A ball valve with composite coating

Abstract

The present invention discloses a ball valve with a composite coating, including a valve body, a ball body and other components. The ball valve with a composite coating reduces the flushing force of liquid on key parts by reasonably setting the shapes and structures of different positions. At the same time, different coatings are set for different parts, which not only improves the corrosion resistance and wear resistance of the ball valve, but also has excellent control on costs.

Description

Technical Field

[0001] The invention relates to the technical field of valves, in particular to a ball valve with a composite coating. Background Art

[0002] Ball valves have a history of nearly 70 years. Since ball valves are most suitable for use as switches and cut-off valves, and with the rapid development of science and technology, production processes and product structures are constantly improving, they have rapidly developed into one of the most important valve types. Among them, ball valves used in special environments need to be treated with wear and corrosion resistance. If the treatment method is inappropriate, the service life of the ball valve will be greatly shortened. Summary of the invention

[0003] The object of the present invention is to provide a ball valve with a composite coating, which has the characteristics of better performance and lower cost.

[0004] The technical solution adopted by the present invention is: a ball valve with a composite coating, comprising a valve body, the left part of the valve body having a liquid inlet hole, the middle part having a matching cavity, and the right part having a liquid outlet hole, wherein the matching cavity is spherical, and a sphere that can rotate about a vertical axis is arranged in the matching cavity, the sphere has a liquid through hole that passes through the left and right, and the upper part of the sphere is fixedly connected to the lower end of a rotating rod, the upper end of the rotating rod extends to the outside of the valve body, and the upper end of the rotating rod is connected to an actuator, and at the same time, the diameters of the liquid inlet hole and the liquid outlet hole are both smaller than the diameter of the matching cavity,

[0005] The connecting portion between the liquid inlet hole and the matching cavity is fixed with an annular matching step, the cross section of the matching step is conical so as to have a left side, a pointed top and a right side, and the left side is an arc surface with a middle part concave outward, the pointed top is an arc surface with a middle part protruding inward, and the right side matches the surface of the sphere;

[0006] The cross section of the joint of the liquid outlet and the matching cavity is in the shape of an arc surface with the middle part convex inwards;

[0007] The inner cavity of the liquid passage hole comprises a left section and a right section, the left section is in the shape of an arc surface with a middle portion protruding inwards, and the right section is in the shape of an arc surface with a middle portion concave outwards; and

[0008] The outer surface of the valve body is coated with WC coating;

[0009] The inner surface of the liquid inlet and the inner surface of the liquid outlet are coated with a WC coating and a CrN coating located outside the WC coating;

[0010] The outer surface of the joint portion is coated with a WC coating;

[0011] The left side of the matching step is coated with a composite ceramic coating, and the top and right side of the pointed step are coated with three layers of strengthening film;

[0012] The sphere is made of stainless steel, and its surface is provided with hot-dip aluminum coating, micro-arc oxidation coating, acrylate coating and polyurethane coating from the inside to the outside.

[0013] Compared with the prior art, the present invention has the advantages of better performance and lower cost. The ball valve with composite coating of the present invention reduces the flushing force of liquid on key parts by reasonably setting the shape and structure of different positions. At the same time, different coatings are set for different parts, which not only improves the corrosion resistance and wear resistance of the ball valve, but also has excellent control on cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0015] Figure 1 It is a front cross-sectional view of a ball valve with a composite coating in an exploded state (the ball valve is in an open state) according to an embodiment of the present invention;

[0016] Figures 2 to 7 They are Figure 1 A partial enlarged view of part A, part B, part C, part D, part E, and part F.

[0017] In the figure:

[0018] 10. valve body, 11. liquid inlet hole, 12. matching cavity, 13. liquid outlet hole, 14. joint part;

[0019] 20. sphere, 21. liquid hole, 211. left section, 212. right section, 201. hot-dip aluminum coating, 202. micro-arc oxidation coating, 203. acrylate coating, 204. polyurethane coating;

[0020] 30. Rotating rod;

[0021] 40. Actuator;

[0022] 50. WC coating;

[0023] 60. CrN coating;

[0024] 70. Composite ceramic coating;

[0025] 80. Three-layer reinforced film;

[0026] 90. Matching steps, 91. Left side, 92. Pointed top, 93. Right side. DETAILED DESCRIPTION

[0027] For example, see Figure 1As shown: A ball valve with a composite coating, including a valve body 10. The valve body 10 has a liquid inlet 11 on the left, a matching cavity 12 in the middle, and a liquid outlet 13 on the right. Obviously, the liquid inlet 11, the matching cavity 12, and the liquid outlet 13 are arranged from left to right and are interconnected. Among them, the matching cavity 12 is spherical, and a ball 20 that can rotate about a vertical axis is provided in the matching cavity 12. Obviously, the vertical axis is the vertical axis of the matching cavity 12. The sphere 20 has a liquid hole 21 that passes through the left and right, and the upper part of the sphere 20 is fixedly connected to the lower end of a rotating rod 30. Of course, the outer surface of the sphere 20 and the inner surface of the matching cavity 12 are sealed and matched. The upper end of the rotating rod 30 extends to the outside of the valve body 10, and the upper end of the rotating rod 30 is connected to an actuator 40. That is, after the actuator 40 is actuated, the rotating rod 30 is driven to rotate, and the ball 20 is driven to rotate, so that the ball valve is opened or closed. At the same time, the diameters of the liquid inlet hole 11 and the liquid outlet hole 13 are both smaller than the diameter of the matching cavity 12.

