Wedge type double-gate-disc gate valve

Abstract

The utility model discloses a wedge type double-gate-plate gate valve, which relates to the technical field of valves and comprises a valve body, a left valve seat, a right valve seat, a liftable valve rod, a left gate plate, a right gate plate, a spherical center and a cross. The valve body is provided with a fluid channel and a valve cavity communicated with the fluid channel; the left valve seat and the right valve seat are fixedly arranged on the two sides of the interior of the fluid channel at the position communicated with the valve middle cavity respectively. The top of the cross is used for being fixedly connected with one end of a valve rod located in the valve middle cavity. A central hole is formed in the cross; the left gate plate is used for blocking the left valve seat, and the right gate plate is used for blocking the right valve seat. The cross is positioned between the left flashboard and the right flashboard; the spherical center is located in the center hole. A first hinge boss is fixedly arranged on the side, close to the center hole, of the left gate plate, and a second hinge boss is fixedly arranged on the side, close to the center hole, of the right gate plate. The first hinge boss and the second hinge boss are each provided with a spherical groove. And good sealing performance of the valve is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of valves, in particular to a wedge-type double-disc gate valve. Background Art

[0002] A valve is a control device in a fluid delivery system. It is a mechanical product with a movable mechanism used to control the flow of media in a pipeline. It has the functions of guiding, intercepting, regulating, controlling flow direction, diverting or regulating pressure, and unloading pressure.

[0003] Valves come in many designs and types due to the variety of systems, fluids, and environments in which they operate. Valves can be divided into shutoff valves, check valves, diverter valves, safety valves, regulating valves, etc. according to their purpose and function; they can be divided into vacuum valves, low-pressure valves, medium-pressure valves, high-pressure valves, and ultra-high-pressure valves according to pressure; they can be divided into high-temperature valves, medium-temperature valves, normal-temperature valves, low-temperature valves, and ultra-low-temperature valves according to operating temperature; and they can be divided into non-metallic valves and metal valves according to valve body materials. At present, the most common types of valves include gate valves, globe valves, ball valves, butterfly valves, diaphragm valves, plug valves, check valves, safety valves, pressure reducing valves, steam traps, etc.

[0004] Among various types of valves, gate valves are the most commonly used in actual industrial fields. The principle of the gate valve is that the gate moves vertically along the inner axis of the valve body driven by the power source, and is used to cut off the medium in the transmission pipeline, that is, fully open or fully closed. The main structure of the gate valve consists of several parts such as the valve stem, valve cover, valve seat, gate, valve body, etc. It can be used in a wide range of temperature, and can be used in both low temperature and high temperature conditions. Due to different media, its properties are also different. For this reason, valve materials with different performances can be used to adapt to the medium. Gate valves are widely used in steam pipelines such as thermal power plants and refineries, and are widely used in oil and natural gas transmission pipelines, crude oil transmission pipelines and storage equipment, and slurry pipeline transmission lines.

[0005] Gate valves usually have single gate, double gate, wedge type, parallel type and other structural designs. Wedge type elastic gate (Z40, Z60 series) gate valves are the most widely used, followed by wedge type double gate (Z42, Z62 series) gate valves. The wedge type elastic gate relies on the elastic groove in the middle of the gate to make the gate produce elastic deformation under the pressure of the medium to achieve the sealing of the wedge type gate valve. Traditional wedge type double gate valves such as Figure 2As shown, it is composed of two different shapes of left gate plate 2' and right gate plate 3'. The left gate plate 2' corresponds to the left valve seat 11' in the valve body 1', and the right gate plate 3' corresponds to the right valve seat 12' in the valve body 1'. The middle of the two gate plates is hinged in the cross 4' with a top core 5' with one side being a spherical surface and the other side being a straight surface to form a wedge-shaped gate plate. The top of the cross 4' is connected to the valve stem 13'. The wedge angle of the gate plate sealing surface is automatically adjusted by the spherical surface of the top core, but because the other side of the top core 5' is a plane, the right gate plate 3' hinged to the straight surface of the top core 5' is easy to get stuck when the temperature changes, and will cause scratches on the sealing surface of the right valve seat 12' of the valve body 1', affecting the sealing performance of the valve. Utility Model Content

[0006] The utility model aims to provide a wedge-type double-disc gate valve to solve the problems existing in the above-mentioned prior art and ensure good sealing performance of the valve.

