body support inner tube and a valve body support outer tube spaced apart at the periphery thereof, and the space between the valve body support inner tube and the valve body support outer tube constitutes a heat-insulating chamber.

[0014] Furthermore, an exhaust device is provided near the installation position of the valve body assembly and the valve cover assembly, and the exhaust device is used to exhaust the gas in the valve body assembly.

[0015] Furthermore, the valve cover assembly also includes a lower valve cover, which is provided with a supporting inner tube, a supporting outer tube and a supporting head at one end of the valve body assembly, and a sealed chamber formed by connecting the two of them. The sealed chamber is located in the valve body assembly, and a gap is set between the supporting outer tube and the inner wall of the valve body assembly, and the exhaust device is located in the gap close to one end of the valve cover assembly.

[0016] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art: 1. The present invention reduces the force required by the pneumatic actuator to drive the valve stem assembly to seal by providing a valve cover assembly and a pressure balance chamber formed therein, and a pressure induction channel connected to the pressure balance chamber. The pressure induction medium enters the pressure balance chamber through the pressure induction channel, thereby avoiding strong convection heat exchange between the low-temperature liquid medium or its evaporation gas in the pressure induction channel and the channel material, thereby effectively reducing the cold amount generated by the pressure induction medium and transferred to the pressure balance chamber; 2. The present invention further forms a closed heat-insulating space through the valve body support inner tube and the valve body support outer tube to prevent external water vapor from frosting or icing on the lower valve cover. The valve body support inner tube is used to bear the pressure of the internal medium and reduce the transfer of cold. The valve body support outer tube assists the valve body support inner tube to support the upper valve cover and the upper weight. 3. The present invention discharges the gas after the low-temperature medium in the valve body cavity is vaporized by the exhaust hole and the exhaust device arranged in the valve body cavity, thereby avoiding accumulation in the valve body cavity. After a large amount of accumulation, it enters the downstream pipeline through the valve body outlet, damages the downstream equipment, and reduces the overall heat leakage of the valve.

[0017] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the drawings described below are only some embodiments. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the accompanying drawings: Figure 1 It is a cross-sectional schematic diagram of a Y-type cryogenic stop valve of the present invention; Figure 2 This is an enlarged schematic diagram of the valve cover of the Y-type cryogenic stop valve of the present invention. Figure 1 ; Figure 3 This is an enlarged schematic diagram of the valve cover of the Y-type cryogenic stop valve of the present invention. Figure 2 ; Figure 4 This is an enlarged schematic diagram of the valve disc assembly of the Y-type low-temperature stop valve of the present invention. Figure 1 .

[0019] In the figure: 1. valve body assembly; 11. valve body body; 12. valve body inlet; 13. valve body outlet; 14. valve body outlet pipe; 15. rib plate; 16. valve body middle cavity; 17. upper guide; 18. lower guide; 19. exhaust device; 2. valve stem assembly; 21. upper valve stem; 22. inner valve stem; 23. outer valve stem; 200. pressure-inducing channel; 201. first channel; 202. second channel; 203. pressure-inducing hole; 3. valve disc assembly; 31. valve disc Main body; 32. Valve disc guide; 33. Air hole; 4. Valve cover assembly; 41. Valve cover body; 411. Upper valve cover; 412. Lower valve cover; 43. Valve body support inner tube; 431. Insulation chamber; 44. Valve body support outer tube; 45. Piston; 46. Pressure balance chamber; 461. First chamber; 462. Second chamber; 47. Support inner tube; 48. Support outer tube; 49. Support head; 5. Pneumatic actuator; 6. Process hole; 7. Seal.

[0020] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments 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, it should be noted that the directions or positional relationships indicated by terms such as “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings, and are 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 direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] like Figures 1 to 4As shown, a Y-type stop valve provided by the present invention includes a valve body assembly 1 and a movable valve stem assembly 2. A valve flap assembly 3 installed at one end of the valve stem assembly 2 is provided in the valve body assembly 1. A valve cover assembly 4 is installed at one end of the valve body assembly 1 axially away from the valve flap assembly 3 along the valve stem assembly 2. The valve cover assembly 4 is provided with a pressure balancing chamber 46. The pressure balancing chamber 46 is connected to the valve body assembly 1 through a pressure-inducing channel 200. A piston 45 that moves synchronously with the valve stem assembly 2 is provided in the pressure balancing chamber 46. The valve flap assembly 3 is movably arranged in the valve body assembly 1 to complete the opening and sealing of the valve body inlet 12.

