A chemical pneumatic diaphragm valve

Abstract

The present invention discloses a chemical pneumatic diaphragm valve, comprising: a base; a valve body, whose bottom end is fixed on the top of the base, a valve cavity for medium circulation is provided in the valve body, and a medium inlet pipe and a medium outlet pipe are formed integrally on both sides of the valve body; a cylinder barrel, whose bottom end is fixed on the top of the valve body, a piston cavity is provided inside the cylinder barrel, and a first air inlet and outlet interface is provided on one side wall of the cylinder barrel; a top cover, whose bottom end is fixed on the top of the cylinder barrel, a receiving cavity is provided at the bottom of the top cover, and a second air inlet and outlet interface is provided on one side wall of the top cover; a valve core, which is crimped between the valve body and the cylinder barrel; a piston, which is arranged in the piston cavity, and the bottom end of the piston is detachably connected to the top of the valve core; a spring, which is arranged between the top wall of the receiving cavity and the top of the piston, or the spring is arranged between the bottom of the piston and the bottom wall of the piston cavity. The chemical pneumatic diaphragm valve can be used as a normally closed single pneumatic valve, a normally open single pneumatic valve or a double pneumatic valve according to the use requirements, and one valve can be used for multiple purposes, with strong versatility.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid shut-off valves, and more specifically to a chemical pneumatic diaphragm valve, which is mainly used in the semiconductor industry as a liquid switch, such as pure water, sulfuric acid, nitric acid, etc. The valve is not only highly corrosion-resistant, but also has a high degree of cleanliness after the liquid passes through the diaphragm valve. Background Art

[0002] At present, the existing pneumatic diaphragm valves generally have normally open single pneumatic, normally closed single pneumatic and double pneumatic types, but these three types are not universal and inconvenient to use; and the existing pneumatic diaphragm valves are generally made of metal. When used to connect and block chemical substances, especially acidic solutions, the diaphragm valve is easily corroded, reducing its service life; and the elastic diaphragm on the current pneumatic diaphragm valve is a separate part, which is often easily over-pressurized and caused to wear, resulting in a short service life of the elastic diaphragm.

[0003] Therefore, how to provide a universal chemical-pneumatic diaphragm valve with a long service life is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0004] In view of this, the present invention provides a chemical-pneumatic diaphragm valve which is universal and has a long service life.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A chemical pneumatic diaphragm valve, comprising:

[0007] Base;

[0008] A valve body, wherein the bottom end of the valve body is fixed to the top end of the base, a valve cavity for medium circulation is provided in the valve body, and a medium inlet pipe and a medium outlet pipe are integrally formed on both sides of the valve body, and the medium inlet pipe and the medium outlet pipe are both connected to the valve cavity;

[0009] A cylinder barrel, wherein the bottom end of the cylinder barrel is fixed to the top end of the valve body, a piston cavity is provided inside the cylinder barrel, and a first air inlet and outlet interface communicating with the piston cavity is provided on one side wall of the cylinder barrel;

[0010] A top cover, wherein the bottom end of the top cover is fixed to the top end of the cylinder barrel, a receiving cavity is formed at the bottom end of the top cover, and a second air inlet and outlet interface communicating with the receiving cavity is formed on one side wall of the top cover;

[0011] A valve core, the valve core is crimped between the valve body and the cylinder barrel, and the valve core can block or connect the valve cavity by moving up and down;

[0012] A piston, wherein the piston is disposed in the piston cavity, and the bottom end of the piston is detachably connected to the top end of the valve core;

[0013] A spring is arranged between the top wall of the accommodating cavity and the top of the piston, or the spring is arranged between the bottom of the piston and the bottom wall of the piston cavity.