[0007] To achieve the above purpose, the utility model provides the following solutions:

[0008] The utility model provides a wedge-type double-disc gate valve, comprising a valve body, a left valve seat, a right valve seat, a valve stem capable of being raised and lowered, a left gate plate, a right gate plate, a spherical top center and a cross; the valve body has a fluid channel and a valve middle cavity connected to the fluid channel; the left valve seat and the right valve seat are respectively fixedly arranged on both sides of the inside of the fluid channel connected to the valve middle cavity; the top of the cross is used to be fixedly connected to one end of the valve stem located in the valve middle cavity; a center hole is provided on the cross; the left gate plate is used to block the left valve seat, and the The right gate plate is used to seal on the right valve seat; the cross is located between the left gate plate and the right gate plate; the spherical top center is located in the center hole; and a first hinged boss is fixedly provided on the side of the left gate plate close to the center hole, and a second hinged boss is fixedly provided on the side of the right gate plate close to the center hole; a spherical groove for fitting with the outer wall of the spherical top center is provided on the first hinged boss and the second hinged boss; the left gate plate and the right gate plate can both rotate relative to the spherical top center around the center of the spherical top center.

[0009] Preferably, the circumferential side walls of the left gate plate and the right gate plate are fixed with annular gate plate limiting bosses; upper limit claws are fixedly provided at positions above the cross corresponding to the annular gate plate limiting bosses of the left gate plate and the right gate plate, and lower limit claws are fixedly provided at positions below the cross corresponding to the annular gate plate limiting bosses of the left gate plate and the right gate plate; the upper limit claw and the corresponding lower limit claw can limit the corresponding left gate plate or the right gate plate from detaching from the cross; when the annular gate plate limiting boss is located in the upper limit claw and the lower limit claw, the left gate plate and the right gate plate can both rotate relative to the spherical top center.

[0010] Preferably, each of the lower limit claws is integrally formed with the cross.

[0011] Preferably, the left gate plate is located on the side of the fluid channel close to the upstream, and an automatic pressure relief device is provided on the left gate plate; when the pressure in the valve cavity is greater than the pressure in the fluid channel on the upstream side, the automatic pressure relief device can connect the valve cavity with the fluid channel on the upstream side.

[0012] Preferably, the automatic pressure relief device includes a screw plug, a sealing steel ball and an elastic member; a through hole is provided on the left gate plate, and the through hole includes a gate plate pressure relief hole, an elastic member resting hole and a screw plug resting hole which are arranged in sequence, and the screw plug resting hole is located on a side close to the spherical top center; a through screw plug pressure relief hole is provided on the screw plug; the inner diameter of the gate plate pressure relief hole is smaller than the inner diameter of the elastic member resting hole, and the inner diameter of the elastic member resting hole is smaller than the inner diameter of the screw plug resting hole; the elastic member is located in the elastic member resting hole, and the screw plug is sealably fixed in the screw plug resting hole; the sealing steel ball is located between the elastic member and the screw plug; the end of the elastic member can squeeze the sealing steel ball to move to a side close to the screw plug, and the sealing steel ball can block the screw plug pressure relief hole.

[0013] Preferably, an internal thread is arranged in the screw plug placement hole, an external thread is arranged on the outer side wall of the screw plug, and the internal thread is threadably connected to the external thread.

[0014] Preferably, a connecting hole for connecting to the valve stem end and a first axis pin hole connected to the connecting hole are provided at the upper end of the cross, and a second axis pin hole is provided at the position of the valve stem end corresponding to the first axis pin hole; fixing pins are fixedly inserted in the first axis pin hole and the second axis pin hole.

