Diaphragm valve for high-temperature gas
By setting a heat-resistance structure and coolant channel in the diaphragm valve, the problem of damage to the piston assembly and sealing ring at high temperatures is solved, achieving a longer service life and higher stability and sealing.
Patent Information
- Application Number
- CN202411510826.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-28
- Publication Date
- 2025-01-07
AI Technical Summary
Under high temperature conditions, the piston assembly and sealing ring of the diaphragm valve are susceptible to high-temperature heat conduction damage, affecting the function and service life of the valve.
A heat-resistance structure is provided between the driving part of the diaphragm valve and the fluid circulation part, including an extension rod and a coolant passage, increasing the distance of the high-temperature gas flow path and cooling through the coolant, blocking heat conduction, and protecting the piston assembly and sealing ring.
It effectively extends the service life of the diaphragm valve, ensures long-term stable operation in high-temperature environments and has higher sealing performance, and reduces the risk of high-temperature gas leakage.
Smart Images
Figure CN119267591A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of diaphragm valves, and in particular to a diaphragm valve for high-temperature gas. Background Art
[0002] As an important fluid control device, the diaphragm valve controls the opening and closing of the valve through the deformation of the diaphragm; the diaphragm not only separates the medium from the atmosphere, but also adjusts the opening of the valve through its own deformation. The diaphragm valve has the characteristics of good sealing, high reliability, small dead zone, and wide application range. Therefore, it has been widely used. For example, in high-purity gas systems, diaphragm valves can effectively isolate the medium from the atmosphere to prevent pollution. At the same time, its structural design and material selection also ensure its stability and durability in high pressure, vacuum, high and low temperature environments. The application of diaphragm valves is not limited to engine systems, but is also widely used in other industrial and scientific fields that require precise control and isolation. For example, in the semiconductor and photovoltaic industries, diaphragm valves are used for the shut-off function of high-temperature gases.
[0003] With the development of semiconductor and photovoltaic material manufacturing technology, the requirements for the working environment of diaphragm valves are becoming higher and higher, especially under high temperature conditions. The application of diaphragm valves must ensure that they can work stably for a long time while effectively avoiding damage to valve components caused by high temperature.
[0004] Reference Figure 1 As shown, the diaphragm valve in the related art includes a valve body 10, a piston assembly 20 located in the valve body 10, and a diaphragm 30; the valve body 10 is provided with a fluid inlet channel 11 and a fluid outlet channel 12 that are connected to each other, and a deformation cavity 13 for installing the diaphragm 30 is provided in the valve body 10 between the fluid inlet channel 11 and the fluid outlet channel 12, and the piston assembly 20 pushes the diaphragm 30 to deform to block the connection between the fluid inlet channel 11 and the fluid outlet channel 12; in order to ensure the sealing performance, a plurality of sealing rings 40 are provided between the piston assembly 20 and the inner wall of the valve body 10.
[0005] Under high temperature conditions, since the flow path of high temperature gas is close to the piston assembly and sealing ring of the diaphragm valve, these components are easily damaged after high temperature heat conduction, thus affecting the function and service life of the valve. Summary of the invention
[0006] In order to increase the service life of a diaphragm valve under high temperature conditions, the present application provides a diaphragm valve for high temperature gas.
[0007] The present application provides a high-temperature gas diaphragm valve adopts the following technical solution: A diaphragm valve for high temperature gas comprises a valve body, wherein the valve body comprises a driving part and a fluid flow part; the driving part and the fluid flow part are fixedly connected; The driving part of the valve body is provided with an installation cavity, a piston assembly is provided in the installation cavity, and a plurality of sealing rings are provided between the piston assembly and the inner wall of the installation cavity; An air inlet passage is provided on one side of the fluid flow portion of the valve body, and an air outlet passage is provided on the other side of the fluid flow portion of the valve body; the air inlet passage and the air outlet passage are connected; A diaphragm is provided between the air inlet channel and the air outlet channel; the piston assembly can push the diaphragm to deform so as to block the connection between the air inlet channel and the air outlet channel; A heat-resistance structure is provided between the driving part and the fluid circulation part to prevent the heat in the fluid circulation part from being conducted into the driving part.
