A valve seal for a natural gas pipeline

Abstract

The application belongs to the field of hydraulic valves, and particularly relates to a valve sealing structure for a natural gas pipeline. The valve comprises a valve body, a grease injection assembly and a detection assembly are respectively arranged on the valve body, a valve seat is arranged in the valve body, a fluid passage is arranged in the valve seat, an upper end of the valve seat is provided with a valve sleeve, an outer circumferential surface of the valve sleeve is matched with the valve body, a plurality of throttle holes are uniformly arranged on one side of the valve sleeve close to the valve seat along the outer circumferential surface, an inner space formed by the valve sleeve and the valve seat is provided with a valve core assembly, an outer circumferential surface of the valve core assembly is slidably matched with an inner circumferential surface of the valve sleeve to open or close the throttle holes; wherein, a composite multi-stage sealing structure is arranged between the valve seat and the valve core assembly, and the composite multi-stage sealing structure is used for closing a flow path from the fluid passage to the throttle holes. The sealing structure has better sealing performance, can timely detect whether the valve leaks, and can perform emergency sealing on the valve when leakage occurs.

Description

Technical Field

[0001] The invention belongs to the field of hydraulic valves, and in particular relates to a valve sealing structure for a natural gas pipeline. Background Art

[0002] During natural gas pipeline maintenance, it's often necessary to install a valve to vent the pipeline. Existing valve sealing structures only have a single soft sealing ring on the valve seat. Over time, this ring can easily wear, corrode, and scratch, leading to valve leakage. Furthermore, existing valve sealing structures are unable to promptly detect valve seal failures or provide timely emergency sealing when such failures occur. 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 valve sealing structure for a natural gas pipeline, which has better sealing performance, can also promptly detect whether the valve is leaking, 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 valve sealing structure for a natural gas pipeline, the valve comprising a valve body, the sealing structure being installed inside the valve, the sealing structure comprising at least a valve seat, a valve sleeve, and a valve core assembly;

[0006] 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 circumference of the valve sleeve is matched with the valve body, a plurality of throttling holes are evenly provided along the outer circumference 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 circumference of the valve core assembly is slidably matched with the inner circumference of the valve sleeve to open or close the throttling hole; wherein,

[0007] 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 close the flow path from the fluid channel to the throttle hole;

[0008] A grease injection assembly and a detection assembly are respectively installed on the valve body, and the valve core assembly includes a valve core body and a guide sleeve threadedly connected to the valve core body; an annular grease injection groove is provided on the valve core body, 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.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] Preferably, 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 cemented carbide is formed in the first groove.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] Compared with the prior art, the valve sealing structure for a natural gas pipeline provided by the present invention has the following beneficial technical effects:

[0019] 1. Conventional valve sealing structures have only one sealing ring on the valve seat, which can be ineffective for highly permeable fluids and prone to leakage. The present invention incorporates two primary and secondary sealing rings in the sealing structure, each made of different materials and structures. 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.

[0020] 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.

[0021] 3、The height difference of the valve seat sealing ring is designed, that is, the height of the main sealing ring is greater than that of the auxiliary sealing ring, and the height of the auxiliary sealing ring is greater than that of the first sealing part. During the closing process of the valve, the valve core assembly first contacts the main sealing ring made of rubber, at which time the valve reaches the first level of sealing (rubber sealing). During the continuous closing process of the valve, the valve core assembly contacts the auxiliary sealing ring, at which time the valve reaches the second level of sealing (plastic sealing). Continue to close the valve, the valve core assembly is pressed down to the auxiliary sealing ring to be flush with the first sealing part, at which time the second sealing part contacts the first sealing part, and the valve reaches the third level of sealing (metal sealing), thereby improving the sealing performance of the valve through the multi-level sealing structure.

[0022] 4、The grease injection assembly and the detection assembly are respectively installed on the valve body, and the detection channels in communication with the detection assembly are respectively formed in the valve body, the valve seat and the valve sleeve, and the grease injection channels in communication with the grease injection assembly are also respectively formed in the valve body, the valve seat and the valve sleeve. When the detection assembly detects that the valve leaks fluid medium, the sealing grease is injected into the valve through the grease injection assembly at this time, and the sealing grease is guided into the sealing structure of the valve through the grease injection channels formed in the valve, so that the emergency sealing of the valve can be realized in time, and the sealing performance of the valve is improved.

