A shut-off check control valve

Abstract

The application relates to a stop check control valve, which comprises a valve body, an inlet channel and an outlet channel arranged in the valve body, a valve cavity arranged in the valve body and communicating with the inlet channel and the outlet channel, a valve head arranged in the valve cavity and moving in the valve cavity in the direction of approaching and leaving the inlet channel, a positioning hole arranged in one end of the valve head and accommodating a sealing gasket, the positioning hole being provided with the sealing gasket for stopping the inlet channel and the outlet channel, a valve disc arranged in the valve cavity and having one end extending into the inlet channel and being in sliding connection with the inlet channel, an outer taper surface arranged at one end of the valve disc and matched with the sealing gasket, and a stud extending into the valve head and being in threaded connection with the valve head. The outer taper surface of the valve disc is used to radially extrude the sealing gasket, the material of the sealing gasket is pressed into the annular groove of the valve head due to the radial plastic deformation, the sealing between the valve head and the sealing gasket is realized due to the extrusion force, and the axial fixation of the sealing gasket is realized.

Description

Technical Field

[0001] This application relates to the field of shut-off valve technology, and in particular to a shut-off check valve. Background Technology

[0002] High-pressure air shut-off check valves have long suffered from issues such as easy damage to the main sealing surface, excessive operating force, and insufficient reliability of the check seal, all of which require further solutions. Hard-seal high-pressure air shut-off check valves have lower operating forces but lower resistance to contamination. When the cleanliness of the medium is not high, the main sealing surface is easily damaged, and the reliability of the check seal is insufficient.

[0003] Existing soft-seal high-pressure air shut-off check valves offer high resistance to contamination, but the gaskets are typically assembled using molding or pressing processes, making it difficult to ensure gasket assembly quality, resulting in low yield and poor maintainability. Because soft-seal gaskets have a lower allowable sealing specific pressure, the sealing surface is usually wider, leading to higher valve operating forces and insufficient check seal reliability. Summary of the Invention

[0004] This application provides a shut-off check valve to solve the problems in related technologies where the sealing gasket is usually assembled by molding or pressing, which makes it difficult to ensure the assembly quality of the sealing gasket, and results in a low yield and poor maintainability.

[0005] This application provides a shut-off check valve, comprising:

[0006] The valve body has an inlet channel and an outlet channel, and the valve body also has a valve cavity that connects the inlet channel and the outlet channel;

[0007] A valve head is located within a valve cavity and moves within the valve cavity in a direction approaching and away from the inlet channel. The end of the valve head approaching the inlet channel is provided with a positioning hole for accommodating a sealing gasket, and a sealing gasket that blocks the inlet channel and the outlet channel is provided in the positioning hole.

[0008] The valve disc is located inside the valve cavity and one end extends into the inlet channel and is slidably connected to the inlet channel. The end of the valve disc away from the inlet channel is provided with an outer conical surface that mates with the sealing gasket, and a stud that extends into the valve head and is threadedly connected to the valve head.

[0009] In some embodiments: the sealing gasket is an annular flexible gasket, and the inner hole of the sealing gasket is provided with an inner conical surface that mates with the outer conical surface;

[0010] The positioning hole has multiple annular protrusions or annular grooves on its wall that mate with the outer wall of the sealing gasket.

[0011] In some embodiments: one end of the inlet channel near the valve cavity is provided with an annular sealing surface extending into the valve cavity, and the annular sealing surface is sealed to the sealing gasket;

[0012] The valve disc has a guide hole at one end that extends into the inlet channel to allow the medium in the inlet channel to enter the valve cavity.

[0013] In some embodiments, the valve head is further included as a lower valve stem that drives the valve head to move within the valve cavity in a direction approaching and away from the inlet passage, the top of the lower valve stem extending outside the valve body;

[0014] The valve head is a hollow cylindrical structure. The valve head has a first shoulder that cooperates with the lower valve stem. The bottom of the lower valve stem is slidably connected to the valve head and has a first shoulder that abuts against the first shoulder.

[0015] In some embodiments, a bushing fixed to the valve body and sealing the valve cavity is also included, the bushing being slidably and sealingly connected to the lower valve stem;

[0016] An elastic element is provided between the bushing and the valve head to elastically drive the valve head to move toward the inlet channel;

[0017] The bushing is sealed to the inner wall of the valve cavity, and an annular spring seat plate is provided between the elastic element and the bushing.

