CN217328715U - Pneumatic valve for controlling on-off of wet chemicals - Google Patents

Abstract

The utility model discloses a pneumatic valve for controlling the on-off of wet chemicals, which comprises a shell and a valve body, wherein the shell is provided with a brake cavity; the valve body is internally provided with an inlet flow passage, an outlet flow passage and a valve seat; a valve assembly; the piston and the inner wall of the brake chamber form a dynamic seal and can axially reciprocate to drive the valve component to close or open the valve seat; the piston comprises a central column which can be connected with a valve component; a main body portion extending radially outward from the outer wall of the center post and separating the brake chamber into a first chamber and a second chamber; the first cavity is provided with a first air port, and the second cavity is provided with a second air port; a force-bearing wall extending axially from the first side surface of the body portion to form a closed annular structure; the pneumatic valve further comprises an elastic member, one end of which abuts against an axial position of the main body portion corresponding to the force-receiving wall. The utility model discloses an increase the atress wall, the one end butt of elastic component has increased the intensity that piston and elastic component offset department in the position that the main part corresponds the atress wall, ensures sealed, long service life between valve module and the disk seat.

Description

Pneumatic valve for controlling on-off of wet chemicals

Technical Field

The utility model belongs to the technical field of the fluid control valve, especially, relate to a pneumatic valve of control wet chemicals break-make.

Background

In the semiconductor industry, fluid control valves are commonly used to transport highly corrosive liquids, in which springs, pistons, and valve components are axially arranged; under the normal state, the piston is pressed by a spring, so that the valve component keeps a normally open or normally closed state relative to the valve seat of the main body; when high-pressure gas is introduced into the brake cavity, the piston overcomes the pressure of the spring to drive the valve component to move axially, and the flowing state of the strong corrosive liquid is changed.

The strength of the piston is very important because the spring provides a large pressure to the piston to better maintain the stability of the relative position between the valve assembly and the valve seat. The fluid control valve in the prior art usually achieves the purpose of increasing strength through the increase of the thickness of the piston, but because the piston is usually formed by injection molding of polymer particles, the increase of the thickness of the piston inevitably leads to the increase of the shrinkage of the piston, and further leads to the reduction of the precision of the piston. The action of the pressure of the spring on such a piston will cause the direction of the force to be not completely axial, that is, the pressure generated by the spring is eccentric, so that the piston cannot axially transmit the pressure of the spring, when the fluid control valve is a normally closed valve, the sealing performance of a partial area between the valve component and the valve seat is poor, the stroke of the valve component is fixed and small, once the movement direction of the valve component is eccentric, a local deformation amount is insufficient, and a strong corrosive fluid passes through the valve seat in a valve closing state. In view of this, the present application is specifically made.

SUMMERY OF THE UTILITY MODEL

In order to overcome the not enough of prior art, the utility model provides a piston intensity is high, and piston machining precision improves, can guarantee that the elastic component produces axial, balanced pressure to the piston, the pneumatic valve of the wet chemical break-make of control that the leakproofness is good between valve module and the disk seat.

The utility model provides a technical scheme that its technical problem adopted is: a pneumatic valve for controlling the on-off of wet chemicals, which comprises,

a housing having a brake chamber formed therein;

a valve body having an inlet flow passage and an outlet flow passage for the flow of wet chemicals therein, and a valve seat formed therebetween;

a valve assembly located on an axial side of the valve seat;

the piston is movably sealed with the inner wall of the brake cavity and can axially reciprocate in the brake cavity to drive the valve component to close or open the valve seat;

the piston includes:

a central post connectable to the valve assembly;

a body portion extending radially outward from the outer wall of the center post and separating the brake chamber into a first chamber on a first side and a second chamber on a second side; a first air port is arranged on the first cavity, and a second air port is arranged on the second cavity;

a force-bearing wall extending axially from the first side surface of the body portion to form a closed annular structure;

and the pneumatic valve further includes an elastic member having one end portion abutting against the second side surface of the main body portion at a position corresponding to the axial direction of the force receiving wall.