[0023] 5、The annular sealing ring is arranged between the mounting boss and the valve sleeve, and 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. When the sealing grease is injected into the valve through the grease injection assembly, on the one hand, the annular sealing ring can prevent the sealing grease from entering the detection channel through the flow gap, and on the other hand, the sealing grease can be injected into the annular grease injection groove through the flow gap, so that the gap between the valve core assembly and the valve sleeve is sealed, and the emergency sealing of the valve is realized. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structural schematic view of the valve sealing structure;

[0025] Figure 2 It is a side view of the valve sealing structure;

[0026] Figure 3 It is a structural schematic view of the valve core body;

[0027] Figure 4 It is a local enlarged schematic view of the valve sealing structure;

[0028] Figure 5 It is a local enlarged schematic view of the main and auxiliary sealing rings when the valve sealing structure is in the open state;

[0029] Figure 6 It is a structural schematic view of the valve seat;

[0030] Figure 7It is a top view of the valve seat;

[0031] Figure 8 It is a partial enlarged schematic diagram of the detection component;

[0032] Figure 9 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;

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

[0036] 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;

[0037] 231, main sealing ring; 232, auxiliary sealing ring; 233, waterline groove; 234, barb;

[0038] 241, detection channel; 251, grease injection channel;

[0039] 41. Orifice; 42. First channel; 43. Flow gap; 44. Second channel;

[0040] 51. Valve core body; 52. Guide sleeve;

[0041] 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;

[0042] 61. Grease injection valve; 62. Check valve. DETAILED DESCRIPTION

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] See attached Figure 1 -Attached Figure 9 As shown, the present invention provides a valve sealing structure for a natural gas pipeline, the valve comprising a valve body 1 , the sealing structure being installed inside the valve, and the sealing structure comprising at least a valve seat 2 , a valve sleeve 4 and a valve core assembly 5 .

[0049] 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 on the upper end of the valve seat 2, the outer circumference of the valve sleeve 4 is matched with the valve body 1, and 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, and 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.

[0050] 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 .

[0051] 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.

[0052] 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.

[0053] 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).

[0054] 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.

[0055] Conventional valve sealing structures have a single sealing ring on the valve seat, which can be ineffective for highly permeable fluids and prone to leakage. In the aforementioned embodiment, the sealing structure incorporates two primary and secondary sealing rings of varying materials and structures. 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 life of the valve.

[0056] 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.

[0057] 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.

[0058] Preferably, the valve core assembly 5 includes a valve core body 51 and a guide sleeve 52 threadedly 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.

[0059] Preferably, the lower end of the valve stem 3 is formed with a valve stem connecting part 31, the upper end of the valve core body 51 is formed with a cavity 518 for inserting the valve stem connecting part 31, and a valve stem connecting assembly is arranged in the cavity 518. The valve stem connecting part 31 is drivingly connected with the valve core body 51 through the valve stem connecting assembly after being inserted into the cavity 518. A second groove 516 for mounting a guide sleeve 52 and a buffer hole 515 for connecting the second groove 516 and the cavity 518 are further formed in the valve core body 51. A threaded section is formed on the inner circumferential surface of the second groove 516, so that the valve core body 51 is threadedly connected with the guide sleeve 52. A flow passage is formed in the guide sleeve 52, and the fluid medium can enter the cavity 518 through the flow passage and the buffer hole 515. The buffer hole can be used to balance the pressure on the upper and lower end surfaces of the valve core, facilitating the opening and closing of the valve.

[0060] Preferably, the valve body 1 is respectively provided with a grease injection assembly 6 and a detection assembly 7. The grease injection assembly 6 includes a grease injection valve 61 and a check valve 62. An annular grease injection groove 514 is formed on the outer circumferential surface of the valve core boss 517. A detection pipeline and a grease injection pipeline are respectively formed in the valve seat 2. The grease injection pipeline is in communication with the grease injection assembly 6 and the annular grease injection groove 514. The detection pipeline is in communication with the detection assembly 7. When the detection assembly 7 detects that the valve leaks fluid medium, it means that the first, second and third seals have all failed. The grease injection assembly 6 is used to inject sealing grease into the valve. The sealing grease reaches the annular grease injection groove 514 through the grease injection pipeline formed in the valve, thereby achieving emergency sealing of the valve.

