A ball valve sealing structure

Abstract

The present invention relates to a ball valve sealing structure, which includes: a valve body, a first channel and a cavity connected to the first channel provided therein; a ball, which is rotatably installed in the cavity, a second channel provided therein, the second channel being used to connect to the first channel when the ball rotates a preset angle; a first valve seat, which is installed in the cavity, the first valve seat being arranged on one side of the ball; a second valve seat, which is arranged on the side of the ball away from the first valve seat, the second valve seat being floatingly installed in the cavity via a sealing pair, the sealing pair being sandwiched between the second valve seat and the valve body. By floatingly installing the valve seat on the outside of the ball and the valve body using the sealing pair, the ball valve can be protected and sealed, preventing coarse particles in the fluid from filling the sealing cavity, thereby increasing the service life of the ball valve, reducing the equipment operating cost, and effectively improving production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical fields of coal chemical industry and polysilicon, and in particular to a ball valve sealing structure. Background Art

[0002] At present, the main function of the ball valve in the pipeline is to cut off, distribute and change the flow direction of the fluid. It can be closed tightly by rotating 90 degrees and applying a very small torque.

[0003] In the related art, the ball valves installed in the polysilicon and coal chemical black water systems contain a large amount of solid particles in the fluid. During the use of the ball valves, coarse particles often fill the sealing cavity, and the ball switch becomes stuck and inflexible, resulting in a short service life of the ball valve and frequent shutdowns for maintenance. This not only increases the equipment operating costs, but also seriously affects production efficiency. Summary of the Invention

[0004] An embodiment of the present invention provides a ball valve sealing structure to solve the problem in the related art that coarse particles fill the sealing cavity and the ball switch becomes stuck and inflexible.

[0005] In a first aspect, a ball valve sealing structure is provided, which includes: a valve body, a first channel and a cavity connected to the first channel provided therein; a ball, rotatably installed in the cavity, a second channel provided therein, the second channel being used to connect with the first channel when the ball rotates by a preset angle; a first valve seat installed in the cavity, the first valve seat being arranged on one side of the ball; a second valve seat being arranged on a side of the ball away from the first valve seat, the second valve seat being floatingly installed in the cavity through a sealing pair, the sealing pair being clamped between the second valve seat and the valve body.

[0006] In some embodiments, the second valve seat has a first boss on a side close to the valve body, and the valve body has a valve seat mounting hole for mounting the second valve seat; the sealing pair is installed between the inner wall of the valve seat mounting hole and the first boss, and the sealing pair includes: a sealing pressure ring; and a leaf spring, which is installed between the first boss and the sealing pressure ring.

[0007] In some embodiments, the sealing ring is press-fitted onto a side of the leaf spring close to the axis of the valve body, and the side of the leaf spring close to the axis of the valve body is biased away from the valve body.

[0008] In some embodiments, the first boss is tilted at a side close to the leaf spring and matches an inclination angle of the leaf spring.

[0009] In some embodiments, the side of the sealing ring used for pressing the leaf spring is tilted and matches the tilt angle of the leaf spring.

[0010] In some embodiments, a sealing ring is installed on a side of the sealing pressure ring away from the leaf spring, and a side of the valve seat mounting hole close to the sealing ring is inclined in a direction opposite to the inclination of the leaf spring.

[0011] In some embodiments, the sides of the first valve seat and the second valve seat that are in contact with the sphere are both provided with a PVD diamond composite coating, and the surface of the sphere is also provided with a PVD diamond composite coating.

[0012] In some embodiments, a platform is installed on the top of the valve body, and the valve stem passes through the platform; a valve stem is installed on the top of the sphere, and the valve stem is used to drive the sphere to rotate so that the second channel is connected to or closed with the first channel; a valve stem packing is installed between the valve stem and the platform, and a packing ring, a disc spring and a packing cover are installed in sequence above the valve stem packing, and two disc springs are provided, and the two disc springs are installed in series.

