Diaphragm valve for ultra-pure pipeline

Abstract

A diaphragm valve for an ultra-pure pipeline comprises a valve deck, an upper valve body and a lower valve body, the upper valve body and the lower valve body are fixedly connected through a bolt, a valve rod, a valve clack, a medium inlet channel and a medium outlet channel are arranged in the lower valve body, a mounting channel is formed in the lower valve body, a plurality of positioning guide grooves which are vertically formed at intervals are formed in the inner wall of the mounting channel, and the positioning guide grooves are communicated with the valve deck. The outer wall of the valve cover is provided with a positioning guide block matched with the positioning guide groove, the bottom of the installation channel extends to be provided with a limiting check ring, the bottom of the valve clack is connected with a cushion membrane piece and a diaphragm piece, the periphery of the cushion membrane piece and the periphery of the diaphragm piece extend to the position between the limiting check ring and the valve cover, and the valve cover is provided with a limiting step. The upper valve body is fixedly connected with the lower valve body in a threaded mode and then abuts against the limiting step, so that the valve deck is fixedly installed in the installation channel, and sealing connection is formed.

Description

Technical Field

[0001] The invention relates to a diaphragm valve for ultrapure pipelines, belonging to the field of valves. Background Art

[0002] With the development of the national semiconductor industry and photovoltaic single crystal cells, in order to solve the problems of semiconductor industry and photovoltaic single crystal cells, food hygiene grade, pharmaceutical grade pure water (such as water for injection / pure water) and deionized water for analytical experiments and other industrial systems, the water quality of ultrapure water directly affects the quality qualification rate of the final product. Therefore, the pipeline requires corrosion-free, zero dead zone, double flow rate, small pressure loss, high reliability, and good sealing performance control valves.

[0003] Existing diaphragm valves are also used in the semiconductor industry, but the valve body and valve cover of a general diaphragm valve are made of metal and are fixedly connected by bolting the valve cover flange to complete the overall assembly. However, the semiconductor industry not only requires corrosion resistance, but also requires no pollution to the fluid materials therein. Therefore, valve bodies made of metal are not suitable for the transportation of some special materials, which will affect the properties of the materials and lead to low processing efficiency. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a diaphragm valve for ultrapure pipelines.

[0005] A diaphragm valve for ultrapure pipelines includes a valve cover, an upper valve body, and a lower valve body. The upper and lower valve bodies are fixedly connected by bolts. The lower valve body is provided with a valve stem, a valve disc, and medium inlet and outlet channels. The lower valve body is provided with a mounting channel. The inner wall of the mounting channel is provided with a plurality of vertically spaced positioning guide grooves. The outer wall of the valve cover is provided with positioning guide blocks that match the positioning guide grooves. A limit ring extends from the bottom of the mounting channel. A diaphragm and a diaphragm are connected to the bottom of the valve disc. The outer periphery of the diaphragm and diaphragm extends between the limit ring and the valve cover. The valve cover is provided with a limit step. The upper valve body is fixedly connected to the lower valve body by a threaded connection and then abuts the limit step, so that the valve cover is fixedly installed in the mounting channel and forms a sealed connection. The conventional diaphragm valve bonnet and valve body connection method is replaced by a threaded connection design between the valve body and the valve cover. This prevents the diaphragm valve from generating metal elements that may contaminate ultrapure water in ultrapure pipelines. The metal precipitate, TOC, and metal ion content meet SEMI F57 standards. The upper and lower valve bodies are securely connected via a threaded connection, and a stopper step at the top abuts against a stopper ring at the bottom of the mounting channel for concentric positioning. Assembly requires no high-precision tooling, enabling quick positioning and pre-tightening, reducing assembly errors and the risk of leakage. Multi-point guide grooves and guide blocks ensure automatic alignment of the valve cover and ensure a stable, rock-proof connection. Strong guidance and smooth insertion and removal during assembly minimize gaps and dead zones caused by valve cover shifting.