[0014] It can be known from the above technical scheme that compared with the prior art, the present invention discloses a chemical pneumatic diaphragm valve. When the spring is arranged in the accommodating cavity, and the first inlet and outlet air interface is connected to the air source, and the second inlet and outlet air interface is not connected to the air source, the diaphragm valve is a normally closed single pneumatic valve; when the spring is arranged in the piston cavity, and the second inlet and outlet air interface is connected to the air source, and the first inlet and outlet air interface is not connected to the air source, the diaphragm valve is a normally open single pneumatic valve; when there is no spring, and the first inlet and outlet air interface and the second inlet and outlet air interface are both connected to the air source, the diaphragm valve is a double pneumatic valve. Therefore, the chemical pneumatic diaphragm valve can be used as a normally closed single pneumatic valve, a normally open single pneumatic valve or a double pneumatic valve according to the use requirements. One valve can be used for multiple purposes and has strong versatility. In addition, the valve core and the piston are connected as an integrated structure, which can avoid the phenomenon of excessive pressure on the valve core and loss, thereby improving the service life of the valve core.

[0015] Furthermore, a sealing hollow column is integrally formed on the bottom wall of the valve cavity, a connecting hole is opened on one side wall of the sealing hollow column, the medium inlet pipe is connected with the interior of the sealing hollow column through the connecting hole, the upper port of the sealing hollow column is connected with the valve cavity, the upper end face of the sealing hollow column is a sealing surface, and the bottom end face of the valve core is in contact with or disconnected from the sealing surface.

[0016] The beneficial effect of adopting the above technical solution is that the chemical medium enters the valve cavity through the medium inlet, the connecting hole, and the sealed hollow column, and finally flows out of the valve body through the medium outlet. When the valve core blocks the valve cavity, the piston moves downward under the action of air pressure, driving the valve core to move downward together, and the bottom end face of the valve core contacts the sealing surface, thereby blocking the valve cavity. At this time, the diaphragm valve is in a closed state and the medium does not flow; when the piston moves upward under the action of air pressure, driving the valve core to move upward together, the bottom end face of the valve core is disconnected from the sealing surface, thereby connecting the valve cavity. At this time, the diaphragm valve is in an open state.

[0017] Furthermore, the valve core includes:

[0018] A core body, wherein the top end of the core body is detachably connected to the bottom end of the piston, and the bottom end surface of the core body is in contact with or disconnected from the sealing surface;

[0019] An elastic diaphragm, the inner side of which is integrally connected to the outer surface of the core;

[0020] A crimping ring, the inner side of which is integrally formed with the outer side of the elastic diaphragm, and the crimping ring is crimped between the valve body and the cylinder barrel.

[0021] The beneficial effect of adopting the above technical solution is that the elastic diaphragm has a certain elasticity, so the piston can drive the core body to move up and down, thereby realizing the opening or conduction of the valve cavity.

[0022] Furthermore, an annular clamping flange is provided on the top of the valve body, an annular clamping groove is provided on the bottom end surface of the crimping ring, and the annular clamping groove is clamped together with the annular clamping flange; an annular positioning flange is integrally formed on the bottom end surface of the cylinder barrel, an annular positioning groove is provided on the top end surface of the crimping ring, and the annular positioning flange is clamped together with the annular positioning groove.

[0023] The beneficial effect of adopting the above technical solution is that the annular clamping groove is clamped with the annular clamping flange, and the annular positioning flange is clamped with the annular positioning groove, which is conducive to the cylinder barrel to quickly and firmly press the valve core onto the valve body to avoid movement of the valve core.

[0024] Furthermore, a guide cylinder is integrally formed on the bottom wall of the piston cavity, and the piston comprises:

[0025] A piston disc, the piston disc being disposed in the piston cavity;

[0026] A guide column, one end of which is integrally formed with the bottom end of the piston disc, the other end of which is passed through the guide cylinder and is threadedly connected to the top end of the core body, and two ends of the spring are respectively sleeved on the guide column and the guide cylinder.

[0027] The beneficial effect of adopting the above technical solution is that when the piston moves up and down, the guide column can move up and down in the guide cylinder, so the guide cylinder plays a positioning and guiding role for the piston, that is, the stability of the up and down movement of the piston is improved, thereby ensuring that the bottom end surface of the core body and the sealing surface position can correspond in real time, ensuring that the valve cavity can be normally opened or closed.

