Stop valve

Abstract

The invention provides a stop valve, which relates to the technical field of valves, and comprises a valve body, and a first sealing surface is arranged at the upper end of the inner circumference of a seat ring in the valve body; a hollow support is arranged above the valve cover, and an observation window is formed in the hollow support; the valve clack is arranged in the upper cavity in a liftable mode, and a second sealing face is arranged at the lower end of the valve plate; the lower end of the valve rod is connected with the valve clack through a first elastic component, a pressure indicating mechanism is arranged on the periphery of the middle of the valve rod and comprises a sleeve connected to the interior of the hollowed-out support, a through groove extending in the vertical direction is formed in the sleeve, and an indicating line is arranged on the periphery of the valve rod; the executing mechanism is arranged above the hollowed-out support, and the executing mechanism is connected with the upper end of the valve rod and used for driving the valve rod to ascend and descend; the problems that when a stop valve in the prior art operates an executing mechanism to cut off medium flow, an operator cannot know the sealing pressure between a valve clack and a seat ring, and the sealing pressure is difficult to control are solved.

Description

Technical Field

[0001] The present invention belongs to the field of valves, and more specifically, relates to a globe valve with a seal pressure indicating mechanism. Background Art

[0002] A globe valve is a valve used to cut off the flow of a medium. The axis of the valve stem of the globe valve is perpendicular to the seat ring sealing surface, and the opening and closing are achieved by driving the valve disc to move up and down. When the fluid introduced into the globe valve is introduced from below the valve disc, it is called a normal installation; when it is introduced from above the valve disc, it is called a reverse installation. In normal installation, after the valve disc is closed, it is necessary to overcome the medium pressure. Therefore, the actuator of the globe valve needs to apply sufficient pressure to the valve disc to ensure the sealing effect of the sealing surface. However, too large a sealing pressure is a challenge to the quality and service life of the sealing surface. When the existing globe valve operates the actuator to cut off the flow of the medium, the operator cannot know the magnitude of the sealing pressure between the valve disc and the seat ring, so it is difficult to control the sealing pressure. Summary of the Invention

[0003] The object of the present invention is to provide a globe valve to solve the problem that when the existing globe valve operates the actuator to cut off the flow of the medium, the operator cannot know the magnitude of the sealing pressure between the valve disc and the seat ring and it is difficult to control the sealing pressure.

[0004] To achieve the above object, the present invention provides a globe valve, including:

[0005] A valve body, inside which a first flow channel and a second flow channel are provided. One end of the first flow channel is below one end of the second flow channel, and the two are connected through a communication hole in the middle of the seat ring. The upper end of the inner circumference of the seat ring is provided with a first sealing surface. Above the one end of the second flow channel, there is an upper chamber. The upper end of the upper chamber is provided with a valve cover, and above the valve cover, there is a hollowed-out support provided with an observation window;

[0006] A valve disc, which is liftably arranged in the upper chamber. The lower end of the valve disc is provided with a second sealing surface that cooperates with the first sealing surface;

[0007] A valve stem, the lower end of which is connected to the valve disc through a first elastic member. A pressure indicating mechanism is arranged on the outer circumference of the middle part of the valve stem. The pressure indicating mechanism includes a sleeve connected inside the hollowed-out support. The sleeve is provided with a through groove extending vertically. An indicating line is arranged on the outer circumference of the valve stem, and the indicating line can be exposed from the through groove;

[0008] An actuator, which is arranged above the hollowed-out support, is connected to the upper end of the valve stem, and is used to drive the valve stem to move up and down.

[0009] Optionally, a pressure scale is provided on the outer side of the sleeve, and the pressure scale is set according to the elastic force of the first elastic member.

[0010] Optionally, the actuator includes a handwheel, the handwheel is arranged above the hollow bracket, a threaded sleeve is arranged in the middle of the handwheel, an external thread is arranged at the upper end of the valve stem, and the inner part of the threaded sleeve is in fit with the external thread through an internal thread.

[0011] Optionally, the first sealing surface is a downwardly concave annular spherical surface, a vertically cylindrical first guiding surface is arranged on the outer periphery of the first sealing surface, a conical second guiding surface is arranged on the outer periphery of the first guiding surface, the lower end of the valve flap is a downwardly convex spherical structure, an annular second sealing surface is formed on the outer ring of the spherical structure, a third guiding surface in fit with the first guiding surface is arranged on the outer periphery of the second sealing surface, and a fourth guiding surface in fit with the second guiding surface is arranged on the outer periphery of the third guiding surface.