The utility model discloses an increase the atress wall structure on the piston, and with the position of the one end butt of elastic component at the main part corresponding atress wall, utilize the atress wall to increase the intensity that piston and elastic component offset, need not increase the thickness of piston main part again simultaneously, effectively avoid the piston to reduce because of the machining precision that thickness is too big leads to, guarantee that the power of elastic component can transmit to the piston along the axial, the piston keeps axial motion, the axial of elastic component also all the time is parallel with the axial of piston, guarantee the two all the time along axial motion, and the motion state is stable, guarantee then effective sealing between valve module and the valve seat, the elastic component also can keep relatively even to each department of the pressure circumference of piston under the long-time use, guarantee good sealing performance between valve module and the valve seat; after the strength of the piston is increased, the piston is not easy to deform, and further, the dynamic sealing performance of the piston and the inner wall of the brake cavity can be kept in a good state.

Furthermore, the piston also comprises first reinforcing parts which are connected with the central column, the main body part and the stress wall, and the first reinforcing parts are uniformly distributed at intervals along the circumferential direction of the central column.

The central column, the main body part and the stress wall are connected together by the first reinforcing part, so that the overall strength of the piston is increased, the stress wall and the main body part are prevented from deforming under the action of external force, the thickness of the piston at each position during processing is not increased, and the precision requirement of piston processing is met.

Further, the piston also comprises second reinforcing parts which are connected with the central column and the main body part, and the second reinforcing parts are uniformly distributed at intervals along the circumferential direction of the central column; and the elastic piece is sleeved on the periphery of the second reinforcing part to limit the radial movement of the elastic piece.

The second rib sets up in the one side relative with first rib, and both cooperations can increase the intensity of piston, and the periphery at the second rib is established to the elastic component cover moreover for the second rib has played limiting displacement to the elastic component, avoids the elastic component to take place radial movement, guarantees that the elastic component produces balanced pressure to the piston, ensures good sealing performance between valve module and the disk seat then. Meanwhile, the second reinforcing part is also beneficial to keeping the structure stability of the piston, so that the piston and the inner wall of the brake cavity are kept in dynamic sealing.

Further, the second reinforcement portion includes an inner race portion and an outer race portion, the outer race portion having an inclined guide surface that facilitates the elastic member to be inclined toward the direction in which the force-receiving wall moves.

The inner ring part of the second reinforcing part can increase the connection strength between the inner ring part and the center column, and the outer ring part is provided with the inclined guide surface, so that when the elastic part is assembled, the outer periphery of the second reinforcing part can be sleeved with the inclined guide surface, and the assembling difficulty is reduced.

Further, the casing includes upper valve cover and lower valve cover, the axial height of inner circle part is greater than the axial height of outer lane part, and inner circle part and the extending direction of elastic component is the same to form the spacing portion that can with upper valve cover butt in the axial tip of inner circle part.

The axial height of the inner ring part is increased, so that a limiting part is formed at the top end of the inner ring part, and when the valve assembly opens the valve seat, the limiting part is abutted with the upper valve cover to form a limiting effect, so that the valve assembly is prevented from excessively moving upwards to further damage the valve assembly; meanwhile, the axial height of the inner ring part is increased, so that the elastic part is supported more stably, and overlarge deflection of the elastic part during compression or extension is avoided; in addition, the axial end part of the inner ring part forms a limiting part, so that when the elastic piece is assembled, the elastic piece only pushes against the inclined guide surface of the outer ring part to slide, and assembly interference with other positions cannot be generated.

Furthermore, the central column is provided with a limiting platform with an increased outer diameter, the inner ring part is connected with the outer wall of the limiting platform, and the axial height of the position with the maximum height of the inner ring part and the outer ring part is equal.

When the valve component opens the valve seat, the limiting platform is abutted with the upper valve cover to form a limiting function, so that the valve component is prevented from excessively moving upwards; meanwhile, the axial heights of the inner ring part and the outer ring part are equal, and the processing is convenient.

Further, the lower valve cover forms a blocking surface, and when the piston drives the valve component to block the valve seat, the distance between the end part of the first reinforcing part and the blocking surface is 0.1-1 mm.

When the valve component blocks the valve seat, the first reinforcing part is not contacted with the blocking surface, so that the first reinforcing part is prevented from interfering with the blocking surface when the valve component does not block the valve seat, the piston cannot move downwards continuously, and the valve component is guaranteed to block the valve seat effectively; meanwhile, the distance setting also prevents the valve component from moving downwards and having overlarge stroke, so that the valve component is protected.

Furthermore, the stress wall bends outwards to form an L-shaped structure, the stress wall and the outer edge of the main body part are surrounded to form a mounting groove, and a sealing element used for forming dynamic sealing of the piston and the inner wall of the brake cavity is arranged in the mounting groove.