[0008] By adopting the above technical solution, the diaphragm valve for high-temperature gas can effectively block heat conduction under high-temperature conditions, thereby protecting the drive unit and the internal piston assembly and sealing ring from high-temperature damage. Specifically, by providing a heat-resistant structure between the drive unit and the fluid circulation unit, the effect of heat conduction from the high-temperature gas circulating in the fluid circulation unit to the drive unit can be significantly reduced. The multiple sets of sealing rings between the piston assembly and the inner wall of the mounting cavity enhance the overall sealing performance, allowing the diaphragm to reliably block the connection between the air inlet channel and the air outlet channel under high-temperature conditions, ensuring the long-term stable operation and longer service life of the diaphragm valve under high-temperature conditions.
[0009] Optionally, the piston assembly includes a first piston and a second piston slidably arranged in the driving part, and one end of the driving part of the valve body is detachably connected to an end cover, and an elastic member is arranged between the side of the first piston facing the end cover and the end cover; the other side of the first piston abuts against one end of the second piston, and the other end of the second piston extends toward the fluid flow part of the valve body and is used to push the diaphragm to deform.
[0010] By adopting the above technical solution, the elastic member can push the first piston to move toward the diaphragm, the first piston pushes the second piston to move toward the diaphragm, the second piston pushes the diaphragm to deform, and then reliably controls the deformation of the diaphragm to achieve effective opening and closing of the valve.
[0011] Optionally, the heat-resistant structure includes an extension rod arranged at one end of the second piston facing the fluid circulation part, one end of the extension rod is fixedly connected to the second piston and the two are manufactured separately; the fluid circulation part of the valve body is provided with a connecting cavity, the air inlet channel and the air outlet channel are respectively connected to the connecting cavity, the diaphragm is installed in the connecting cavity and the diaphragm can be abutted against the connection between the air inlet channel and the connecting cavity and block the port of the air inlet channel, and a third piston is provided on the side of the diaphragm facing away from the air inlet channel, and the other end of the extension rod is connected to or abuts against the third piston.
[0012] By adopting the above technical solution, the extension rod increases the distance between the high-temperature gas flow path and the driving part of the valve body, and the extension rod and the second piston are manufactured separately, which effectively prevents the heat of the high-temperature gas flowing in the fluid flow part from being transferred to the driving part, protects the driving part and the internal piston assembly and sealing ring from high temperature damage, and improves the overall service life of the valve.
[0013] Optionally, the port connecting the air inlet channel with the connecting chamber is located in the middle of the bottom of the connecting chamber, and the port connecting the air outlet channel with the connecting chamber is located on one side of the bottom of the connecting chamber; an annular groove is provided around the port of the air inlet channel in the middle of the bottom of the connecting chamber, and an annular sealing gasket is embedded in the annular groove, and the side of the diaphragm can be sealed against the side of the annular sealing gasket.
[0014] By adopting the above technical solution, the side of the diaphragm can be sealed against the side of the annular sealing gasket, thereby improving the sealing performance between the diaphragm and the connecting cavity, enhancing the sealing effect of the valve in a high-temperature gas environment, and reducing the risk of high-temperature gas leakage.
[0015] Optionally, an extension nut is threadedly connected to one end of the driving part facing the fluid circulation part, and the end of the fluid circulation part facing the driving part is fixedly connected to the end of the extension nut by a locking nut; the extension rod is inserted into the extension nut and the locking nut.
[0016] By adopting the above technical solution, the driving part and the fluid circulation part are fixedly connected by the extension nut and the locking nut, and the extension rod is inserted into the extension nut and the locking nut, which effectively blocks heat conduction, prevents high-temperature gas from causing damage to the driving part, and improves the service life of the diaphragm valve under high-temperature conditions.
[0017] Optionally, an annular piston gasket is fixed between the fluid circulation portion and the locking nut; the diaphragm is clamped around the piston gasket and the side wall of the connecting cavity, and the third piston is slidably arranged in the middle of the piston gasket.
[0018] By adopting the above technical solution, the piston gasket can enhance the clamping and sealing effect around the diaphragm, effectively preventing high-temperature gas leakage. At the same time, the sliding arrangement of the third piston in the middle of the piston gasket makes the diaphragm more uniform when subjected to force, further improving the sealing and stability of the diaphragm valve under high-temperature conditions.