[0015] Preferably, it also includes an inverted U-shaped limit bracket and a fixing nut; the upper end of the cross is a cylindrical rod, the lower end of the cylindrical rod is fixedly provided with a rotation limit block, and the inverted U-shaped limit bracket is provided with a penetrating mounting hole, the mounting hole includes a through hole and a rotation limiting groove, the through hole is sleeved on the cylindrical rod, the rotation limiting groove is sleeved on the rotation limit block, and the cooperation between the rotation limit block and the rotation limiting groove can limit the rotation of the inverted U-shaped limit bracket around the axis of the cylindrical rod; the upper limit claws are formed at both ends of the inverted U-shaped limit bracket; a fixed external thread is provided on the outer side wall of the cylindrical rod, the fixing nut is threadedly connected to the fixed external thread, and the fixing nut and the rotation limit block jointly limit the movement of the inverted U-shaped limit bracket in the direction along the axis of the cylindrical rod.

[0016] Preferably, the outer side walls of the first hinge boss and the second hinge boss are both arc-shaped surfaces, and the arc-shaped surfaces are tangent to the inner wall of the center hole.

[0017] Compared with the prior art, the utility model has achieved the following technical effects:

[0018] The wedge-type double-disc gate valve provided by the utility model adopts a spherical top center and spherical grooves arranged on the left gate plate and the right gate plate, so that the left gate plate and the right gate plate can automatically rotate with the center of the spherical top center as the rotation point, thereby matching the corresponding left valve seat and the right valve seat, and realizing the automatic matching effect of the sealing pair on the corresponding side; reducing the occurrence of sticking due to temperature changes, and ensuring good sealing performance of the valve.

[0019] Furthermore, the upper limit claw and the lower limit claw jointly limit the left gate plate or the right gate plate, preventing the left gate plate or the right gate plate from falling off the cross, thereby ensuring its stable operation; and the limitation of the upper limit claw and the lower limit claw can also keep the left gate plate and the right gate plate from rotating relative to the spherical top center within a certain range, thereby ensuring the rotational sealing fit of the left gate plate and the right gate plate within a certain range, achieving fast and efficient sealing.

[0020] Furthermore, the lower limit claw is integrally formed with the cross, which can solve the problem of the traditional use of fixing screws to fix the lower limit claw on the cross, causing the lower positioning claw to fall off due to alternating temperature stress and vibration of the process equipment, thereby causing the left and right gate plates to fall off, and ultimately causing the gate to fail to work. It is more reliable than the traditional structure.

[0021] Furthermore, the automatic pressure relief device arranged on the left gate plate can automatically relieve the pressure in the valve cavity, thereby ensuring the stability of the pressure in the valve cavity.

[0022] Furthermore, a sealing steel ball and an elastic part are used, and the elastic part squeezes the sealing steel ball to close and open the screw plug pressure relief hole on the screw plug. When the pressure in the valve cavity is greater than the squeezing force of the elastic part and the upstream medium on the sealing steel ball, the automatic pressure relief function can be achieved; when it is less than or equal to the squeezing force of the elastic part and the upstream medium on the sealing steel ball, the sealing steel ball can block the screw plug pressure relief hole. The structure is simple and the pressure relief is stable and reliable.

[0023] Furthermore, the screw plug is installed by means of threads, and has a simple structure and is easy to assemble and disassemble; and the extrusion force of the elastic member can be adjusted to meet different pressure relief requirements.

[0024] Furthermore, the connection between the cross and the end of the valve stem is achieved by means of a connecting hole and a fixing pin, and the connection structure is simple, the connection is firm, and it is stable and reliable.

[0025] Furthermore, a rotation limiting groove provided on the inverted U-shaped limit bracket is used in combination with a rotation limiting block to realize the bearing of the inverted U-shaped limit bracket and limit its circumferential rotation; and the movement of the inverted U-shaped limit bracket in the axial direction is realized by a fixing nut in combination with a fixed external thread on the cylindrical rod. The connection structure is simple and easy to disassemble and assemble.

[0026] Furthermore, the outer walls of the first hinged boss and the second hinged boss are arc-shaped and tangent to the inner wall of the center hole, which can realize the function of automatic alignment of the sealing pair of the left gate plate and the right gate plate at 360°, making the sealing on the corresponding side more reliable; and can eliminate the problem of temperature stress jamming the sealing pair, and avoid the occurrence of sealing pair scratches caused by the traditional top center structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 The overall structural diagram of the wedge-type double-disc gate valve provided by the utility model;

[0029] Figure 2 It is a schematic diagram of the overall structure of a traditional wedge-type double-disc gate valve;

