Double-seal stop valve with replaceable valve seat

Abstract

The invention belongs to the technical field of stop valves, and particularly relates to a valve seat-replaceable dual-seal stop valve which comprises a valve body, a valve cover is fixedly mounted at the upper end of the valve body and connected with a hand wheel assembly through a connecting frame, the hand wheel assembly is in threaded connection with a valve rod, a dual-seal assembly is arranged between the valve cover and the valve rod, and a valve needle assembly is connected to the lower end of the valve rod. The lower end of the valve needle assembly abuts against the valve seat, the valve seat is fixed in the valve body through the valve seat dismounting and mounting assembly, and the hand wheel assembly is rotated to drive the valve rod to ascend or descend, drive the valve needle assembly to ascend or descend and drive the valve needle assembly to be separated from or make contact with the valve seat, so that opening and closing of the stop valve are achieved. The sealing performance between the valve cover and the valve rod is enhanced through the double-sealing assembly, fluid in the valve body is prevented from leaking outwards, if the situation that the stop valve is not tightly sealed due to the fact that the valve seat is damaged, the valve seat can be taken out of the valve body to be replaced through the valve seat disassembling and assembling assembly, and therefore the sealing performance of the stop valve is improved, and the service life of the stop valve is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of gate valve technology, and particularly relates to a gate valve with replaceable valve seat and double sealing. Background Technology

[0002] Gate valves, as key components in fluid control systems, are widely used in industries such as petroleum, chemical, power, water treatment, and pharmaceuticals. They are mainly used for precise control of fluid flow and flow regulation. Traditional gate valves typically employ an integral or welded valve seat structure, where the valve seat and valve body are fixed together through precision machining or welding to ensure the reliability of the initial seal. However, during long-term operation, the valve seat is prone to damage, deformation, or failure of the sealing surface due to medium wear, erosion, high-temperature oxidation, or chemical corrosion. Since the valve seat cannot be replaced separately, users must disassemble the entire valve or even replace the entire valve body assembly. This not only results in high maintenance costs but also leads to prolonged system downtime, severely impacting production continuity. For example, Chinese patent application number CN202010836528.8 discloses a bidirectional sealing stop valve, comprising: a sleeve installed inside a valve seat, a main valve disc and a main valve disc nut installed inside the sleeve, the main valve disc nut being installed on the main valve disc, and a cavity between the main valve disc nut and the main valve disc; a first flow hole communicating through the lower part of the cavity; a second flow hole communicating through the side wall of the valve disc and connecting to the bottom of the cavity; a pilot valve disc provided inside the cavity; the pilot valve disc being positioned above the outlet of the second flow hole; a columnar recess on the upper surface of the pilot valve disc, within which a disc is rotatably installed; a pilot valve disc nut installed in the columnar recess above the disc; and a valve stem passing through the valve seat, the pilot valve disc nut, and fixed to the disc. However, the disadvantage of this technical solution is that the valve seat and valve body are fixed as one piece, and the valve seat cannot be replaced separately. When the valve seat is damaged, the user must disassemble the entire valve or even replace the entire valve body assembly, which can easily lead to high maintenance costs. Summary of the Invention

[0003] The purpose of this invention is to provide a replaceable seat double-seal shut-off valve to solve the problems in the prior art. The specific technical solution is as follows: A replaceable seat double-seal shut-off valve includes a valve body, a valve cover fixedly mounted on the upper end of the valve body, the valve cover being connected to a handwheel assembly via a connecting bracket, the handwheel assembly being threadedly connected to a valve stem, a double-seal assembly being provided between the valve cover and the valve stem, a valve needle assembly being connected to the lower end of the valve stem, the lower end of the valve needle assembly abutting against the valve seat, and the valve seat being fixed to the valve body via a valve seat disassembly and assembly assembly.

[0004] Furthermore, the handwheel assembly includes a bracket, the valve cover is fixedly connected to the bracket via a connecting frame, the bracket is rotatably connected to the rotating shaft via a bearing, the upper end of the rotating shaft is fixedly connected to the handwheel, and the rotating shaft is threadedly connected to the valve stem.

[0005] Furthermore, the dual sealing assembly includes a sealing ring, which is pressed into an inclined groove between the valve cover and the valve stem by a lower pressure plate. The upper end of the lower pressure plate is provided with packing, and the upper end of the packing is pressed against the upper pressure plate. The valve cover is connected to the pressure cap by locking bolts, and a spring is provided between the upper pressure plate and the pressure cap.

[0006] Furthermore, the valve needle assembly includes a connecting sleeve, which is fixed to the lower end of the valve stem. A second spring is provided between the connecting sleeve and the valve needle body. The valve needle body is fixedly connected to one end of a slide rod, and the other end of the slide rod slides in a cylindrical cavity provided at the lower end of the connecting sleeve. The lower end of the valve needle body abuts against the valve seat.