[0012] Optionally, it further includes a plurality of sealing surface protection mechanisms, and the plurality of sealing surface protection mechanisms are evenly distributed along the inner circumference of the upper chamber. The sealing surface protection mechanism includes:

[0013] A driving rod, one end of the driving rod is rotatably connected to the inner wall of the upper chamber, and the other end of the driving rod is used for contacting the upper end surface of the valve flap;

[0014] A first follower rod, one end of the first follower rod is connected to one end of the driving rod to form a V-shaped structure, a fan-shaped first covering plate is arranged at the other end of the first follower rod, and a plurality of the first covering plates can form an annular structure covering the second sealing surface.

[0015] Optionally, the first covering plate includes a first bottom plate and a first rubber plate arranged on one side of the first bottom plate. The first bottom plate is connected to the first follower rod, and the surface shape of the first rubber plate away from the first bottom plate is adapted to the surface shape of the second sealing surface. When the valve flap is in the open state, the upper end surface of the valve flap pushes the other end of the driving rod upward, so that the first follower rod drives the first covering plate to cover the second sealing surface.

[0016] Optionally, the sealing surface protection mechanism further includes a second follower rod and a third follower rod. The upper end of the second follower rod is connected to the first follower rod. The third follower rod is a V-shaped rod, the middle of the third follower rod is rotatably connected to the seat ring, the upper end of the third follower rod is hinged to the hinge shaft at the lower end of the second follower rod through a long waist hole, and a fan-shaped second covering plate is connected to the lower end of the third follower rod. A plurality of the second covering plates can form an annular structure covering the first sealing surface.

[0017] Optionally, the second cover plate includes a second bottom plate and a second rubber plate disposed on one side of the second bottom plate. The second bottom plate is connected to the third follower rod. The surface shape of the second rubber plate away from the second bottom plate is adapted to the surface shape of the first sealing surface. When the valve flap is in the open state, the second follower rod drives the third follower rod to rotate, so that the third follower rod drives the second cover plate to cover the first sealing surface.

[0018] Optionally, the drive rod is rotatably connected to the inner wall of the upper chamber through a rotating shaft. A second elastic member is disposed on the outer periphery of the rotating shaft. The second elastic member is used to apply a torque to the drive rod, so that when the valve flap is closed, the drive rod, the first follower rod and the second follower rod rotate, and the first cover plate and the second cover plate move away from the valve flap to avoid the valve flap.

[0019] Optionally, the first elastic member is a compression spring.

[0020] The present invention provides a globe valve, and its beneficial effects are as follows: A pressure indicating mechanism is provided on the outer periphery of the middle part of the valve stem of the globe valve. When the valve stem moves downward to the valve flap closed state, the valve stem compresses the first elastic member, and the indicating line on the valve stem comes into the through groove, and the indicating line is exposed from the through groove, and the exposed indicating line can be observed through the observation window on the hollow support. By observing the height of the indicating line, the compression amount of the first elastic member by the valve stem can be judged, and then the pressure applied by the valve flap to the seat ring can be reflected, that is, the sealing pressure between the first sealing surface and the second sealing surface can be reflected, so as to facilitate controlling the sealing pressure of the globe valve to meet different sealing requirements and ensure the service life.

[0021] Other features and advantages of the present invention will be described in detail in the following specific implementation manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] By describing the exemplary embodiments of the present invention in more detail in conjunction with the drawings, the above and other objects, features and advantages of the present invention will become more obvious. Among them, in the exemplary embodiments of the present invention, the same reference numerals generally represent the same components.

[0023] Figure 1 The structural schematic diagram of the open state of the valve flap of a globe valve according to an embodiment of the present invention is shown.

[0024] Figure 2 The structural schematic diagram of the closed state of the valve flap of a globe valve according to an embodiment of the present invention is shown.

[0025] Figure 3 Shows Figure 1Schematic diagram of the enlarged structure at position A.

[0026] Figure 4 shows Figure 2 Schematic diagram of the enlarged structure at position B.

[0027] Figure 5 shows Figure 2 Schematic diagram of the enlarged structure at position C.

[0028] Figure 6 Shows a schematic diagram of the covering state of the first cover plate of a globe valve according to an embodiment of the present invention.

[0029] Figure 7 Shows a schematic diagram of the covering state of the second cover plate of a globe valve according to an embodiment of the present invention.