[0013] In some embodiments, a thrust boss is provided on the valve stem, the lower end of the platform is located above the thrust boss, a first sliding ring and a second sliding ring are installed between the thrust boss and the platform, and the second sliding ring is located between the first sliding ring and the platform.

[0014] In some embodiments, the sides of the first sliding ring and the second sliding ring that contact each other both have a PVD diamond composite coating.

[0015] The beneficial effects brought about by the technical solution provided by the present invention include:

[0016] An embodiment of the present invention provides a ball valve sealing structure. By floatingly mounting the valve seat on the outside of the ball and the valve body using a sealing pair, the ball can move under the pressure of the fluid and drive the valve seat to tighten the secondary seal, thereby protecting and sealing the ball valve, preventing coarse particles in the fluid from filling the sealing cavity, and allowing the ball switch to remain flexible, thereby increasing the service life of the ball valve, reducing equipment operating costs, and effectively improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic diagram of the overall structure of a ball valve sealing structure provided by an embodiment of the present invention;

[0019] Figure 2 for Figure 1 Schematic diagram of the enlarged structure of B;

[0020] Figure 3 for Figure 1 Schematic diagram of the enlarged structure of A;

[0021] Figure 4 for Figure 1 Schematic diagram of the enlarged structure of C in the middle;

[0022] Figure 5 for Figure 1 Schematic diagram of the enlarged structure of D in the middle;

[0023] Figure 6 A schematic diagram of the three-dimensional structure of a second valve seat of a ball valve sealing structure provided by an embodiment of the present invention;

[0024] Figure 7 A cross-sectional view of a second valve seat of a ball valve sealing structure provided by an embodiment of the present invention;

[0025] Figure 8 A schematic diagram of the three-dimensional structure of a first valve seat of a ball valve sealing structure provided by an embodiment of the present invention;

[0026] Figure 9 A cross-sectional view of a first valve seat of a ball valve sealing structure provided by an embodiment of the present invention;

[0027] Figure 10 A schematic structural diagram of a platform of a ball valve sealing structure provided by an embodiment of the present invention;

[0028] Figure 11 A cross-sectional view of a platform of a ball valve sealing structure provided by an embodiment of the present invention;

[0029] Figure 12 A cross-sectional view of a ball in a ball valve sealing structure provided by an embodiment of the present invention;

[0030] Figure 13 A schematic structural diagram of a valve body of a ball valve sealing structure provided by an embodiment of the present invention;

[0031] Figure 14 A cross-sectional view of a portion of a valve body of a ball valve sealing structure provided by an embodiment of the present invention;

[0032] Figure 15 A cross-sectional view of another portion of a valve body of a ball valve sealing structure provided by an embodiment of the present invention.

[0033] Numbers in the figure:

[0034] 1. Valve body; 11. Valve seat mounting hole; 12. Center flange locking bolt hole; 13. Center flange sealing groove; 14. Platform mounting sealing shoulder; 15. Platform mounting bolt hole; 16. Platform mounting locating pin; 17. Platform mounting hole; 18. First channel; 19. Cavity;

[0035] 3. Sphere; 31. Valve stem mounting hole; 32. Sphere surface; 33. Second channel;

[0036] 4. Valve stem; 41. First sliding ring; 42. Second sliding ring; 43. Packing gland locking screw; 44. Valve stem packing; 45. Disc spring; 46. Packing gland; 47. Packing gland; 48. Sliding sleeve; 49. Thrust boss;

[0037] 5. First valve seat; 51. Fixed valve seat locking bolt hole; 52. First sealing surface; 53. Second sealing surface; 54. Valve seat locking screw;

[0038] 6. Second valve seat; 61. Third sealing surface; 62. Leaf spring; 63. Sealing pressure ring; 64. Sealing ring; 65. First boss;

[0039] 7. Platform; 71. Platform locking bolt hole; 72. Packing gland locking bolt hole; 73. Bracket mounting bolt hole; 74. Dowel pin hole; 75. Platform sealing ring. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0041] The embodiment of the present invention provides a ball valve sealing structure, which can solve the problem in the related art that coarse particles fill the sealing cavity and the ball switch is stuck and inflexible.

