A vent valve with double sealing valve seat

Abstract

The present invention belongs to the field of hydraulic valves, and specifically relates to a vent valve with a double-sealed valve seat, comprising: a valve body, on which a grease injection assembly and a detection assembly are respectively mounted; a valve seat is disposed within the valve body, a fluid passage is defined within the valve seat, a valve sleeve is disposed at the upper end of the valve seat, the outer circumference of the valve sleeve engages with the valve body, and its top end engages with the valve cover; a plurality of throttle holes are evenly distributed along the outer circumference of the valve sleeve on the side adjacent to the valve seat; a valve core assembly is mounted within the interior space formed by the valve sleeve and the valve seat, the outer circumference of the valve core assembly slidably engages with the inner circumference of the valve sleeve to open or close the throttle holes; a composite multi-stage sealing structure is provided between the valve seat and the valve core assembly, and the composite multi-stage sealing structure is used to seal the flow path from the fluid passage to the throttle hole. The vent valve has improved sealing performance and can also promptly detect whether the valve is leaking and achieve emergency sealing of the valve if a leak occurs.

Description

Technical Field

[0001] The present invention belongs to the field of hydraulic valves, and in particular relates to a vent valve with a double sealing valve seat. Background Art

[0002] A throttle, stop, and vent valve is used to vent natural gas pipelines during maintenance. Existing throttle, stop, and vent valves have only a single soft sealing ring on their valve seat. Over time, this ring is susceptible to wear, corrosion, and scratching, leading to valve leakage. Furthermore, existing throttle, stop, and vent valves are unable to promptly detect seal failures or provide emergency sealing in the event of a seal failure. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a vent valve with a double sealing valve seat. The vent valve has better sealing performance, and can also detect whether the valve is leaking in time, and realize emergency sealing of the valve when leakage occurs, thereby improving the performance of the valve.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] A vent valve with a double-sealed valve seat, the vent valve comprising: a valve body, a valve cover, a valve stem, a valve sleeve, a valve seat and a valve core assembly; a valve seat mounting groove is provided in the valve body, the valve seat is provided in the valve seat mounting groove, a fluid channel is provided in the valve seat, the valve sleeve is provided at the upper end of the valve seat, the outer circumferential surface of the valve sleeve cooperates with the valve body, and the top end thereof cooperates with the valve cover, a plurality of throttling holes are evenly provided along the outer circumferential surface of the valve sleeve on the side close to the valve seat, the valve core assembly is installed in the internal space formed by the valve sleeve and the valve seat, the outer circumferential surface of the valve core assembly is slidably matched with the inner circumferential surface of the valve sleeve to open or close the throttling hole; wherein,

[0006] A composite multi-stage sealing structure is provided between the valve seat and the valve core assembly, the composite multi-stage sealing structure being used to seal the flow path from the fluid channel to the throttle hole;

[0007] A grease injection assembly and a detection assembly are respectively installed on the valve body, an annular grease injection groove is provided on the valve core assembly, and a detection pipeline and a grease injection pipeline are respectively provided on the valve seat. The grease injection pipelines are respectively connected to the grease injection assembly and the annular grease injection groove, and the detection pipeline is connected to the detection assembly.

[0008] Preferably, the composite multi-stage sealing structure includes: a first sealing portion arranged at the upper end of the valve seat, a second sealing portion and a third sealing portion arranged at the lower end of the valve core assembly, and a main sealing ring and a secondary sealing ring arranged between the valve seat and the third sealing portion; wherein, the third sealing portion and the main sealing ring cooperate with each other to form a first sealing structure, the third sealing portion and the secondary sealing ring cooperate with each other to form a second sealing structure, the first sealing portion and the second sealing portion cooperate with each other to form a third sealing structure, and the first sealing structure, the second sealing structure and the third sealing structure are arranged in sequence along the radial direction of the valve seat.

[0009] Preferably, a mounting boss is provided at the upper end of the valve seat, and the mounting boss cooperates with the valve seat mounting groove. A mounting groove for installing the secondary sealing ring is provided on the mounting boss, and a plurality of water line grooves are provided at the bottom of the mounting groove for installing the secondary sealing ring, and a plurality of barbs are provided on the side wall.

[0010] Preferably, the main sealing ring and the secondary sealing ring are respectively configured as follows: when the valve is in an open state, the axial height difference B between the main sealing ring and the first sealing part is 0.5mm~0.8mm, and the axial height difference A between the secondary sealing ring and the first sealing part is 0.3mm~0.5mm.