[0030] Description of reference numerals:

[0031] 1, valve body; 2, first flow channel; 3, second flow channel; 4, seat ring; 5, first sealing surface; 6, valve cover; 7, hollowed-out bracket; 8, valve disc; 9, second sealing surface; 10, valve stem; 11, first elastic member; 12, sleeve; 13, indicating line; 14, handwheel; 15, first guiding surface; 16, second guiding surface; 17, driving rod; 18, first follower rod; 19, first cover plate; 20, second follower rod; 21, third follower rod; 22, second cover plate. Detailed description of the specific implementation

[0032] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0033] As Figure 1 and Figure 2 shown, the present invention provides a globe valve, comprising:

[0034] A valve body 1, inside which a first flow channel 2 and a second flow channel 3 are provided. One end of the first flow channel 2 is below one end of the second flow channel 3, and the two are connected through a communication hole in the middle of the seat ring 4. The upper end of the inner circumference of the seat ring 4 is provided with a first sealing surface 5. Above one end of the second flow channel 3, there is an upper chamber. The upper end of the upper chamber is provided with a valve cover 6. Above the valve cover 6, there is a hollowed-out bracket 7, and the hollowed-out bracket 7 is provided with an observation window;

[0035] A valve disc 8, which is arranged in the upper chamber in a liftable manner. The lower end of the valve plate is provided with a second sealing surface 9 that cooperates with the first sealing surface 5;

[0036] The valve stem 10, the lower end of the valve stem 10 is connected to the valve flap 8 through a first elastic member 11, and a pressure indicating mechanism is arranged on the outer periphery of the middle part of the valve stem 10. The pressure indicating mechanism includes a sleeve 12 connected inside the hollow support 7. The sleeve 12 is provided with a through groove extending vertically. An indicating line 13 is arranged on the outer periphery of the valve stem 10, and the indicating line 13 can be exposed from the through groove;

[0037] An actuator, the actuator is arranged above the hollow support 7, the actuator is connected to the upper end of the valve stem 10, and is used to drive the valve stem 10 to move up and down.

[0038] Specifically, to solve the problem that when the existing globe valve operates the actuator to cut off the medium flow, the operator cannot know the sealing pressure between the valve flap 8 and the seat ring 4, and it is difficult to control the sealing pressure; the globe valve provided by the present invention is provided with a pressure indicating mechanism on the outer periphery of the middle part of the valve stem 10. When the valve stem 10 moves downward to the closed state of the valve flap 8, the valve stem 10 compresses the first elastic member 11, and the indicating line 13 on the valve stem 10 comes into the through groove, and the indicating line 13 is exposed from the through groove, and the exposed indicating line 13 can be observed through the observation window on the hollow support 7. By observing the height of the indicating line 13, the compression amount of the valve stem 10 on the first elastic member 11 can be judged, and then the pressure applied by the valve flap 8 on the seat ring 4 can be reflected, that is, the sealing pressure between the first sealing surface 5 and the second sealing surface 9 can be reflected, so as to facilitate controlling the sealing pressure of the globe valve to meet different sealing requirements and ensure the service life.

[0039] In this embodiment, the indicating line 13 is annular.

[0040] In this embodiment, a sealing member is arranged between the valve cover 6 and the valve stem 10, and the sealing member can adopt sealing packing.

[0041] Optionally, a pressure scale is arranged on the outer side of the sleeve 12, and the pressure scale is set according to the elastic force of the first elastic member 11.

[0042] Specifically, the pressure scale line is arranged on the outer wall of the sleeve 12 along the axial direction of the sleeve 12, and the pressure scale is set based on the elastic force of the first elastic member 11. The greater the compression amount of the first elastic member 11, the greater the sealing pressure. The setting of the pressure scale can directly correspond to the elastic force change of the first elastic member 11, or can be set by comprehensively considering the pressure situation combined with the medium pressure, as long as it can reflect the magnitude of the sealing pressure and is convenient for the operator to control.

[0043] Optionally, the actuator includes a handwheel 14, the handwheel 14 is arranged above the hollow support 7, a threaded sleeve is arranged in the middle of the handwheel 14, an external thread is arranged at the upper end of the valve stem 10, and the inside of the threaded sleeve is matched with the external thread through an internal thread.

[0044] Specifically, when the handwheel 14 rotates, it can drive the valve stem 10 to move up and down through the threaded fit between the threaded sleeve and the valve stem 10, and then drive the valve flap 8 to move up and down.