[0042] See also Figure 1 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 12 、 Figure 13 、 Figure 14 、 Figure 15 As shown in FIG, a ball valve sealing structure provided by an embodiment of the present invention may include a valve body 1 , a ball 3 , a first valve seat 5 and a second valve seat 6 .

[0043] Among them, a first channel 18 and a cavity 19 connected to the first channel 18 are provided inside the valve body 1. The valve body 1 can be divided into two parts and fixed and installed by bolts, or it can be cast as an integral part. The first channel 18 is cylindrical, and the cavity 19 is arranged in the middle of the first channel 18 and is roughly spherical.

[0044] The sphere 3 is rotatably installed in the cavity 19. A second channel 33 is provided inside the sphere 3. The second channel 33 is used to communicate with the first channel 18 when the sphere 3 is rotated by a preset angle. The inner wall of the cavity 19 is provided with an arc that matches the sphere 3. When the sphere 3 rotates to the point where the second channel 33 is connected to the first channel 18, fluid is allowed to pass through. When the sphere 3 rotates to the point where the second channel 33 is not connected to the first channel 18, fluid is not allowed to pass through.

[0045] The first valve seat 5 can be installed in the cavity 19. The first valve seat 5 is arranged on one side of the ball 3. The first valve seat 5 is installed at the fluid outlet end. The first valve seat 5 and the valve body 1 can be fixedly installed with bolts. The contact surface of the first valve seat 5 and the valve body 1 is ground and polished so that a metal-to-metal sealing effect is formed after assembly. In other embodiments, the first valve seat 5 can also be installed in a floating manner with the valve body 1. Under this installation method, the ball 3 is fixed on a certain axis by the valve stem 4 and the lower end support shaft for rotation. This ball valve is called a fixed ball valve, and the fluid of the fixed ball valve can enter and exit from either end.

[0046] The second valve seat 6 can be arranged on the side of the ball 3 away from the first valve seat 5. The second valve seat 6 is floatingly installed in the cavity 19 through a sealing pair. The sealing pair is clamped between the second valve seat 6 and the valve body 1. The second valve seat 6 is installed at the fluid inlet end. The ball 3 is floating. Under the pressure of the fluid, the ball 3 can produce a certain displacement and press tightly on the sealing surface of the outlet end to ensure the sealing of the outlet end. The end of the second valve seat 6 is designed to be inserted into the inner hole shoulder of the valve body 1 to protect the seal and prevent coarse particles in the medium from filling the sealing cavity.

[0047] See also Figure 2 As shown, in some embodiments, the second valve seat 6 may have a first boss 65 on a side close to the valve body 1, and the valve body 1 has a valve seat mounting hole 11 for mounting the second valve seat 6; the sealing pair is installed between the inner wall of the valve seat mounting hole 11 and the first boss 65, and the sealing pair includes: a sealing pressure ring 63; a leaf spring 62, which is installed between the first boss 65 and the sealing pressure ring 63. In this embodiment, the sealing pressure ring 63 is used to seal the second valve seat 6 and the valve body 1, and the leaf spring 62 is elastic. It is installed between the first boss 65 and the inner wall of the valve seat mounting hole 11 to prevent coarse particles in the medium from filling the sealing cavity, causing the second valve seat 6 to rebound and fail, resulting in switch jamming.

[0048] See also Figure 2 As shown, further, the sealing pressure ring 63 can be pressed onto the side of the leaf spring 62 close to the axis of the valve body 1, and the side of the leaf spring 62 close to the axis of the valve body 1 is biased away from the valve body 1. In this embodiment, the leaf spring 62 is tilted by the sealing pressure ring 63, and the distance between the side close to the axis of the valve body 1 and the valve body 1 is greater than the distance between the side away from the axis of the valve body 1 and the valve body 1. The sealing pressure ring 63 is made of a rigid material and is pressed onto the side of the leaf spring 62 close to the axis of the valve body 1. It can press the leaf spring 62 to a state of inner concaveness, similar to the shape of a disc spring, so that the rebound performance of the leaf spring 62 is better and the temperature resistance of the leaf spring 62 is better.