[0018] In some embodiments: a balance piston is slidably and sealingly connected inside the bushing, the balance piston abuts against the valve head, and the lower valve stem is slidably and sealingly connected to the balance piston on the same axis;

[0019] The balance piston and the bushing form a closed balance chamber, and the valve disc and the lower valve stem are provided with balance channels to allow the medium in the inlet channel to enter the balance chamber.

[0020] In some embodiments: the lower valve stem is provided with a second shoulder at one end near the first shoulder, which abuts against the balance piston, and the outer diameter of the second shoulder is smaller than the outer diameter of the first shoulder;

[0021] The second shoulder is slidably sealed to the valve head, and a gap is preset between the first shoulder and the first shoulder to allow the valve head to move in the direction of approaching and moving away from the inlet channel.

[0022] In some embodiments, a valve bracket is further included to fix the bushing to the valve body, the valve bracket being fixed to the valve body by a double-ended bolt;

[0023] The valve frame is slidably provided with a middle valve stem that connects to the lower valve stem, and the top of the lower valve stem is provided with a T-shaped head that connects to the middle valve stem;

[0024] An anti-rotation boss is fixedly provided on the side wall of the middle valve stem, and a positioning groove for sliding connection of the anti-rotation boss is provided on the valve frame along the axial direction of the middle valve stem.

[0025] The valve frame is also provided with an upper valve stem that is threadedly connected to the middle valve stem. The top of the upper valve stem extends out of the valve frame and is connected to a handwheel.

[0026] In some embodiments: the upper valve stem is provided with a screw threadedly connected to the middle valve stem at one end away from the handwheel, and the middle valve stem is provided with a threaded hole connected to the screw at one end;

[0027] A third shoulder is fixedly provided on the side wall of the upper valve stem, and a second shoulder with an inner diameter smaller than the outer diameter of the third shoulder is provided inside the valve frame. The second shoulder is located below the third shoulder.

[0028] A first thrust bearing is provided between the second shoulder and the third shoulder, and a second thrust bearing is provided at the top of the third shoulder.

[0029] In some embodiments: a locking nut is threaded to the top of the upper valve stem, a gasket and a first wave spring are provided between the locking nut and the second thrust bearing, and a second wave spring is provided between the first thrust bearing and the third shoulder;

[0030] The top of the upper valve stem is provided with a square prism for connecting the handwheel. The top of the upper valve stem is also provided with a cap-shaped nut for fixing the handwheel to the upper valve stem. A washer is provided between the cap-shaped nut and the handwheel. A cylindrical pin for connecting the upper valve stem is also provided on the cap-shaped nut.

[0031] The beneficial effects of the technical solution provided in this application include:

[0032] This application provides a shut-off check valve. The shut-off check valve includes a valve body with an inlet channel and an outlet channel, and a valve cavity connecting the inlet and outlet channels. A valve head is located within the valve cavity and moves towards and away from the inlet channel. The end of the valve head near the inlet channel has a positioning hole for accommodating a sealing gasket, and the positioning hole contains a sealing gasket that shuts off the inlet and outlet channels. A valve disc is located within the valve cavity, with one end extending into the inlet channel and slidingly connected to it. The end of the valve disc away from the inlet channel has an outer conical surface that mates with the sealing gasket, and a stud that extends into the valve head and is threadedly connected to it.

[0033] Therefore, the shut-off check valve of this application has a positioning hole on the valve head to accommodate the sealing gasket, and the sealing gasket is assembled onto the valve head using a valve disc. When the sealing gasket is assembled into the positioning hole of the valve head, the stud of the valve disc is threadedly connected to the valve head, and the outer conical surface of the valve disc radially compresses the sealing gasket, causing the material of the sealing gasket to be pressed into the annular groove of the valve head due to radial plastic deformation. This achieves a seal between the valve head and the sealing gasket due to the compressive force, thus realizing the axial fixation of the sealing gasket. Compared with sealing gaskets assembled by molding or pressing processes, the assembly quality of this application is controllable, the yield is high, and the maintainability is good. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of an embodiment of this application;

[0036] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0037] Figure 3 for Figure 1 A magnified view of a section at point B in the middle;