The processing mode of mounting groove is simple, and the sealing member can stabilize the assembly in the mounting groove, and the sealing member can not take place to shift, effectively guarantees the movive seal of piston and braking intracavity wall.

Further, the center post is hollow and has internal threads that are adapted to be coupled to a valve assembly.

The hollow inner part of the central column not only reduces the whole weight of the central column, but also is convenient to arrange an internal thread to be connected with the valve component, and the connecting structure is simple and effective.

Further, the maximum thickness of the piston is less than 6 mm.

The numerical value setting of above-mentioned maximum thickness guarantees that the piston can not produce great shrinkage in injection moulding process, improves the machining precision of piston.

The utility model has the advantages that: the stress wall structure is added on the piston, and one end of the elastic piece is abutted to the position of the main body part corresponding to the stress wall, so that the strength of the abutted part of the piston and the elastic piece is increased, meanwhile, the thickness of the main body part of the piston is not required to be increased, the processing precision of the piston is ensured, the effective sealing between the valve component and the valve seat is ensured, and the service life is prolonged; the elastic piece is high in assembly stability and low in assembly difficulty; after the strength of the piston is increased, the piston is not easy to deform, and further the dynamic sealing performance of the piston and the inner wall of the brake cavity can be kept.

Drawings

Fig. 1 is a side view of a pneumatic valve according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view of a pneumatic valve according to an embodiment of the present invention.

Fig. 3 is a perspective view of a piston of a pneumatic valve according to an embodiment of the present invention.

Fig. 4 is a front view of a piston of a pneumatic valve according to an embodiment of the present invention.

Fig. 5 is a top view of a piston of a pneumatic valve according to an embodiment of the present invention.

Fig. 6 is a bottom view of a piston of a pneumatic valve according to an embodiment of the present invention.

Fig. 7 is a sectional view a-a in fig. 6.

Fig. 8 is a perspective view of a piston of a pneumatic valve according to a second embodiment of the present invention.

Fig. 9 is a front view of a piston of a pneumatic valve according to a second embodiment of the present invention.

Fig. 10 is a sectional view taken along line B-B in fig. 9.

Wherein, 1-shell, 11-brake chamber, 111-first chamber, 112-second chamber, 113-first air port, 114-second air port, 12-upper valve cover, 13-lower valve cover, 131-blocking surface, 2-valve body, 21-inlet flow channel, 22-outlet flow channel, 23-valve seat, 3-valve component, 31-valve core, 32-membrane part, 33-fixed part, 4-piston, 41-center column, 411-limit platform, 412-internal thread, 413-schematic part, 42-main part, 43-stress wall, 431-L-shaped structure, 44-first reinforcement part, 45-second reinforcement part, 451-inner ring part, 452-outer ring part, 453-inclined guide surface, 454-limit part, 46-mounting groove, 47-sealing element, 5-elastic element.

Detailed Description

In order to make the technical solution of the present invention better understood, the following figures in the embodiments of the present invention are combined to clearly and completely describe the technical solution in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall belong to the protection scope of the present invention.

Example one

As shown in fig. 1 and 2, a pneumatic valve for controlling the on-off of wet chemicals comprises a housing 1 having a brake chamber 11 formed therein, a valve body 2, a valve assembly 3, and a piston 4, wherein the valve body 2 has an inlet flow passage 21 and an outlet flow passage 22 for the wet chemicals to flow through, and a valve seat 23 formed between the inlet flow passage 21 and the outlet flow passage 22, the valve assembly 3 is located on the axial side of the valve seat 23, and the valve assembly 3 is located axially above the valve seat 23 in the direction shown in fig. 1, and the housing 1 includes an upper valve cover 12 and a lower valve cover 13.

The piston 4 forms a dynamic seal with the inner wall of the brake chamber 11 and can reciprocate axially within the brake chamber 11 to move the valve assembly 3 to close or open the valve seat 23. Specifically, as shown in fig. 3-7, piston 4 includes a center post 41 that can be coupled to valve assembly 3, a main body portion 42 that extends radially outward from an outer wall of center post 41, and a force-receiving wall 43.

As shown in fig. 2, the main body portion 42 divides the brake chamber 11 into a first chamber 111 at a first side and a second chamber 112 at a second side, in this embodiment, the first chamber 111 is located below the main body portion 42, a sidewall of the first chamber 111 is provided with a first air port 113, the second chamber 112 is located above the main body portion 42, and a sidewall of the second chamber 112 is provided with a second air port 114.