[0028] Furthermore, a first sealing ring installation groove is opened on the outer peripheral wall of the piston disc, and a first sealing ring is installed in the first sealing ring installation groove; a second sealing ring installation groove is opened on the outer column wall of the guide column, and a second sealing ring is installed in the second sealing ring installation groove; a sealing ring sleeve tube is integrally formed on the bottom end of the top cover and located on the outer peripheral side of the accommodating cavity, and a third sealing ring is sleeved on the sealing ring sleeve tube.

[0029] The beneficial effect of adopting the above technical solution is to improve the sealing performance of the diaphragm valve and avoid leakage of chemical media.

[0030] Furthermore, the base, the valve body, the cylinder barrel and the top cover are fixedly connected by a plurality of connecting screw assemblies.

[0031] Furthermore, each of the connecting screw assemblies comprises:

[0032] A connecting nut, the connecting nut being placed inside the base;

[0033] A connecting screw rod, which is sequentially passed through the holes on the top cover, the cylinder barrel, and the valve body and then is threadedly connected to the connecting nut;

[0034] A cover cap is connected to the through hole on the top cover and is located above the head end of the connecting screw.

[0035] The beneficial effect of adopting the above technical solution is that the diaphragm valve can be disassembled, and the setting of the cover cap can avoid leakage of the connecting screw head end, thereby improving the overall aesthetics of the diaphragm valve.

[0036] Furthermore, it also includes:

[0037] A pipe nut, wherein the pipe nut is two in number and is respectively threadedly connected to the medium inlet pipe and the medium outlet pipe, and a plurality of clamping strips are integrally formed on the outer wall of the pipe nut;

[0038] Anti-loosening rings, there are two anti-loosening rings, which are respectively sleeved on the medium inlet pipe and the medium outlet pipe. The anti-loosening rings are evenly provided with a plurality of anti-loosening notches, and the ends of the clamping strips are plug-connected with the anti-loosening notches.

[0039] The beneficial effect of adopting the above technical solution is that after the connecting nut is screwed onto the medium inlet pipe or the medium outlet pipe, the end of the clamping strip is plugged into the anti-loosening notch, which effectively prevents the connecting nut from loosening, achieves the purpose of anti-loosening, and ensures the reliability of the connection between the medium pipeline and the diaphragm valve.

[0040] Furthermore, the diaphragm valve is made of PTFE or PFA.

[0041] The beneficial effect of adopting the above technical solution is that the diaphragm valve is made of plastic as a whole, which effectively avoids corrosion by chemical media during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0043] Figure 1 The accompanying drawing is a schematic structural diagram of a chemical pneumatic diaphragm valve provided by the present invention.

[0044] Figure 2 The attached picture is Figure 1Schematic diagram of the decomposition structure.

[0045] Figure 3 The accompanying drawing is a schematic diagram of the structure of the spring when it is in the accommodating cavity.

[0046] Figure 4 The accompanying drawing is a schematic diagram of the structure of the spring in the piston chamber.

[0047] Figure 5 The attached picture is Figure 2 Schematic diagram of the enlarged structure of local A in the middle.

[0048] Figure 6 The attached picture is Figure 3 Schematic diagram of the enlarged structure of part B in the middle. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] See also Figure 1-Figure 6 , the embodiment of the present invention discloses a chemical pneumatic diaphragm valve, comprising:

[0051] Base 1;

[0052] The valve body 2 has a bottom end fixed on the top of the base 1, a valve cavity 201 for medium circulation is provided in the valve body 2, and a medium inlet pipe 21 and a medium outlet pipe 22 are integrally formed on both sides of the valve body 2, and both the medium inlet pipe 21 and the medium outlet pipe 22 are communicated with the valve cavity 201;

[0053] The cylinder barrel 3 has its bottom end fixed on the top of the valve body 2, a piston chamber 301 is provided inside the cylinder barrel 3, and a first air inlet and outlet port 302 communicating with the piston chamber 301 is provided on one side wall of the cylinder barrel 3;

[0054] A top cover 4, the bottom end of which is fixed on the top end of the cylinder barrel 3, a receiving cavity 401 is provided at the bottom end of the top cover 4, and a second air inlet and outlet port 402 communicating with the receiving cavity 401 is provided on one side wall of the top cover 4;

[0055] The valve core 5 is crimped between the valve body 2 and the cylinder barrel 3, and the valve core 5 can block or connect the valve chamber 201 by moving up and down;

[0056] The piston 6 is disposed in the piston cavity 301, and the bottom end of the piston 6 is detachably connected to the top end of the valve core 5;

[0057] Spring 7, spring 7 is arranged between the top wall of the accommodating chamber 401 and the top of the piston 6, or, spring 7 is arranged between the bottom of the piston 6 and the bottom wall of the piston chamber 301.