[0045] In this embodiment, a circular first limiting portion is arranged on the outer periphery of the lower end of the valve stem 10, the upper end of the valve flap 8 is circular, a receiving groove is arranged at the top thereof, a circular second limiting portion is arranged at the upper end of the receiving groove, the first limiting portion is arranged in the receiving groove and is in mutual limiting cooperation with the second limiting portion, and the first elastic member 11 is arranged in the receiving groove and is below the valve stem 10.

[0046] Optionally, the first sealing surface 5 is a downwardly concave circular spherical surface, a vertically cylindrical first guiding surface 15 is arranged on the outer periphery of the first sealing surface 5, a conical second guiding surface 16 is arranged on the outer periphery of the first guiding surface 15, the lower end of the valve flap 8 is a downwardly convex spherical surface structure, an annular second sealing surface 9 is formed on the outer ring of the spherical surface structure, a third guiding surface matching with the first guiding surface 15 is arranged on the outer periphery of the second sealing surface 9, and a fourth guiding surface matching with the second guiding surface 16 is arranged on the outer periphery of the third guiding surface.

[0047] Specifically, the first sealing surface 5 and the second sealing surface 9 adopt spherical sealing. In order to ensure that the second sealing surface 9 more accurately aligns with the first sealing surface 5 during the closing process of the valve flap 8, ensure the sealing effect and protect the second sealing surface 9, as Figure 5 shown, mutually matching first guiding surface 15 and third guiding surface are respectively arranged on the outer periphery of the first sealing surface 5 and the outer periphery of the second sealing surface 9. The cooperation between the first guiding surface 15 and the third guiding surface can enable the valve flap 8 to vertically enter the seat ring 4, and at the same time, the arrangement of the second guiding surface 16 can provide guidance for the cylindrical third guiding surface.

[0048] Optionally, it further includes a plurality of sealing surface protection mechanisms, the plurality of sealing surface protection mechanisms are evenly distributed along the inner circumference of the upper chamber, and the sealing surface protection mechanism includes:

[0049] A driving rod 17, one end of the driving rod 17 is rotatably connected to the inner wall of the upper chamber, and the other end of the driving rod 17 is used for contacting the upper end surface of the valve flap 8;

[0050] A first follower rod 18, one end of the first follower rod 18 is connected to one end of the driving rod 17 to form a V-shaped structure, a fan-shaped first covering plate 19 is arranged at the other end of the first follower rod 18, and a plurality of first covering plates 19 can form an annular structure covering the second sealing surface 9.

[0051] Specifically, as Figure 3 shown, the driving rod 17 rotates as its other end contacts the upper end surface of the valve flap 8 and moves upward with the valve flap 8. When the valve flap 8 rises to near the limit position, its upper end surface contacts the driving rod 17, pushing the driving rod 17 and the first follower rod 18 to rotate, so that when the valve flap 8 rises to the limit position, the first covering plate 19 on the first follower rod 18 can cover the lower side of the second sealing surface 9 to protect the second sealing surface 9. It can not only prevent the medium from scouring the second sealing surface 9, but also keep the second sealing surface 9 clean.

[0052] Optionally, the first covering plate 19 includes a first bottom plate and a first rubber plate arranged on one side of the first bottom plate. The first bottom plate is connected to the first follower rod 18. The surface shape of the first rubber plate away from the first bottom plate is adapted to the surface shape of the second sealing surface 9. When the valve flap 8 is in the open state, the upper end surface of the valve flap 8 pushes the other end of the driving rod 17 upward, so that the first follower rod 18 drives the first covering plate 19 to cover the second sealing surface 9.

[0053] Specifically, the first bottom plate is made of a hard material, and the first rubber plate is arranged on its upper side. By contacting the second sealing surface 9 through the first rubber plate, it can not only cover the second sealing surface 9, but also make the plurality of first rubber plates form an annular structure due to the elastic deformation of the first rubber plate when it is pressed, and the sealing performance at the connection of adjacent two first rubber plates is better.

[0054] In this embodiment, there are eight sealing surface protection mechanisms. As Figure 6 shown, it is a bottom view of the valve flap 8 when the valve flap 8 is in the open state.

[0055] In this embodiment, both the driving rod 17 and the first follower rod 18 are L-shaped rods.

[0056] Optionally, the sealing surface protection mechanism further includes a second follower rod 20 and a third follower rod 21. The upper end of the second follower rod 20 is connected to the first follower rod 18. The third follower rod 21 is a V-shaped rod. The middle part of the third follower rod 21 is rotatably connected to the seat ring 4. The upper end of the third follower rod 21 is hinged to the hinge shaft at the lower end of the second follower rod 20 through a long oval hole. The lower end of the third follower rod 21 is connected with a fan-shaped second covering plate 22, and a plurality of second covering plates 22 can form an annular structure covering the first sealing surface 5.