[0019] Optionally, as another scheme, the heat-resistant structure includes an extension portion on the second piston, the extension portion extending toward the direction of the diaphragm; the driving portion has a connecting tube at one end facing the fluid circulation portion, a locking nut is threaded on the connecting tube, and the fluid circulation portion and the driving portion are fixedly connected via the locking nut, and two groups of sealing rings are spaced apart between the outer peripheral surface of the extension portion and the inner wall of the connecting tube; and a cooling liquid channel is provided on the locking nut and the connecting tube.
[0020] By adopting the above technical solution, the design of the extension part makes it difficult for the heat of the high-temperature gas to be transferred to the driving part. More importantly, the coolant channels on the locking nut and the connecting tube can effectively cool the components and block the conduction of heat by injecting coolant, thereby protecting the vulnerable parts in the driving part from high temperature damage and improving the service life and stability of the entire diaphragm valve under high temperature conditions.
[0021] Optionally, there are several groups of coolant channels distributed along the axial direction of the locking nut, and the coolant channels extend from the outer peripheral surface of the locking nut to the interior of the connecting tube. The ports of the coolant channels on the inner wall of the connecting tube are located between two groups of sealing rings in the connecting tube.
[0022] By adopting the above technical solution, the coolant can flow in several groups of coolant channels of the locking nut and the connecting cylinder, so that the coolant can form an effective circulation in the connecting cylinder, improve the cooling efficiency of the parts, avoid coolant leakage, effectively block the conduction of heat, ensure that the piston assembly and the sealing ring are not easily affected by high temperature, and extend the overall service life of the diaphragm valve.
[0023] Optionally, the side surface of the end cover has a mounting cylinder facing the inside of the mounting cavity, the first piston includes a first piston rod and a first piston disk fixed at the end of the first piston rod, the first piston rod is slidably inserted in the mounting cylinder; a group of sealing rings are arranged between the outer circumferential surface of the first piston rod and the inner wall of the mounting cylinder, a group of sealing rings are arranged between the outer circumferential surface of the first piston disk and the wall of the mounting cavity, and a gasket is also provided on the outside of the first piston rod.
[0024] By adopting the above technical solution, the sealing between the piston assembly and the installation cavity is improved, gas leakage is effectively prevented, and the stability and reliability of the use of the diaphragm valve are improved.
[0025] Optionally, the second piston includes a second piston rod and a second piston disk fixed in the middle of the second piston rod, one end of the second piston rod abuts against the first piston, and the second piston rod is sleeved with a fourth piston and the fourth piston is located between the first piston disk and the second piston disk; a group of sealing rings are arranged between the outer circumferential surface of the second piston disk and the wall of the installation cavity and between the outer circumferential surface of the fourth piston and the wall of the installation cavity, and a group of sealing rings are also arranged on the inner walls of the second piston rod and the fourth piston.
[0026] By adopting the above technical solution, the provision of a multi-layer sealing ring improves the sealing performance of the piston assembly, enhances the stability of the diaphragm valve under high temperature conditions, and extends the service life of the valve.
[0027] In summary, the present application includes at least one of the following beneficial technical effects: 1. In the present application, by setting a heat-resistant structure between the driving part and the fluid circulation part, the heat of the high-temperature gas circulating in the fluid circulation part can be effectively blocked from being transferred to the inside of the driving part, thereby protecting the internal parts of the driving part from high-temperature damage and extending the overall service life of the diaphragm valve.
[0028] 2. In the present application, multiple sets of sealing rings arranged between the piston assembly and the inner wall of the installation cavity enhance the sealing effect and ensure the reliability and sealing of the valve in a high temperature environment.
[0029] 3. In the present application, under high-temperature gas conditions, the extension rod of the heat-resistant structure is isolated from the high-temperature area in the fluid flow part, further preventing the influence of high temperature on the upper parts of the valve, thereby ensuring the long-term stable operation of the diaphragm valve. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 It is a schematic diagram of the cross-sectional structure of a diaphragm valve in the related art.
[0031] Figure 2 It is a schematic diagram of the cross-sectional structure of the diaphragm valve in Example 1 of the present application.
[0032] Figure 3 yes Figure 2 Schematic diagram of the local enlarged structure at point A in the middle.
[0033] Figure 4 It is a schematic diagram of the cross-sectional structure of the diaphragm valve in Example 2 of the present application.
[0034] Figure 5 yes Figure 4 Schematic diagram of the local enlarged structure at point B in the middle.