[0007] Furthermore, the valve cover is provided with vertical grooves 1, 2, 3 and 4 at equal intervals. The starting positions of grooves 1, 2, 3 and 4 are on the same horizontal line, and their lengths increase sequentially. The limiting protrusion 2 provided on the side of the connecting cylinder frame slides in groove 4. The connecting cylinder frame is provided with four through holes at equal intervals around its circumference. An adjustment component is rotatably connected inside the connecting cylinder frame. The adjustment component is slidably connected to the valve stem.

[0008] Furthermore, the adjustment assembly includes an inner cylinder frame that rotates within a connecting cylinder frame. A turntable is slidably connected within the inner cylinder frame. A rubber ring is fixed to the upper end of the turntable. A spring is provided between the lower end of the turntable and the inner cylinder frame. A pressing plate is fixed to the lower end of the turntable. The pressing plate is rotatably connected to a pulley. The pulley rotates within a movable frame. The movable frame slides within the inner cylinder frame. A spring is provided between one end of the movable frame and the inner wall of the inner cylinder frame. A limiting protrusion is fixed to the other end of the movable frame. A central column is fixed to the lower end of the inner cylinder frame. The central column is rotatably connected to the connecting cylinder frame. A limiting plate is fixed to the lower end of the central column. A cylindrical groove is provided within the sliding rod. A protruding plate is provided within the cylindrical groove on the side near the sliding groove.

[0009] Furthermore, the turntable is fixedly connected to the lower end of the inner rotating rod, the inner rotating rod is slidably connected to the valve stem, and a knob is fixed to the upper end of the inner rotating rod, with a direction indicator arrow at the upper end of the knob.

[0010] Furthermore, the valve seat assembly includes a support frame that is slidably inserted into the valve body. The lower end of the support frame is fixedly connected to the valve body by screws. An upper protrusion is fixed to the upper end of the support frame, and a valve seat protrusion is fixed to the lower end of the valve seat. A groove is provided inside the valve seat, and the upper protrusion slides into the groove from between the valve seat and the valve seat protrusion. A sealing gasket is provided between the valve body and the valve seat. An inner protrusion is provided inside the support frame, and the inner protrusion engages with the filter assembly.

[0011] Furthermore, the filter assembly includes a filter support, on which a filter protrusion is fixed, and an inner protrusion is engaged between the filter support and the filter protrusion. A filter is fixed inside the filter support, and the filter is rotatably connected to the cleaning unit.

[0012] Furthermore, the cleaning unit includes a central wheel that rotates at the center of the filter screen. The filter screen is provided with oblique toothed grooves. One end of the central wheel is rotatably connected to a locking block, and the other end of the locking block is engaged in the oblique toothed grooves. A spring five is provided between the locking block and the central wheel. The central wheel is slidably connected to a polygonal column. The upper end of the polygonal column is fixedly connected to an upper brush. The upper brush is fixedly connected to a right-angle brush. The polygonal column is slidably connected to a lower brush. A spring six is ​​provided between the lower end of the polygonal column and the lower brush. A sealing filler is provided at the sliding connection between the lower end of the polygonal column and the support frame.

[0013] The advantages of this invention are: By rotating the handwheel assembly, the valve stem is raised or lowered, which in turn raises or lowers the valve needle assembly, causing the valve needle assembly to separate from or contact the valve seat, thereby opening and closing the gate valve. The double sealing assembly enhances the sealing between the valve cover and the valve stem, preventing fluid leakage from the valve body. If the valve seat is damaged, causing the gate valve to not seal properly, the valve seat can be removed from the valve body and replaced using the valve seat removal assembly, thereby improving the gate valve's sealing performance and extending its service life. This also avoids replacing the entire valve body assembly, saving maintenance costs. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the overall structure of the present invention. Figure 2 ; Figure 3 for Figure 2 Enlarged view of a portion of point A in the middle; Figure 4 for Figure 2 Enlarged view of a section at point B in the middle; Figure 5 for Figure 2 Enlarged view of a section at point C; Figure 6 This is a schematic diagram of the overall structure of the present invention. Figure 3 ; Figure 7 for Figure 6 Enlarged view of a section at point D; Figure 8 for Figure 6 Enlarged view of a section at point E in the middle; Figure 9 This is a schematic diagram of the overall structure of the present invention. Figure 4 ; Figure 10 for Figure 9 Enlarged view of a section at point F in the middle; Figure 11 This is a schematic diagram of the valve seat assembly structure of the present invention. Figure 1 ; Figure 12 This is a schematic diagram of the valve seat assembly structure of the present invention. Figure 2 ; Figure 13 This is a schematic diagram of the valve seat assembly structure of the present invention. Figure 3 ; Figure 14 for Figure 13 Enlarged view of a section at point F in the middle; Figure 15 This is a schematic diagram of the support frame structure of the present invention; Figure 16 This is a schematic diagram of the valve seat structure of the present invention; Figure 17 This is a schematic diagram of the cleaning unit structure of the present invention; Explanation of markings in the diagram: 1. Valve body; 2. Valve cover; 3. Connecting frame; 4. Bracket; 5. Handwheel; 6. Shaft; 7. Bearing; 8. Valve stem; 9. Sealing gasket 1; 10. Sealing ring; 11. Lower pressure plate; 12. Packing; 13. Upper pressure plate; 14. Spring 1; 15. Pressure cap; 16. Locking bolt; 17. Slide groove 1; 18. Slide groove 2; 19. Slide groove 3; 20. Slide groove 4; 21. Connecting cylinder frame; 22. Cylindrical chamber; 23. Slide rod; 24. Spring 2; 25. Valve needle body; 26. Valve seat; 27. Sealing gasket 2; 28. Knob; 29. ​​Inner rotating rod; 30. Turntable; 31. Rubber ring; 32. Inner cylinder frame; 33. Spring 3 3; Extrusion plate 34; Pulley 35; Moving frame 36; Spring 4 37; Limiting protrusion 1 38; Limiting protrusion 2 39; Support cylinder 40; Upper protruding edge 41; Inner protruding edge 42; Sealing packing 43; Valve seat protruding edge 44; Groove 45; Filter screen bracket 46; Filter screen protruding edge 47; Filter screen 48; Oblique tooth groove 49; Center wheel 50; Locking block 51; Spring 52; Polygonal column 53; Upper brush 54; Right angle brush 55; Lower brush 56; Spring 6 57; Through hole 58; Columnar groove 59; Center column 60; Limiting plate 61; Protruding plate 62. Detailed Implementation