[0061] Preferably, the mounting boss 21 is respectively provided with a first annular channel 24 and a second annular channel 25, which are not in communication with each other. A plurality of detection channels 241 and a plurality of grease injection channels 251 are further formed in the mounting boss 21. The plurality of detection channels 241 are in communication with the first annular channel 24, and the plurality of grease injection channels 251 are in communication with the second annular channel 25.

[0062] 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 in communication with the corresponding detection channel 241, and the other end extends to the outer circumferential surface of the valve core boss 517 and is not in communication with the annular grease injection groove 514. One end of the plurality of second channels 44 is in communication with the corresponding grease injection channel 251, and the other end is in communication with the annular grease injection groove 514.

[0063] 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.

[0064] 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 guiding the sealing grease circumferentially into the valve's sealing structure, the gap between the valve core assembly 5 and the valve sleeve 4 is sealed, achieving emergency sealing of the valve and improving the valve's sealing performance.

[0065] 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. Grease injection channels communicating with the grease injection assembly are also provided on 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 into the valve's sealing structure, enabling timely emergency sealing of the valve and improving its sealing performance.

[0066] 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.

[0067] 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.

[0068] 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 valve sealing structure for a natural gas pipeline, characterized by: The valve comprises a valve body, a sealing structure installed inside the valve, and the sealing structure comprises at least a valve seat, a valve sleeve and a valve core assembly; 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 close the flow path from the fluid channel to the throttle hole; 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 auxiliary sealing ring are respectively set as follows: when the valve is in the open state, the height difference B between the main sealing ring and the first sealing part in the axial direction is 0.5mm-0.8mm, and the height difference A between the auxiliary sealing ring and the first sealing part in the axial direction is 0.3mm-0.5mm; A grease injection assembly and a detection assembly are respectively installed on the valve body. The valve core assembly includes a valve core body and a guide sleeve threadedly connected to the valve core body. An annular grease injection groove is provided on the valve core body. A detection pipeline and a grease injection pipeline are respectively provided on the valve seat. The grease injection pipeline is connected to the grease injection assembly and the annular grease injection groove respectively, and the detection pipeline is connected to the detection assembly. A mounting boss is provided at the upper end of the valve seat, and a first annular channel and a second annular channel are respectively formed on the mounting boss, wherein the first annular channel and the second annular channel are not connected to each other; a plurality of detection channels and a plurality of grease injection channels are also formed on the mounting boss, 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; An annular grease injection groove is formed on the outer circumferential surface of the valve core boss, and a plurality of first channels and a plurality of second channels are respectively formed on the lower end of the valve sleeve. 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 circumferential 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; the first channel is axially located between the second channel and the valve seat; 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 third channel is provided with a detection component, and the fourth channel is provided with a check valve and a grease injection valve in sequence. The mounting boss is further provided with a sealing groove, in which an annular sealing ring is installed, a plurality of detection channels are located on the inner side of the annular sealing ring, and a plurality of grease injection channels are located on the outer side of the annular sealing ring; The grease injection component and the detection component are arranged opposite to each other on the valve body.

2. The valve sealing structure according to claim 1, wherein: A valve seat mounting groove is provided in the valve body, a valve seat is provided in the valve seat mounting groove, a fluid channel is opened in the valve seat, a valve sleeve is provided on the upper end of the valve seat, the outer circumference of the valve sleeve is matched with the valve body, a plurality of throttling holes are evenly provided along the outer circumference of the valve sleeve on the side close to the valve seat, a valve core assembly is installed in the internal space formed by the valve sleeve and the valve seat, the outer circumference of the valve core assembly is slidably matched with the inner circumference of the valve sleeve to open or close the throttling hole.

3. The valve sealing structure according to claim 2, wherein: The mounting boss cooperates with the valve seat mounting groove. The mounting boss is provided with a mounting groove for installing the auxiliary sealing ring. The bottom of the mounting groove for installing the auxiliary sealing ring is provided with a plurality of water line convex grooves, and the side wall is provided with a plurality of barbs.

4. The valve sealing structure according to claim 3, wherein: A valve core boss is provided at the lower end of the valve core body, a 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 a second sealing portion made of cemented carbide is formed in the first groove.

5. The valve sealing structure according to claim 4, wherein: The secondary sealing ring is made of plastic and has a pressing slope on one side; the main sealing ring has a triangular cross-section and is made of rubber; 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 the closed state, the other side of the main sealing ring is pressed by the pressing slope at the lower end of the valve sleeve.

Images