[0035] In the figure: 10. Valve body; 11. Fluid inlet channel; 12. Fluid outlet channel; 13. Deformation cavity; 14. Driving part; 141. Installation cavity; 142. Connecting cylinder; 15. Fluid flow part; 151. Air inlet channel; 152. Air outlet channel; 153. Communication cavity; 154. Annular groove; 16. End cover; 161. Installation cylinder; 20. Piston assembly; 21. First piston; 211. First piston rod; 212. First piston disc; 22. Second piston; 221. Second piston rod; 222. Second piston disc; 23. Fourth piston; 30. Diaphragm; 40. Sealing ring; 50. Third piston; 60. Elastic parts; 70. heat-resistant structure; 71. extension rod; 72. extension nut; 73. locking nut; 74. extension part; 75. coolant channel; 80. Ring-shaped sealing gasket; 90. Piston gasket; 100. Cushion cover. DETAILED DESCRIPTION
[0036] The following will be combined with the attached Figure 2 -Attached Figure 5 , the technical solutions in the embodiments of the present invention are clearly and completely described. The described embodiments are only possible technical implementations of the present invention, not all possible implementations. Those skilled in the art can completely combine the embodiments of the present invention to obtain other embodiments without creative work, and these embodiments are also within the scope of protection of the present invention.
[0037] Example 1 Reference Figure 2 and Figure 3 As shown, the diaphragm valve for high-temperature gas provided in the embodiment of the present application includes a valve body 10, and the valve body 10 includes two upper and lower parts, a driving part 14 and a fluid passing part 15, and the driving part 14 and the fluid passing part 15 are fixedly connected to each other; the driving part 14 of the valve body 10 is in a cylindrical shape, and an installation cavity 141 is arranged in the driving part 14, and the end of the driving part 14 away from the fluid passing part 15 has an opening, and the opening is closed by an end cover 16 fixedly connected to the end of the driving part 14, and the end cover 16 can be threadedly matched with the driving part 14 to realize a detachable connection. The end of the driving part 14 facing the fluid circulation part 15 has a connecting tube 142, and the outer diameter of the connecting tube 142 is smaller than the outer diameter of the driving part 14 body, thus forming a necking structure. An extension nut 72 is threaded on the connecting tube 142, and the end of the fluid circulation part 15 facing the driving part 14 is fixedly connected to the end of the extension nut 72 by a locking nut 73, that is, the driving part 14 and the fluid circulation part 15 are fixedly connected by the extension nut 72 and the locking nut 73.
[0038] Reference Figure 2 and Figure 3 As shown, a piston assembly 20 is arranged in the installation cavity 141, and a plurality of sealing rings 40 are arranged between the piston assembly 20 and the inner wall of the installation cavity 141; an air inlet channel 151 is opened on one side of the fluid circulation part 15 of the valve body 10, and an air outlet channel 152 is opened on the other side of the fluid circulation part 15 of the valve body 10; the air inlet channel 151 and the air outlet channel 152 are connected; a diaphragm 30 is arranged between the air inlet channel 151 and the air outlet channel 152; the piston assembly 20 can push the diaphragm 30 to deform to block the connection between the air inlet channel 151 and the air outlet channel 152; a heat-resistant structure 70 is arranged between the driving part 14 and the fluid circulation part 15 to prevent the heat in the fluid circulation part 15 from being conducted to the driving part 14.
[0039] Specifically, refer to Figure 2 As shown, the piston assembly 20 includes a first piston 21 and a second piston 22 slidably disposed in the driving portion 14. An elastic member 60 is disposed between the first piston 21 and the end cover 16 on one side thereof facing the end cover 16. The elastic member 60 in the present application may be a coil spring. The other side of the first piston 21 abuts against one end of the second piston 22. The other end of the second piston 22 extends toward the fluid flow portion 15 of the valve body 10 and is used to push the diaphragm 30 to deform. The elastic member 60 can push the first piston 21 to move toward the diaphragm 30, the first piston 21 pushes the second piston 22 to move toward the diaphragm 30, and the second piston 22 pushes the diaphragm 30 to deform, thereby reliably controlling the deformation of the diaphragm 30 and realizing effective opening and closing of the valve.