Of course, in other embodiments, the positions of the first cavity and the second cavity may be interchanged, for example, the first cavity is located above the main body portion, the second cavity is located below the main body portion, the force-bearing wall extends axially upward from the upper surface of the main body portion, the elastic element is located in the second cavity, the upper end of the elastic element abuts against the lower surface of the main body portion, the lower end of the elastic element abuts against the axial position of the force-bearing wall of the lower valve cover, the pneumatic valve is a normally open valve, high-pressure gas enters the first cavity through the first gas port, and pushes the piston to move downward, so that the valve assembly blocks off the valve seat.

Further, in the present embodiment, the force-receiving wall 43 is formed to extend axially from the first side surface of the main body portion 42, that is, the force-receiving wall 43 is formed to extend axially downward from the lower surface of the main body portion 42, and the force-receiving wall 43 is a closed annular structure.

The air-operated valve further includes an elastic member 5, one end of the elastic member 5 abuts against the second side surface of the main body portion 42, and is at an axial position corresponding to the force-receiving wall 43, that is, the lower end of the elastic member 5 abuts against the upper surface of the main body portion 42, and is at an axial position corresponding to the force-receiving wall 43, in other words, the shadow plane formed by the axial projection of the elastic member 5 and the force-receiving wall 43 at least partially coincides, it should be noted that the extending direction of the central axis of the elastic member 5 is taken as the axial direction in the present embodiment.

The utility model discloses piston 4 of well pneumatic valve has increased atress wall 43 structure, position through corresponding atress wall 43 with the one end butt of elastic component 5 in main part 42, utilize atress wall 43 to increase the intensity that piston 4 and elastic component 5 offset department, need not increase the thickness of piston 4 main part 42 again simultaneously, effectively avoid piston 4 to reduce because of the too big machining precision that leads to of thickness, guarantee that the power of elastic component 5 can transmit for piston 4 along the axial, guarantee then effective sealing between valve module 3 and the disk seat 23, elastic component 5 also can keep relatively even to each department of piston 4's pressure circumference under the long-time use, guarantee good sealing performance between valve module 3 and the disk seat 23.

In the present embodiment, the maximum thickness of the piston 4, which is the thickness of the piston 4 at the maximum wall thickness, is less than 6 mm. Further, the maximum thickness of the piston in example 1 was 5 mm.

In order to further increase the strength of the piston 4, the piston 4 further includes first reinforcing portions 44 connecting the center post 41, the main body portion 42, and the force-receiving wall 43, the first reinforcing portions 44 being arranged at regular intervals along the circumferential direction of the center post 41. As shown in fig. 6 and 7, the first reinforcing portion 44 is provided on the lower surface of the main body portion 42, and is fixedly connected to the outer wall of the center pillar 41 and the inner wall of the force receiving wall 43, and the lower end surface of the first reinforcing portion 44 is substantially flush with the lower end surface of the force receiving wall 43. Of course, in other embodiments, the first reinforcement portion 44 may only connect the main body portion 42 and the force-receiving wall 43, and may not be connected to the center pillar 41.

Also in order to increase the strength of the piston 4, the piston 4 further includes second reinforcing portions 45 connecting the center post 41 and the main body portion 42, the second reinforcing portions 45 being arranged at regular intervals along the circumferential direction of the center post 41. As shown in fig. 4 and 5, the second reinforcing portion 45 is provided on the upper surface of the main body portion 42. The elastic member 5 is sleeved on the outer periphery of the second reinforcing part 45, so that the radial movement of the elastic member 5 can be limited, that is, the inner wall of the elastic member 5 can be abutted against the outer wall of the second reinforcing part 45, and the assembly stability of the elastic member 5 is maintained.

The first reinforcing part 44 and the second reinforcing part 45 may be disposed at positions opposite to each other in the vertical direction or may be disposed at positions shifted from each other.

As shown in fig. 7, the vertical line of the outer edge of the second reinforcing part 45 is L1, and the vertical line of the inner wall of the force-receiving wall 43 is L2, since L1 and L2 do not overlap, in other words, there is a distance between the outer edge of the second reinforcing part 45 and the force-receiving wall 43, and the first reinforcing part 44 is disposed to compensate for the distance, so that the strength of the main body part 42 is increased, and the position between the second reinforcing part 45 and the force-receiving wall 43 is prevented from being deformed.