[0015] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0017] Example 1: As Figures 1-17 As shown, the replaceable valve seat double-seal shut-off valve includes a valve body 1, a valve cover 2 fixedly installed on the upper end of the valve body 1, the valve cover 2 being connected to the handwheel assembly via a connecting bracket 3, the handwheel assembly being threadedly connected to the valve stem 8, a double-seal assembly being provided between the valve cover 2 and the valve stem 8, a valve needle assembly being connected to the lower end of the valve stem 8, the lower end of the valve needle assembly abutting against the valve seat 26, and the valve seat 26 being fixed inside the valve body 1 via a valve seat disassembly and assembly assembly; The working principle of the above technical solution is as follows: By rotating the handwheel assembly, the valve stem 8 is driven to rise or fall, which in turn drives the valve needle assembly to rise or fall, causing the valve needle assembly to separate from or contact the valve seat 26, thereby realizing the opening and closing of the gate valve. The double sealing assembly enhances the sealing between the valve cover 2 and the valve stem 8, preventing fluid leakage from the valve body 1. If the valve seat 26 is damaged, resulting in poor sealing of the gate valve, the valve seat 26 can be removed from the valve body 1 and replaced using the valve seat disassembly and assembly, thereby improving the sealing performance of the gate valve and extending its service life.

[0018] Example 2: Figures 1-17 As shown, the handwheel assembly includes a bracket 4, a valve cover 2 is fixedly connected to the bracket 4 via a connecting frame 3, the bracket 4 is rotatably connected to the rotating shaft 6 via a bearing 7, the upper end of the rotating shaft 6 is fixedly connected to the handwheel 5, and the rotating shaft 6 is threadedly connected to the valve stem 8; A sealing gasket 9 is provided at the fixed connection between the valve body 1 and the valve cover 2; The working principle of the above technical solution is as follows: rotating the handwheel 5 drives the rotating shaft 6 to rotate, which in turn drives the valve stem 8 to rise or fall, and drives the valve needle assembly to rise or fall, thereby realizing the opening and closing of the shut-off valve. The bearing 7 makes the handwheel 5 easier to rotate, making it easier to open or close the valve. The sealing gasket 9 increases the sealing between the valve body 1 and the valve cover 2, preventing fluid leakage from the valve body 1.

[0019] Example 3: Figures 1-17As shown, the dual sealing assembly includes a sealing ring 10, which is pressed into an inclined groove between the valve cover 2 and the valve stem 8 by a lower pressure plate 11. A packing 12 is provided at the upper end of the lower pressure plate 11, and an upper pressure plate 13 is pressed at the upper end of the packing 12. The valve cover 2 is connected to the pressure cover 15 by a locking bolt 16, and a spring 14 is provided between the upper pressure plate 13 and the pressure cover 15. The working principle of the above technical solution is as follows: Under the elastic force of spring 14, the lower pressure plate 11 exerts a downward squeezing force on the sealing ring 10, and the sealing ring 10 is squeezed into the inclined groove. Under the action of the inclined surface of the groove, the sealing ring 10 is tightly attached to the valve stem 8, increasing the sealing performance between the sealing ring 10 and the valve stem 8. The sealing ring 10 and the valve stem 8 form a first seal. Under the elastic force of spring 14, the packing 12 is tightly pressed between the lower pressure plate 11 and the upper pressure plate 13, and the packing 12 and the valve stem 8 form a second seal. Through the above double sealing structure, the sealing performance between the upper end of the valve cover 2 and the valve stem 8 is greatly improved, preventing the fluid in the valve body 1 from leaking out from this point.