[0057] Specifically, as Figure 4As shown, the sealing surface protection mechanism can also protect the first sealing surface 5. The upper end of the second follower rod 20 is connected to the first follower rod 18 and rotates together with the first follower rod 18 and the driving rod 17. The second covering plate 22 is hinged to the upper side of the seat ring 4 through the third follower rod 21. As the third follower rod 21 rotates, the second covering plate 22 can cover and open the first sealing surface 5. The rotation of the third follower rod 21 is driven by the rotation of the second follower rod 20. When the second follower rod 20 rotates, the hinge shaft of the second follower rod 20 can move and rotate in the long waist hole, thereby driving the third follower rod 21 to drive the second covering plate 22 to rotate. When the valve flap 8 is in the open state, the first sealing surface 5 is exposed upward. And due to the concave shape of the first sealing surface 5 and the settings of the first guiding surface 15 and the second guiding surface 16, impurities or particulate matters are likely to deposit at the position where the first sealing surface 5 is located, which is likely to have an adverse effect on the sealing effect of the first sealing surface 5 and the second sealing surface 9. Through the setting of the second covering plate 22, this stop valve can cover the first sealing surface 5 when the valve flap 8 is in the open state, ensure its cleanliness, and thus ensure the sealing effect.

[0058] Optionally, the second covering plate 22 includes a second bottom plate and a second rubber plate provided on one side of the second bottom plate. The second bottom plate is connected to the third follower rod 21. The surface shape of the second rubber plate away from the second bottom plate is adapted to the surface shape of the first sealing surface 5. When the valve flap 8 is in the open state, the second follower rod 20 drives the third follower rod 21 to rotate, so that the third follower rod 21 drives the second covering plate 22 to cover the first sealing surface 5.

[0059] Specifically, the second bottom plate is made of a hard material, and the second rubber plate is provided on its upper side. By contacting the first sealing surface 5 through the second rubber plate, it can not only cover the first sealing surface 5, but also make the plurality of second rubber plates form an annular structure due to the elastic deformation when the second rubber plate is pressed, and the sealing performance at the connection between adjacent two second rubber plates is better.

[0060] In this embodiment, the side of the second rubber plate away from the second bottom plate not only matches the shape of the first sealing surface 5, but also matches the shapes of the first guiding surface 15 and the second guiding surface 16.

[0061] In this embodiment, as Figure 7 shown, it is a top view of the seat ring 4 when the valve flap 8 is in the open state.

[0062] Optionally, the driving rod 17 is rotationally connected to the inner wall of the upper chamber through a rotating shaft. A second elastic member is provided on the outer periphery of the rotating shaft. The second elastic member is used to apply a torque to the driving rod 17, so that when the valve flap 8 is closed, the driving rod 17, the first follower rod 18 and the second follower rod 20 rotate, and the first covering plate 19 and the second covering plate 22 move away from the valve flap 8 to avoid the valve flap 8.

[0063] Specifically, the arrangement of the second elastic member causes the drive rod 17 to have a rotational tendency. When the other end of the drive rod 17 is not subjected to the thrust from the upper end surface of the valve flap 8, the other end of the drive rod 17 moves downward. At the same time, the other end of the first follower rod 18 and the first cover plate 19 move downward, which can avoid the descent of the valve flap 8. At the same time, the lower end of the second follower rod 20 moves downward, which can drive the third follower rod 21 to rotate and drive the second cover plate 22 to lift and move outside the first sealing surface 5, and can also avoid the descent of the valve flap 8.

[0064] In this embodiment, the globe valve is a medium-large globe valve.

[0065] In this embodiment, the second elastic member is a torsion spring.

[0066] In this embodiment, the first elastic member 11 is a compression spring.

[0067] Specifically, in other embodiments, the first elastic member 11 can also adopt other forms of springs such as disc springs or shrapnel, but its elastic force is preferably linearly related to the compression amount to more accurately reflect the magnitude of the sealing pressure.

[0068] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments.