[0025] Specifically, the valve body assembly 1 includes a valve body middle cavity 16 formed by a valve body main body 11, a valve body inlet 12 and a valve body outlet 13. The valve flap assembly 3 is movably located at the valve body inlet 12, connected with the valve stem assembly 2 and moved together to complete the opening and sealing of the valve body inlet 12. The valve cover assembly 4 includes a valve cover main body 41, and an upper valve cover 411 is installed on the valve cover main body 41. The valve cover main body 41 and the upper valve cover 411 constitute a pressure balance chamber 46. A piston 45 is movably provided in the pressure balance chamber 46. The piston 45 is connected to the valve stem assembly 2 and moves together. A pressure-inducing channel 200 is provided on the valve stem assembly 2. The pressure-inducing channel 200 is communicated with the pressure balance chamber 46. The pressure balance chamber 46 is divided into two chambers through the piston 45. During the movement of the piston 45, the space of the two chambers changes, and the airflow enters or is discharged from the chamber through the pressure-inducing channel 200 to maintain pressure balance. The pressure-inducing channel 200 includes a first channel 201 and a second channel 202. The two chambers include a first chamber 461 and a second chamber 462. The first chamber 461 is communicated with the first channel 201. The other end of the first channel 201 extends to the valve body inlet 12. The second chamber 462 is communicated with the valve body middle cavity 16 through the second channel 202. When the valve flap assembly 2 is sealed, the piston 45 is close to the inner wall of the second chamber 462. During the opening and movement of the valve flap assembly 2, the space of the first chamber 461 is reduced and the space of the second chamber 462 is increased. The medium in the first chamber 461 is discharged into the valve body through the first channel 201, and the medium enters the second chamber 462 through the second channel 202 to maintain the air pressure balance of the pressure balance chamber 46. The pressure balance chamber 46 is set to balance the medium pressure at the valve body inlet 12, thereby reducing the force required for the pneumatic actuator 5 to seal the valve body inlet 12. The pressure induction channel 200 vaporizes the low-temperature medium to prevent the cold from being transferred to the pressure balance chamber 46 and affecting normal use.

[0026] In another embodiment, the pressure balancing chamber 46 on the side of the piston 45 away from the valve body inlet 12 is connected to the pressure inlet channel 200, and the pressure balancing chamber close to the valve body inlet 12 is a sealed chamber. The pressure inlet channel 200 connects the valve body inlet 12 and the pressure balancing chamber 46. The low-temperature medium at the valve body inlet 12 exerts a certain pressure on the valve flap assembly 3, prompting the valve stem assembly 2 and the valve flap assembly 3 to move away from the valve body inlet 12. The pressure balancing chamber on the side of the piston 45 close to the valve body inlet 12 forms a negative pressure, prompting the valve stem assembly 2 and the valve flap assembly 3 to move toward the valve body inlet 12, thereby reducing the force required for sealing by the pneumatic actuator 5, and then the pressure balance in the pressure balancing chamber 46 and the valve body inlet 12 is balanced through the pressure inlet channel 200, thereby reducing the force required for sealing by the pneumatic actuator 5.

[0027] like Figure 2 As shown, in a further embodiment, a sealing member 7 is provided between the piston 45 and the valve stem assembly 2 , and a sealing member 7 is provided between the piston 45 and the inner wall of the pressure balance chamber 46 .

[0028] Specifically, the valve stem assembly 2 includes an upper valve stem 21, an inner valve stem 22 and an outer valve stem 23, one end of the inner valve stem 22 is connected to one end of the upper valve stem 21, the outer valve stem 23 is located at the outer periphery of the inner valve stem 22, and its end is connected to one end of the upper valve stem 21, and at least a partial gap is set between the outer valve stem 23 and the inner valve stem 22, and the gap constitutes a first channel 201. In one embodiment, the inner valve stem 22 and the outer valve stem 23 are spaced apart to form an annular columnar first channel 201. In another embodiment, the outer periphery of the inner valve stem 22 is The surface abuts against the inner circumference of the outer valve stem 23, and a groove is provided on the outer circumference of the inner valve stem 22, and the groove extends straight, spirally, or curvedly, and the groove is the first channel 201. A seal 7 is provided at the connection between the piston 45 and the upper valve stem 21, and the piston 45 abuts against the inner wall of the pressure balance chamber 36, and the abutting point is provided in the groove near the middle position, and a seal 7 is provided in the groove to prevent the air pressure of the first chamber 461 and the second chamber 462 from being communicated with each other, and cooperate with the first channel 201 to prevent the cold from being transferred to the pressure balance chamber to affect the work of the seal.

[0029] like Figure 2 As shown, in a further embodiment, at least one pressure-inducing hole 203 is provided on both sides of the upper valve stem 21 along the axial direction of the piston 45 , and the pressure-inducing hole 203 is communicated with the pressure-inducing channel 200 .