[0006] Preferably, the upper valve body, lower valve body, valve cover, valve disc, diaphragm, and diaphragm are all made of non-metallic materials, such as polytetrafluoroethylene (PTFE), ultra-high-purity polyvinylidene fluoride (UHP-PVDF), polypropylene glycol (PPG), or polyphenylene sulfide (PPS). Fluoroplastic materials such as PTFE and UHP-PVDF are resistant to corrosion by strong acids, strong bases, and most organic solvents, ensuring long-term stable operation of the valve in ultrapure water and various chemical media without secondary contamination. Non-metallic polymer materials do not contain metal ions and are less likely to produce particles or micro-dissolution, effectively preventing cross-contamination of semiconductors, photovoltaic cells, pharmaceutical-grade water for injection, and analytical-grade deionized water. Non-metallic materials inherently have insulating properties that effectively prevent static electricity accumulation, making them particularly suitable for certain ultrapure process applications that are sensitive to static electricity.

[0007] Preferably, the media inlet and outlet channels are disposed on either side of the lower valve body and are shaped like a slope that gradually increases in height from the outside to the inside. This gradually increases in height from the outside to the inside, creating an ascending slope as the fluid flows through it. This creates a self-cleaning and flushing effect, effectively removing tiny particles and sediment from the pipeline and valve cavity, reducing dead zones and preventing contaminant accumulation. The inclined channel design facilitates the upward and expulsion of bubbles carried along the slope, reducing the likelihood of bubbles accumulating in the valve cavity, preventing air lock, and improving the stability and reliability of valve operation.

[0008] Furthermore, the inlet of the medium inlet and the outlet of the outlet channel are open and expanded to both sides until they are butted together, so that the water flow of the medium inlet and outlet channels can flow to all corners inside. The inlet and outlet are both expanded to open on both sides, which can enable the fluid jet to cover the entire cross-section of the valve cavity, bringing all corners into the flow range, thoroughly flushing potential sediments everywhere, and avoiding dead zone residues. The open design not only expands the flushing range, but also facilitates the discharge of bubbles along with the liquid flow, further reducing the risk of air lock. When flushing or emptying the system, the opening can also accelerate the escape of residual liquid and impurities, making maintenance more convenient.

[0009] Preferably, the limit ring is provided with a circumferentially arranged sealing groove, and a protruding sealing convex ring is provided on the outside of the sealing groove. The outer wall of the sealing convex ring is an inclined surface and a plane connected to the inclined surface. The outer edges of the pad diaphragm and the diaphragm extend into the sealing groove, and the bottom surface abuts the inclined surface of the sealing convex ring to form a sealed connection. The circumferential sealing groove cooperates with the sealing convex ring protruding from the outside, and the bottom surface of the diaphragm abuts the inclined surface, forming a double sealing interface. During the operation of the valve disc, the diaphragm in the groove can deform slightly with the convex ring, maintaining a good fit and preventing medium leakage. The sealing convex ring is composed of an inclined surface and a plane. The bottom surface of the diaphragm first contacts the inclined surface and gradually stabilizes in the plane area, which has a guiding effect. The geometric fit between the convex ring and the groove forms a "locking" structure, which makes the diaphragm less likely to slip due to flow impact or vibration.

[0010] Furthermore, the bottom of the diaphragm is provided with a first sealing protrusion that abuts the flat surface. This protrusion can slightly rebound under long-term use or media erosion, effectively compensating for minor wear or deformation of the flat surface area and diaphragm, maintaining sealing performance. During fluid impact or valve disc vibration, the protrusion maintains partial contact with the flat surface area, reducing seal loosening or slippage caused by dynamic loads.

[0011] Preferably, the outer periphery of the diaphragm is provided with a second sealing protrusion, and the bottom of the valve cover is provided with a sealing groove that cooperates with the second sealing protrusion to form a sealed connection. The second sealing protrusion has good elasticity, which can compensate for slight height or plane deviations between the diaphragm and the valve cover, reducing the requirements for assembly precision and saving assembly and commissioning time. During valve disc movement or fluid pulsation, the protrusion is continuously compressed and maintains contact with the sealing groove, reducing the possibility of sealing surface separation due to vibration or fluid impact, and ensuring a reliable seal under dynamic operating conditions.