Claims

1. A stop valve, characterized in that: include: A valve body, wherein a first flow channel and a second flow channel are arranged inside the valve body, one end of the first flow channel is below one end of the second flow channel, and the two are connected through a connecting hole in the middle of the seat ring, a first sealing surface is arranged at the upper end of the inner circumference of the seat ring, an upper chamber is arranged above the one end of the second flow channel, a valve cover is arranged at the upper end of the upper chamber, a hollow bracket is arranged above the valve cover, and an observation window is opened on the hollow bracket; A valve flap, the valve flap is liftably arranged in the upper chamber, and the lower end of the valve plate is provided with a second sealing surface matching the first sealing surface; A valve stem, wherein the lower end of the valve stem is connected to the valve disc through a first elastic component, a pressure indicating mechanism is arranged on the periphery of the middle part of the valve stem, the pressure indicating mechanism comprises a sleeve connected to the inside of the hollow bracket, the sleeve is provided with a through groove extending in the vertical direction, and an indicating line is arranged on the periphery of the valve stem, and the indicating line can be exposed from the through groove; An actuator is arranged above the hollow bracket, connected to the upper end of the valve stem, and used to drive the valve stem to rise and fall.

2. The stop valve according to claim 1, characterized in that: A pressure scale is arranged on the outer side of the sleeve, and the pressure scale is arranged according to the elastic force of the first elastic component.

3. The stop valve according to claim 1, characterized in that: The actuator includes a handwheel, which is arranged above the hollow bracket. A threaded sleeve is arranged in the middle of the handwheel, and an external thread is arranged on the upper end of the valve stem. The interior of the threaded sleeve cooperates with the external thread through an internal thread.

4. The stop valve according to claim 1, characterized in that: The first sealing surface is a downwardly concave annular spherical surface, the outer periphery of the first sealing surface is provided with a vertical cylindrical first guide surface, the outer periphery of the first guide surface is provided with a conical second guide surface, the lower end of the valve disc is a downwardly protruding spherical structure, the outer ring of the spherical structure forms an annular second sealing surface, the outer periphery of the second sealing surface is provided with a third guide surface matching with the first guide surface, and the outer periphery of the third guide surface is provided with a fourth guide surface matching with the second guide surface.

5. The stop valve according to claim 1, characterized in that: It also includes a plurality of sealing surface protection mechanisms, which are evenly distributed along the inner circumference of the upper chamber, and the sealing surface protection mechanisms include: A driving rod, one end of which is rotatably connected to the inner wall of the upper chamber, and the other end of which is used to contact the upper end surface of the valve disc; A first follower rod, one end of which is connected to one end of the driving rod to form a V-shaped structure, and the other end of the first follower rod is provided with a fan-shaped first covering plate, and a plurality of the first covering plates can form a circular ring structure covering the second sealing surface.

6. The stop valve according to claim 5, characterized in that: The first covering plate includes a first bottom plate and a first rubber plate arranged on one side of the first bottom plate, the first bottom plate is connected to the first follower rod, the surface shape of the first rubber plate away from the first bottom plate is adapted to the surface shape of the second sealing surface, and when the valve flap is in an open state, the upper end surface of the valve flap pushes the other end of the driving rod upward, so that the first follower rod drives the first covering plate to cover the second sealing surface.

7. The stop valve according to claim 5, characterized in that: The sealing surface protection mechanism also includes a second follower rod and a third follower rod, the upper end of the second follower rod is connected to the first follower rod, the third follower rod is a V-shaped rod, the middle part of the third follower rod is rotatably connected to the seat ring, the upper end of the third follower rod is hinged to the hinge shaft at the lower end of the second follower rod through a long waist hole, and the lower end of the third follower rod is connected to a fan-shaped second covering plate, and multiple second covering plates can form a circular ring structure covering the first sealing surface.

8. The stop valve according to claim 7, characterized in that: The second covering plate includes a second bottom plate and a second rubber plate arranged on one side of the second bottom plate, the second bottom plate is connected to the third follower rod, the surface shape of the second rubber plate away from the second bottom plate is matched with the surface shape of the first sealing surface, when the valve flap is in an open state, the second follower rod drives the third follower rod to rotate, so that the third follower rod drives the second covering plate to cover the first sealing surface.

9. The stop valve according to claim 7, characterized in that: The driving rod is rotatably connected to the inner wall of the upper chamber via a rotating shaft, and a second elastic component is provided on the outer periphery of the rotating shaft. The second elastic component is used to apply torque to the driving rod, so that when the valve flap is closed, the driving rod, the first follower rod and the second follower rod rotate, and the first covering plate and the second covering plate move in a direction away from the valve flap to avoid the valve flap.

10. The stop valve according to claim 1, characterized in that: The first elastic component is a compression spring.

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