[0049] See also Figure 2 As shown, further, the side of the first boss 65 close to the leaf spring 62 can be inclined and match the inclination angle of the leaf spring 62. In this embodiment, the first boss 65 is set to an inwardly concave shape, which can make it fit more closely with the leaf spring 62 and have a better sealing effect. In addition, the supporting surface of the leaf spring 62 is larger, more stable, and has a better rebound effect.

[0050] See also Figure 2 As shown, further, the side of the sealing pressure ring 63 used to press the leaf spring 62 can be tilted and matched with the tilt angle of the leaf spring 62. In this embodiment, the side of the sealing pressure ring 63 in contact with the leaf spring 62 is tilted, so that it fits more closely with the leaf spring 62, the sealing effect is better, the tilt state of the leaf spring 62 can be kept stable, and the elastic effect of the leaf spring 62 is better.

[0051] See also Figure 2As shown, further, a sealing ring 64 can be installed on the side of the sealing pressure ring 63 away from the leaf spring 62, and the side of the valve seat mounting hole 11 close to the sealing ring 64 can be inclined, and in the opposite direction to the inclined direction of the leaf spring 62. In this embodiment, the sealing ring 64 is elastic, which can make the sealing effect between the second valve seat 6 and the valve body 1 better, and prevent coarse particles in the medium from filling the sealing cavity. An inclined surface opposite to the direction of the leaf spring 62 is provided between the sealing ring 64 and the inner wall of the valve seat mounting hole 11, that is, the cross-section of the sealing pressure ring 63 and the sealing ring 64 is The surface shape is trapezoidal, and the inner wall of the valve seat mounting hole 11 and the side opposite to the first boss 65 are inclined surfaces in opposite directions, so that the force directions on both sides of the sealing pair composed of the leaf spring 62, the sealing pressure ring 63 and the sealing ring 64 are opposite, and the combination between the three is tighter, the sealing effect is better, the force is more reasonable, and the stability of the sealing pair is improved; in addition, the top of the leaf spring 62 is against the inner wall of the valve seat mounting hole 11, and there is a gap between the side away from the first boss 65 and the inner wall of the valve seat mounting hole 11, so that the leaf spring 62 has a certain elastic space, thereby improving the reliability of the seal.

[0052] See also Figure 1 As shown, preferably, the sides of the first valve seat 5 and the second valve seat 6 in contact with the sphere 3 can be provided with a PVD diamond composite coating, and the surface of the sphere 3 is also provided with a PVD diamond composite coating. In this embodiment, the surface of the sphere 3 and the inner sides of the first valve seat 5 and the second valve seat 6 are surface hardened. Conventional hardening is electroplating, or surfacing welding of wear-resistant alloys, or supersonic spraying of tungsten carbide, or spraying of ceramic materials. The present application adopts a vapor deposition process to deposit a layer of extremely wear-resistant diamond, which greatly improves the wear resistance of the sealing surface between the sphere 3 and the valve seat, so that the service life of the valve can be doubled even under the worst wear conditions.

[0053] See also Figure 1 、 Figure 3 、 Figure 10 、 Figure 11 and Figure 12 As shown, in some embodiments, the ball valve sealing structure may further include a platform 7 and a valve stem 4 .

[0054] Among them, the platform 7 is installed on the top of the valve body 1, and the valve stem 4 passes through the platform 7. The platform 7 is provided with multiple platform locking bolt holes 71 bolted to the valve body 1, positioning pin holes 74 for positioning, packing gland locking bolt holes 72 for fixing the packing gland, and bracket mounting bolt holes 73. A platform sealing ring 75 is installed between the platform 7 and the valve body 1.