[0011] Preferably, the valve core assembly includes a valve core body and a guide sleeve connected to the valve core body; a valve core boss is provided at the lower end of the valve core body, the third sealing portion is provided at the bottom of the valve core boss, a first groove is provided on the inner side of the third sealing portion, and the second sealing portion made of carbide material is formed in the first groove.

[0012] Preferably, the secondary sealing ring is made of plastic material and has a compression slope on one side; the cross-section of the main sealing ring is triangular and is made of rubber material; when the secondary sealing ring is assembled to the valve seat, one side of the main sealing ring is pressed by the compression slope on the secondary sealing ring, and when the valve is in a closed state, the other side of the main sealing ring is pressed by the compression slope at the lower end of the valve sleeve.

[0013] Preferably, the mounting boss is respectively provided with a first annular channel and a second annular channel, wherein the first annular channel and the second annular channel are not connected to each other; the mounting boss is also provided with a plurality of detection channels and a plurality of grease injection channels, wherein the plurality of detection channels are connected to the first annular channel, and the plurality of grease injection channels are connected to the second annular channel.

[0014] Preferably, the annular grease injection groove is provided on the outer peripheral surface of the valve core boss, and a plurality of first channels and a plurality of second channels are respectively provided at the lower end of the valve sleeve, and the ends of the plurality of first channels and the plurality of second channels are staggered in the axial direction, so that one end of the plurality of first channels is connected to the corresponding detection channel, and the other end extends to the outer peripheral surface of the valve core boss and is not connected to the annular grease injection groove, and one end of the plurality of second channels is connected to the corresponding grease injection channel, and the other end is connected to the annular grease injection groove.

[0015] Preferably, a third channel communicating with the first annular channel and a fourth channel communicating with the second annular channel are respectively provided on the valve body, the detection component is installed on the third channel, and a check valve and a grease injection valve are installed in sequence on the fourth channel.

[0016] Preferably, a sealing groove is further provided on the mounting boss, an annular sealing ring is installed in the sealing groove, the plurality of detection channels are located on the inner side of the annular sealing ring, and the plurality of grease injection channels are located on the outer side of the annular sealing ring.

[0017] Compared with the prior art, the vent valve with a double sealing valve seat provided by the present invention has the following beneficial technical effects:

[0018] Conventional throttling, stop, and vent valves have only one sealing ring on the valve seat, which makes them poorly sealed for highly permeable fluids and prone to leakage. The present invention incorporates two primary and secondary sealing rings made of different materials and structures within the valve. The outer primary sealing ring is made of rubber, such as FKM or NBR, depending on the operating conditions. The inner secondary sealing ring is made of plastic, such as PTFE or PEEK, depending on the operating conditions. If one primary or secondary sealing ring is damaged, the other secondary or primary sealing ring can still function independently, extending the valve's service life.

[0019] 2. The present invention provides barbs within the mounting groove. When the secondary sealing ring is assembled into the mounting groove, the barbs can hold the secondary sealing ring in place, preventing it from being pushed out of the mounting groove. Furthermore, a compression slope is provided on the secondary sealing ring and the valve sleeve. When the secondary sealing ring is assembled into the mounting groove, one side of the primary sealing ring is pressed by the compression slope on the secondary sealing ring. When the valve is closed, the other side of the primary sealing ring is pressed by the compression slope at the lower end of the valve sleeve. This sealing structure allows the primary and secondary sealing rings to be effectively fixed to the mounting position of the valve seat, ensuring stable sealing of the valve.

[0020] 3. This invention incorporates a height differential for the valve seat seals: the primary seal is higher than the secondary seal, which in turn is higher than the first sealing portion. This ensures that during valve closing, the valve core assembly first contacts the rubber primary seal, achieving a first-level seal (rubber seal). As the valve continues to close, the valve core assembly contacts the secondary seal, achieving a second-level seal (plastic seal). As the valve continues to close, the valve core assembly presses the secondary seal downward until it is flush with the first sealing portion, at which point the second sealing portion contacts the first, achieving a third-level seal (metal seal). This multi-stage sealing structure improves the valve's sealing performance.

