A stop valve

Abstract

The application discloses a stop valve and relates to the technical field of stop valves, which comprises a valve body, a valve cover, a valve rod, a packing, a valve clack, a sealing cavity, a sealing element and a backflushing element. The valve body is provided with the valve cover at the top end. One end of the valve rod is slidably penetrated through the bottom end of the valve cover and extends to the inside of the valve body to be connected with the valve clack. The other end is threadedly connected with the top end of the valve cover. The sealing cavity is arranged between the valve clack and the inner wall of the valve cover. The valve clack and the inner wall of the valve cover are connected through the sealing element. The valve rod outer wall and the valve cover inner wall are connected through the packing. The backflushing element is arranged on the valve cover. The application realizes stable shunting and sufficient supply of the medium through double shunting channels, guarantees stable medium flow and balanced pressure of the medium entering the sealing cavity, forms stable reverse pressure in the sealing cavity, efficiently balances the medium force when the valve body is closed, reduces the operation force of the operator rotating the hand wheel and realizes easy closing of the valve body.

Description

Technical Field

[0001] This utility model relates to the field of gate valve technology, and specifically to a gate valve. Background Technology

[0002] Gate valves are the most widely used shut-off and regulating valves in industrial pipelines. Their core functions are to cut off, connect, and regulate the flow of media. They are opened and closed by the vertical movement of the valve disc along the center line of the valve seat. They have a simple structure, reliable sealing, and excellent regulating performance, and are widely used in fluid transportation systems in petroleum, chemical, power, water supply and drainage, and HVAC industries.

[0003] Gate valves offer tight closure, good regulation, and convenient maintenance, but their high flow resistance increases the difficulty for operators to open and close them. To save effort, operators often use auxiliary tools to operate the valves, but such unconventional operations can easily damage valve components, causing jamming or leakage and reducing the valve's service life.

[0004] Therefore, a shut-off valve is needed to solve the above-mentioned technical problems. Utility Model Content

[0005] To achieve the above objectives, this utility model provides the following technical solution: a stop valve, comprising: a valve body, a valve cover, a valve stem, a packing element, a valve disc, a sealing cavity, a sealing element, and a backflush element;

[0006] The valve body has a valve cover at its top. One end of the valve stem slidably passes through the bottom end of the valve cover and extends into the valve body to connect with the valve disc. The other end is threaded to the top of the valve cover. The valve disc and the inner wall of the valve cover form a sealing cavity. The valve disc and the inner wall of the valve cover are connected by a sealing element. The outer wall of the valve stem and the inner wall of the valve cover are connected by a packing element. The valve cover is provided with a backflush element.

[0007] The valve disc includes: a disc body, a clamping nut, a long straight hole, a filter plate, and a disc spring;

[0008] Wherein, the outer wall of the end of the valve stem away from the valve cover is threadedly connected to the clamping nut, the clamping nut is connected to the inside of the valve body, the bottom circumference of the valve body is provided with a plurality of the elongated straight holes, the filter plate is provided inside the valve body, a transition cavity is formed between the filter plate and the elongated straight holes, and the disc spring is provided between the filter plate and the valve stem.

[0009] Furthermore, as a preferred embodiment, the filter plate includes: a plate body, filter holes, a small port, and a large port;

[0010] The plate body is provided with a plurality of filter holes evenly distributed thereon. Each filter hole includes a small port and a large port. Each small port faces the disc spring and each large port faces the transition cavity.

[0011] Furthermore, as a preferred embodiment, the valve stem includes: a stem body, an upper threaded end, a lower threaded end, a flat surface, and a connecting hole;

[0012] Wherein, one end of the rod is the upper threaded end, and the other end is the lower threaded end. The upper threaded end is threadedly connected to the valve stem nut located inside the top of the valve cover, and the lower threaded end is threadedly connected to the clamping nut located inside the valve disc. The lower threaded end has symmetrically opened flat surfaces, and there is a flow gap between the flat surfaces and the clamping nut. The lower threaded end has the connecting hole inside.