[0030] Figure 3 for Figure 1 A partial enlarged view of the middle A;

[0031] Figure 4 This is a schematic diagram of the overall structure of the cross in the wedge-type double-disc gate valve provided by the utility model;

[0032] Figure 5 for Figure 4 A schematic cross-sectional view from a frontal perspective;

[0033] Figure 6 for Figure 4 A schematic cross-sectional view from a side view perspective;

[0034] Figure 7 A schematic diagram of the structure of the left gate in the wedge-type double-gate gate valve provided by the utility model;

[0035] Figure 8 for Figure 7 Another perspective structural diagram of;

[0036] Fig. 9 for Figure 7 Structural cross-sectional view of

[0037] Fig.10 A schematic diagram of the structure of an inverted U-shaped limit bracket in a wedge-type double-disc gate valve provided by the utility model;

[0038] Fig.11 for Fig.10 Structural cross-sectional view of

[0039] Fig.12 The utility model provides a structural schematic diagram of a spherical top center in a wedge-type double-disc gate valve.

[0040] In the figure:

[0041] 100-Wedge type double disc gate valve;

[0042] 1 / 1'-valve body; 11 / 11'-left valve seat; 12 / 12'-right valve seat; 13 / 13'-valve stem; 14-fluid channel;

[0043] 2 / 2'-left gate; 21-first hinged boss; 22-spherical groove; 23-gate pressure relief hole; 24-elastic member placement hole; 25-screw plug placement hole;

[0044] 3 / 3'-right gate; 31-second hinged boss; 32-annular gate limiting boss;

[0045] 4 / 4'-cross; 41-center hole; 42-lower limit claw; 43-connecting hole; 44-fixing pin; 45-cylindrical rod; 46-rotation limit block;

[0046] 5-spherical top center; 5'-top center;

[0047] 6-automatic pressure relief device; 61-screw plug; 611-screw plug pressure relief hole; 62-elastic member; 63-sealing steel ball;

[0048] 7-inverted U-shaped limiting bracket; 71-perforation; 72-rotation limiting groove; 73-upper limit claw;

[0049] 8-Secure nut. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0051] The utility model aims to provide a wedge-type double-disc gate valve to solve the problems existing in the prior art and ensure good sealing performance of the valve.

[0052] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0053] Embodiment 1

[0054] This embodiment provides a wedge-type double-disc gate valve 100, which is mainly but not limited to thermal power generation and refining equipment, such as Figure 1 and Figure 3 to Figure 12 As shown, it comprises a valve body 1, a left valve seat 11, a right valve seat 12, a valve stem 13 that can be raised and lowered, a left gate plate 2, a right gate plate 3, a spherical top center 5 and a cross 4; the valve body 1 has a fluid channel 14 and a valve cavity connected to the fluid channel 14; the left valve seat 11 and the right valve seat 12 are respectively fixed on both sides of the inside of the fluid channel 14 at the position connected to the valve cavity; the top of the cross 4 is used to be fixedly connected to one end of the valve stem 13 located in the valve cavity; a center hole 41 is provided on the cross 4; the left gate plate 2 is used to block the left valve seat 11, and the right gate plate 3 is used to seal the left valve seat 11. The gate plate 3 is used to seal on the right valve seat 12; the cross 4 is located between the left gate plate 2 and the right gate plate 3; the spherical top center 5 is located in the center hole 41; and a first hinged boss 21 is fixedly provided on the side of the left gate plate 2 close to the center hole 41, and a second hinged boss 31 is fixedly provided on the side of the right gate plate 3 close to the center hole 41; a spherical groove 22 for fitting with the outer wall of the spherical top center 5 is provided on the first hinged boss 21 and the second hinged boss 31; the left gate plate 2 and the right gate plate 3 can both rotate relative to the spherical top center 5 around the center of the spherical top center 5.

[0055] By adopting the spherical top center 5, in combination with the spherical groove 22 provided on the left gate plate 2 and the right gate plate 3, the left gate plate 2 and the right gate plate 3 can automatically rotate with the center of the spherical top center 5 as the rotation point, thereby matching the corresponding left valve seat 11 and the right valve seat 12, thereby achieving the automatic matching effect of the sealing pair on the corresponding side; reducing the possibility of getting stuck due to temperature changes, and ensuring good sealing performance of the valve.