[0012] Preferably, a valve stem sleeve is provided in the valve cover, a valve stem is provided in the valve stem sleeve, a first fixing nut is provided in the valve disc, a limit pin is clamped in the first fixing nut, the end of the valve stem is fixedly mounted on the limit pin, and a stud for connecting to a handwheel is threadedly fixed on the other end of the valve stem. The valve stem sleeve fully wraps around the valve stem, effectively limiting the radial and tilting drift of the valve stem, ensuring that the valve stem always moves along the predetermined center line, and reducing wear on the valve stem and the inner hole of the valve body. The other end of the valve stem is firmly connected to the handwheel via the stud, which can achieve direct and efficient transmission of torque; at the same time, the threaded fit of the stud and the valve stem makes the connection resistant to tension and torsion, ensuring that the handwheel can be operated sensitively without tooth jumping.

[0013] Furthermore, the bottom of the valve stem is fixedly connected to the diaphragm via a nut, and the diaphragm pad is sleeved over the diaphragm. Sleeved over the diaphragm, the diaphragm pad bears the compressive force transmitted by the nut and applies a uniform preload to the diaphragm, ensuring a consistent seal and reducing the risk of micro-leakage. Serving as a flexible intermediary layer, the diaphragm pad absorbs vibration and impact loads generated by valve stem movement and fluid impact, mitigating fatigue damage to the diaphragm and extending the life of the diaphragm assembly.

[0014] Preferably, the end of the stud extends out of the valve stem sleeve and is connected to a handwheel. The handwheel, through rotation, drives the valve disc to move up and down within the valve cover to seal and release the seal. The handwheel drives the valve disc up and down within the valve cover, tightly pressing or separating the valve disc and the diaphragm / pad diaphragm, with clear sealing and opening actions and stable repeatable positioning. When it is necessary to quickly cut off or restore the pipeline medium, the handwheel can be quickly rotated manually without the need for additional tools. Emergency manual operation can also be achieved in the event of a power outage or automatic system failure.

[0015] The beneficial effects of the present invention are as follows: the traditional bolt connection between the diaphragm valve bonnet and the valve body is changed to a threaded connection design between the valve body and the bonnet, so that the diaphragm valve does not produce metal elements in the ultrapure pipeline to contaminate the ultrapure water. The metal precipitates, TOC, and metal ion contents meet the requirements of the SEMI F57 standard. The upper and lower valve bodies are firmly combined by threaded connection, and a limit step is set at the top to abut against the limit retaining ring at the bottom of the installation channel to achieve concentric limit; during assembly, no high-precision tooling is required to quickly position and complete pre-tightening, reducing assembly errors and leakage risks. The multi-point guide groove / guide block cooperates to automatically align the valve cover and stabilize it without shaking; the assembly process has strong guidance and smooth plugging and unplugging, reducing the gap and dead zone caused by the displacement of the valve cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, other drawings obtained based on these drawings still fall within the scope of the present invention.

[0017] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a schematic cross-sectional structure diagram of the present invention; Figure 3 yes Figure 2 A magnified diagram of the details at point A; Figure 4 It is a schematic diagram of the explosion structure of the present invention; Figure 5 Schematic diagram of the structure of the valve stem in the present invention; Figure 6 Schematic diagram of the cross-sectional structure of the lower valve body of the present invention; In the figure, 1. upper valve body; 2. lower valve body; 21. mounting channel; 22. positioning guide groove; 23. limit retaining ring; 24. sealing groove; 25. sealing convex ring; 3. valve cover; 31. positioning guide block; 32. limit step; 33. sealing groove; 4. valve stem sleeve; 5. valve stem; 6. valve disc; 61. first fixing nut; 62. limit pin; 7. medium inlet; 8. outlet channel; 9. diaphragm; 91. second sealing protrusion; 10. diaphragm; 101. first sealing protrusion; 11. stud; 12. handwheel. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0019] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two non-identical entities with the same name or non-identical parameters. It can be seen that "first" and "second" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. Subsequent embodiments will not explain this one by one.

[0020] The terms "upper," "lower," "front," "back," "left," "right," "inner," "outer," "top," "bottom," and "side" used herein are merely references to the directions or positions in the accompanying drawings. These terms are intended to illustrate and facilitate understanding of the present invention and are not intended to limit the scope of protection of the present invention.