[0013] The valve body interior, the elongated straight hole, the transition cavity, the filter hole, the flow gap, and the sealing cavity are sequentially connected to form a first flow channel, and the valve body interior, the elongated straight hole, the transition cavity, the filter hole, the connecting hole, and the sealing cavity are sequentially connected to form a second flow channel.

[0014] Furthermore, as a preferred embodiment, the valve body includes: an inlet, an outlet, and a first sealing surface;

[0015] The valve body has an inlet at one end and an outlet at the other end, and the first sealing surface is located in the middle of the valve body.

[0016] Furthermore, preferably, the valve disc further includes: a second sealing surface;

[0017] The bottom end of the valve body is provided with a second sealing surface, and the shape of the second sealing surface matches that of the first sealing surface.

[0018] Furthermore, as a preferred embodiment, the sealing element includes: a metal sealing ring, an end cap, a screw, and a ring groove;

[0019] The valve body has a groove, and a metal sealing ring is disposed in the groove. The end cap uses screws to confine the metal sealing ring in the groove.

[0020] Furthermore, as a preferred embodiment, the backflush component includes: an external pressure source, a valve, a flushing connector, a flushing end, and a nozzle;

[0021] The external pressure source is connected to the flushing connector through the valve. The end of the flushing connector away from the valve passes through the valve cover and extends into the sealing cavity to communicate with the flushing end. The flushing end is provided with multiple inclined nozzles.

[0022] Furthermore, as a preferred embodiment, the packing element includes: a packing pressure plate, a packing pressure sleeve, and a packing assembly;

[0023] The packing pressure plate, through the packing sleeve, places the packing assembly between the outer wall of the valve stem and the inner wall of the valve cover.

[0024] Compared with the prior art, the present invention provides a shut-off valve, which has the following advantages:

[0025] Advantage 1: This application optimizes the media flow path design, ensuring that the media flowing inside the valve body is not completely discharged from the outlet to the outside of the valve body. Instead, through the diversion effect of the first and second flow channels, a portion of the media reaches the sealing cavity for temporary storage. Furthermore, this application achieves stable media diversion and sufficient supply through dual diversion channels, guaranteeing a stable flow rate and balanced pressure of the media entering the sealing cavity. A stable reverse pressure can be formed within the sealing cavity, accurately and efficiently balancing the media force when the valve body is closed. This significantly reduces the operating force required for the operator to turn the handwheel and reset the valve stem, enabling easy valve closure and significantly improving operational convenience, especially suitable for long-term, frequent opening and closing conditions.

[0026] Advantage 2: This application can effectively reduce frictional loss and stress load between transmission components through dual flow channels, avoid damage to components due to overload, further extend the service life of core transmission components such as valve stems and handwheels, and reduce equipment maintenance costs.

[0027] Advantage 3: In the dual diversion channel of this application, the medium needs to be filtered through the filter holes of the filter plate before entering the sealing cavity, which can effectively intercept impurities. At the same time, when the diverted medium flows through the filter holes, it can form local back pressure, reducing the adhesion of impurities. Combined with the flushing effect of the backflushing component, it can further avoid filter hole blockage, while maintaining the pressure stability in the sealing cavity and ensuring the overall stability of valve body operation. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a shut-off valve structure;

[0029] Figure 2 This is a top view of a shut-off valve;

[0030] Figure 3 for Figure 1 Enlarged detail image of point A in the middle;

[0031] Figure 4 This is a schematic diagram of the valve disc structure of a shut-off valve;

[0032] Figure 5 This is a schematic diagram of a gate valve filter plate structure;

[0033] Figure 6This is a schematic diagram of the stem structure of a gate valve;

[0034] Figure 7 This is a schematic diagram of a gate valve connection hole structure;

[0035] Figure 8 This is a schematic diagram of a gate valve sealing component.