[0030] Specifically, at least one pressure-inducing hole 203 is provided in the portion of the upper valve stem 21 in the first chamber 461. In one implementation scheme, one pressure-inducing hole 203 is provided, and part of the first channel 201 is coaxially provided at the axis of the upper valve stem 21. The pressure-inducing hole 203 extends from the outer circumferential axis of the upper valve stem 21 to the first channel 201 and is connected thereto. In another implementation scheme, two pressure-inducing holes 203 are provided, and the pressure-inducing holes 203 extend from the outer circumferential axis of the upper valve stem 21 to the pressure-inducing channel 200 or the first channel 201, respectively. In other more implementation schemes, the difference is that the number of pressure-inducing holes 203 is different and is evenly distributed on the outer periphery of the upper valve stem 21. On the basis of the above embodiment, a gap is provided between the outer valve stem 23 and the valve cover assembly 4 to form a second channel 202, and the second chamber 462 is connected to the valve body middle cavity 16 through the second channel 202. During the movement of the piston 45, the space of the second chamber 462 increases or decreases, and the air pressure in the chamber is communicated and balanced with the valve body chamber 16 through the second channel 202.

[0031] like Figures 1 to 3 As shown, in a further implementation scheme, the valve cover assembly 4 also includes a valve body support inner tube 43 located at the outer periphery of the outer valve stem 23, and a valve body support outer tube 44 is provided at the outer periphery of the valve body support inner tube 43, and an insulating chamber is formed between the valve body support inner tube 43 and the valve body support outer tube 44.

[0032] Specifically, the valve cover assembly 4 also includes a lower valve cover 412, and the valve cover body 41 is connected to the lower valve cover 412 through a valve body support inner tube 43 and a valve body support outer tube 44. The valve body support inner tube 43 is arranged at intervals on the outer periphery of a portion of the outer valve stem 13, and the valve body support outer tube 44 is arranged at intervals on the outer periphery of the valve body support inner tube 43. The valve body support outer tube 44, the valve body support inner tube 43, the valve cover body 41 and the lower valve cover 412 form an insulating chamber 431. When the valve stem assembly 2 moves to drive the valve flap assembly 3 to open and seal, the valve body middle cavity 19 is filled with low-temperature medium, and the first channel 201 and the second channel 202 are connected to the medium due to air pressure, and the low-temperature medium is discharged by the liquid in the pressure-inducing channel 200. The state is converted into a gaseous state, and the pressure balance chamber 46 is filled with gas. This structure avoids the strong convection heat exchange between the low-temperature liquid medium or its evaporation gas in the pressure-inducing channel 200 and the valve stem metal material, thereby effectively reducing the cold transfer of the low-temperature medium to the pressure balance chamber 46, affecting the use of the seal 7 in the pressure balance chamber 46, and its valve body support inner tube 43 is used to carry the medium between it and the outer valve stem 23. The valve body support inner tube 43 has a smaller wall thickness, which reduces the transfer of cold. The valve body support outer tube 44 is used to support the auxiliary valve body support inner tube 43 and support the weight of the upper part of the valve cover. The heat-insulating space is beneficial to prevent external water vapor from frosting or icing on the lower valve cover 412 or the valve body support outer tube 44, affecting normal use.

[0033] like Figure 3 As shown, in a further implementation scheme, the lower valve cover 412 is connected to a supporting outer tube 48 and a supporting inner tube 47, and the other ends of the supporting outer tube 48 and the supporting inner tube 47 are connected by a supporting head 49, which are connected to each other to form a closed cavity, and the cavity is located in the valve body cavity 16 near one end of the lower valve cover 412.

[0034] Specifically, the lower valve cover 412 is installed on the valve body assembly 1, and the valve body assembly 1 constitutes a valve body middle cavity 16. The lower valve cover 412 is connected to a supporting outer tube 48 and a supporting inner tube 47 at one end facing the valve body middle cavity 16. The supporting outer tube 48 and the supporting inner tube 47 are spaced apart and are located on the outer periphery of the outer valve stem 23. The gap between the supporting inner tube 47 and the outer valve stem 23 constitutes a part of the second channel 202. The supporting inner tube 47 and the supporting outer tube 48 are connected at one end away from the lower valve cover 412 through a supporting head 49, and are connected to each other to form a sealed cavity. The end face of the supporting head 49 away from the cavity is inclined to transition with the valve body outlet 13 and are on the same inclined surface.

[0035] In a further embodiment, a guide member for keeping the valve stem assembly 2 tilted is provided on the outer periphery of the valve stem assembly 2 .