[0021] like Figure 1-6The figure shows an embodiment of a diaphragm valve for ultrapure pipelines of the present invention, comprising a valve cover 3, an upper valve body 1 and a lower valve body 2, the upper valve body 1 and the lower valve body 2 being fixedly connected by bolts, the lower valve body 2 being provided with a valve stem 5, a valve disc 6, a medium inlet 7 and an outlet channel 8, the lower valve body 2 being provided with a mounting channel 21, the inner wall of the mounting channel 21 being provided with a plurality of positioning guide grooves 22 arranged at vertical intervals, the outer wall of the valve cover 3 being provided with a positioning guide block 31 matching the positioning guide grooves 22, a limit retaining ring 23 extending from the bottom of the mounting channel 21, a pad diaphragm 9 and a diaphragm 10 being connected to the bottom of the valve disc 6, the outer periphery of the pad diaphragm 9 and the diaphragm 10 extending between the limit retaining ring 23 and the valve cover 3, a limit step 32 being provided on the valve cover 3, the upper valve body 1 being fixedly connected to the lower valve body 2 by a threaded connection and then abutting against the limit step 32, so that the valve cover 3 is fixedly mounted in the mounting channel 21 and forms a sealed connection. The traditional bolted connection between the diaphragm valve bonnet 3 and the valve body is replaced with a threaded connection between the valve body and bonnet 3. This prevents the diaphragm valve from contaminating the ultrapure water with metallic elements in the ultrapure pipeline. This ensures that metal precipitates, TOC, and metal ion levels meet SEMI F57 standards. A threaded connection secures the upper and lower valve bodies 2 together, and a stopper 32 is provided at the top to abut against the stopper 23 at the bottom of the mounting channel 21, achieving concentric positioning. During assembly, the bonnet 3 can be quickly positioned and pre-tightened without the need for high-precision tooling, reducing assembly errors and the risk of leakage. Multi-point guide grooves and guide blocks ensure automatic alignment and stability of the bonnet 3. Strong guidance and smooth insertion and removal during assembly reduce gaps and dead zones caused by displacement of the bonnet 3.

[0022] The upper valve body 1, lower valve body 2, valve cover 3, valve disc 6, diaphragm 9, and diaphragm 10 are all made of non-metallic materials, such as polytetrafluoroethylene (PTFE), ultra-high-purity polyvinylidene fluoride (UHP-PVDF), polypropylene glycol (PPG), or polyphenylene sulfide (PPS). Fluoroplastic materials like PTFE and UHP-PVDF are resistant to corrosion from strong acids, strong bases, and most organic solvents, ensuring long-term stable operation of the valve in ultrapure water and various chemical media without secondary contamination. Non-metallic polymer materials contain no metal ions and are less likely to produce particles or leach out, effectively preventing cross-contamination of semiconductors, photovoltaic cells, pharmaceutical-grade water for injection, and analytical-grade deionized water. The inherent insulating properties of non-metallic materials effectively prevent static electricity accumulation, making them particularly suitable for certain static-sensitive ultrapure process applications.

[0023] In the embodiment of the present application, this embodiment differs from the above-mentioned embodiment in that the medium inlet 7 and outlet channel 8 are arranged on both sides of the lower valve body 2, and the medium inlet 7 and outlet channel 8 are in the shape of a slope with a gradually increasing height from the outside to the inside. The channel gradually increases in height from the outside to the inside, and the fluid takes an ascending slope shape when flowing through, which can produce a self-cleaning and flushing effect, effectively removing tiny particles and sediments in the pipeline and valve cavity, reducing dead zones, and preventing the accumulation of pollutants. The inclined channel design facilitates the bubbles carried by the flow to rise and be discharged along the slope, reducing the possibility of bubbles being retained in the valve cavity, avoiding air lock, and improving the stability and reliability of the valve operation.

[0024] The inlet of the medium inlet 7 and the outlet of the outlet channel 8 are set to be open and expanded on both sides until they are connected, so that the water flow of the medium inlet 7 and the outlet channel 8 can flow to all corners inside. The inlet and outlet are expanded to both sides to be open, which can enable the fluid jet to cover the entire cross-section of the valve cavity, include all corners in the flow range, thoroughly flush potential sediments everywhere, and avoid dead zone residues. The open design not only expands the flushing range, but also makes it convenient to discharge bubbles along with the liquid flow, further reducing the risk of air lock. When flushing or emptying the system, the opening can also accelerate the escape of residual liquid and impurities, making maintenance more convenient.