[0038] Figure 4 for Figure 1 A magnified view of a section at point C;

[0039] Figure 5 This is a schematic diagram of the valve head structure according to an embodiment of this application;

[0040] Figure 6 for Figure 5 A magnified view of a section at point D;

[0041] Figure 7 This is a schematic diagram of the valve disc structure in an embodiment of this application;

[0042] Figure 8 This is a schematic diagram of the sealing gasket structure according to an embodiment of this application;

[0043] Figure 9 This is a schematic diagram of the valve stem structure in an embodiment of this application;

[0044] Figure 10 This is a schematic diagram of the valve stem structure in an embodiment of this application;

[0045] Figure 11 This is a cross-sectional view of the valve stem in an embodiment of this application;

[0046] Figure 12 This is a top view of the valve stem structure in an embodiment of this application.

[0047] Figure label:

[0048] 1. Valve body; 2. Inlet channel; 3. Outlet channel; 4. Valve cavity; 5. Valve head; 6. Valve disc; 7. Sealing gasket; 8. Lower valve stem; 9. Bushing; 10. Elastic element; 11. Annular spring seat plate; 12. Balance piston; 13. Clearance; 14. Balance chamber; 15. First seal; 16. Second seal; 17. Valve frame; 18. Double-ended bolt; 19. Positioning groove; 20. Middle valve stem; 21. Upper valve stem; 22. Second thrust bearing; 23. First thrust bearing; 24. Second wave spring; 25. First wave spring; 26. Gasket; 27. Locking element 28. Nut; 29. ​​Handwheel; 30. Washer; 31. Cap nut; 32. Annular sealing surface; 33. Third seal; 34. Fourth seal; 35. Locating hole; 36. Internal thread; 37. First shoulder; 38. Annular groove; 49. Inner conical surface; 40. Guide hole; 41. Outer conical surface; 42. Stud; 43. First balance channel; 44. First shoulder; 45. Second shoulder; 46. Second balance channel; 47. T-head; 48. Screw; 49. Third shoulder; 50. Square prism; 51. Anti-rotation boss; 52. Threaded hole; 53. T-slot. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] This application provides a shut-off check valve that solves the problems in related technologies where the sealing gasket is usually assembled using molding or encapsulation processes, which makes it difficult to ensure the assembly quality of the sealing gasket, and results in low yield and poor maintainability.

[0051] See Figure 1 , Figures 4 to 8 As shown, this application embodiment provides a shut-off check valve, including:

[0052] The valve body 1 has an inlet channel 2 and an outlet channel 3, which are perpendicular to each other. The valve body 1 also has a valve cavity 4 connecting the inlet channel 2 and the outlet channel 3, with the axis of the valve cavity 4 collinear with the axis of the inlet channel 2. A valve head 5, a valve disc 6, and a sealing gasket 7 are installed in the valve cavity 4 to control the connection and disconnection between the inlet channel 2 and the outlet channel 3.

[0053] A valve head 5 is located within a valve cavity 4 and moves within the cavity towards and away from the inlet channel 2. A positioning hole 34 for accommodating a sealing gasket 7 is provided at the end of the valve head 5 closest to the inlet channel 2. The sealing gasket 7, which blocks the flow between the inlet channel 2 and the outlet channel 3, is located within the positioning hole 34. As the sealing gasket 7 moves with the valve head 5 towards the inlet channel 2, it reduces the flow area between the inlet channel 2 and the outlet channel 3.

[0054] The valve disc 6 is located within the valve cavity 4, with one end extending into and slidably connected to the inlet channel 2. The end of the valve disc 6 away from the inlet channel 2 has an outer conical surface 40 that mates with the sealing gasket 7, and a stud 41 that extends into and is threadedly connected to the valve head 5. The slidable connection of one end of the valve disc 6 to the inlet channel 2 provides movement guidance for the valve head 5. The valve disc 6 is threadedly connected to the valve head 5 via the stud 41 to fix the sealing gasket 7 onto the valve head 5.