[0056] Among them, about the structure of the spherical top center 5:

[0057] Specifically, Fig.12 As shown, the spherical top center 5 adopts a spherical structure, and its function is that the spherical top center 5 can automatically rotate and automatically match with the spherical grooves 22 of the left gate plate 2 and the right gate plate 3.

[0058] Specifically, the spherical radius of the spherical groove 22 arranged on the left gate plate 2 and the right gate plate 3 is SR+10, that is, the spherical radius of the spherical top center 5 is SR, and the spherical radius of the spherical groove 22 is 10 mm larger than the spherical radius of the spherical top center 5, so that after the left gate plate 2 and the right gate plate 3 are installed on the cross 4, they are in an inscribed state with the spherical top center 5, reducing the contact area and reducing the friction, so that the gate sealing surfaces of the left gate plate 2 and the right gate plate 3 and the valve seat sealing surfaces of the corresponding left valve seat 11 and the right valve seat 12 on the valve body 1 form a sealing pair that automatically matches.

[0059] Among them, about the structure of cross 4:

[0060] Specifically, the connection structure between the cross 4 and the valve stem 13 is as follows:

[0061] Among the optional solutions of this embodiment, it is more preferred that Figure 1 , Figure 3 and Figure 6 As shown, the upper end of the cross 4 is provided with a connection hole 43 for connecting with the end of the valve stem 13 and a first axis pin hole communicating with the connection hole 43, and the end of the valve stem 13 is provided with a second axis pin hole at a position corresponding to the first axis pin hole; a fixing pin 44 is fixedly inserted in the first axis pin hole and the second axis pin hole. The connection between the cross 4 and the end of the valve stem 13 is achieved by means of the connection hole 43 and the fixing pin 44, and the connection structure is simple, the connection is firm, and it is stable and reliable.

[0062] Specifically, the connection structure between the cross 4 and the left gate plate 2 and the right gate plate 3 is as follows:

[0063] Among the optional solutions of this embodiment, it is more preferred that Figure 1 and Figure 3 As shown, the outer side walls of the first hinge boss 21 and the second hinge boss 31 are both arc-shaped surfaces, and the arc-shaped surfaces are tangent to the inner wall of the center hole 41. The outer side walls of the first hinge boss 21 and the second hinge boss 31 are arc-shaped surfaces, and are tangent to the inner wall of the center hole 41, which can realize the function of automatic alignment of the left gate plate 2 and the right gate plate 3 at 360°, making the sealing of the corresponding side more reliable; and can eliminate the problem of temperature stress blocking the sealing pair, and avoid the occurrence of the sealing pair scratch phenomenon caused by the traditional top center structure.

[0064] Among them, regarding the matching structure of the left gate plate 2, the right gate plate 3 and the cross 4:

[0065] Among the optional solutions of this embodiment, it is more preferred that Figure 1 , Figure 3 and Figure 7 to Figure 9As shown, the circumferential side walls of the left gate plate 2 and the right gate plate 3 are fixedly provided with annular gate plate limiting bosses 32; upper limit claws 73 are fixedly provided at the positions of the annular gate plate limiting bosses 32 of the left gate plate 2 and the right gate plate 3 above the cross 4, and lower limit claws 42 are fixedly provided at the positions of the annular gate plate limiting bosses 32 of the left gate plate 2 and the right gate plate 3 below the cross 4; the upper limit claws 73 and the corresponding lower limit claws 42 can limit the corresponding left gate plate 2 or right gate plate 3 from detaching from the cross 4; when the annular gate plate limiting bosses 32 are located in the upper limit claws 73 and the lower limit claws 42, the left gate plate 2 and the right gate plate 3 can both rotate relative to the spherical top center 5. The upper limit claw 73 and the lower limit claw 42 jointly limit the left gate plate 2 or the right gate plate 3, preventing the left gate plate 2 or the right gate plate 3 from falling off the cross 4, and ensuring its stable operation; and the limitation of the upper limit claw 73 and the lower limit claw 42 can also keep the left gate plate 2 and the right gate plate 3 rotating relative to the spherical top center 5 within a certain range, thereby ensuring the rotational sealing fit of the left gate plate 2 and the right gate plate 3 within a certain range, and realizing fast and efficient sealing.