[0021] 4. The present invention separately mounts a grease injection assembly and a detection assembly on the valve body. Detection channels communicating with the detection assembly are defined in the valve body, valve seat, and valve sleeve. Grease injection channels communicating with the grease injection assembly are also defined in the valve body, valve seat, and valve sleeve. When the detection assembly detects a fluid leak in the valve, sealing grease is injected into the valve via the grease injection assembly. The sealing grease is then directed through the grease injection channels within the valve to the valve's sealing structure, enabling timely emergency sealing of the valve and improving its sealing performance.

[0022] 5. The present invention provides an annular sealing ring between the mounting boss and the valve sleeve, with several detection channels located on the inner side of the annular sealing ring and several grease injection channels located on the outer side of the annular sealing ring. When the grease injection assembly is used to inject sealing grease into the valve, the annular sealing ring prevents the sealing grease from entering the detection channels through the flow gap. Furthermore, the sealing grease can be injected into the annular grease injection groove through the flow gap, thereby sealing the gap between the valve core assembly and the valve sleeve, thereby achieving emergency sealing of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the main view of the vent valve;

[0024] Figure 2 is a side view of the vent valve;

[0025] Figure 3 It is a structural diagram of the sealing structure of the vent valve;

[0026] Figure 4 It is a structural diagram of the valve core body;

[0027] Figure 5 It is a partial enlarged schematic diagram of the sealing structure;

[0028] Figure 6 This is a partial enlarged schematic diagram of the main and auxiliary sealing rings when the vent valve is in the open state;

[0029] Figure 7 Schematic diagram of the structure of the valve seat;

[0030] Figure 8 It is a top view of the valve seat;

[0031] Figure 9 It is a local enlarged schematic diagram of the detection component;

[0032] Figure 10 This is a partial enlarged schematic diagram of the grease injection component.

[0033] The meanings of the symbols in the figure are as follows:

[0034] 1. Valve body; 2. Valve seat; 3. Valve stem; 4. Valve sleeve; 5. Valve core assembly; 6. Grease injection assembly; 7. Detection assembly; 8. Bracket; 9. Valve stem nut; 10. Packing gland;

[0035] 11. Valve seat mounting groove; 12. Third channel; 13. Fourth channel;

[0036] 111. Packing ring; 112. Valve cover; 113. Handwheel;

[0037] 21. Mounting boss; 22. First sealing portion; 23. Mounting groove; 24. First annular channel; 25. Second annular channel; 26. Upper mounting surface of valve seat; 27. Lower mounting surface of valve seat; 28. Sealing groove; 29. ​​Fluid channel; 30. Annular sealing ring; 31. Valve stem connection portion;

[0038] 231, main sealing ring; 232, auxiliary sealing ring; 233, waterline groove; 234, barb;

[0039] 241, detection channel; 251, grease injection channel;

[0040] 41. Orifice; 42. First channel; 43. Flow gap; 44. Second channel;

[0041] 51. Valve core body; 52. Guide sleeve;

[0042] 511, third sealing portion; 512, second sealing portion; 513, first groove; 514, annular grease injection groove; 515, buffer hole; 516, second groove; 517, valve core boss; 518, cavity;

[0043] 61. Grease injection valve; 62. Check valve. DETAILED DESCRIPTION

[0044] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0045] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0046] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions therein may be combined with each other.

[0047] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0048] In the description of the present invention, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the inventive product is typically placed when in use, or the orientations or positional relationships commonly understood by those skilled in the art. Such terms are intended solely to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" and the like are used solely for distinction and should not be construed as indicating or implying relative importance.

[0049] See attached Figure 1 -Attached Figure 10 As shown, the present invention provides a vent valve with a double sealing valve seat, the vent valve comprising:

[0050] The valve body 1, valve cover 112, valve stem 3, valve sleeve 4, valve seat 2, and valve core assembly 5 are shown. The valve cover 112 is located at the upper end of the valve body 1. A bracket 8 is mounted on the upper end of the valve cover 112. The lower end of the valve stem 3 passes through the bracket 8 and the valve cover 112 in sequence, and is then connected to the valve core assembly 5. The upper end of the valve stem 3 is provided with a threaded section, on which a handwheel 113 is mounted. A stem nut 9 is located within the bracket 8 and mates with the threaded section at the upper end of the valve stem 3. A sealing packing is also provided between the valve stem 3 and the valve cover 112. A packing press ring 111 is located at the upper end of the packing. A packing gland 10 is also located within the bracket 8. The lower side of the packing gland 10 abuts against the packing press ring 111, and the upper side abuts against the bracket 8 via threaded fasteners. Adjusting the threaded fasteners allows the sealing preload of the sealing packing to be adjusted.