[0036] Figure 9 This is a schematic diagram of a backflush component for a shut-off valve.

[0037] Figure 10 This is a schematic diagram of the flushing end structure of a shut-off valve;

[0038] Figure 11 This is a schematic diagram of the structure of a gate valve packing component;

[0039] In the diagram: 1. Valve body; 11. Inlet; 12. Outlet; 13. First sealing surface; 2. Valve cover; 3. Valve stem; 31. Stem body; 32. Upper threaded end; 33. Lower threaded end; 34. Flat surface; 35. Connecting hole; 4. Packing components; 41. Packing pressure plate; 42. Packing sleeve; 43. Packing assembly; 5. Handwheel; 6. Valve disc; 61. Disc body; 62. Compression nut; 63. Long straight hole; 64. 641. Filter plate; 642. Plate body; 643. Filter holes; 644. Small port; 645. Large port; 66. Disc spring; 67. Second sealing surface; 7. Sealing cavity; 88. Sealing element; 81. Metal sealing ring; 82. End cap; 83. Screw; 84. Ring groove; 99. Backflush element; 91. External pressure source; 92. Valve; 93. Flushing connector; 94. Flushing end; 95. Nozzle; 10. Valve stem nut. Detailed Implementation

[0040] Please see Figures 1-11 This utility model provides a shut-off valve, comprising: valve body 1, valve cover 2, valve stem 3, packing 4, valve disc 6, sealing cavity 7, sealing element 8, and backflush element 9;

[0041] The valve body 1 has a valve cover 2 at its top. One end of the valve stem 3 can slide through the bottom end of the valve cover 2 and extend into the valve body 1 to connect with the valve disc 6. The other end is threaded to the top of the valve cover 2. There is a sealing cavity 7 between the valve disc 6 and the inner wall of the valve cover 2. The valve disc 6 and the inner wall of the valve cover 2 are connected by a sealing element 8. The outer wall of the valve stem 3 and the inner wall of the valve cover 2 are connected by a packing element 4. The valve cover 2 is provided with a backflush element 9.

[0042] In this embodiment, please refer to Figure 1 and Figure 2As shown, the valve body 1, as the core load-bearing component for media transportation, has an internal flow channel adapted to the required media flow, allowing stable flow of various media under preset operating conditions and ensuring smooth media transportation. The valve cover 2 is sealed to the top of the valve body 1, effectively sealing the opening at the top of the valve body 1 and preventing external impurities from entering the internal flow channel of the valve body 1. It also provides an installation support reference for internal components such as the valve stem 3. The valve stem 3 and valve disc 6 constitute the opening and closing control mechanism of the valve body 1. They work together through transmission. When the valve body 1 is open, the media can flow smoothly along the internal flow channel, meeting the transportation requirements of the operating conditions. When the valve body 1 is closed, it effectively shuts off the media, ensuring that the media cannot pass through the flow channel of the valve body 1. The sealing element 8 and the packing element 4 together prevent the media from leaking from the inside of the valve body 1 to the outside, ensuring operational sealing and safety, and avoiding losses or safety hazards caused by media leakage. The sealing cavity 7 is a pressure relief cavity, and the backflushing element 9 is used to clean the internal space of the sealing cavity 7, ensuring the cleanliness of the sealing cavity 7 and extending the overall service life.

[0043] Valve disc 6 includes: disc body 61, clamping nut 62, elongated straight hole 63, filter plate 64, and disc spring 65;

[0044] Among them, the outer wall of the valve stem 3 away from the valve cover 2 is threaded to the clamping nut 62, the clamping nut 62 is connected to the inside of the valve body 61, the bottom circumference of the valve body 61 is provided with multiple long straight holes 63, the inside of the valve body 61 is provided with a filter plate 64, a transition cavity is formed between the filter plate 64 and the long straight holes 63, and a disc spring 65 is provided between the filter plate 64 and the valve stem 3.