[0020] Example 4: Figures 1-17 As shown, the valve needle assembly includes a connecting sleeve 21, which is fixed to the lower end of the valve stem 8. A spring 24 is provided between the connecting sleeve 21 and the valve needle body 25. The valve needle body 25 is fixedly connected to one end of the slide rod 23, and the other end of the slide rod 23 slides in the cylindrical chamber 22 provided at the lower end of the connecting sleeve 21. The lower end of the valve needle body 25 abuts against the valve seat 26. The valve cover 2 is provided with vertical sliding grooves 17, 18, 19 and 20 at equal intervals. The starting positions of sliding grooves 17, 18, 19 and 20 are on the same horizontal line, and their lengths increase sequentially. The limiting protrusion 39 provided on the side of the connecting cylinder 21 slides in the sliding groove 20. The connecting cylinder 21 is provided with four through holes 58 at equal intervals around its circumference. An adjustment component is rotatably connected inside the connecting cylinder 21. The adjustment component is slidably connected to the valve stem 8. The working principle of the above technical solution is as follows: Initially, the front end of the adjusting component passes through the first through hole 58 and is located in the slide groove 20. Turning the handwheel 5 clockwise causes the rotating shaft 6 to rotate clockwise, which in turn causes the valve stem 8 to move down, which in turn causes the connecting sleeve 21 to move down, which in turn causes the limiting protrusion 39 to slide down in the slide groove 20, which in turn causes the valve needle body 25 to move down. The lower end of the valve needle body 25 abuts against the valve seat 26, and the valve needle body 25 stops moving down. The connecting sleeve 21 continues to move down, which causes the spring 24 to be compressed, which causes the slide rod 23 to slide up in the cylindrical chamber 22 until the lower end of the connecting sleeve 21 abuts against the upper end of the valve needle body 25. The valve stem 8 and the connecting sleeve 21 stop descending, and the valve needle body 25 seals the valve seat 26, thus achieving the purpose of closing the valve. Turning the handwheel 5 counterclockwise causes the shaft 6 to rotate counterclockwise, which in turn causes the valve stem 8 to rise, which in turn causes the connecting cylinder 21 to rise, which in turn causes the limiting protrusion 39 to rise in the slide groove 20. Under the elastic force of the spring 24, the valve needle body 25 remains stationary, and the slide rod 23 slides downward in the cylindrical chamber 22 until the slide rod 23 slides to the bottom of the cylindrical chamber 22. The connecting cylinder 21 then causes the slide rod 23 and the valve needle body 25 to move upward, and the valve needle body 25 separates from the valve seat 26. After the connecting cylinder 21 and the valve needle body 25 rise to the preset height, the purpose of opening the valve is achieved. When the shut-off valve is in the open position, the adjusting component rotates 90 degrees within the connecting cylinder 21, with its front end passing through the second through hole 58 and positioned within the slide groove 17. Turning the handwheel 5 clockwise causes the rotating shaft 6 to rotate clockwise, moving the valve stem 8 downwards, which in turn moves the connecting cylinder 21 downwards. This causes the second limiting protrusion 39 to slide down within the slide groove 20, further lowering the valve needle body 25. When the lower end of the valve needle body 25 abuts against the valve seat 26, the front end of the adjusting component slides to the bottom of the slide groove 17, and the adjusting component... The valve body moves downward, preventing the connecting cylinder 21 from descending. When fluid flows forward through the valve body 1, the fluid compresses the valve needle body 25 upward, causing the slide rod 23 to slide upward within the cylindrical chamber 22. The spring 24 is compressed, and after the valve needle body 25 separates from the valve seat 26, fluid can pass through the valve body 1. When fluid flows backward through the valve body 1, the reverse fluid cannot pass through because the lower end of the valve needle body 25 abuts against the valve seat 26, thus converting the shut-off valve into a check valve to adapt to different scenarios. When the shut-off valve is in the open state, the adjusting component rotates 90 degrees again in the connecting sleeve 21. Its front end passes through the third through hole 58 and is located in the slide groove 2 18. Turning the handwheel 5 clockwise drives the rotating shaft 6 to rotate clockwise, which in turn drives the valve stem 8 to move down, which in turn drives the connecting sleeve 21 to move down. This causes the limiting protrusion 2 39 to slide down in the slide groove 4 20, which in turn drives the valve needle body 25 to move down. When the lower end of the valve needle body 25 abuts against the valve seat 26, the connecting sleeve 21 can continue to move down by 10mm. The spring 2 24 is slightly compressed, and the front end of the adjusting component slides to the bottom of the slide groove 2 18. The adjusting component cannot move down. When fluid flows forward in the valve body 1, the fluid needs a large thrust to push the valve needle body 25 upward so that the fluid can pass through the valve body 1. When the valve is in the open state, the adjusting component rotates 90 degrees again within the connecting sleeve 21. Its front end passes through the fourth through hole 58 and is located within the slide groove 19. Turning the handwheel 5 clockwise causes the rotating shaft 6 to rotate clockwise, which in turn causes the valve stem 8 to move down, which in turn causes the connecting sleeve 21 to move down. This causes the limiting protrusion 39 to slide down within the slide groove 20, which in turn causes the valve needle body 25 to move down. When the lower end of the valve needle body 25 abuts against the valve seat 26, the connecting sleeve 21 can continue to move down by 20mm. The spring 24 is compressed again, and the front end of the adjusting component slides to the bottom of the slide groove 19. The adjusting component can no longer move down. When fluid flows forward through the valve body 1, the fluid needs a greater thrust to push the valve needle body 25 upward so that the fluid can pass through the valve body 1. This is suitable for different check valve scenarios.