[0051] A valve seat mounting groove 11 is provided in the valve body 1, a valve seat 2 is provided in the valve seat mounting groove 11, a fluid channel 29 is provided in the valve seat 2, a valve sleeve 4 is provided at the upper end of the valve seat 2, the outer circumference of the valve sleeve 4 cooperates with the valve body 1, and its top end cooperates with the valve cover 112. A plurality of throttle holes 41 are evenly provided along the outer circumference of the valve sleeve 4 on the side close to the valve seat 2. A valve core assembly 5 is installed in the internal space formed by the valve sleeve 4 and the valve seat 2. The outer circumference of the valve core assembly 5 is slidably matched with the inner circumference of the valve sleeve 4 to open or close the throttle hole.

[0052] A composite multi-stage sealing structure is provided between the valve seat 2 and the valve core assembly 5 , and the composite multi-stage sealing structure is used to close the flow path from the fluid channel 29 to the throttle hole 41 .

[0053] The composite multi-stage sealing structure includes: a first sealing portion 22 disposed at the upper end of the valve seat 2, a second sealing portion 512 and a third sealing portion 511 disposed at the lower end of the valve core assembly 5, and a primary sealing ring 231 and a secondary sealing ring 232 disposed between the valve seat 2 and the third sealing portion 511. The third sealing portion 511 cooperates with the primary sealing ring 231 to form a first sealing structure, the third sealing portion 511 cooperates with the secondary sealing ring 232 to form a second sealing structure, and the first sealing portion 22 cooperates with the second sealing portion 512 to form a third sealing structure. The first, second, and third sealing structures are sequentially arranged along the radial direction of the valve seat 2. The first sealing portion 22 and the second sealing portion 512 are both made of cemented carbide, so that the third sealing structure forms a metal hard sealing structure, and the first and second sealing structures form a composite sealing structure.

[0054] Preferably, the upper end of the valve seat 2 is provided with a mounting boss 21, which engages with the valve seat mounting groove 11. The mounting boss 21 defines a mounting groove 23 for mounting a secondary sealing ring 232. The bottom of the mounting groove 23 is provided with a plurality of waterline grooves 233, and the sidewalls are provided with a plurality of barbs 234. Once the secondary sealing ring 232 is assembled into the mounting groove 23, the barbs 234 retain the secondary sealing ring 232, preventing it from being pushed out of the mounting groove 23. The secondary sealing ring 232 is made of plastic and has a compression slope on one side. The primary sealing ring 231 has a triangular cross-section and is made of rubber. When the secondary sealing ring 232 is assembled to the mounting groove 23, one side of the main sealing ring 231 is pressed by the pressing inclined surface on the secondary sealing ring 232, and when the valve is in the closed state, the other side of the main sealing ring 231 is pressed by the pressing inclined surface at the lower end of the valve sleeve 4, so that the main sealing ring 231 and the secondary sealing ring 232 are fixed in the mounting position of the valve seat 2.

[0055] The main sealing ring 231 and the secondary sealing ring 232 are configured so that, when the valve is open, the axial height difference B between the main sealing ring 231 and the first sealing portion 22 is 0.5mm to 0.8mm, and the axial height difference A between the secondary sealing ring 232 and the first sealing portion 22 is 0.3mm to 0.5mm. As a result, when the valve is closing, the valve core assembly 5 first contacts the rubber main sealing ring 231. Due to the large elastic deformation of the rubber, it deforms significantly, and the valve achieves the first level of sealing (rubber sealing). As the valve continues to close, the valve core assembly 5 contacts the secondary sealing ring 232, and the valve reaches the second level of sealing (plastic sealing). As the valve continues to close, the valve core assembly 5 presses the secondary sealing ring 232 downward until it is flush with the first sealing portion 22. At this point, the second sealing portion 512 contacts the first sealing portion 22, and the valve reaches the third level of sealing (metal sealing).

[0056] Preferably, the mounting boss 21 has an upper valve seat mounting surface 26 and a lower valve seat mounting surface 27. A valve seat sealing ring is disposed between the lower valve seat mounting surface 27 and the valve seat mounting groove 11 to seal between the valve seat 2 and the valve body 1. The thickness of the mounting boss 21 is less than the depth of the valve seat mounting groove 11, so that the lower end of the valve sleeve 4 is located in the valve seat mounting groove 11. Thus, the valve sleeve 4 is securely mounted and positioned using the inner circumferential wall of the valve body 1 and the valve seat mounting groove 11, respectively.