The second reinforcing portion 45 includes an inner race portion 451 and an outer race portion 452, and the outer race portion 452 has an inclined guide surface 453 inclined in a direction facilitating the movement of the elastic member 5 toward the force receiving wall 43. as illustrated in the direction shown in fig. 4, the inclined guide surface 453 extends obliquely from top to bottom and from inside to outside, so that the elastic member 5 can be fitted around the outer periphery of the second reinforcing portion 45 from above downward against the inclined guide surface 453 when assembled.

In this embodiment, the central column 41 has a limiting platform 411 with an increased outer diameter, the inner ring portion 451 is connected to the outer wall of the limiting platform 411, the top end of the limiting platform 411 is located at a height greater than the axial height of the inner ring portion 451, and the axial height of the inner ring portion 451 is equal to the axial height of the outer ring portion 452 at the maximum height.

The valve assembly 3 comprises a valve core 31, a membrane part 32 and a fixing part 33, the purpose of plugging the valve core 31 or opening the valve seat 23 is realized through the deformation of the membrane part 32, if the limiting platform 411 is not arranged, after the valve assembly 3 opens the valve seat 23, the valve assembly 3 has the possibility of moving upwards excessively, and at the moment, the membrane part 32 is deformed excessively and then damaged.

To facilitate the assembly connection of the piston 4 and the valve assembly 3, at least a portion of the center post 41 is provided as an inner hollow structure, and an internal thread 412 is formed on the inner hollow wall, through which internal thread 412 is screwed with the valve assembly 3. Of course, in other embodiments, the hollow inner wall may be connected to the valve assembly 3 by other structures such as a snap fit, and is not limited in particular.

The lower end of the force-bearing wall 43 is bent outwards to form an L-shaped structure 431, the L-shaped structure 431 and the outer edge of the main body part 42 are surrounded to form a mounting groove 46, a sealing element 47 is arranged in the mounting groove 46, and the sealing element 47 is used for forming dynamic sealing between the piston 4 and the inner wall of the brake chamber 11. The combination of the stress wall 43 makes the piston 4 not easy to deform after the strength is increased, and an adaptive and stable space is formed between the installation groove 46 and the inner wall of the brake cavity 11; and the dynamic sealing performance between the piston 4 and the inner wall of the brake cavity 11 can be maintained when the piston moves axially through the sealing piece 47.

In order to ensure that the valve seat 23 is effectively blocked when the piston 4 moves axially downwards in the braking chamber 11, a blocking surface 131 is formed on the lower valve cover 13 of the housing 1, and when the piston 4 drives the valve component 3 to block the valve seat 23, the distance between the lower end of the first reinforcing part 44 and the blocking surface 131 is 0.1-1 mm. That is to say, when the valve assembly 3 blocks the valve seat 23, the first reinforcing portion 44 is not yet in contact with the blocking surface 131, so as to avoid that when the valve assembly 3 does not block the valve seat 23, the first reinforcing portion 44 interferes with the blocking surface 131, so that the piston 4 cannot move downwards continuously, and further ensure that the valve assembly 3 blocks the valve seat 23 effectively; meanwhile, the distance setting also prevents the valve component 3 from excessively moving downwards, so that the valve component 3 is protected.

In order to visually indicate whether the valve seat 23 is in the closed or open state, the top of the center post 41 is provided with an indication portion 413 which can be extended or retracted into the housing 1 to give a user a clear indication.

The utility model discloses a use is, the top of elastic component 5 offsets with the interior top surface of casing 1, and its bottom offsets with the main part 42 upper surface of piston 4, and under the downward pressure effect of elastic component 5, piston 4 takes valve module 3 to push down shutoff valve seat 23, and entry runner 21 and exit runner 22 are not linked together this moment, and for initial condition, the pneumatic valve is in normal close state, still leaves the clearance between the lower tip of first rib 44 and barrier surface 131; when the valve seat 23 needs to be opened, high-pressure gas is introduced into the first air port 113, enters the first cavity 111, pushes the piston 4 to move upwards, until the top end of the limiting platform 411 is abutted to the upper valve cover 12, at the moment, the inlet flow channel 21 is communicated with the outlet flow channel 22, the circulation of wet chemicals is realized, meanwhile, the sealing element 47 and the inner wall of the brake cavity 11 form dynamic seal, and the gas in the second cavity 112 is discharged from the second air port 114 so as to reduce the resistance of the piston 4 to move upwards.