[0021] Example 5: Figures 1-17 As shown, the adjustment assembly includes an inner cylinder frame 32, which rotates within a connecting cylinder frame 21. A turntable 30 is slidably connected within the inner cylinder frame 32. A rubber ring 31 is fixed to the upper end of the turntable 30. A spring 33 is provided between the lower end of the turntable 30 and the inner cylinder frame 32. A pressing plate 34 is fixed to the lower end of the turntable 30. The pressing plate 34 is rotatably connected to a pulley 35. The pulley 35 rotates within a movable frame 36. The movable frame 36 slides within the inner cylinder frame 32. A spring 4 37 is provided between one end of the movable frame 36 and the inner wall of the inner cylinder frame 32. A limit protrusion 1 38 is fixed to the other end of the movable frame 36. A central column 60 is fixed to the lower end of the inner cylinder frame 32. The central column 60 is rotatably connected to the connecting cylinder frame 21. A limit plate 61 is fixed to the lower end of the central column 60. A cylindrical groove 59 is provided within the sliding rod 23. A protruding plate 62 is provided within the cylindrical groove 59 near the sliding groove 4 20. The turntable 30 is fixedly connected to the lower end of the inner rotating rod 29. The inner rotating rod 29 is slidably connected to the valve stem 8. A knob 28 is fixedly attached to the upper end of the inner rotating rod 29. A directional indicator arrow is provided on the upper end of the knob 28. A sealing packing is provided between the valve stem 8 and the inner rotating rod 29; The working principle of the above technical solution is as follows: Initially, the limiting protrusion 38 passes through the first through hole 58, and its front end is located in the slide groove 20. The front end of the limiting plate 61 abuts against the protrusion 62, so that the slide rod 23 cannot slide in the cylindrical cavity 22. The connecting cylinder 21 and the valve needle body 25 are a whole. By raising or lowering the valve rod 8, the connecting cylinder 21 and the valve needle body 25 are raised or lowered as a whole, so as to achieve the purpose of opening the valve, closing the valve and regulating the flow. When the shut-off valve is in the open position, pressing down on the knob 28 causes the inner rotating rod 29 to slide downward within the valve stem 8, which in turn causes the turntable 30 to slide down within the inner cylinder frame 32. This compresses the spring 33, causing the pressing plate 34 to move downward. The pressing plate 34 then presses the pulley 35 and the moving frame 36 towards the spring 37, compressing the spring 37 and causing the limiting protrusion 38 to retract from the slide groove 20 and the first through hole 58 back into the inner cylinder frame 32. Rotating knob 28 by 90 degrees causes inner rotating rod 29 to rotate by 90 degrees, which in turn causes turntable 30 and inner cylinder frame 32 to rotate by 90 degrees, causing moving frame 36 and limiting protrusion 38 to rotate by 90 degrees, and causing center column 60 and limiting plate 61 to rotate by 90 degrees. Limiting plate 61 separates from protrusion 62, releasing the restriction on the downward pressure of knob 28. Under the elastic force of spring 33, knob 28, inner rotating rod 29, turntable 30 and pressing plate 34 are moved. The valve moves upward, and under the elastic force of spring 37, pulley 35, moving frame 36 and limiting protrusion 38 move forward, causing limiting protrusion 38 to pass through the second through hole 58. Its front end is located in slide groove 17. During the valve closing process of the shut-off valve, when the lower end of the valve needle body 25 abuts against the valve seat 26, the limiting protrusion 38 abuts against the bottom of slide groove 17. Under the limiting action of limiting protrusion 38, the connecting cylinder 21 cannot descend. When fluid flows forward in the valve body 1, the fluid squeezes the valve needle body 25 to move upward, causing slide rod 23 to slide upward in cylindrical chamber 22. Spring 24 is compressed. After the valve needle body 25 separates from the valve seat 26, the fluid can pass