[0045] Furthermore, the filter plate 64 includes: a plate body 641, filter holes 642, a small port 643, and a large port 644;

[0046] The plate 641 has a plurality of filter holes 642 evenly distributed on it. Each filter hole 642 includes a small port 643 and a large port 644. Each small port 643 faces the disc spring 65, and each large port 644 faces the transition cavity.

[0047] Furthermore, the valve stem 3 includes: a stem body 31, an upper threaded end 32, a lower threaded end 33, a flat surface 34, and a connecting hole 35;

[0048] Among them, one end of the rod body 31 is an upper threaded end 32 and the other end is a lower threaded end 33. The upper threaded end 32 is threadedly connected to the valve stem nut 10 located inside the top of the valve cover 2, and the lower threaded end 33 is threadedly connected to the clamping nut 62 located inside the valve disc 6. The lower threaded end 33 has symmetrically opened flat surfaces 34, and there is a flow gap between the flat surfaces 34 and the clamping nut 62. The lower threaded end 33 has a connecting hole 35 inside.

[0049] The valve body 1 interior, the elongated straight hole 63, the transition cavity, the filter hole 642, the flow gap and the sealing cavity 7 are connected in sequence to form a first flow channel. The valve body 1 interior, the elongated straight hole 63, the transition cavity, the filter hole 642, the connecting hole 35 and the sealing cavity 7 are connected in sequence to form a second flow channel.

[0050] In this embodiment, please refer to Figure 1 , Figure 3 and Figure 6 As shown, to achieve convenient and controllable opening and closing operation of valve body 1, a handwheel 5 is fixedly mounted on the end of the upper threaded end 32 of valve stem 3 away from the stem body 31. The handwheel 5 and the upper threaded end 32 adopt an anti-loosening connection structure to ensure that there is no relative slippage between them during transmission. When it is necessary to open valve body 1 (connect the medium flow path), the operator can manually turn the handwheel 5, which can drive the entire valve stem 3 to rotate synchronously with the handwheel 5. Under the threaded transmission cooperation between the upper threaded end 32 and the valve stem nut 10, the rotational motion is converted into linear motion, and the valve stem 3 moves smoothly upward in the vertical direction. At the same time, the valve stem 3 drives the entire valve disc 6 to move vertically upward synchronously until the disc body 61 of the valve disc 6 completely disengages from the sealing contact inside the valve body 1. Thus, the opening operation of valve body 1 is completed.

[0051] It is important to note that the clamping nut 62 is fixedly connected and assembled inside the valve body 61. Through the threaded engagement of the lower threaded end 33 of the valve stem 3 with the clamping nut 62, when the valve stem 3 moves vertically upwards, the valve disc 6 only slides vertically along the inner wall of the valve cover 2, and does not rotate synchronously with the valve stem 3. This effectively avoids significant frictional loss between the valve disc 6 and the inner wall of the valve cover 2, ensuring the stability of the sealing performance. When it is necessary to close the valve body 1 (cut off the medium flow path), the operator reverses the operation by turning the handwheel 5, thus completing the closing operation of the valve body 1. The operation is convenient and highly controllable.