[0055] The valve disc 6 has an outer conical surface 40 that mates with the sealing gasket 7. The diameter of the outer conical surface 40 gradually increases in the direction away from the valve head 5, so that after the sealing gasket 7 is fitted onto the outer conical surface 40 and threadedly fastened to the valve head 5 by the stud 41, the outer conical surface 40 reliably connects the sealing gasket 7 to the valve head 5 by pressing it axially and radially. The sealing gasket 7 facilitates assembly, maintenance, and replacement, thus improving the service life of the control valve.

[0056] The shut-off check valve of this application embodiment has a positioning hole 34 on the valve head 5 to accommodate the sealing gasket 7, and the sealing gasket 7 is assembled onto the valve head 5 using the valve disc 6. When the sealing gasket 7 is assembled into the positioning hole 34 of the valve head 5, the stud 41 of the valve disc 6 is threadedly fixed to the valve head 5, and the outer conical surface 40 of the valve disc 6 radially compresses the sealing gasket 7, causing the material of the sealing gasket 7 to be pressed into the annular groove 37 of the valve head 5 due to radial plastic deformation, thereby achieving a seal between the valve head 5 and the sealing gasket 7 due to the compressive force, and realizing the axial fixation of the sealing gasket 7.

[0057] In some alternative embodiments: see Figure 1 , Figures 4 to 8As shown in the figure, this application embodiment provides a shut-off check valve. The sealing gasket 7 of the shut-off check valve is an annular flexible gasket, and the inner hole of the sealing gasket 7 is provided with an inner conical surface 38 that mates with the outer conical surface 40. The positioning hole 34 has a plurality of annular protrusions or annular grooves 37 that mate with the outer wall of the sealing gasket 7. The annular protrusions or annular grooves 37 increase the friction between the hole walls of the positioning hole 34 of the sealing gasket 7 and improve the structural stability between the sealing gasket 7 and the valve head 5.

[0058] An annular sealing surface 31 extending into the valve cavity 4 is provided at one end of the inlet channel 2 near the valve cavity 4. The annular sealing surface 31 is used for sealing connection with the sealing gasket 7. When the annular sealing surface 31 is used for sealing connection with the sealing gasket 7, it blocks the inlet channel 2 and the outlet channel 3. A guide hole 39 is provided at one end of the valve disc 6 near the inlet channel 2 to allow the medium in the inlet channel 2 to enter the valve cavity 4. The guide hole 39 includes an axial hole communicating with the inlet channel 2 and a plurality of radial holes located around the axial hole.

[0059] The sealing gasket 7 in this embodiment has an inner conical surface 38 that mates with the outer conical surface 40. The inner diameter of the inner conical surface 38 gradually increases in the direction approaching the valve head 5. The inner conical surface 38 and the outer conical surface 40 cooperate with each other to restrict the sealing gasket 7 from sliding on the valve disc 6. The positioning hole 34 has a plurality of annular protrusions or annular grooves 37 that mate with the outer wall of the sealing gasket 7 to increase the friction between the sealing gasket 7 and the valve head 5 and restrict the sealing gasket 7 from sliding on the valve head 5.

[0060] The valve disc 6 has a guide hole 39 at one end near the inlet channel 2 to allow the medium in the inlet channel 2 to enter the valve cavity 4. When the guide hole 39 of the valve disc 6 is completely located in the inlet channel 2, the guide hole 39 is blocked by the inlet channel 2. At this time, the valve disc 6 has largely blocked the medium from entering the valve cavity 4 from the inlet channel 2.

[0061] To further improve the sealing performance between the valve disc 6 and the inlet channel 2, an annular sealing surface 31 is provided at one end of the inlet channel 2 near the valve cavity 4, which is sealed and connected to the sealing gasket 7. When the annular sealing surface 31 and the sealing gasket 7 are pressed together, the medium in the inlet channel 2 is completely blocked from entering the valve cavity 4, thus improving the sealing performance of the shut-off check valve.

[0062] In some alternative embodiments: see Figure 1 and Figure 9 As shown, this application embodiment provides a shut-off check valve, which further includes a lower valve stem 8 that drives the valve head 5 to move in the valve chamber 4 in a direction approaching and away from the inlet channel 2, with the top of the lower valve stem 8 extending outside the valve body 1.