[0040] A mounting tube 161 facing the inside of the mounting cavity 141 is provided on the side surface of the end cover 16, and the elastic member 60 is sleeved on the outside of the mounting tube 161. The first piston 21 includes a first piston rod 211 and a first piston disc 212 fixedly provided at the end of the first piston rod 211. The first piston rod 211 is slidably inserted in the mounting tube 161, and one end of the elastic member 60 abuts against the inner wall of the end cover 16, and the other end abuts against the side surface of the first piston disc 212; a group of sealing rings 40 are provided between the outer circumferential surface of the first piston rod 211 and the inner wall of the mounting tube 161, and a group of sealing rings 40 are provided between the outer circumferential surface of the first piston disc 212 and the cavity wall of the mounting cavity 141, and a gasket 100 is also sleeved on the outside of the first piston rod 211, and the gasket 100 is located between the sealing ring 40 in the mounting tube 161 and the first piston disc 212. The second piston 22 includes a second piston rod 221 and a second piston disc 222 fixed in the middle of the second piston rod 221. One end of the second piston rod 221 abuts against the first piston 21. The fourth piston 23 is sleeved on the second piston rod 221 and the fourth piston 23 is located between the first piston disc 212 and the second piston disc 222. A group of sealing rings 40 are arranged between the outer circumferential surface of the second piston disc 222 and the cavity wall of the installation cavity 141 and between the outer circumferential surface of the fourth piston 23 and the cavity wall of the installation cavity 141. A group of sealing rings 40 are also arranged on the inner walls of the second piston rod 221 and the fourth piston 23.
[0041] Combination Figure 3 As shown, the heat-resistant structure 70 includes an extension rod 71 arranged at one end of the second piston rod 221 facing the fluid flow portion 15, and the extension rod 71 is inserted into an extension nut 72 and a locking nut 73; one end of the extension rod 71 is fixedly connected to the second piston rod 221 and the two are manufactured separately, and the two can be made of different materials, thereby reducing the heat conduction performance.
[0042] Reference Figure 2As shown, a connecting cavity 153 is provided at one end of the fluid circulation portion 15 of the valve body 10 close to the driving portion 14, an inlet port of the inlet channel 151 and an outlet port of the outlet channel 152 are respectively arranged on the left and right sides of the driving portion 14, and the inlet channel 151 and the outlet channel 152 are both bent and extended in the direction of the connecting cavity 153 inside the fluid circulation portion 15; the inlet channel 151 and the outlet channel 152 are respectively connected to the connecting cavity 153, the diaphragm 30 is installed in the connecting cavity 153, and the inlet channel 151 is connected to the connecting cavity 153 The port is located in the middle of the bottom of the connecting chamber 153, and the port connecting the air outlet channel 152 with the connecting chamber 153 is located on one side of the bottom of the connecting chamber 153; an annular groove 154 is provided on the periphery of the port of the air inlet channel 151 in the middle of the bottom of the connecting chamber 153, and an annular sealing gasket 80 is embedded in the annular groove 154. The side of the diaphragm 30 can be abutted and sealed against the side of the annular sealing gasket 80, so that the diaphragm 30 can be attached to the connection between the air inlet channel 151 and the connecting chamber 153 and block the port of the air inlet channel 151.
[0043] Further, see Figure 3 As shown, an annular piston gasket 90 is fixed between the fluid circulation part 15 and the locking nut 73; the diaphragm 30 is clamped around the piston gasket 90 and the side wall of the connecting cavity 153, and a third piston 50 is arranged on the side of the diaphragm 30 away from the intake channel 151. The third piston 50 is slidably arranged in the middle of the piston gasket 90, and the other end of the extension rod 71 is connected to or abuts against the third piston 50. The piston gasket 90 can enhance the clamping and sealing effect around the diaphragm 30 and effectively prevent high-temperature gas leakage. At the same time, the sliding arrangement of the third piston 50 in the middle of the piston gasket 90 makes the diaphragm 30 more uniform when subjected to force, further improving the sealing and stability of the diaphragm valve under high-temperature conditions.
[0044] The implementation principle of this embodiment is as follows: when the diaphragm valve in this application is in use, high-temperature gas enters from the air inlet channel 151 of the fluid circulation part 15 and is discharged from the air outlet channel 152, which will bring a lot of heat in this process. Therefore, in order to protect the drive part 14 and the internal piston assembly 20 and the sealing ring 40 from high temperature damage, the application is provided with an extension nut 72 and an extension rod 71, which physically increases the distance between the high-temperature gas flow path and the drive part 14 of the valve body 10 without affecting the normal operation of the diaphragm valve, and the extension rod 71 is manufactured separately from the second piston 22, so as to further effectively prevent the heat of the high-temperature gas circulating in the fluid circulation part 15 from being transferred to the drive part 14, and by effectively blocking the heat conduction, the drive part 14 and the internal piston assembly 20 and the sealing ring 40 are protected from high temperature damage, thereby improving the service life of the diaphragm valve under high temperature conditions.