[0057] Conventional throttling, stop, and vent valves have only one sealing ring on their valve seat, which results in poor sealing for highly permeable fluids and makes them prone to leakage. In the aforementioned embodiment, two primary and secondary sealing rings of different materials and structures are installed within the valve. The outer primary sealing ring is made of rubber, such as FKM or NBR, depending on the operating conditions. The inner secondary sealing ring is made of plastic, such as PTFE or PEEK, depending on the operating conditions. If one primary or secondary sealing ring is damaged, the other secondary or primary sealing ring can still function independently, extending the valve's service life.

[0058] Barbs are provided in the mounting groove. When the secondary sealing ring is assembled into the mounting groove, the barbs can hold the secondary sealing ring in place, preventing it from being pushed out of the mounting groove. Furthermore, inclined compression surfaces are provided on the secondary sealing ring and the valve sleeve. When the secondary sealing ring is assembled into the mounting groove, one side of the primary sealing ring is pressed by the inclined compression surface on the secondary sealing ring. When the valve is closed, the other side of the primary sealing ring is pressed by the inclined compression surface at the lower end of the valve sleeve. This sealing structure effectively secures the primary and secondary sealing rings to their respective mounting positions on the valve seat, ensuring a stable valve seal.

[0059] In addition, the above-described embodiment also features a height difference in the valve seat seals, namely, the height of the primary seal is greater than that of the secondary seal, which in turn is greater than that of the first sealing portion. This allows the valve core assembly to first contact the rubber primary seal during valve closing, achieving a first-level seal (rubber seal). As the valve continues to close, the valve core assembly contacts the secondary seal, achieving a second-level seal (plastic seal). As the valve continues to close, the valve core assembly presses the secondary seal downward until it is flush with the first sealing portion, at which point the second sealing portion contacts the first, achieving a third-level seal (metal seal). This multi-stage sealing structure improves the valve's sealing performance.

[0060] Preferably, the valve core assembly 5 includes a valve core body 51 and a guide sleeve 52 connected to the valve core body 51. A valve core boss 517 is provided at the lower end of the valve core body 51, and a third sealing portion 511 is provided at the bottom of the valve core boss 517. A first groove 513 is formed inside the third sealing portion 511, and a second sealing portion 512 made of cemented carbide is formed in the first groove 513.

[0061] Preferably, a stem connection portion 31 is formed at the lower end of the valve stem 3, and a cavity 518 is formed at the upper end of the valve core body 51 for inserting the stem connection portion 31. A stem connection assembly is disposed within the cavity 518. After the stem connection portion 31 is inserted into the cavity 518, the stem connection portion 31 is connected to the valve core body 51 through the stem connection assembly. The valve core body 51 also has a second groove 516 for mounting the guide sleeve 52, as well as a buffer hole 515 for connecting the second groove 516 with the cavity 518. The guide sleeve 52 has a flow channel defined therein, allowing fluid medium to enter the cavity 518 through the flow channel and the buffer hole 515. The buffer hole can be used to ensure pressure balance between the upper and lower end surfaces of the valve core, facilitating opening and closing of the valve.

[0062] Preferably, a grease injection assembly 6 and a detection assembly 7 are respectively mounted on the valve body 1, wherein the grease injection assembly 6 includes a grease injection valve 61 and a check valve 62, an annular grease injection groove 514 is provided on the outer peripheral surface of the valve core boss 517, and a detection pipeline and a grease injection pipeline are respectively provided on the valve seat 2, the grease injection pipeline being in communication with the grease injection assembly 6 and the annular grease injection groove 514, respectively, and the detection pipeline being in communication with the detection assembly 7. When the detection assembly 7 detects a fluid medium leakage in the valve, indicating that the first-stage seal, the second-stage seal, and the third-stage seal have all failed, sealing grease is injected into the valve through the grease injection assembly 6, and the sealing grease reaches the annular grease injection groove 514 through the grease injection pipeline provided in the valve, thereby achieving emergency sealing of the valve.

[0063] Preferably, the mounting boss 21 is provided with a first annular channel 24 and a second annular channel 25, respectively, wherein the first annular channel 24 and the second annular channel 25 are not connected to each other. The mounting boss 21 is also provided with a plurality of detection channels 241 and a plurality of grease injection channels 251, wherein the plurality of detection channels 241 are connected to the first annular channel 24, and the plurality of grease injection channels 251 are connected to the second annular channel 25.