[0058] A sealing hollow column 202 is integrally formed on the bottom wall of the valve cavity 201, and a connecting hole 2021 is opened on one side wall of the sealing hollow column 202. The medium inlet pipe 21 is connected with the inside of the sealing hollow column 202 through the connecting hole 2021, and the upper port of the sealing hollow column 202 is connected with the valve cavity 201. The upper end face of the sealing hollow column 202 is a sealing surface, and the bottom end face of the valve core 5 is in contact with or disconnected from the sealing surface.

[0059] The valve core 5 comprises:

[0060] The core body 51, the top end of the core body 51 is detachably connected to the bottom end of the piston 6, and the bottom end surface of the core body 51 is in contact with or disconnected from the sealing surface;

[0061] An elastic diaphragm 52, the inner side of the elastic diaphragm 52 is integrally connected to the outer surface of the core 51;

[0062] The crimping ring 53 has an inner side that is integrally formed with an outer side of the elastic diaphragm 52 , and the crimping ring 53 is crimped between the valve body 2 and the cylinder barrel 3 .

[0063] An annular clamping flange 203 is provided on the top of the valve body 2, and an annular clamping groove 531 is provided on the bottom end surface of the crimping ring 53, and the annular clamping groove 531 is clamped and matched with the annular clamping flange 203; an annular positioning flange 303 is integrally formed on the bottom end surface of the cylinder barrel 3, and an annular positioning groove 532 is provided on the top end surface of the crimping ring 53, and the annular positioning flange 303 is clamped and matched with the annular positioning groove 532.

[0064] A guide cylinder 304 is integrally formed on the bottom wall of the piston chamber 301. The piston 6 comprises:

[0065] A piston plate 61, the piston plate 61 is disposed in the piston chamber 301;

[0066] The guide column 62 has one end which is integrally formed with the bottom end of the piston disc 61 , and the other end of the guide column 62 is inserted into the guide cylinder 304 and is threadedly connected to the top end of the core body 51 . The two ends of the spring 7 are respectively sleeved on the guide column 62 and the guide cylinder 304 .

[0067] A first sealing ring installation groove 611 is opened on the outer peripheral wall of the piston disc 61, and a first sealing ring 8 is installed in the first sealing ring installation groove 611. A second sealing ring installation groove 621 is opened on the outer column wall of the guide column 62, and a second sealing ring 9 is installed in the second sealing ring installation groove 621. A sealing ring sleeve tube 403 is integrally formed on the outer peripheral side of the accommodating cavity 401 at the bottom end of the top cover 4, and a third sealing ring 10 is sleeved on the sealing ring sleeve tube 403.

[0068] The base 1 , the valve body 2 , the cylinder barrel 3 and the top cover 4 are fixedly connected via a plurality of connecting screw assemblies 11 .

[0069] Each connecting screw assembly 11 comprises:

[0070] A connecting nut 111, which is placed inside the base 1;

[0071] A connecting screw 112, which is sequentially passed through holes on the top cover 4, the cylinder barrel 3, and the valve body 2 and then threadedly connected to the connecting nut 111;

[0072] The cover cap 113 is connected to the through hole on the top cover 4 and is located above the head end of the connecting screw 112.

[0073] Chemical-pneumatic diaphragm valves also include:

[0074] The connecting nut 12 is two in number and is respectively threadedly connected to the medium inlet pipe 21 and the medium outlet pipe 22 . A plurality of clamping strips 121 are integrally formed on the outer wall of the connecting nut 12 .