[0045] Experiments have shown that the improved structure in the present application significantly reduces the effect of heat transfer from the high-temperature gas flowing in the fluid circulation part 15 to the drive part 14, ensuring the long-term stable operation and longer service life of the diaphragm valve under high temperature conditions.
[0046] Example 2 Reference Figure 3 and Figure 4 As shown, this embodiment is substantially the same as the embodiment 1, except that the heat-resisting structure 70 in this embodiment includes an extension portion 74 on the second piston 22, and the extension portion 74 extends toward the diaphragm 30; the extension nut 72 in the embodiment 1 is omitted in this embodiment, and the extension portion 74 can be integrally formed with the second piston rod 221, that is, the extension portion 74 can be used as a part of the second piston rod 221, and its overall length can also be not as long as the extension rod 71 in the embodiment 1. In order to effectively block heat conduction, in this embodiment, two groups of sealing rings 40 are arranged between the outer circumference of the extension portion 74 and the inner wall of the connecting cylinder 142, and a coolant channel 75 is provided on the locking nut 73 and the connecting cylinder 142. Further, the coolant channel 75 is distributed in several groups along the axial direction of the locking nut 73, and the coolant channel 75 extends from the outer circumference of the locking nut 73 to the inside of the connecting cylinder 142, and the port of the coolant channel 75 on the inner wall of the connecting cylinder 142 is located between the two groups of sealing rings 40 in the connecting cylinder 142.
[0047] The implementation principle of this embodiment is as follows: the design of the extension portion 74 makes it difficult for the heat of the high-temperature gas to be transferred to the drive portion 14. More importantly, the coolant channel 75 on the locking nut 73 and the connecting tube 142 can effectively cool the components and block the conduction of heat by injecting coolant, thereby protecting the vulnerable parts in the drive portion 14 from high-temperature damage and improving the service life and stability of the entire diaphragm valve under high-temperature conditions.
[0048] The embodiments of this specific implementation are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. The same components are represented by the same figure marks. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.
Claims
1. A diaphragm valve for high-temperature gas, comprising a valve body (10), wherein the valve body (10) comprises a drive portion (14) and a fluid flow portion (15); the drive portion (14) and the fluid flow portion (15) are fixedly connected; It is characterized in that The driving portion (14) of the valve body (10) is provided with an installation cavity (141), a piston assembly (20) is provided in the installation cavity (141), and a plurality of groups of sealing rings (40) are provided between the piston assembly (20) and the inner wall of the installation cavity (141); An air inlet channel (151) is provided on one side of the fluid flow portion (15) of the valve body (10), and an air outlet channel (152) is provided on the other side of the fluid flow portion (15) of the valve body (10); the air inlet channel (151) and the air outlet channel (152) are connected; A diaphragm (30) is provided between the air inlet channel (151) and the air outlet channel (152); the piston assembly (20) is capable of pushing the diaphragm (30) to deform so as to block the connection between the air inlet channel (151) and the air outlet channel (152); A heat-resistance structure (70) is provided between the driving part (14) and the fluid circulation part (15) for preventing heat in the fluid circulation part (15) from being conducted into the driving part (14).
2. The diaphragm valve for high temperature gas according to claim 1, characterized in that: The piston assembly (20) comprises a first piston (21) and a second piston (22) which are slidably arranged in the driving portion (14); one end of the driving portion (14) of the valve body (10) is detachably connected to an end cover (16); an elastic member (60) is arranged between the side of the first piston (21) facing the end cover (16) and the end cover (16); the other side of the first piston (21) abuts against one end of the second piston (22); the other end of the second piston (22) extends toward the fluid flow portion (15) of the valve body (10) and is used to push the diaphragm (30) to deform.