[0055] The valve stem 4 is installed on the top of the sphere 3. The valve stem 4 is used to drive the sphere 3 to rotate, so that the second channel 33 is connected to or closed with the first channel 18. A square valve stem mounting hole 31 is provided on the sphere 3. The valve stem 4 rotates through the valve stem mounting hole 31 to drive the sphere 3 to rotate, thereby realizing rapid opening and closing of the valve.

[0056] A valve stem packing 44 is installed between the valve stem 4 and the platform 7. A packing pressure ring 46, a disc spring 45 and a packing gland 47 are installed in sequence above the valve stem packing 44. The packing gland 47 is fixed to the platform 7 by a bolt 43. There are two disc springs 45, and the two disc springs 45 are installed in series. The packing pressure ring 46, the disc spring 45 and the packing gland 47 serve as an automatic compensation device provided above the valve stem packing 44. When the valve stem packing 44 is worn, the disc spring 45 releases part of the elastic force and continues to compress the packing pressure ring 46 to keep the packing seal in an effective state. There are two disc springs 45, and the two disc springs 45 are installed in opposite directions, so that the disc spring 45 can provide a larger deformation.

[0057] See also Figure 4 As shown, in some embodiments, a thrust boss 49 may be provided on the valve stem 4, and the lower end of the platform 7 is located above the thrust boss 49. A first sliding ring 41 and a second sliding ring 42 are installed between the thrust boss 49 and the platform 7. The second sliding ring 42 is located between the first sliding ring 41 and the platform 7. The contact surfaces of the first sliding ring 41 and the second sliding ring 42 are ground and polished, and the surfaces are hardened, which can not only effectively reduce the switching torque, but also prevent solid particles from entering the valve stem packing area, avoid excessive wear of the valve stem 4 and the valve stem packing 44, and reduce the risk of leakage. In addition, a sliding sleeve 48 is installed between the valve stem 4 and the valve body 1 to further reduce the valve switching torque.

[0058] See also Figure 4 As shown, preferably, the sides of the first sliding ring 41 and the second sliding ring 42 that contact each other can both have a PVD diamond composite coating. In this embodiment, the surfaces of the two sliding rings that contact each other are hardened, and a vapor deposition process is also used to deposit a layer of highly wear-resistant diamond. After hardening, not only the wear resistance of the sliding ring is improved, but also the friction coefficient is reduced, so that the switching torque is effectively reduced.

[0059] The principle of a ball valve sealing structure provided by an embodiment of the present invention is:

[0060] The second valve seat 6 is installed in a sealing and floating manner on the valve body 1 through a leaf spring 62, a sealing pressure ring 63 and a sealing ring 64 to protect the seal and prevent coarse particles in the medium from filling the sealing cavity, causing the second valve seat 6 to rebound and fail, resulting in switch jamming; a layer of super-wear-resistant PVD diamond composite coating is deposited on the surface of the ball 3 and the spherical surface of the valve seat through a chemical vapor deposition process, which improves the wear resistance of the sealing surface between the ball and the valve seat and extends the service life of the valve; the first sliding ring 41 and the second sliding ring 42 of the valve stem thrust sealing element are installed on the thrust boss 49 of the valve stem 4, which can prevent solid particles from entering the valve stem packing area, avoid excessive wear of the valve stem 4 and the packing, and reduce the risk of leakage; the packing automatic compensation device consists of at least one disc spring 45, a packing compression spring 45 and a packing cover 47. When the valve stem packing 44 is worn, the disc spring 45 releases part of the elastic force and continues to compress the packing pressure ring 46 to keep the valve stem packing 44 seal in an effective state.