[0064] The lower end of the valve sleeve 4 is respectively provided with a plurality of first channels 42 and a plurality of second channels 44. The ends of the plurality of first channels 42 and the plurality of second channels 44 are staggered in the axial direction, so that one end of the plurality of first channels 42 is connected to the corresponding detection channel 241, and the other end extends to the outer peripheral surface of the valve core boss 517 and is not connected to the annular grease injection groove 514. One end of the plurality of second channels 44 is connected to the corresponding grease injection channel 251, and the other end is connected to the annular grease injection groove 514.

[0065] The valve body 1 is provided with a third channel 12 communicating with the first annular channel 24 and a fourth channel 13 communicating with the second annular channel 25. The third channel 12 is provided with a detection assembly 7, and the fourth channel 13 is provided with a check valve 62 and a grease injection valve 61 in sequence.

[0066] When a valve seal fails, the fluid medium (such as natural gas) flows through the gap between the valve seat 2 and the valve core assembly 5, the gap between the valve core assembly 5 and the valve sleeve 4, the plurality of first channels 42, the plurality of detection channels 241, the first annular channel 24, and the third channel 12, where it is detected by the detection assembly 7. This confirms the presence of fluid leakage and, therefore, determines that the valve seal has failed. Upon detecting a valve seal failure, sealing grease is injected into the valve via the grease injection assembly 6. The sealing grease flows through the grease injection valve 61, the check valve 62, the fourth channel 13, the second annular channel 25, the plurality of grease injection channels 251, the plurality of second channels 44, and the annular grease injection groove 514, thereby achieving pressurized grease injection. By circumferentially directing the sealing grease into the valve's sealing structure, the gap between the valve core assembly 5 and the valve sleeve 4 is sealed, achieving an emergency seal and improving the valve's sealing performance.

[0067] In the above embodiment, a grease injection assembly and a detection assembly are mounted on the valve body, respectively. Detection channels communicating with the detection assembly are provided on the valve body, valve seat, and valve sleeve, respectively. Grease injection channels communicating with the grease injection assembly are also provided on the valve body, valve seat, and valve sleeve, respectively. When the detection assembly detects a fluid leak in the valve, sealing grease is injected into the valve via the grease injection assembly. The sealing grease is then directed through the grease injection channels within the valve into the valve's sealing structure, enabling timely emergency sealing of the valve and improving its sealing performance.

[0068] Preferably, the mounting boss 21 further defines a sealing groove 28, within which an annular sealing ring 30 is mounted. A plurality of detection channels 241 are located inside the annular sealing ring 30, and a plurality of grease injection channels 251 are located outside the annular sealing ring 30. When the valve is closed, the lower end of the valve sleeve 4 is sealed to the annular sealing ring 30, and a flow gap 43 is defined between the lower end of the valve sleeve 4 and the mounting surface 26 of the valve seat.

[0069] In the above embodiment, an annular sealing ring is provided between the mounting boss and the valve sleeve, with a plurality of detection channels located on the inner side of the annular sealing ring and a plurality of grease injection channels located on the outer side of the annular sealing ring. When the grease injection assembly is used to inject sealing grease into the valve, the annular sealing ring prevents the sealing grease from entering the detection channels through the flow gap, while the sealing grease can be injected into the annular grease injection groove through the flow gap, thereby sealing the gap between the valve core assembly and the valve sleeve, thereby achieving emergency sealing of the valve.

[0070] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although this specification has described the present invention in detail with reference to the above embodiments, the present invention is not limited to the above specific implementation methods. Therefore, any modification or equivalent replacement of the present invention; and all technical solutions and improvements thereof that do not depart from the spirit and scope of the invention are included in the scope of the claims of the present invention.