[0063] The valve head 5 is a hollow cylindrical structure extending vertically. Inside the valve head 5, there is a first shoulder 36 that mates with the lower valve stem 8, and an internal thread 35 that is threaded to the stud 41. The bottom of the lower valve stem 8 is slidably connected to the valve head 5 and has a first shoulder 43 that abuts against the first shoulder 36. The lower valve stem 8 drives the valve head 5 and the valve disc 6 to move vertically up and down through vertical movement.

[0064] When the valve stem 8 moves downwards, causing the valve head 5 and valve disc 6 to move closer to the inlet channel 2, the guide hole 39 of the valve disc 6 gradually enters the inlet channel 2. When the guide hole 39 is completely within the inlet channel 2, it is blocked, achieving most of the throttling. When the sealing gasket 7 presses against the annular sealing surface 31, it completely blocks the medium in the inlet channel 2 from entering the valve chamber 4, thus achieving the closing action of the check valve.

[0065] When the valve stem 8 moves upward, causing the valve head 5 and valve disc 6 to move away from the inlet channel 2, the sealing gasket 7 disengages from the annular sealing surface 31, and a small portion of the medium in the inlet channel 2 begins to enter the valve chamber 4. As the guide hole 39 of the valve disc 6 gradually slides out of the inlet channel 2, the guide hole 39 is opened by the inlet channel 2 to increase the amount of medium entering the valve chamber 4, thus realizing the opening action of the shut-off check valve.

[0066] In some alternative embodiments: see Figure 1 As shown, this application embodiment provides a shut-off check valve, which further includes a bushing 9 fixed to the valve body 1 and sealing the valve cavity 4. The bushing 9 is slidably and sealingly connected to the lower valve stem 8. An elastic element 10 is provided between the bushing 9 and the valve head 5 to elastically drive the valve head 5 to move towards the inlet channel 2. The bushing 9 is sealed to the inner wall of the valve cavity 4, and an annular spring seat plate 11 is provided between the elastic element 10 and the bushing 9.

[0067] In this embodiment, a bushing 9 is fixedly provided on the valve body 1 to seal the valve cavity 4. The bushing 9 extends into the valve cavity 4, and the bushing 9 makes the valve cavity 4 form a sealed cavity. When the medium pressure in the valve cavity 4 is greater than the medium pressure in the inlet channel 2, the medium in the valve cavity 4 pushes the valve head 5, the sealing gasket 7 and the valve disc 6 to close the inlet channel 2.

[0068] An elastic element 10 is provided between the bushing 9 and the valve head 5 to elastically drive the valve head 5 to move toward the inlet channel 2. The elastic element 10 is used to push the valve head 5, the sealing gasket 7 and the valve disc 6 to quickly close the inlet channel 2 when the medium pressure in the valve chamber 4 is greater than the medium pressure in the inlet channel 2. On the other hand, it reduces the operating force of the lower valve stem 8.

[0069] In some alternative embodiments: see Figure 1 , Figure 3 , Figure 7 and Figure 9As shown, this application embodiment provides a shut-off check valve. A balance piston 12 is slidably and sealingly connected inside the bushing 9 of the shut-off check valve. The balance piston 12 is located at the top of the valve head 5 and abuts against the valve head 5. The lower valve stem 8 is coaxially and slidably and sealingly connected to the balance piston 12.

[0070] A closed balance chamber 14 is formed between the balance piston 12 and the bushing 9. Balance channels are provided on the valve disc 6 and the lower valve stem 8 to allow the medium in the inlet channel 2 to enter the balance chamber 14. The balance channels include a first balance channel 42 provided on the valve disc 6 and a second balance channel 45 provided on the lower valve stem 8. The first balance channel 42 and the second balance channel 45 are interconnected.

[0071] In this embodiment, a balance piston 12 is slidably and sealingly connected inside the bushing 9. A closed balance chamber 14 is formed between the balance piston 12 and the bushing 9. The balance chamber 14 is connected to the inlet channel 2 through the balance channel. The medium located in the inlet channel 2 enters the balance chamber 14 through the balance channel and pushes the balance piston 12 down to press down the valve head 5, thereby reducing the operating force of the lower valve stem 8 and realizing the rapid closing action of the shut-off check valve.

[0072] To improve the sealing performance between the bushing 9 and the balance piston 12, a fourth seal 33 is provided between the bushing 9 and the balance piston 12. To improve the sealing performance between the bushing 9 and the inner wall of the valve cavity 4, a third seal 32 is provided between the bushing 9 and the inner wall of the valve cavity 4. To improve the sealing performance between the balance piston 12 and the lower valve stem 8, a first seal 15 is provided between the balance piston 12 and the lower valve stem 8.