[0066] Among them, regarding the structure of the upper limit claw 73:

[0067] Among the optional solutions of this embodiment, it is more preferred that Figure 1 , Figure 3 , Figures 4 to 6 and Fig.10 and Fig.11 As shown, the wedge-type double-disc gate valve 100 also includes an inverted U-shaped limit bracket 7 and a fixing nut 8; the upper end of the cross 4 is a cylindrical rod 45, and a rotation limit block 46 is fixedly arranged at the lower end of the cylindrical rod 45. A through mounting hole is opened on the inverted U-shaped limit bracket 7, and the mounting hole includes a through hole 71 and a rotation limiting groove 72. The through hole 71 is sleeved on the cylindrical rod 45, and the rotation limiting groove 72 is sleeved on the rotation limit block 46, and the cooperation between the rotation limit block 46 and the rotation limiting groove 72 can limit the rotation of the inverted U-shaped limit bracket 7 around the axis of the cylindrical rod 45; upper limit claws 73 are formed at both ends of the inverted U-shaped limit bracket 7; a fixed external thread is arranged on the outer side wall of the cylindrical rod 45, and the fixing nut 8 is threadedly connected to the fixed external thread, and the fixing nut 8 and the rotation limit block 46 jointly limit the movement of the inverted U-shaped limit bracket 7 in the axial direction of the cylindrical rod 45. The rotation limiting groove 72 provided on the inverted U-shaped limit bracket 7 is used in combination with the rotation limiting block 46 to realize the bearing of the inverted U-shaped limit bracket 7 and limit its circumferential rotation; and the movement of the inverted U-shaped limit bracket 7 in the axial direction is realized by using the fixing nut 8 in combination with the fixed external thread on the cylindrical rod 45. The connection structure is simple and easy to disassemble and assemble.

[0068] Specifically, the upper limit claw 73 is located on the side of the annular gate plate limiting boss 32 away from the cross 4, and the lower end of the upper limit claw 73 is an arc-shaped structure corresponding to the outer side wall of the left gate plate 2 and the right gate plate 3, such as Fig.10shown.

[0069] Among them, regarding the structure of the lower limit claw 42:

[0070] Among the optional solutions of this embodiment, it is more preferred that Figure 1 , Figure 3 and Figures 4 to 6 As shown, each lower limit claw 42 is integrally formed with the cross 4. The lower limit claw 42 is integrally formed with the cross 4, which can solve the problem that the lower limit claw 42 is fixed to the cross 4 by fixing screws in the traditional way, and the lower positioning claw falls off due to alternating temperature stress and vibration of process equipment, thereby causing the left gate plate 2 and the right gate plate 3 to fall off, and finally causing the gate to fail to work. It is more reliable than the traditional structure.

[0071] Among them, the structure description of the left gate plate 2 and the right gate plate 3 is as follows:

[0072] Specifically, except that the left gate plate 2 is provided with an automatic pressure relief device 6 , the left gate plate 2 and the right gate plate 3 have the same structure and size.

[0073] Among the optional solutions of this embodiment, it is more preferred that Figure 1 , Figure 3 and Figure 8 As shown, the left gate plate 2 is located on the side of the fluid channel 14 close to the upstream, and an automatic pressure relief device 6 is provided on the left gate plate 2; when the pressure in the valve cavity is greater than the pressure in the fluid channel 14 on the upstream side, the automatic pressure relief device 6 can make the valve cavity communicate with the fluid channel 14 on the upstream side. The automatic pressure relief device 6 provided on the left gate plate 2 can automatically relieve the pressure in the valve cavity, ensuring the stability of the pressure in the valve cavity.

[0074] Specifically, the automatic pressure relief device 6 can be any existing device that can achieve communication between the valve cavity and the fluid channel 14 on the upstream side, including but not limited to the automatic pressure relief device 6 with the following structure.