[0036] Specifically, the guide member includes an upper guide 17 and a lower guide 18, and the upper guide 17 and the lower guide 18 are in the shape of an annular column. The valve flap assembly 3 and the valve stem assembly 2 can be movably abutted against the inner wall thereof. The upper guide 17 is connected to the support inner tube 47, and a groove is provided on the inner side of the support inner tube 47. The upper guide 17 is clamped in the groove. The upper guide 17 is axially provided with a plurality of through holes, and the plurality of through holes are part of the second channel 202. The interior of the upper guide 17 abuts against the outer valve stem 23 of the valve stem assembly 2. The lower guide 18 is located at the valve body inlet 12. A rib plate 15 is provided on the outer periphery of the lower guide 18. The rib plate 15 is connected to the inner wall of the valve body inlet 12, and the other end thereof abuts and is connected to the outer periphery of the lower guide 18. The rib plate 15 abuts against the valve body and the valve flap assembly 3. Through the upper guide 17 and the lower guide 18, the valve stem assembly 2 and the valve flap assembly 3 can better seal and cooperate with the valve body inlet 12, and support the inclination of the valve stem assembly 2.

[0037] In a further implementation scheme, the valve flap assembly 3 includes a valve flap body 31 and a valve flap guide 32. The valve flap body 31 is provided with a notch, and the end of the outer valve stem 23 extends into the notch. The valve flap body 21 is provided with a valve flap guide 22 at one end close to the valve body inlet 12. The valve flap guide 22 is movably arranged in the lower guide 18.

[0038] Specifically, the valve flap assembly 3 includes a valve flap body 31, the valve flap body 31 is coaxially provided with a notch, the notch is a through hole, the outer valve stem 23 extends into the notch, the valve flap body 31 is connected to a valve flap guide 32 at one end near the valve body inlet 12, and the connecting part of the valve flap guide 32 and the valve flap body 31 is provided with at least one through hole, the through hole is connected with the pressure guide channel 200, the low-temperature medium enters the pressure guide channel 200 through the through hole, and then connects to the pressure balance chamber 46 to maintain air pressure balance, the valve flap body 31 is fixedly connected to the outer valve stem 23, and moves synchronously with the valve stem assembly 2.

[0039] In a further implementation scheme, the valve body cavity 16 in the valve body assembly 1 is provided with an exhaust device 19 connected to the outside. The exhaust device 19 is arranged near the lower valve cover 412. The low-temperature gas in the valve body cavity 16 is discharged through the exhaust device 19, while avoiding the accumulation of a large amount of gas. The gas enters the downstream pipeline along the valve body outlet 13 and damages the downstream equipment.

[0040] Specifically, the valve body main body 11 of the valve body assembly 1 is provided with an air outlet connected to the outside, and the air outlet is provided with an exhaust device 19. In one embodiment, the supporting outer tube 48 is abutted against the valve body main body 11, and the exhaust device 19 and the exhaust hole are arranged near the supporting outer tube 48. In another embodiment, a gap is arranged between the supporting outer tube 48 and the valve body main body 11, and the exhaust device 19 and the exhaust hole are arranged in the gap and near the lower valve cover 412. After the low-temperature medium enters the valve body middle cavity 16, it will be vaporized, and part of the gas will accumulate in the middle cavity. The gas is discharged through the exhaust hole and the exhaust device 19 to avoid large-scale vaporization and accumulation of the low-temperature medium. Under some specific working conditions, the gas enters the downstream pipeline along the valve outlet 13 and damages the downstream equipment.

[0041] In the implementation of the present invention, the valve cover assembly 4 is connected to one end of the valve stem assembly 2 axially away from the valve body assembly 1, and a pneumatic actuator 5 is connected. The pneumatic actuator 5 is fixedly connected to the upper valve cover 411, and its pneumatic stem is connected to the valve stem assembly 2 to drive it to move axially to realize the opening and sealing of the valve body inlet 12. The Y-type low-temperature stop valve of the present invention, the axes of the valve body inlet 12 and the valve body outlet 13 are both 45° to the axis of the valve body middle cavity 16, and the piston 45 and the valve disc body 31 are provided with a plurality of process holes 6. Due to the size and weight of the equipment itself, it cannot be installed manually and needs to be assisted by mechanical equipment. The process holes are used for clamping the installation of the component and for reducing its weight.