through the valve body 1. When fluid flows backward in the valve body 1, the reverse fluid cannot pass through because the lower end of the valve needle body 25 abuts against the valve seat 26. Thus, the shut-off valve is converted into a check valve, increasing the application range of the shut-off valve. When the shut-off valve is in the open state, pressing the knob 28 down again causes the inner rotating rod 29 to slide downward within the valve stem 8, causing the turntable 30 to slide down within the inner cylinder frame 32. Spring 33 is compressed, causing the extrusion plate 34 to move downward. The extrusion plate 34 extrudes the pulley 35 and the moving frame 36 towards the spring 37, compressing the spring 37. This causes the limiting protrusion 38 to retract from the slide groove 20 and the first through hole 58 back into the inner cylinder frame 32. Turning the knob 28 90 degrees again causes the inner rotating rod 29 to rotate 90 degrees again, causing the turntable 30 and the inner cylinder frame 32 to rotate 90 degrees again, and the moving frame 36 and the limiting protrusion 38 to rotate 90 degrees again. This releases the restriction on pressing the knob 28 down, and spring 33... Under the elastic force, the knob 28, inner rotating rod 29, turntable 30 and extrusion plate 34 are moved upward. Under the elastic force of spring 4 37, the pulley 35, moving frame 36 and limiting protrusion 1 38 are moved forward, and the limiting protrusion 1 38 is moved through the third through hole 58. Its front end is located in the slide groove 2 18. During the closing process of the shut-off valve, when the lower end of the valve needle body 25 abuts against the valve seat 26, the connecting cylinder 21 and the limiting protrusion 1 38 continue to move downward by 10mm. The limiting protrusion 1 38 abuts against the bottom of the slide groove 2 18, and the spring 2 24 is slightly compressed. When fluid flows forward in the valve body 1, the fluid needs a large thrust to squeeze the valve needle body 25 to move upward so that the fluid can pass through the valve body 1. The shut-off valve is adjusted to a light pressure check valve. When the shut-off valve is in the open state, pressing the knob 28 down again causes the inner rotating rod 29 to slide downward within the valve stem 8, causing the turntable 30 to slide down within the inner cylinder frame 32. Spring 33 is compressed, causing the extrusion plate 34 to move downward. The extrusion plate 34 extrudes the pulley 35 and the moving frame 36 towards the spring 37, compressing the spring 37. This causes the limiting protrusion 38 to retract from the slide groove 20 and the first through hole 58 back into the inner cylinder frame 32. Turning the knob 28 90 degrees again causes the inner rotating rod 29 to rotate 90 degrees again, causing the turntable 30 and the inner cylinder frame 32 to rotate 90 degrees again, and causing the moving frame 36 and the limiting protrusion 38 to rotate 90 degrees again. This releases the restriction on pressing the knob 28 down. Under the elastic force of the spring 33, the knob 28, inner rotating rod 29, turntable 30, and extrusion plate 35 move downward. 4. Moving upwards, under the elastic force of spring 4 37, pulley 35, moving frame 36 and limiting protrusion 1 38 move forward, causing limiting protrusion 1 38 to pass through the fourth through hole 58, with its front end located in slide groove 3 19. During the valve closing process, when the lower end of valve needle body 25 abuts against valve seat 26, connecting cylinder 21 and limiting protrusion 1 38 continue to move downwards by 20mm, limiting protrusion 1 38 abuts against the bottom of slide groove 3 19, and spring 2 24 is compressed again. When fluid flows forward in the valve body 1, the fluid needs a large thrust to push valve needle body 25 upwards so that the fluid can pass through the valve body 1. The shut-off valve is adjusted to a high-pressure check valve. By adjusting the downward height of connecting cylinder 21, the shut-off valve can be quickly switched between ordinary check valve, light-pressure check valve and high-pressure check valve to adapt to different scenarios.