[0061] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0062] It should be noted that, in the present invention, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0063] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. 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 the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is intended to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A ball valve sealing structure, characterized in that: It includes: A valve body (1) having a first channel (18) and a cavity (19) in communication with the first channel (18) provided therein; A sphere (3) is rotatably mounted in the cavity (19), and a second channel (33) is provided inside the sphere (3). The second channel (33) is used to communicate with the first channel (18) when the sphere (3) rotates a preset angle. a first valve seat (5) installed in the cavity (19), wherein the first valve seat (5) is arranged on one side of the sphere (3); The first valve seat (5) and the valve body (1) are fixedly mounted by bolts, and the contact surfaces of the first valve seat (5) and the valve body (1) are ground and polished to form a metal-to-metal seal after assembly; a second valve seat (6) disposed on a side of the ball (3) away from the first valve seat (5), the second valve seat (6) being floatingly mounted in the cavity (19) via a sealing pair, the sealing pair being sandwiched between the second valve seat (6) and the valve body (1); a first boss (65) being provided on a side of the second valve seat (6) close to the valve body (1), and the valve body (1) having a valve seat mounting hole (11) for mounting the second valve seat (6); a valve stem (4), the valve stem (4) being mounted on the top of the sphere (3), the valve stem (4) being used to drive the sphere (3) to rotate, thereby connecting or closing the second channel (33) to the first channel (18); A platform (7) is mounted on the top of the valve body (1), and the valve stem (4) passes through the platform (7); a leaf spring (62), a sealing pressure ring (63) and a sealing ring (64) are sequentially provided between the first boss (65) and the inner wall of the valve seat mounting hole (11); the sealing pressure ring (63) is made of a rigid material and presses the leaf spring (62) to a state where the inner side is concave; the sealing ring (64) is elastic; The sealing pressure ring (63) is pressed onto a side of the leaf spring (62) close to the axis of the valve body (1), and the side of the leaf spring (62) close to the axis of the valve body (1) is biased away from the valve body (1); The first boss (65) is arranged at an angle close to the leaf spring (62), and matches the angle of inclination of the leaf spring (62); the first boss (65) is arranged in an inwardly concave shape; The sealing pressure ring (63) is used to press the leaf spring (62) on one side thereof and is tilted and matches the tilt angle of the leaf spring (62); the first boss (65) and the side opposite to the inner wall of the valve seat mounting hole (11) are provided with inclined surfaces in opposite directions, the leaf spring (62) is tilted in the same direction as the first boss (65), the side of the sealing pressure ring (63) close to the leaf spring (62) has an inclined surface in the same direction as the first boss (65), and the side of the sealing ring (64) away from the sealing pressure ring (63) has an inclined surface in the same direction as the inner wall of the valve seat mounting hole (11); The sealing pressure ring (63) and the sealing ring (64) are in close contact, and the cross-sectional shapes of the sealing pressure ring (63) and the sealing ring (64) are trapezoidal; a thrust boss (49) is provided on the valve stem (4), the lower end of the platform (7) is located above the thrust boss (49), a first sliding ring (41) and a second sliding ring (42) are installed between the thrust boss (49) and the platform (7), and the second sliding ring (42) is located between the first sliding ring (41) and the platform (7); The contact surfaces of the first sliding ring (41) and the second sliding ring (42) are ground and polished, and the surfaces are hardened; The first sliding ring (41) and the second sliding ring (42) both have a PVD diamond composite coating on their sides that contact each other; A sliding sleeve (48) is installed between the valve stem (4) and the valve body (1); The sides of the first valve seat (5) and the second valve seat (6) in contact with the sphere (3) are both provided with a PVD diamond composite coating, and the surface of the sphere (3) is also provided with a PVD diamond composite coating; The PVD diamond composite coatings are all deposited using a chemical vapor deposition process.

2. The ball valve sealing structure according to claim 1, wherein: A valve stem packing (44) is installed between the valve stem (4) and the platform (7), and a packing pressure ring (46), a disc spring (45) and a packing gland (47) are installed in sequence above the valve stem packing (44). Two disc springs (45) are provided, and the two disc springs (45) are installed in series.

Images