Example two

As shown in fig. 8 to 10, the piston 4 of the present embodiment is different from the first embodiment in that the axial height of the inner ring portion 451 is greater than the axial height of the outer ring portion 452, and the extending direction of the inner ring portion 451 is the same as the extending direction of the elastic member 5, so that a stopper portion 454 is formed at the axial tip end portion of the inner ring portion 451, and when the valve seat 23 is opened, the piston 4 moves upward, and the stopper portion 454 can abut against the upper valve cover 12.

In this case, the stopper platform 411 of the first embodiment may be provided on the inner side of the inner ring portion 451, or the stopper platform 411 may not be provided.

Other structures are the same as those of the first embodiment, and are not described again.

The above detailed description is provided for illustrative purposes, and is not intended to limit the present invention, and any modifications and variations of the present invention are within the spirit and scope of the following claims.

Claims (10)

1. A pneumatic valve for controlling the on-off of wet chemicals, which comprises,

a housing having a brake chamber formed therein;

a valve body having an inlet flow passage and an outlet flow passage for the flow of wet chemicals therein, and a valve seat formed therebetween;

a valve assembly located on an axial side of the valve seat;

the piston is movably sealed with the inner wall of the brake cavity and can axially reciprocate in the brake cavity to drive the valve component to close or open the valve seat; the method is characterized in that:

the piston includes:

a central post connectable to the valve assembly;

a body portion extending radially outward from the outer wall of the center post and separating the brake chamber into a first chamber on a first side and a second chamber on a second side; a first air port is arranged on the first cavity, and a second air port is arranged on the second cavity;

a force-bearing wall extending axially from the first side surface of the body portion to form a closed annular structure;

and the air-operated valve further includes an elastic member having one end portion abutting against the second side surface of the main body portion at a position corresponding to the axial direction of the force receiving wall.

2. A pneumatic valve for controlling the make and break of wet chemicals as claimed in claim 1, further comprising: the piston further comprises first reinforcing parts which are connected with the central column, the main body part and the stress wall, and the first reinforcing parts are uniformly distributed at intervals along the circumferential direction of the central column.

3. A pneumatic valve for controlling the make and break of wet chemicals as claimed in claim 2, further comprising: the piston also comprises second reinforcing parts which are connected with the central column and the main body part, and the second reinforcing parts are uniformly distributed at intervals along the circumferential direction of the central column; and the elastic piece is sleeved on the periphery of the second reinforcing part to limit the radial movement of the elastic piece.

4. A pneumatic valve for controlling the make and break of wet chemicals as claimed in claim 3, further comprising: the second reinforcement portion includes an inner race portion and an outer race portion, the outer race portion having an inclined guide surface that facilitates the elastic member to be inclined toward the direction of movement of the force-receiving wall.

5. A pneumatic valve for controlling the make and break of wet chemicals as claimed in claim 4, further comprising: the shell comprises an upper valve cover and a lower valve cover, the axial height of the inner ring part is larger than that of the outer ring part, and the extending direction of the inner ring part is the same as that of the elastic piece, so that a limiting part capable of being abutted against the upper valve cover is formed at the axial end part of the inner ring part.

6. A pneumatic valve for controlling the make and break of wet chemicals as claimed in claim 4, further comprising: the central column is provided with a limiting platform with the increased outer diameter, the inner ring part is connected with the outer wall of the limiting platform, and the axial heights of the positions with the largest height of the inner ring part and the outer ring part are equal.

7. A pneumatic valve for controlling the make and break of wet chemicals as claimed in claim 5, further comprising: the lower valve cover forms a blocking surface, and when the piston drives the valve component to block the valve seat, the distance between the end part of the first reinforcing part and the blocking surface is 0.1-1 mm.

8. A pneumatic valve for controlling the on-off of wet chemicals as set forth in claim 1, further characterized by: the stress wall is bent outwards to form an L-shaped structure, an installation groove is formed by the stress wall and the outer edge of the main body part in an enclosing mode, and a sealing piece used for forming dynamic sealing of the piston and the inner wall of the brake cavity is arranged in the installation groove.

9. A pneumatic valve for controlling the make and break of wet chemicals as claimed in claim 1, further comprising: the center post is hollow and has internal threads that are connectable to a valve assembly.

10. A pneumatic valve for controlling the make and break of wet chemicals as claimed in claim 1, further comprising: the maximum thickness of the piston is less than 6 mm.

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