[0052] In this embodiment, please refer to Figure 1 , Figure 3 , Figure 5 , Figure 6 and Figure 7As shown, when valve body 1 is in the open state, not all the medium flowing inside is transported to the outlet 12 along the main flow channel. Some of the medium will flow separately along the preset first flow channel and second flow channel to achieve medium replenishment and pressure balance in the sealing cavity 7. Specifically, the medium flowing along the first flow channel first enters the transition cavity through the long straight hole 63 on the valve disc 6. The transition cavity provides a buffer space for the medium to avoid sudden changes in medium flow velocity from impacting the filter plate 64. Subsequently, the medium completes the filtration process under the action of the filter plate 64 in the transition cavity. The medium enters the filter hole 642 from the large port 644, and after impurities are removed by the filter hole 642, it flows out from the small port 643. Because the filter hole 642 adopts a variable cross-section design, the flow cross-sectional area decreases when the medium flows through the filter hole 642, and the medium flow velocity will increase simultaneously, thereby forming a local back pressure inside the filter hole 642. This local back pressure can effectively prevent impurities from adhering to the inner wall of the filter hole 642 and ensure the unobstructed flow of the filtration channel. The medium discharged through the small port 643 flows directly into the sealing cavity 7 for temporary storage along the flow gap between the flat surface 34 of the valve stem 3 and the clamping nut 62, completing the medium transport in the first flow channel. The medium flowing along the second flow channel, after being filtered through the filter holes 642 of the filter plate 64, directly enters the connecting hole 35 opened inside the valve stem 3, and is directly transported into the sealing cavity 7 for temporary storage through the outlet of the connecting hole 35, realizing the medium diversion in the second flow channel.

[0053] It should be noted that the disc spring 65 plays a buffering role throughout the entire flow of the medium, increasing the service life of each component.

[0054] In a preferred embodiment, this application optimizes the media flow path design so that the media flowing inside the valve body 1 is not completely discharged to the outside of the valve body 1 through the outlet 12. Instead, through the diversion effect of the first and second flow channels, a portion of the media reaches the sealing cavity 7 for temporary storage. Furthermore, this application achieves stable media diversion and sufficient supply through the dual diversion channels, ensuring a stable flow rate and balanced pressure of the media entering the sealing cavity 7. A stable reverse pressure can be formed within the sealing cavity 7, accurately and efficiently balancing the media force when the valve body 1 is closed. This significantly reduces the operating force required for the operator to turn the handwheel 5 and reset the valve stem 3, enabling easy closure of the valve body 1 and significantly improving operational convenience, especially suitable for long-term, frequent opening and closing conditions. The dual diversion channels effectively reduce frictional losses and stress loads between transmission components, preventing damage due to overload, further extending the service life of core transmission components such as the valve stem 3 and handwheel 5, and reducing equipment maintenance costs.

[0055] In a preferred embodiment, in the dual diversion channel of this application, the medium needs to be filtered through the filter holes 642 of the filter plate 64 before entering the sealing cavity 7, which can effectively intercept impurities. At the same time, when the diverted medium flows through the filter holes 642, it can form a local back pressure, reducing the adhesion of impurities. Combined with the flushing effect of the backflushing component 9, it can further prevent the filter holes 642 from being blocked, while maintaining the pressure stability in the sealing cavity 7 and ensuring the overall stability of the valve body 1.

[0056] Furthermore, the valve body 1 includes: an inlet 11, an outlet 12, and a first sealing surface 13;

[0057] The valve body 1 has an inlet 11 at one end and an outlet 12 at the other end, and a first sealing surface 13 is provided in the middle of the valve body 1.

[0058] Furthermore, the valve disc 6 also includes: a second sealing surface 66;

[0059] The bottom end of the valve body 61 is provided with a second sealing surface 66, which is shaped to match the first sealing surface 13.

[0060] In this embodiment, please refer to Figure 1 and Figure 3 As shown, a complete media flow channel is formed inside the valve body 1. The media smoothly enters the internal flow channel of the valve body 1 through the inlet 11, and after being transported through the flow channel, it is discharged from the outlet 12 on the other side of the valve body 1, realizing the directional transportation of the media and meeting the media flow requirements under working conditions. Both the inlet 11 and the outlet 12 adopt a sealing connection structure adapted to the external pipeline, which can effectively prevent media leakage at the inlet and outlet, ensuring the sealing and stability of media transportation. The sealing and shut-off function of the valve body 1 is achieved through the cooperation of the first sealing surface 13 and the second sealing surface 66, which are respectively set inside the valve body 1 and on the valve disc 61, forming the core sealing pair in the closed state of the valve body 1. When the valve body 1 is in the closed state, under the driving force of the valve stem 3, the second sealing surface 66 of the valve disc 6 and the first sealing surface 13 of the valve body 1 achieve a tight seal, forming a reliable sealing barrier, which can effectively intercept the media flowing inside the valve body 1, preventing the media from continuing to be transported along the flow channel, and ensuring the shut-off sealing performance of the valve body 1. When the valve body 1 is in the open state, the valve stem 3 drives the valve disc 6 to move vertically upward, causing the first sealing surface 13 and the second sealing surface 66 to disengage from the sealing fit state, forming a gap between them to accommodate the flow of the medium. At this time, the internal flow channel of the valve body 1 is fully open, and the medium can flow smoothly along the flow channel to achieve normal transport of the medium.