[0025] In this embodiment of the present application, this embodiment differs from the above-described embodiments in that the retaining ring 23 is provided with a circumferential sealing groove 24. A protruding sealing collar 25 is positioned outside the sealing groove 24. The outer wall of the sealing collar 25 comprises an inclined surface and a flat surface connected to the inclined surface. The outer edges of the diaphragm 9 and 10 extend into the sealing groove 24, with their bottom surfaces abutting the inclined surface of the sealing collar 25 to form a sealed connection. The circumferential sealing groove 24, combined with the protruding sealing collar 25 and the tight contact between the bottom surface of the diaphragm and the inclined surface, creates a double sealing interface. During the operation of the valve disc 6, the diaphragm within the groove deforms slightly with the collar, maintaining a secure fit and preventing medium leakage. The sealing collar 25 is composed of an inclined surface and a flat surface. The bottom surface of the diaphragm first contacts the inclined surface and gradually stabilizes on the flat surface, providing a guiding function. The geometric fit between the collar and the groove creates a "locking" structure, preventing the diaphragm from slipping due to flow shock or vibration.

[0026] The bottom of the diaphragm 10 is provided with a first sealing protrusion 101 that abuts the flat surface. This protrusion can slightly rebound under long-term use or media erosion, effectively compensating for minor wear or deformation of the flat surface area and diaphragm, maintaining sealing performance. During fluid impact or valve disc 6 vibration, the protrusion maintains partial contact with the flat surface area, reducing seal loosening or slippage caused by dynamic loads.

[0027] In this embodiment of the present application, this embodiment differs from the above-described embodiments in that a second sealing protrusion 91 is provided on the outer periphery of the diaphragm 9, and a sealing groove 33 is provided at the bottom of the valve cover 3, which cooperates with the second sealing protrusion 91 to form a sealed connection. The second sealing protrusion 91 has good elasticity, compensating for slight height or plane deviations between the diaphragm 9 and the valve cover 3, reducing assembly precision requirements and saving assembly and commissioning time. When the valve disc 6 moves or the fluid pulsates, the protrusion is continuously compressed and maintains contact with the sealing groove 33, reducing sealing surface separation caused by vibration or fluid impact, and ensuring a reliable seal under dynamic operating conditions.

[0028] The valve cover 3 is provided with a valve stem sleeve 4, which is provided with a valve stem 5. The valve disc 6 is provided with a first fixing nut 61, which is engaged with a limit pin 62. The end of the valve stem 5 is fixedly mounted on the limit pin 62, and the other end of the valve stem 5 is threadedly fixed with a stud 11 for connecting to a handwheel 12. The valve stem sleeve 4 fully wraps around the valve stem 5, effectively limiting the radial and tilting drift of the valve stem 5, ensuring that the valve stem 5 always moves along the predetermined centerline, and reducing wear on the valve stem 5 and the inner hole of the valve body. The other end of the valve stem 5 is firmly connected to the handwheel 12 via the stud 11, which can achieve direct and efficient transmission of torque. At the same time, the threaded fit of the stud 11 and the valve stem 5 makes the connection resistant to tension and torsion, ensuring that the handwheel 12 is sensitive to operation and without tooth jumping.

[0029] The bottom of the valve stem 5 is fixedly connected to the diaphragm 10 via a nut, and the diaphragm 9 is sleeved over the diaphragm 10. Sleeved over the diaphragm 10, the diaphragm 9 withstands the compressive force transmitted by the nut and applies a uniform preload to the diaphragm 10, ensuring a consistent seal and reducing the risk of micro-leakage. Serving as a flexible intermediary layer, the diaphragm 9 absorbs vibration and impact loads generated by the movement of the valve stem 5 and fluid impact, mitigating fatigue damage to the diaphragm 10 and extending the service life of the diaphragm assembly.