[0075] There are two anti-loosening rings 13 , which are respectively sleeved on the medium inlet pipe 21 and the medium outlet pipe 22 . A plurality of anti-loosening notches 131 are evenly distributed on the anti-loosening rings 13 , and the ends of the clamping strips 121 are plug-connected with the anti-loosening notches 131 .

[0076] The diaphragm valve is made of PTFE or PFA.

[0077] The chemical pneumatic diaphragm valve of the present invention has universality, that is, when the spring is arranged in the accommodating cavity, and the first inlet and outlet air interface is connected to the air source, and the second inlet and outlet air interface is not connected to the air source, the diaphragm valve is a normally closed single pneumatic valve (when the downward elastic force of the spring is greater than the air pressure provided by the first inlet and outlet air interface, the valve core is always in contact with the sealing surface under the action of the spring); when the spring is arranged in the piston cavity, and the second inlet and outlet air interface is connected to the air source, and the first inlet and outlet air interface is not connected to the air source, the diaphragm valve is a normally open single pneumatic valve (when the upward elastic force of the spring is greater than the air pressure provided by the second inlet and outlet air interface, the valve core is always disconnected from the sealing surface under the action of the spring); when there is no spring, and the first inlet and outlet air interface and the second inlet and outlet air interface are both connected to the air source, the diaphragm valve is a double pneumatic valve. Therefore, the chemical pneumatic diaphragm valve can be used as a normally closed single pneumatic valve, a normally open single pneumatic valve or a double pneumatic valve according to the use requirements, and one valve can be used for multiple purposes, with strong universality. In addition, the valve core and the piston are connected as an integrated structure, which can avoid the phenomenon of excessive pressure on the valve core and loss, and increase the service life of the valve core. The diaphragm valve is made of PTFE or PFA plastic material as a whole, which effectively avoids corrosion by chemical media during operation. In addition, the chemical medium only contacts the valve body and the valve core, and the contact surface between the chemical medium and the diaphragm valve is small, which can reduce the possibility of contamination of the chemical medium, ensure the cleanliness of the chemical medium after passing through the diaphragm valve, and ensure the subsequent use effect of the chemical medium, so that the diaphragm valve is mainly used in the semiconductor industry as a liquid switch, such as pure water, sulfuric acid, nitric acid, etc., which is not only highly corrosion-resistant, but also has a high degree of cleanliness after the liquid passes through the diaphragm valve.

[0078] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0079] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A chemical pneumatic diaphragm valve, characterized in that: include: Base (1); A valve body (2), wherein the bottom end of the valve body (2) is fixed to the top end of the base (1), a valve cavity (201) for medium circulation is provided in the valve body (2), and a medium inlet pipe (21) and a medium outlet pipe (22) are integrally formed on both sides of the valve body (2), and the medium inlet pipe (21) and the medium outlet pipe (22) are both in communication with the valve cavity (201); A cylinder barrel (3), the bottom end of the cylinder barrel (3) being fixed to the top end of the valve body (2), a piston chamber (301) being provided inside the cylinder barrel (3), and a first air inlet and outlet port (302) being in communication with the piston chamber (301) being provided on a side wall of the cylinder barrel (3); A top cover (4), the bottom end of the top cover (4) being fixed to the top end of the cylinder barrel (3), a receiving cavity (401) being provided at the bottom end of the top cover (4), and a second air inlet and outlet interface (402) being in communication with the receiving cavity (401) being provided on a side wall of the top cover (4); A valve core (5), the valve core (5) being crimped between the valve body (2) and the cylinder barrel (3), and the valve core (5) being able to block or connect the valve chamber (201) by moving up and down; A piston (6), the piston (6) being arranged in the piston chamber (301), and the bottom end of the piston (6) being detachably connected to the top end of the valve core (5); A spring (7), wherein the spring (7) is arranged between the top wall of the accommodating chamber (401) and the top end of the piston (6), or the spring (7) is arranged between the bottom of the piston (6) and the bottom wall of the piston chamber (301); A sealing hollow column (202) is integrally formed on the bottom wall of the valve cavity (201), and the upper end surface of the sealing hollow column (202) is a sealing surface; The valve core (5) comprises: A core body (51), wherein the top end of the core body (51) is detachably connected to the bottom end of the piston (6), and the bottom end surface of the core body (51) is in contact with or disconnected from the sealing surface; an elastic diaphragm (52), the inner side of the elastic diaphragm (52) being integrally connected to the outer surface of the core (51); a crimping ring (53), the inner side of the crimping ring (53) and the outer side of the elastic diaphragm (52) being integrally formed, and the crimping ring (53) being crimped between the valve body (2) and the cylinder barrel (3); An annular clamping flange (203) is provided at the top end of the valve body (2), an annular clamping groove (531) is provided on the bottom end surface of the crimping ring (53), and the annular clamping groove (531) is clamped and matched with the annular clamping flange (203); an annular positioning flange (303) is integrally formed on the bottom end surface of the cylinder barrel (3), an annular positioning groove (532) is provided on the top end surface of the crimping ring (53), and the annular positioning flange (303) is clamped and matched with the annular positioning groove (532); A guide cylinder (304) is integrally formed on the bottom wall of the piston chamber (301), and the piston (6) comprises: A piston disc (61), wherein the piston disc (61) is disposed in the piston cavity (301); A guide column (62), one end of the guide column (62) is integrally formed with the bottom end of the piston disc (61), the other end of the guide column (62) is inserted into the guide cylinder (304) and is threadedly connected to the top end of the core body (51), and two ends of the spring (7) are respectively sleeved on the guide column (62) and the guide cylinder (304).