[0061] It is important to note that the first sealing surface 13 and the second sealing surface 66 employ a complementary shape design, with their contours, curvatures, and mating surface precision strictly matched. This maximizes the sealing contact area and enhances the sealing performance after mating, effectively preventing media leakage caused by mating gaps or shape deviations. Furthermore, both the first sealing surface 13 and the second sealing surface 66 are polished, reducing the coefficient of friction during mating. This reduces wear and enhances the sealing effect, ensuring that when the valve body 1 is in the closed state, the media flowing inside can be completely intercepted, guaranteeing the reliability and safety of valve body 1's operation.

[0062] Furthermore, the seal 8 includes: a metal sealing ring 81, an end cap 82, a screw 83, and a ring groove 84;

[0063] The valve body 61 has a groove 84, and a metal sealing ring 81 is provided in the groove 84. The end cap 82 uses screws 83 to limit the metal sealing ring 81 in the groove 84.

[0064] In this embodiment, please refer to Figure 8 As shown, the metal sealing ring 81 in this application is of type C. This type of metal sealing ring 81 has excellent elastic deformation capability and pressure resistance, and is suitable for the pressurized working conditions in the sealing cavity 7. A groove 84 is machined on the upper end of the valve disc 6, and the metal sealing ring 81 is placed in the groove 84. The depth, width, and groove precision of the groove 84 are matched with the structural parameters of the metal sealing ring 81. The C-shaped opening of the metal sealing ring 81 faces the sealing cavity 7. When the pressurized medium in the sealing cavity 7 enters the position of the metal sealing ring 81, it will force the C-shaped opening of the metal sealing ring 81 to expand elastically. Due to the structural constraints on both sides, the metal sealing ring 81 fits tightly with the adjacent wall surface, forming a multi-faceted sealing barrier, effectively blocking the leakage path of the medium and ensuring the sealing performance of the sealing cavity 7.

[0065] It should be noted that, to prevent the metal sealing ring 81 from dislodging or shifting during operation due to factors such as medium pressure impact and valve disc 6 movement, thus affecting the sealing effect, this application uses an end cap 82 to limit and fix it. The end cap 82 is fixedly connected to the upper end face of the valve disc 6 by screws 83, and its lower end face is tightly fitted with the upper end face of the metal sealing ring 81, reliably confining the metal sealing ring 81 inside the ring groove 84, ensuring the stability of its assembly position, and thus ensuring the long-term effectiveness and reliability of the sealing function.

[0066] Furthermore, the backflush component 9 includes: an external pressure source 91, a valve 92, a flushing connector 93, a flushing end 94, and a nozzle 95;

[0067] The external pressure source 91 is connected to the flushing connector 93 through the valve 92. The end of the flushing connector 93 away from the valve 92 passes through the valve cover 2 and extends into the sealing cavity 7 to communicate with the flushing end 94. The flushing end 94 is provided with multiple inclined nozzles 95.