[0075] Among the optional solutions of this embodiment, it is more preferred that Figure 1 , Figure 3 and Figure 8As shown, the automatic pressure relief device 6 includes a screw plug 61, a sealing steel ball 63 and an elastic member 62; a through hole is provided on the left gate plate 2, and the through hole includes a gate plate pressure relief hole 23, an elastic member resting hole 24 and a screw plug resting hole 25 which are arranged in sequence, and the screw plug resting hole 25 is located on a side close to the spherical top center 5; a through screw plug pressure relief hole 611 is provided on the screw plug 61; the inner diameter of the gate plate pressure relief hole 23 is smaller than the inner diameter of the elastic member resting hole 24, and the inner diameter of the elastic member resting hole 24 is smaller than the inner diameter of the screw plug resting hole 25; the elastic member 62 is located in the elastic member resting hole 24, and the screw plug 61 is sealed and fixed in the screw plug resting hole 25; the sealing steel ball 63 is located between the elastic member 62 and the screw plug 61; the end of the elastic member 62 can squeeze the sealing steel ball 63 to move to the side close to the screw plug 61, and the sealing steel ball 63 can block the screw plug pressure relief hole 611. A sealing steel ball 63 and an elastic member 62 are used, and the elastic member 62 squeezes the sealing steel ball 63 to close and open the screw plug pressure relief hole 611 on the screw plug 61. When the pressure in the valve cavity is greater than the squeezing force of the elastic member 62 and the upstream medium on the sealing steel ball 63, the automatic pressure relief function can be achieved; when it is less than or equal to the squeezing force of the elastic member 62 and the upstream medium on the sealing steel ball 63, the sealing steel ball 63 can block the screw plug pressure relief hole 611. The structure is simple and the pressure relief is stable and reliable.

[0076] Specifically, when the pressure accumulated in the valve cavity of the cryogenic gate valve increases due to the increase in temperature causing the cryogenic liquid to vaporize, under the action of the medium pressure in the valve cavity, the medium pressure enters the screw plug pressure relief hole 611 and pushes the sealing steel ball 63 to compress the elastic member 62. The medium in the valve cavity then communicates with the upstream through the screw plug pressure relief hole 611, the elastic member shelf hole 24 and the gate plate pressure relief hole 23, completing the pressure relief function of the valve cavity.

[0077] Specifically, the elastic member 62 is a spring; the function of the screw plug 61 is to compress the spring and the sealing steel ball 63, so that the sealing steel ball 63 and the screw plug pressure relief hole 611 are sealed under the action of the upstream medium pressure and the elastic force of the spring.

[0078] Among the optional solutions of this embodiment, it is more preferred that Figure 1 , Figure 3 and Figure 8 As shown, the plug placement hole 25 is provided with an internal thread, and the outer wall of the plug 61 is provided with an external thread, and the internal thread is threadedly connected with the external thread. The plug 61 is installed by means of threads, and its structure is simple and easy to disassemble and assemble; and the extrusion force of the elastic member 62 can be adjusted to meet different pressure relief requirements.

[0079] Specifically, since the left gate plate 2 is provided with an automatic pressure relief device 6 for automatically sealing the upstream medium and self-releasing the medium pressure in the valve cavity, the application range of the valve is increased, and it can be used in ultra-low temperature LNG conditions such as -162°C.

[0080] Among them, other structural descriptions about the wedge-type double-disc gate valve 100 are as follows:

[0081] Specifically, the wedge-type double-disc gate valve 100 is also provided with other structures that are present on other existing gate valves of the same type, including but not limited to: Figure 1 As the part shown in the figure is an existing structure and component, it will not be described in detail here.

[0082] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A wedge-type double-disc gate valve, characterized in that: It includes a valve body, a left valve seat, a right valve seat, a valve stem capable of being raised and lowered, a left gate plate, a right gate plate, a spherical top center and a cross; The valve body has a fluid passage and a valve cavity communicating with the fluid passage; The left valve seat and the right valve seat are respectively fixed on both sides of the inside of the fluid channel connected with the valve cavity; The top of the cross is used to be fixedly connected to one end of the valve stem located in the valve cavity; a center hole is provided on the cross; The left gate plate is used to block the left valve seat, and the right gate plate is used to block the right valve seat; the cross is located between the left gate plate and the right gate plate; The spherical top center is located in the center hole; and a first hinged boss is fixedly provided on the side of the left gate plate close to the center hole, and a second hinged boss is fixedly provided on the side of the right gate plate close to the center hole; a spherical groove for fitting with the outer wall of the spherical top center is provided on the first hinged boss and the second hinged boss; the left gate plate and the right gate plate can both rotate relative to the spherical top center around the center of the spherical top center.