3. The diaphragm valve for high temperature gas according to claim 2, characterized in that: The heat-resistant structure (70) comprises an extension rod (71) arranged at one end of the second piston (22) facing the fluid circulation part (15), one end of the extension rod (71) is fixedly connected to the second piston (22) and the two are manufactured separately; the fluid circulation part (15) of the valve body (10) is provided with a connecting cavity (153), the air inlet channel (151) and the air outlet channel (152) are respectively connected to the connecting cavity (153), the diaphragm (30) is installed in the connecting cavity (153) and the diaphragm (30) can be abutted against the connection between the air inlet channel (151) and the connecting cavity (153) and block the port of the air inlet channel (151), and a third piston (50) is arranged on the side of the diaphragm (30) away from the air inlet channel (151), and the other end of the extension rod (71) is connected to or abuts against the third piston (50).
4. The diaphragm valve for high temperature gas according to claim 3, characterized in that: The port connecting the air inlet channel (151) and the connecting chamber (153) is located in the middle of the bottom of the connecting chamber (153), and the port connecting the air outlet channel (152) and the connecting chamber (153) is located on one side of the bottom of the connecting chamber (153); an annular groove (154) is provided in the middle of the bottom of the connecting chamber (153) on the periphery of the port of the air inlet channel (151), and an annular sealing gasket (80) is embedded in the annular groove (154), and the side surface of the diaphragm (30) can be abutted and sealed against the side surface of the annular sealing gasket (80).
5. The diaphragm valve for high temperature gas according to claim 3, characterized in that: An extension nut (72) is threadedly connected to one end of the driving portion (14) facing the fluid circulation portion (15); the end of the fluid circulation portion (15) facing the driving portion (14) is fixedly connected to the end of the extension nut (72) via a locking nut (73); and the extension rod (71) is inserted into the extension nut (72) and the locking nut (73).
6. The diaphragm valve for high temperature gas according to claim 5, characterized in that: An annular piston gasket (90) is fixed between the fluid circulation portion (15) and the locking nut (73); the diaphragm (30) is clamped around the piston gasket (90) and the side wall of the connecting cavity (153), and the third piston (50) is slidably arranged in the middle of the piston gasket (90).
7. The high temperature gas diaphragm valve according to claim 2, characterized in that: The heat-resistant structure (70) includes an extension portion (74) on the second piston (22), and the extension portion (74) extends in the direction of the diaphragm (30); the driving portion (14) has a connecting tube (142) at one end facing the fluid circulation portion (15), a locking nut (73) is threaded on the connecting tube (142), and the fluid circulation portion (15) and the driving portion (14) are fixedly connected via the locking nut (73); two groups of sealing rings (40) are arranged between the outer peripheral surface of the extension portion (74) and the inner wall of the connecting tube (142); and a cooling liquid channel (75) is provided on the locking nut (73) and the connecting tube (142).
8. The high temperature gas diaphragm valve according to claim 7, characterized in that: The coolant channels (75) are distributed in a plurality of groups along the axial direction of the locking nut (73). The coolant channels (75) extend from the outer peripheral surface of the locking nut (73) to the interior of the connecting tube (142). The ports of the coolant channels (75) on the inner wall of the connecting tube (142) are located between the two groups of sealing rings (40) in the connecting tube (142).
9. The high temperature gas diaphragm valve according to claim 2, 3 or 7, characterized in that: The side surface of the end cover (16) is provided with a mounting cylinder (161) facing the inside of the mounting cavity (141); the first piston (21) comprises a first piston rod (211) and a first piston disc (212) fixedly arranged at the end of the first piston rod (211); the first piston rod (211) is slidably inserted in the mounting cylinder (161); a group of sealing rings (40) are arranged between the outer peripheral surface of the first piston rod (211) and the inner wall of the mounting cylinder (161); a group of sealing rings (40) are arranged between the outer peripheral surface of the first piston disc (212) and the cavity wall of the mounting cavity (141); and a gasket (100) is also arranged outside the first piston rod (211).
10. The high temperature gas diaphragm valve according to claim 9, characterized in that: The second piston (22) comprises a second piston rod (221) and a second piston disc (222) fixedly arranged in the middle of the second piston rod (221); one end of the second piston rod (221) abuts against the first piston (21); a fourth piston (23) is sleeved on the second piston rod (221) and the fourth piston (23) is located between the first piston disc (212) and the second piston disc (222); a group of sealing rings (40) are arranged between the outer peripheral surface of the second piston disc (222) and the cavity wall of the installation cavity (141) and between the outer peripheral surface of the fourth piston (23) and the cavity wall of the installation cavity (141); and a group of sealing rings (40) are also arranged on the inner walls of the second piston rod (221) and the fourth piston (23).