[0068] In this embodiment, please refer to Figure 9 and Figure 10 As shown, the backflushing component 9 is a cleaning and maintenance component for the sealing cavity 7. Its function is to flush the internal space of the sealing cavity 7 and the surface of related components, remove media residue, ensure the pressure relief and containment function of the sealing cavity 7 and the unobstructed flow of the filter orifice 642, thereby maintaining the overall operational stability of the valve body 1. Specifically: The operator opens the external pressure source 91 and valve 92, so that the external pressure source 91 stably supplies backflushing liquid at a preset pressure. The backflushing liquid must meet the cleanliness and pressure compatibility requirements to avoid corrosion or impact damage to the inner wall of the sealing cavity 7, the metal sealing ring 81, and other components. The backflushing liquid is delivered to the flushing connector 93 and enters the flushing end 94, and finally sprays out through multiple preset nozzles 95 on the flushing end 94 to perform a comprehensive backflushing cleaning of the inside of the sealing cavity 7. To improve the flushing effect, multiple nozzles 95 are designed to be evenly distributed, and the angle of the nozzles 95 is precisely adjusted so that the backflushing liquid can be sprayed evenly into various areas inside the sealing cavity 7 in a diffused manner, effectively expanding the flushing coverage area and improving the flushing efficiency. It can quickly remove media residues and impurities from the inner wall of the sealing cavity 7, the surface of the valve disc 6, and the vicinity of the filter plate 64, and avoid the accumulation of impurities affecting the normal operation of the sealing cavity 7.

[0069] It is important to note that during the flushing process, the backflushing liquid flows through the filter holes 642 of the filter plate 64. Its flow direction is opposite to that of the medium during normal operation of the valve body 1. Specifically, the backflushing liquid enters from the small port 643 of the filter hole 642, passes through the interior of the filter hole 642, and exits from the large port 644. Because the filter hole 642 has a variable cross-sectional structure, the flow cross-sectional area gradually increases as the backflushing liquid flows through it, and the liquid velocity decreases synchronously. Furthermore, the liquid flows out in a divergent manner. This flow characteristic generates a reverse flushing force, which can effectively flush out blockages and impurities attached to the large port 644 of the filter hole 642 and its surrounding area. This effectively unclogs the filter hole 642, preventing blockage from affecting the medium diversion and pressure balance function of the sealing cavity 7, and further ensuring the long-term stable operation of the valve body 1.

[0070] Furthermore, the packing element 4 includes: a packing pressure plate 41, a packing pressure sleeve 42, and a packing assembly 43;

[0071] Among them, the packing pressure plate 41 sets the packing group 43 between the outer wall of the valve stem 3 and the inner wall of the valve cover 2 through the packing pressure sleeve 42.

[0072] In this embodiment, please refer to Figure 11As shown, the packing assembly 43 can effectively prevent the medium from leaking outward along the gap between the valve stem 3 and the valve cover 2.

[0073] In practice, when it is necessary to open valve body 1 (connecting the medium flow path), the operator manually rotates handwheel 5, which drives the valve stem 3 to rotate synchronously with handwheel 5. Under the threaded transmission action of the upper thread end 32 and the valve stem nut 10, the rotational motion is converted into linear motion, and the valve stem 3 moves smoothly upward in the vertical direction. At the same time, the valve stem 3 drives the valve disc 6 to move upward vertically synchronously until the disc 6 body 61 completely disengages from the sealing contact inside the valve body 1. Thus, the opening operation of valve body 1 is completed. When it is necessary to close valve body 1 (cut off the medium flow path), the operator rotates handwheel 5 in the opposite direction to reverse the above process, thereby completing the closing operation of valve body 1. The operation is convenient and highly controllable.