2. The wedge-type double-disc gate valve according to claim 1, characterized in that: The circumferential side walls of the left gate plate and the right gate plate are both fixed with an annular gate plate limiting boss; Upper limit claws are fixedly provided above the cross at positions corresponding to the annular gate plate limiting bosses of the left gate plate and the right gate plate, and lower limit claws are fixedly provided below the cross at positions corresponding to the annular gate plate limiting bosses of the left gate plate and the right gate plate; the upper limit claws and the corresponding lower limit claws can limit the corresponding left gate plate or the right gate plate from leaving the cross; When the annular gate plate limiting boss is located in the upper limiting claw and the lower limiting claw, the left gate plate and the right gate plate can both rotate relative to the spherical top center.

3. The wedge-type double-disc gate valve according to claim 2, characterized in that: Each of the lower limiting claws is integrally formed with the cross.

4. The wedge-type double-disc gate valve according to claim 1, characterized in that: The left gate is located on the upstream side of the fluid passage, and an automatic pressure relief device is provided on the left gate; When the pressure in the valve cavity is greater than the pressure in the fluid channel on the upstream side, the automatic pressure relief device can connect the valve cavity with the fluid channel on the upstream side.

5. The wedge-type double-disc gate valve according to claim 4, characterized in that: The automatic pressure relief device comprises a screw plug, a sealing steel ball and an elastic member; The left gate plate is provided with a through hole, and the through hole includes a gate plate pressure relief hole, an elastic member placement hole and a screw plug placement hole which are arranged in sequence, and the screw plug placement hole is located on a side close to the spherical top center; the screw plug is provided with a through screw plug pressure relief hole; The inner diameter of the gate plate pressure relief hole is smaller than the inner diameter of the elastic member placement hole, and the inner diameter of the elastic member placement hole is smaller than the inner diameter of the screw plug placement hole; The elastic member is located in the elastic member placement hole, and the screw plug seal is fixed in the screw plug placement hole; the sealing steel ball is located between the elastic member and the screw plug; the end of the elastic member can squeeze the sealing steel ball to move toward the side close to the screw plug, and the sealing steel ball can block the screw plug pressure relief hole.

6. The wedge-type double-disc gate valve according to claim 5, characterized in that: An internal thread is arranged in the screw plug placement hole, and an external thread is arranged on the outer side wall of the screw plug, and the internal thread is threadably connected with the external thread.

7. The wedge-type double-disc gate valve according to claim 2, characterized in that: The upper end of the cross is provided with a connecting hole for connecting with the end of the valve stem and a first shaft pin hole communicating with the connecting hole. A second shaft pin hole is provided at the end of the valve stem at a position corresponding to the first shaft pin hole; A fixing pin is fixedly inserted in the first shaft pin hole and the second shaft pin hole.

8. The wedge-type double-disc gate valve according to claim 2, characterized in that: It also includes an inverted U-shaped limit bracket and a fixing nut; The upper end of the cross is a cylindrical rod, and a rotation limit block is fixedly arranged at the lower end of the cylindrical rod. A penetrating mounting hole is opened on the inverted U-shaped limit bracket, and the mounting hole includes a through hole and a rotation limit groove. The through hole is sleeved on the cylindrical rod, and the rotation limit groove is sleeved on the rotation limit block. The cooperation between the rotation limit block and the rotation limit groove can limit the rotation of the inverted U-shaped limit bracket around the axis of the cylindrical rod. The upper limit claws are formed at both ends of the inverted U-shaped limit bracket; A fixed external thread is arranged on the outer side wall of the cylindrical rod, the fixed nut is threadedly connected to the fixed external thread, and the fixed nut and the rotation limit block jointly limit the movement of the inverted U-shaped limit bracket along the axial direction of the cylindrical rod.

9. The wedge-type double-disc gate valve according to claim 1, characterized in that: The outer side walls of the first hinge boss and the second hinge boss are both arc-shaped surfaces, and the arc-shaped surfaces are tangent to the inner wall of the center hole.

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