[0073] In some alternative embodiments: see Figure 1 , Figure 5 and Figure 9 As shown in the embodiment of this application, a shut-off check valve is provided. The lower valve stem 8 of this shut-off check valve has a second shoulder 44 at one end near the first shoulder 43, which abuts against the balance piston 12. The outer diameter of the second shoulder 44 is smaller than the outer diameter of the first shoulder 43. The second shoulder 44 is slidably sealed to the valve head 5. A gap 13 is pre-set between the first shoulder 43 and the first shoulder 36 to allow the valve head 5 to move in directions approaching and away from the inlet channel 2.

[0074] In this embodiment, a second shoulder 44 is provided on the lower valve stem 8 near the first shoulder 43, which abuts against the balance piston 12. When the shut-off check valve is opened, the lower valve stem 8 uses the second shoulder 44 to drive the balance piston 12 upward, so that the balance piston disengages from the valve head 5. The medium in the inlet channel 2 pushes the valve head 5, valve disc 6, and sealing gasket 7 to move away from the inlet channel 2, thereby connecting the inlet channel 2 and the outlet channel 3.

[0075] A gap 13 is preset between the first shoulder 43 and the first shoulder 36 to allow the valve head 5 to move in the direction of approaching and moving away from the inlet channel 2. This gap 13 is used to automatically shut off the valve head 5, valve disc 6 and sealing gasket 7 when the medium pressure in the valve chamber 4 is greater than the medium pressure in the inlet channel 2, by having the medium in the valve chamber 4 push the medium in the valve chamber 4 to move in the direction of approaching the inlet channel 2.

[0076] When the medium pressure in valve chamber 4 is less than the medium pressure in inlet channel 2, the medium in inlet channel 2 pushes valve head 5, valve disc 6 and sealing gasket 7 to move away from inlet channel 2 to achieve automatic opening.

[0077] To improve the sealing performance between the valve head 5 and the lower valve stem 8, a second seal 16 is provided between the valve head 5 and the second shoulder 44. To improve the sealing performance between the bushing 9 and the lower valve stem 8, a fifth seal is provided between the bushing 9 and the lower valve stem 8.

[0078] In some alternative embodiments: see Figure 1 , Figure 2 , Figures 9 to 12 As shown, this application embodiment provides a shut-off check valve, which further includes a valve frame 17 for fixing a bushing 9 to a valve body 1. The valve frame 17 is fixed to the valve body 1 by a double-ended bolt 18.

[0079] A middle valve stem 20, which connects to the lower valve stem 8, is slidably mounted inside the valve frame 17. A T-shaped head 46, which connects to the middle valve stem 20, is located at the top of the lower valve stem 8. A T-shaped groove 52, which connects to the T-shaped head 46, is located at the bottom of the middle valve stem 20. The middle valve stem 20 drives the lower valve stem 8 to move up and down.

[0080] An anti-rotation boss 50 is fixedly provided on the side wall of the middle valve stem 20, and a positioning groove 19 for sliding connection of the anti-rotation boss 50 is provided on the valve frame 17 along the axial direction of the middle valve stem 20. An upper valve stem 21 is also provided inside the valve frame 17 and is threadedly connected to the middle valve stem 20. The top of the upper valve stem 21 extends out of the valve frame 17 and is connected to a handwheel 28.

[0081] The upper valve stem 21 has a screw 47 at the end away from the handwheel 28, which is threadedly connected to the middle valve stem 20. The middle valve stem 20 has a threaded hole 51 at one end, which is connected to the screw 47. The screw 47 of the upper valve stem 21 is threadedly connected to the threaded hole 51 of the middle valve stem 20, which converts the rotational motion of the upper valve stem 21 into linear motion that drives the lower valve stem 8 to rise and fall.

[0082] A third shoulder 48 is fixedly provided on the side wall of the upper valve stem 21. A second shoulder with an inner diameter smaller than the outer diameter of the third shoulder 48 is provided inside the valve holder 17, and the second shoulder is located below the third shoulder 48. A first thrust bearing 23 is provided between the second shoulder and the third shoulder 48, and a second thrust bearing 22 is provided at the top of the third shoulder 48. The second shoulder and the third shoulder 48 restrict the axial movement of the upper valve stem 21.