2. A chemical pneumatic diaphragm valve according to claim 1, characterized in that: A communication hole (2021) is provided on one side wall of the sealing hollow column (202); the medium inlet pipe (21) is connected to the interior of the sealing hollow column (202) through the communication hole (2021); the upper port of the sealing hollow column (202) is connected to the valve cavity (201); and the bottom end surface of the valve core (5) is in contact with or disconnected from the sealing surface.

3. A chemical pneumatic diaphragm valve according to claim 1, characterized in that: A first sealing ring installation groove (611) is provided on the outer peripheral wall of the piston disc (61), and a first sealing ring (8) is installed in the first sealing ring installation groove (611). A second sealing ring installation groove (621) is provided on the outer column wall of the guide column (62), and a second sealing ring (9) is installed in the second sealing ring installation groove (621). A sealing ring sleeve tube (403) is integrally formed on the outer peripheral side of the accommodating cavity (401) at the bottom end of the top cover (4), and a third sealing ring (10) is sleeved on the sealing ring sleeve tube (403).

4. The chemical pneumatic diaphragm valve according to claim 1, characterized in that: The base (1), the valve body (2), the cylinder barrel (3) and the top cover (4) are fixedly connected via a plurality of connecting screw assemblies (11).

5. The chemical pneumatic diaphragm valve according to claim 4, characterized in that: Each of the connecting screw assemblies (11) comprises: A connecting nut (111), wherein the connecting nut (111) is disposed inside the base (1); a connecting screw (112), the connecting screw (112) being sequentially passed through holes on the top cover (4), the cylinder barrel (3), and the valve body (2) and then being threadedly connected to the connecting nut (111); A cover cap (113), the cover cap (113) is connected to the through hole on the top cover (4) and is located above the head end of the connecting screw (112).

6. A chemical pneumatic diaphragm valve according to any one of claims 1 to 5, characterized in that: Also includes: A pipe nut (12), wherein the pipe nut (12) is two in number and is respectively threadedly connected to the medium inlet pipe (21) and the medium outlet pipe (22), and a plurality of clamping strips (121) are integrally formed on the outer wall of the pipe nut (12); Anti-loosening rings (13), the anti-loosening rings (13) being two in number and respectively sleeved on the medium inlet pipe (21) and the medium outlet pipe (22), the anti-loosening rings (13) being evenly distributed with a plurality of anti-loosening notches (131), the ends of the clamping strips (121) being plug-connected to the anti-loosening notches (131).

7. A chemical pneumatic diaphragm valve according to any one of claims 1 to 5, characterized in that: The diaphragm valve is made of PTFE or PFA.

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