[0074] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A shut-off valve, characterized in that: include: Valve body (1), valve cover (2), valve stem (3), packing (4), valve disc (6), sealing cavity (7), sealing element (8), and backflush element (9); The valve body (1) is provided with a valve cover (2) at its top end. One end of the valve stem (3) is slidably passed through the bottom end of the valve cover (2) and extends into the valve body (1) to be connected to the valve disc (6). The other end is threaded to the top end of the valve cover (2). The valve disc (6) and the inner wall of the valve cover (2) form the sealing cavity (7). The valve disc (6) and the inner wall of the valve cover (2) are connected by the sealing element (8). The outer wall of the valve stem (3) and the inner wall of the valve cover (2) are connected by the packing element (4). The valve cover (2) is provided with the backflush element (9). The valve disc (6) includes: a disc body (61), a clamping nut (62), a long straight hole (63), a filter plate (64), and a disc spring (65); Wherein, the outer wall of the valve stem (3) away from the valve cover (2) is threaded to the clamping nut (62), the clamping nut (62) is connected to the inside of the valve body (61), the bottom circumference of the valve body (61) is provided with a plurality of the elongated straight holes (63), the filter plate (64) is provided inside the valve body (61), the filter plate (64) and the elongated straight holes (63) form a transition cavity, and the disc spring (65) is provided between the filter plate (64) and the valve stem (3).

2. A shut-off valve according to claim 1, characterized in that: The filter plate (64) includes: a plate body (641), filter holes (642), a small port (643), and a large port (644). The plate (641) is provided with a plurality of filter holes (642) evenly distributed. Each filter hole (642) includes a small port (643) and a large port (644). Each small port (643) faces the disc spring (65), and each large port (644) faces the transition cavity.

3. A shut-off valve according to claim 2, characterized in that: The valve stem (3) includes: a stem body (31), an upper threaded end (32), a lower threaded end (33), a flat surface (34), and a connecting hole (35); The rod (31) has an upper threaded end (32) at one end and a lower threaded end (33) at the other end. The upper threaded end (32) is threaded to the valve stem nut (10) located inside the top of the valve cover (2). The lower threaded end (33) is threaded to the clamping nut (62) located inside the valve disc (6). The lower threaded end (33) has a flat surface (34) symmetrically provided on it. There is a flow gap between the flat surface (34) and the clamping nut (62). The lower threaded end (33) has a connecting hole (35) inside it. The valve body (1) interior, the elongated straight hole (63), the transition cavity, the filter hole (642), the flow gap and the sealing cavity (7) are sequentially connected to form a first flow channel, and the valve body (1) interior, the elongated straight hole (63), the transition cavity, the filter hole (642), the connecting hole (35) and the sealing cavity (7) are sequentially connected to form a second flow channel.

4. A shut-off valve according to claim 1, characterized in that: The valve body (1) includes: an inlet (11), an outlet (12), and a first sealing surface (13); The valve body (1) has an inlet (11) at one end and an outlet (12) at the other end, and the valve body (1) has a first sealing surface (13) in the middle.

5. A shut-off valve according to claim 4, characterized in that: The valve disc (6) further includes: a second sealing surface (66); The bottom end of the valve body (61) is provided with a second sealing surface (66), and the second sealing surface (66) and the first sealing surface (13) are shaped to match.

6. A shut-off valve according to claim 1, characterized in that: The sealing element (8) includes: a metal sealing ring (81), an end cap (82), a screw (83), and a ring groove (84); The valve body (61) has a groove (84) and a metal sealing ring (81) is provided in the groove (84). The end cap (82) uses screws (83) to confine the metal sealing ring (81) in the groove (84).

7. A shut-off valve according to claim 1, characterized in that: The backflush component (9) includes: an external pressure source (91), a valve (92), a flushing connector (93), a flushing end (94), and a nozzle (95). The external pressure source (91) is connected to the flushing connector (93) through the valve (92). The end of the flushing connector (93) away from the valve (92) passes through the valve cover (2) and extends into the sealing cavity (7) to communicate with the flushing end (94). The flushing end (94) is provided with a plurality of inclined nozzles (95).

8. A shut-off valve according to claim 1, characterized in that: The packing component (4) includes: a packing pressure plate (41), a packing pressure sleeve (42), and a packing assembly (43); The packing plate (41) places the packing assembly (43) between the outer wall of the valve stem (3) and the inner wall of the valve cover (2) through the packing sleeve (42).

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