[0083] A locking nut 27 is threaded onto the top of the upper valve stem 21. A gasket 26 and a first wave spring 25 are provided between the locking nut 27 and the second thrust bearing 22. A second wave spring 24 is provided between the first thrust bearing 23 and the third shoulder 48. The first wave spring 25 and the second wave spring 24 elastically support the first thrust bearing 23 and the second thrust bearing 22 in close contact with the second shoulder.

[0084] The top of the upper valve stem 21 is provided with a square prism 49 for connecting the handwheel 28. The top of the upper valve stem 21 is also provided with a cap nut 30 for fixing the handwheel 28 to the upper valve stem 21. A washer 29 is provided between the cap nut 30 and the handwheel 28. A cylindrical pin for connecting the upper valve stem 21 is also provided on the cap nut 30.

[0085] Working principle

[0086] This application provides a shut-off check valve. The shut-off check valve includes a valve body 1 with an inlet channel 2 and an outlet channel 3, and a valve cavity 4 connecting the inlet channel 2 and the outlet channel 3. A valve head 5 is located within the valve cavity 4 and moves within it towards and away from the inlet channel 2. The end of the valve head 5 near the inlet channel 2 has a positioning hole 34 for accommodating a sealing gasket 7, and the positioning hole 34 contains a sealing gasket 7 that shuts off the inlet channel 2 and the outlet channel 3. A valve disc 6 is located within the valve cavity 4, with one end extending into the inlet channel 2 and slidingly connected to it. The end of the valve disc 6 away from the inlet channel 2 has an outer conical surface 40 that mates with the sealing gasket 7, and a stud 41 that extends into the valve head 5 and is threadedly connected to it.

[0087] Therefore, the check valve of this application has a positioning hole 34 on the valve head 5 to accommodate the sealing gasket 7, and the sealing gasket 7 is assembled onto the valve head 5 using the valve disc 6. When the sealing gasket 7 is assembled into the positioning hole 34 of the valve head 5, the stud 41 of the valve disc 6 is threadedly fixed to the valve head 5, and the outer conical surface 40 of the valve disc 6 radially compresses the sealing gasket 7, causing the material of the sealing gasket 7 to be pressed into the annular groove 37 of the valve head 5 due to radial plastic deformation. This achieves a seal between the valve head 5 and the sealing gasket 7 due to the compressive force, thus realizing the axial fixation of the sealing gasket 7. Compared with sealing gaskets assembled by molding or encapsulation processes, the sealing gasket 7 assembled in this application has controllable assembly quality, high yield, and good maintainability.

[0088] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and 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, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0089] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0090] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A shut-off check valve, characterized in that, include: The valve body (1) is provided with an inlet channel (2) and an outlet channel (3), and the valve body (1) is also provided with a valve cavity (4) that connects the inlet channel (2) and the outlet channel (3). Valve head (5), the valve head (5) is located in valve cavity (4) and moves in the direction of approaching and moving away from inlet channel (2) in valve cavity (4), the valve head (5) is provided with a positioning hole (34) for accommodating sealing gasket (7) at one end of the valve head (5) approaching inlet channel (2), and a sealing gasket (7) for blocking inlet channel (2) and outlet channel (3) is provided in the positioning hole (34). Valve disc (6), the valve disc (6) is located in the valve cavity (4) and one end extends into the inlet channel (2) and is slidably connected to the inlet channel (2). The valve disc (6) is provided with an outer conical surface (40) that cooperates with the sealing gasket (7) at one end away from the inlet channel (2), and a stud (41) that extends into the valve head (5) and is threadedly connected to the valve head (5). It also includes a lower valve stem (8) that drives the valve head (5) to move in the valve cavity (4) in a direction approaching and away from the inlet channel (2), the top of the lower valve stem (8) extending outside the valve body (1); The valve head (5) is a hollow cylindrical structure. The valve head (5) has a first shoulder (36) that cooperates with the lower valve stem (8). The bottom of the lower valve stem (8) is slidably connected to the valve head (5) and has a first shoulder (43) that abuts against the first shoulder (36). It also includes a bushing (9) fixed on the valve body (1) and sealing the valve cavity (4), the bushing (9) being slidably and sealingly connected to the lower valve stem (8); An elastic element (10) is provided between the bushing (9) and the valve head (5) to elastically drive the valve head (5) to move toward the inlet channel (2). The bushing (9) is sealed to the inner wall of the valve cavity (4), and an annular spring seat plate (11) is provided between the elastic element (10) and the bushing (9). The bushing (9) is slidably sealed with a balance piston (12), which abuts against the valve head (5), and the lower valve stem (8) is slidably sealed with the balance piston (12) on the same axis. The balance piston (12) and the bushing (9) form a closed balance chamber (14), and the valve disc (6) and the lower valve stem (8) are provided with balance channels to allow the medium in the inlet channel (2) to enter the balance chamber (14); The lower valve stem (8) has a second shoulder (44) at one end near the first shoulder (43) that abuts against the balance piston (12). The outer diameter of the second shoulder (44) is smaller than the outer diameter of the first shoulder (43). The second shoulder (44) is slidably sealed to the valve head (5), and a gap (13) is preset between the first shoulder (43) and the first shoulder (36) to allow the valve head (5) to move in the direction of approaching and moving away from the inlet channel (2).