[0022] Example 6: Figures 1-17 As shown, the valve seat assembly includes a support cylinder 40, which is slidably inserted into the valve body 1. The lower end of the support cylinder 40 is fixedly connected to the valve body 1 by screws. An upper protrusion 41 is fixed to the upper end of the support cylinder 40, and a valve seat protrusion 44 is fixed to the lower end of the valve seat 26. A groove 45 is provided inside the valve seat 26. The upper protrusion 41 slides from between the valve seat 26 and the valve seat protrusion 44 into the groove 45. A sealing gasket 27 is provided between the valve body 1 and the valve seat 26. An inner protrusion 42 is provided inside the support cylinder 40, and the inner protrusion 42 is engaged with the filter assembly. The working principle of the above technical solution is as follows: the valve seat 26 is placed on the upper end of the support cylinder 40, the valve seat 26 is rotated, and the upper protrusion 41 on the support cylinder 40 is engaged between the valve seat 26 and the valve seat protrusion 44. The support cylinder 40 and the valve seat 26 are inserted into the valve body 1 as a whole. Under the thrust of the support cylinder 40, the upper protrusion 41 is engaged into the groove 45 to prevent the support cylinder 40 and the valve seat 26 from rotating after the valve seat 26 is installed in place.

[0023] Example 7: Figures 1-17As shown, the filter assembly includes a filter support 46, a filter protrusion 47 is fixed on the filter support 46, an inner protrusion 42 is engaged between the filter support 46 and the filter protrusion 47, a filter 48 is fixed inside the filter support 46, and the filter 48 is rotatably connected to the cleaning unit. The cleaning unit includes a central wheel 50, which rotates at the center of a filter screen 48. The filter screen 48 has a slanted toothed groove 49. The central wheel 50 is rotatably connected to one end of a locking block 51, and the other end of the locking block 51 is engaged in the slanted toothed groove 49. A spring 52 is provided between the locking block 51 and the central wheel 50. The central wheel 50 is slidably connected to a polygonal column 53. The upper end of the polygonal column 53 is fixedly connected to an upper brush 54. The upper brush 54 is fixedly connected to a right-angle brush 55. The polygonal column 53 is slidably connected to a lower brush 56. A spring 57 is provided between the lower end of the polygonal column 53 and the lower brush 56. A sealing filler 43 is provided at the slidable connection between the lower end of the polygonal column 53 and the support frame 40. The filter screen 48 has multiple reinforcing ribs on its upper and lower surfaces; The working principle of the above technical solution is as follows: When the polygonal column 53 is pulled down, the polygonal column 53 slides with the central wheel 50. The upper brush 54 at the upper end of the polygonal column 53 presses against the upper end of the filter screen 48. When the polygonal column 53 is rotated clockwise, the central wheel 50 rotates clockwise at the center of the filter screen 48. The locking block 51 is slidably connected with the oblique tooth groove 49. The upper brush 54 follows the rotation of the polygonal column 53 and brushes the upper end of the filter screen 48. Push the polygonal column 53 upwards, and the polygonal column 53 slides with the center wheel 50. The upper brush 54 at the upper end of the polygonal column 53 moves upwards and separates from the filter screen 48. The lower brush 56 moves upwards and contacts the lower end of the filter screen 48. Continue to push the polygonal column 53 upwards, and the lower brush 56 slides with the polygonal column 53. The spring 6 57 is compressed. The right-angle brush 55 on the upper brush 54 contacts the bottom of the valve needle body 25 and the inner side of the valve seat 26. Rotate the polygonal column 53 clockwise, which drives the center wheel 50 to rotate clockwise at the center position of the filter screen 48. The locking block 51 slides with the oblique tooth groove 49. The right-angle brush 55 and the lower brush 56 follow the rotation of the polygonal column 53. The lower brush 56 brushes the lower end of the filter screen 48, and the right-angle brush 55 brushes the bottom of the valve needle body 25 and the inner side of the valve seat 26. When the polygonal column 53 is rotated counterclockwise, the center wheel 50 rotates counterclockwise at the center of the filter screen 48, causing the front end of the locking block 51 to engage in the oblique tooth groove 49, which in turn causes the filter screen bracket 46 and the filter screen 48 to rotate as a whole. This causes the filter screen protrusion 47 to rotate with the filter screen bracket 46, and causes the inner protrusion 42 to separate from the filter screen bracket 46 and the filter screen protrusion 47. This allows the support cylinder 40 to be separated from the filter screen bracket 46, making it easier to maintain or replace the filter screen 48. In addition, when the filter screen 48 is severely clogged inside the valve body 1, the polygonal column 53 can be rotated counterclockwise to separate the support cylinder 40 from the filter screen bracket 46. Then, the polygonal column 53 can be pulled down to move the filter screen bracket 46 and the filter screen 48 downwards. The filter screen 48 can sink to the bottom of the support cylinder 40, which facilitates the flow of fluid inside the valve body 1 and avoids accidents caused by the filter screen 48 being clogged.

[0024] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A double-seal shut-off valve with replaceable valve seat, characterized in that, The valve body (1) is fixedly mounted on the upper end of the valve body (1). The valve cover (2) is connected to the handwheel assembly through the connecting bracket (3). The handwheel assembly is threadedly connected to the valve stem (8). A double sealing assembly is provided between the valve cover (2) and the valve stem (8). A valve needle assembly is connected to the lower end of the valve stem (8). The lower end of the valve needle assembly abuts against the valve seat (26). The valve seat (26) is fixed inside the valve body (1) through the valve seat disassembly assembly.

2. The replaceable seat double-seal shut-off valve according to claim 1, characterized in that, The handwheel assembly includes a bracket (4), a valve cover (2) is fixedly connected to the bracket (4) via a connecting frame (3), the bracket (4) is rotatably connected to the rotating shaft (6) via a bearing (7), the upper end of the rotating shaft (6) is fixedly connected to the handwheel (5), and the rotating shaft (6) is threadedly connected to the valve stem (8).