Claims

1. A vent valve with a double sealing valve seat, characterized in that: The vent valve includes: A valve body, a valve cover, a valve stem, a valve sleeve, a valve seat and a valve core assembly; a valve seat mounting groove is provided in the valve body, the valve seat is provided in the valve seat mounting groove, a fluid channel is provided in the valve seat, the valve sleeve is provided at the upper end of the valve seat, the outer circumferential surface of the valve sleeve cooperates with the valve body, and the top end thereof cooperates with the valve cover, a plurality of throttling holes are evenly provided along the outer circumferential surface of the valve sleeve on the side close to the valve seat, the valve core assembly is installed in the internal space formed by the valve sleeve and the valve seat, the outer circumferential surface of the valve core assembly is slidably matched with the inner circumferential surface of the valve sleeve to open or close the throttling hole; wherein, A composite multi-stage sealing structure is provided between the valve seat and the valve core assembly, the composite multi-stage sealing structure being used to seal the flow path from the fluid channel to the throttle hole; A grease injection assembly and a detection assembly are respectively installed on the valve body, an annular grease injection groove is provided on the valve core assembly, and a detection pipeline and a grease injection pipeline are respectively provided on the valve seat. The grease injection pipeline is respectively connected to the grease injection assembly and the annular grease injection groove, and the detection pipeline is connected to the detection assembly; The composite multi-stage sealing structure includes: a first sealing portion arranged at the upper end of the valve seat, a second sealing portion and a third sealing portion arranged at the lower end of the valve core assembly, and a main sealing ring and a secondary sealing ring arranged between the valve seat and the third sealing portion; wherein the third sealing portion and the main sealing ring cooperate with each other to form a first sealing structure, the third sealing portion and the secondary sealing ring cooperate with each other to form a second sealing structure, and the first sealing portion and the second sealing portion cooperate with each other to form a third sealing structure, and the first sealing structure, the second sealing structure and the third sealing structure are arranged in sequence along the radial direction of the valve seat; The main sealing ring and the secondary sealing ring are respectively configured as follows: when the valve is in an open state, the axial height difference B between the main sealing ring and the first sealing portion is 0.5mm to 0.8mm, and the axial height difference A between the secondary sealing ring and the first sealing portion is 0.3mm to 0.5mm.

2. The vent valve according to claim 1, characterized in that: The upper end of the valve seat is provided with a mounting boss, which cooperates with the valve seat mounting groove. The mounting boss is provided with a mounting groove for installing the secondary sealing ring. The bottom of the mounting groove for installing the secondary sealing ring is provided with a plurality of water line grooves, and the side wall is provided with a plurality of barbs.

3. The vent valve according to claim 2, characterized in that: The valve core assembly includes a valve core body and a guide sleeve connected to the valve core body; a valve core boss is provided at the lower end of the valve core body, the bottom of the valve core boss is provided with the third sealing part, a first groove is provided on the inner side of the third sealing part, and the second sealing part made of cemented carbide is formed in the first groove.

4. The vent valve according to claim 3, characterized in that: The secondary sealing ring is made of plastic material and has a pressing slope on one side; the cross-section of the main sealing ring is triangular and is made of rubber material; when the secondary sealing ring is assembled to the valve seat, one side of the main sealing ring is pressed by the pressing slope on the secondary sealing ring, and when the valve is in a closed state, the other side of the main sealing ring is pressed by the pressing slope at the lower end of the valve sleeve.

5. The vent valve according to claim 4, characterized in that: The mounting boss is respectively provided with a first annular channel and a second annular channel, wherein the first annular channel and the second annular channel are not connected to each other; the mounting boss is also provided with a plurality of detection channels and a plurality of grease injection channels, wherein the plurality of detection channels are connected to the first annular channel, and the plurality of grease injection channels are connected to the second annular channel.

6. The vent valve according to claim 5, characterized in that: The annular grease injection groove is provided on the outer peripheral surface of the valve core boss, and a plurality of first channels and a plurality of second channels are respectively provided at the lower end of the valve sleeve, and the ends of the plurality of first channels and the plurality of second channels are staggered in the axial direction, so that one end of the plurality of first channels is connected with the corresponding detection channel, and the other end extends to the outer peripheral surface of the valve core boss and is not connected with the annular grease injection groove, and one end of the plurality of second channels is connected with the corresponding grease injection channel, and the other end is connected with the annular grease injection groove.

7. The vent valve according to claim 6, characterized in that: The valve body is provided with a third channel communicating with the first annular channel and a fourth channel communicating with the second annular channel. The detection component is installed on the third channel, and a check valve and a grease injection valve are installed in sequence on the fourth channel.

8. The vent valve according to claim 7, characterized in that: The mounting boss is further provided with a sealing groove, in which an annular sealing ring is installed. The plurality of detection channels are located on the inner side of the annular sealing ring, and the plurality of grease injection channels are located on the outer side of the annular sealing ring.

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