2. The shut-off check valve as described in claim 1, characterized in that: The sealing gasket (7) is a circular flexible gasket, and the inner hole of the sealing gasket (7) is provided with an inner conical surface (38) that mates with the outer conical surface (40). The positioning hole (34) has multiple annular protrusions or annular grooves (37) that mate with the outer wall of the sealing gasket (7).

3. A shut-off check valve as described in claim 1 or 2, characterized in that: The inlet channel (2) has an annular sealing surface (31) extending into the valve cavity (4) at one end, and the annular sealing surface (31) is sealed to the sealing gasket (7). The valve disc (6) has a guide hole (39) at one end that extends into the inlet channel (2) to allow the medium in the inlet channel (2) to enter the valve cavity (4).

4. The shut-off check valve as described in claim 1, characterized in that: It also includes a valve bracket (17) for fixing the bushing (9) to the valve body (1), the valve bracket (17) being fixed to the valve body (1) by a double-headed bolt (18); The valve frame (17) is slidably provided with a middle valve rod (20) that connects to the lower valve rod (8), and the top of the lower valve rod (8) is provided with a T-shaped head (46) that connects to the middle valve rod (20). An anti-rotation boss (50) is fixedly provided on the side wall of the middle valve stem (20), and a positioning groove (19) for sliding connection of the anti-rotation boss (50) is provided on the valve frame (17) along the axial direction of the middle valve stem (20). The valve frame (17) is also provided with an upper valve rod (21) that is threadedly connected to the middle valve rod (20). The top of the upper valve rod (21) extends out of the valve frame (17) and is connected to a handwheel (28).

5. A shut-off check valve as described in claim 4, characterized in that: The upper valve stem (21) is provided with a screw (47) threadedly connected to the middle valve stem (20) at one end away from the handwheel (28), and the middle valve stem (20) is provided with a threaded hole (51) connected to the screw (47) at one end. A third shoulder (48) is fixedly provided on the side wall of the upper valve stem (21), and a second shoulder with an inner diameter smaller than the outer diameter of the third shoulder (48) is provided inside the valve frame (17). The second shoulder is located below the third shoulder (48). A first thrust bearing (23) is provided between the second shoulder and the third shoulder (48), and a second thrust bearing (22) is provided on the top of the third shoulder (48).

6. A shut-off check valve as described in claim 5, characterized in that: The top of the upper valve stem (21) is threaded with a locking nut (27), and a gasket (26) and a first wave spring (25) are provided between the locking nut (27) and the second thrust bearing (22), and a second wave spring (24) is provided between the first thrust bearing (23) and the third shoulder (48). The top of the upper valve stem (21) is provided with a square prism (49) for connecting the handwheel (28). The top of the upper valve stem (21) is also provided with a cap nut (30) for fixing the handwheel (28) to the upper valve stem (21). A washer (29) is provided between the cap nut (30) and the handwheel (28). A cylindrical pin for connecting the upper valve stem (21) is also provided on the cap nut (30).

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