3. The replaceable seat double-seal shut-off valve according to claim 2, characterized in that, The dual sealing assembly includes a sealing ring (10), which is pressed into the inclined groove between the valve cover (2) and the valve stem (8) by the lower pressure plate (11). The upper end of the lower pressure plate (11) is provided with packing (12), and the upper end of the packing (12) is pressed with an upper pressure plate (13). The valve cover (2) is connected to the pressure cap (15) by locking bolts (16), and a spring (14) is provided between the upper pressure plate (13) and the pressure cap (15).

4. The replaceable seat double-seal shut-off valve according to claim 3, characterized in that, The valve needle assembly includes a connecting sleeve (21), which is fixed to the lower end of the valve stem (8). A spring (24) is provided between the connecting sleeve (21) and the valve needle body (25). The valve needle body (25) is fixedly connected to one end of the slide rod (23), and the other end of the slide rod (23) slides in the cylindrical cavity (22) provided at the lower end of the connecting sleeve (21). The lower end of the valve needle body (25) abuts against the valve seat (26).

5. The replaceable seat double-seal shut-off valve according to claim 4, characterized in that, The valve cover (2) is provided with vertical grooves 1 (17), 2 (18), 3 (19) and 4 (20) at equal intervals. The starting positions of grooves 1 (17), 2 (18), 3 (19) and 4 (20) are on the same horizontal line, and their lengths increase sequentially. The limiting protrusion 2 (39) provided on the side of the connecting cylinder (21) slides in the groove 4 (20). The connecting cylinder (21) is provided with four through holes (58) at equal intervals around its circumference. An adjustment component is rotatably connected inside the connecting cylinder (21). The adjustment component is slidably connected to the valve stem (8).

6. The replaceable seat double-seal shut-off valve according to claim 5, characterized in that, The adjusting assembly includes an inner cylinder frame (32), which rotates within a connecting cylinder frame (21). A turntable (30) is slidably connected within the inner cylinder frame (32). A rubber ring (31) is fixed to the upper end of the turntable (30). A spring (33) is provided between the lower end of the turntable (30) and the inner cylinder frame (32). A pressing plate (34) is fixed to the lower end of the turntable (30). The pressing plate (34) is rotatably connected to a pulley (35). The pulley (35) rotates within a movable frame (36), and the movable frame (36) slides. Inside the inner tube frame (32), a spring four (37) is provided between one end of the movable frame (36) and the inner wall of the inner tube frame (32), and a limit protrusion one (38) is fixed at the other end of the movable frame (36). A central column (60) is fixed at the lower end of the inner tube frame (32). The central column (60) is rotatably connected to the connecting tube frame (21). A limit plate (61) is fixed at the lower end of the central column (60). A cylindrical groove (59) is provided inside the slide rod (23). A protrusion plate (62) is provided on the side of the cylindrical groove (59) near the slide groove four (20).

7. The replaceable seat double-seal shut-off valve according to claim 6, characterized in that, The turntable (30) is fixedly connected to the lower end of the inner rotating rod (29), and the inner rotating rod (29) is slidably connected to the valve stem (8). A knob (28) is fixed at the upper end of the inner rotating rod (29), and a direction indicator arrow is provided at the upper end of the knob (28).

8. The replaceable seat double-seal shut-off valve according to claim 7, characterized in that, The valve seat assembly includes a support cylinder (40), which is slidably inserted into the valve body (1). The lower end of the support cylinder (40) is fixedly connected to the valve body (1) by screws. The upper end of the support cylinder (40) is fixed with an upper protrusion (41), and the lower end of the valve seat (26) is fixed with a valve seat protrusion (44). The valve seat (26) is provided with a groove (45). The upper protrusion (41) slides from between the valve seat (26) and the valve seat protrusion (44) into the groove (45). A sealing gasket (27) is provided between the valve body (1) and the valve seat (26). The support cylinder (40) is provided with an inner protrusion (42), which is engaged with the filter assembly.

9. The replaceable seat double-seal shut-off valve according to claim 8, characterized in that, The filter assembly includes a filter support (46), on which a filter protrusion (47) is fixed. An inner protrusion (42) is engaged between the filter support (46) and the filter protrusion (47). A filter (48) is fixed inside the filter support (46), and the filter (48) is rotatably connected to the cleaning unit.

10. The replaceable seat double-seal shut-off valve according to claim 9, characterized in that, The cleaning unit includes a center wheel (50), which rotates at the center of the filter screen (48). The filter screen (48) is provided with a slanted tooth groove (49). The center wheel (50) is rotatably connected to one end of a locking block (51), and the other end of the locking block (51) is locked in the slanted tooth groove (49). A spring five (52) is provided between the locking block (51) and the center wheel (50). The center wheel (50) is slidably connected to a polygonal column (53). The upper end of the polygonal column (53) is fixedly connected to an upper brush (54). The upper brush (54) is fixedly connected to a right-angle brush (55). The polygonal column (53) is slidably connected to a lower brush (56). A spring six (57) is provided between the lower end of the polygonal column (53) and the lower brush (56). A sealing filler (43) is provided at the sliding connection between the lower end of the polygonal column (53) and the support frame (40).

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