[0042] In the embodiment of the present invention, the pneumatic actuator 5 is provided with two air ports, both of which can be used for air intake and exhaust. When executing at the same time, one of the air ports is used for air intake and the other is used for air exhaust. Figure 1When the pneumatic actuator 5 is started, air is taken in through port C and exhaust is taken out through port D, the pneumatic actuator 5 drives the valve stem assembly 2 and the piston 45 to move axially upward, and the valve body inlet 12 is opened; when air is taken in through port D and exhaust is taken out through port C, the pneumatic actuator 5 drives the valve stem assembly 2 and the piston 45 to move axially downward, and the valve body inlet 12 is sealed and closed.

[0043] The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this patent can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical content suggested above without departing from the scope of the technical solution of the present invention. The implementation scheme in the above embodiment can also be further combined or replaced. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the solution of the present invention.

Claims

1. A Y-type cryogenic stop valve, comprising a valve body assembly (1), a movable valve stem assembly (2), a valve flap assembly (3) mounted on one end of the valve stem assembly (2) disposed in the valve body assembly (1), characterized in that: Also includes A valve cover assembly (4) is mounted on one end of the valve body assembly (1) axially away from the valve disc assembly (3) along the valve stem assembly (2), and a pressure balance chamber (46) is provided in the valve cover assembly (4); A pressure-introducing passage (200) for connecting the pressure-balancing chamber (46) to the valve body assembly (1); The piston (45) is installed in the pressure balance chamber (46) and moves synchronously with the valve stem assembly (2).

2. A Y-type cryogenic stop valve according to claim 1, characterized in that: The pressure-inducing channel (200) is arranged on the valve stem assembly (2), one end of which is in communication with the pressure balance chamber (46), and the other end of which is in communication with the valve body assembly (1).

3. A Y-type cryogenic stop valve according to claim 2, characterized in that: The pressure-inducing channel (200) extends to the pressure balance chamber (46) at the axis or deviating from the axis along the axis direction; Preferably, the pressure-inducing channel (200) extends along the axis to the portion of the valve stem assembly (2) located in the pressure-balancing chamber (46), and then extends radially to communicate with the pressure-balancing chamber (46); More preferably, the pressure-inducing channel (200) is an annular channel disposed close to the outer periphery of the valve stem assembly (2), and extends axially to communicate with the pressure balancing chamber (46).

4. A Y-type cryogenic stop valve according to claim 3, characterized in that: The pressure balance chamber (46) is divided into a variable first chamber (461) and a second chamber (462) by a piston (45), and the pressure-inducing channel comprises a first channel (201) and a second channel (202); In a sealed state, the first chamber (461) is in communication with the valve body inlet (12) through the first channel (201), and the second chamber (462) is in communication with the valve body assembly (1) through the second channel (202); In the open state, the first chamber (461) and the second chamber (462) are in communication with the valve body assembly (1).

5. A Y-type cryogenic stop valve according to claim 4, characterized in that: The valve stem assembly (2) comprises an inner valve stem (22) and an outer valve stem (23) disposed in at least a partial gap around the outer periphery of the inner valve stem (22), the gap portion constituting the first channel (201).

6. A Y-type cryogenic stop valve according to claim 5, characterized in that: The valve cover assembly (4) comprises a support rod, the support rod is sleeved on the outer circumference of the outer valve stem (23) and is provided with a gap, and the gap constitutes the second channel (203).

7. A Y-type cryogenic stop valve according to any one of claims 1 to 6, characterized in that: A heat-insulating chamber (431) is provided on the outer periphery of the pressure-inducing channel (200), and the heat-insulating chamber (431) is used to reduce the amount of cold transferred to the outside of the valve cover assembly (4).

8. A Y-type cryogenic stop valve according to claim 7, characterized in that: The valve cover assembly (4) comprises a valve body support inner tube (43) and a valve body support outer tube (44) spaced apart on the outer periphery thereof, wherein the space between the valve body support inner tube (43) and the valve body support outer tube (44) constitutes a heat-insulating chamber (431).

9. A Y-type cryogenic stop valve according to any one of claims 1 to 8, characterized in that: An exhaust device (19) is provided near the installation position of the valve body assembly (2) and the valve cover assembly (4), and the exhaust device (19) is used to exhaust the gas in the valve body assembly (2).

10. A Y-type cryogenic stop valve according to claim 9, characterized in that: The valve cover assembly (4) further comprises a lower valve cover (412), wherein the lower valve cover (412) is provided with a supporting inner tube (47), a supporting outer tube (48) and a supporting head (49) at one end of the valve body assembly (1), and the two are connected to form a sealed chamber, wherein the sealed chamber is located in the valve body assembly (1), and a gap is provided between the supporting outer tube (48) and the inner wall of the valve body assembly (1), and the exhaust device (19) is located in the gap close to one end of the valve cover assembly (4).

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