[0030] The end of the stud 11 extends out of the valve stem sleeve 4 and is connected to a handwheel 12. The handwheel 12 rotates to move the valve disc 6 up and down within the valve cover 3 to seal and release the seal. The handwheel 12 drives the valve disc 6 up and down within the valve cover 3, tightly pressing or separating the valve disc 6 and the diaphragm 10 / backing diaphragm 9. The sealing and opening actions are clear, and the repeatable positioning is stable. To quickly shut off or restore the pipeline medium, the handwheel 12 can be quickly rotated manually without the need for additional tools. Emergency manual operation can also be achieved in the event of a power outage or automatic system failure.

[0031] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

[0032] Although the present invention has been described with reference to several specific embodiments, it should be understood that the invention is not limited to the specific embodiments disclosed, and the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A diaphragm valve for ultrapure pipelines, characterized by: The closure comprises a valve cover, an upper valve body and a lower valve body, the upper valve body and the lower valve body being fixedly connected by bolts, the lower valve body being provided with a valve stem, a valve disc, a medium inlet and outlet channels, the lower valve body being provided with a mounting channel, the inner wall of the mounting channel being provided with a plurality of positioning guide grooves arranged at vertical intervals, the outer wall of the valve cover being provided with a positioning guide block matching the positioning guide groove, a limiting retaining ring extending from the bottom of the mounting channel, a pad diaphragm and a diaphragm being connected to the bottom of the valve disc, the outer periphery of the pad diaphragm and the diaphragm extending between the limiting retaining ring and the valve cover, the valve cover being provided with a limiting step, the upper valve body being fixedly connected to the lower valve body by a threaded connection and then abutting against the limiting step, so that the valve cover is fixedly mounted in the mounting channel and forms a sealed connection.

2. The diaphragm valve for ultrapure piping according to claim 1, characterized in that: The materials of the upper valve body, the lower valve body, the valve cover, the valve disc, the diaphragm and the diaphragm are all non-metallic materials.

3. The diaphragm valve for ultrapure piping according to claim 1, wherein: The medium inlet and outlet channels are arranged on both sides of the lower valve body, and the medium inlet and outlet channels are in a slope shape with a height gradually increasing from the outside to the inside.

4. The diaphragm valve for ultrapure piping according to claim 3, wherein: The inlet of the medium inlet and the outlet of the outlet channel are open and expand toward both sides until they are butted together, so that the water flow of the medium inlet and outlet channels can flow to all corners inside.

5. The diaphragm valve for ultrapure pipeline according to claim 1, characterized in that: The limit retaining ring is provided with a circumferentially arranged sealing groove, and a protruding sealing convex ring is provided on the outer side of the sealing groove. The outer wall of the sealing convex ring is an inclined surface and a plane connected to the inclined surface. The outer edges of the pad diaphragm and the diaphragm extend into the sealing groove, and the bottom surface abuts against the inclined surface of the sealing convex ring to form a sealed connection.

6. The diaphragm valve for ultrapure piping according to claim 5, characterized in that: The bottom of the diaphragm is provided with a first sealing protrusion that abuts against the plane.

7. The diaphragm valve for ultrapure piping according to claim 1, wherein: A second sealing protrusion is provided on the outer periphery of the diaphragm, and a sealing groove is provided on the bottom of the valve cover to form a sealing connection with the second sealing protrusion.

8. The diaphragm valve for ultrapure piping according to claim 1, wherein: A valve stem sleeve is provided in the valve cover, a valve stem is provided in the valve stem sleeve, a first fixing nut is provided in the valve disc, a limit pin is clamped in the first fixing nut, the end of the valve stem is fixedly mounted on the limit pin, and a stud for connecting to a handwheel is threadedly fixed on the other end of the valve stem.

9. The diaphragm valve for ultrapure piping according to claim 8, characterized in that: The bottom of the valve stem is fixedly connected to the diaphragm through a nut, and the pad diaphragm is sleeved on the diaphragm.

10. The diaphragm valve for ultrapure pipeline according to claim 1, characterized in that: The end of the stud extends out of the valve stem sleeve and is connected to a hand wheel. The hand wheel drives the valve disc to move up and down in the valve cover to seal and release the seal through a rotation action.

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