[0028] Further speaking:

[0029] Combination Figure 4 As shown, a ring-shaped matching step 90 is fixed to the connection part of the liquid inlet hole 11 and the matching cavity 12. The cross section of the matching step 90 is conical, so it has a left side 91, a pointed top 92 and a right side 93, and the left side 91 is an arc surface with a middle part concave outward, the pointed top 92 is an arc surface with a middle part protruding inward, and the right side 93 matches the surface of the sphere 20. The so-called inside and outside here means that the center position close to the matching step 90 is the inside, and the center position away from the matching step 90 is the outside.

[0030] The cross section of the joint 14 of the liquid outlet 13 and the matching cavity 12 is an arc-shaped surface with a central portion convex inward. Here, the so-called inside and outside refer to the center position close to the liquid outlet 13 as the inside and the center position far from the liquid outlet 13 as the outside.

[0031] The inner cavity of the liquid hole 21 includes a left section 211 and a right section 212. The longitudinal section of the left section 211 is an arc-shaped surface with a central portion protruding inward, and the longitudinal section of the right section 212 is an arc-shaped surface with a central portion recessed outward. That is, from a general perspective, the contours of the two sides of the inner cavity longitudinal section of the liquid hole 21 are in an "S" shape. When the liquid passes through the liquid hole 21, it is first subjected to pressure and then released.

[0032] More specifically:

[0033] Combination Figure 2As shown, the outer surface of the valve body 10 is coated with a WC coating 50. The WC coating 50 can be sprayed by supersonic flame spraying. The WC coating has high hardness and good wear resistance. Although it has certain defects, it is sufficient to meet the use requirements when applied to the outer surface of the valve body 10 and reduces the preparation cost. The thickness of the WC coating 50 coated on the outer surface of the valve body 10 can be controlled at 300-400 μm.

[0034] Combination Figure 3 As shown, the inner surface of the liquid inlet 11 and the inner surface of the liquid outlet 13 are coated with a WC coating 50 and a CrN coating 60 located outside the WC coating 50. That is, the WC coating 50 serves as a bottom layer and the CrN coating 60 serves as a surface layer. The CrN coating 60 can be deposited by magnetron sputtering. That is, a double coating is used in a part where corrosion resistance and wear resistance are relatively high. The thickness of the WC coating 50 on the inner surface of the liquid inlet 11 and the inner surface of the liquid outlet 13 is preferably less than the thickness of the WC coating 50 on the outer surface of the valve body 10, for example, it is controlled at 50-100 μm, and the CrN coating 60 outside the WC coating 50 can be controlled at about 8-10 μm. In other words, different thicknesses of bottom coatings are used depending on the location of use.

[0035] Combination Figure 5 As shown, the outer surface of the joint 14 is coated with a WC coating 50. Since the matching step 90 decelerates the liquid, a single layer of coating is used at the joint 14.

[0036] The left side 91 of the matching step 90 is coated with a composite ceramic coating 70, and the tip 92 and the right side 93 are coated with a three-layer strengthening film 80. The composite ceramic coating 70 uses a mixture of submicron ceramic particles and phenolic epoxy resin. The volume ratio and weight ratio of the two can adopt common proportions, and can be formed by high-temperature curing after coating. The total thickness is preferably 100-150μm. In this way, the wear resistance and corrosion resistance of the left side 91 of the matching step 90 meet relatively higher requirements. The three-layer strengthening film 80 uses WC as the bottom layer, TiN as the interlayer, and CrN as the surface layer to form a three-layer structure, so that the most strengthened treatment is used in the most critical parts. In this way, on the basis of improving the corrosion resistance and wear resistance of the ball valve, the cost of the ball valve will not be excessively increased.

[0037] Combination Figure 6 and Figure 7As shown, the sphere 20 is made of stainless steel, and its surface is sequentially provided with hot-dip aluminum coating 201, micro-arc oxidation coating 202, acrylate coating 203, and polyurethane coating 204 from the inside to the outside, and the coating process adopts a common process. It has been verified in practice that the sphere 20 of this embodiment and the matching step 90 are well matched, so that the service life of the sphere 20 can be increased by more than 20%.

[0038] In summary, the ball valve with composite coating of the present invention reduces the scouring force of liquid on key parts by reasonably setting the shape structure of different positions, especially at the moment of opening and closing, the impact of liquid on the edge and inside of the liquid hole 21, the pointed top 92 of the matching step 90, the joint 14, etc. is greatly reduced. At the same time, different coatings are set for different parts, which greatly improves the performance of the ball valve, but the cost can be well controlled. It has been verified in practice that the cost of the same ball valve can be reduced by about 15% under the premise of obtaining similar performance.

[0039] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A ball valve with a composite coating, comprising a valve body (10), wherein the valve body (10) has a liquid inlet hole (11) at the left part, a matching cavity (12) at the middle part, and a liquid outlet hole (13) at the right part, in, The matching cavity (12) is spherical, and a sphere (20) capable of rotating about a vertical axis is arranged in the matching cavity (12). The sphere (20) has a liquid passage hole (21) extending leftward and rightward, and the upper part of the sphere (20) is fixedly connected to the lower end of a rotating rod (30), the upper end of the rotating rod (30) extends to the outside of the valve body (10), and the upper end of the rotating rod (30) is connected to an actuator (40). At the same time, the diameters of the liquid inlet hole (11) and the liquid outlet hole (13) are both smaller than the diameter of the matching cavity (12), and the characteristics are as follows: An annular matching step (90) is fixed to the connecting portion between the liquid inlet hole (11) and the matching cavity (12); the matching step (90) has a conical cross section and has a left side surface (91), a pointed top portion (92) and a right side surface (93); the left side surface (91) is in the shape of an arc surface with a middle portion concave outward, the pointed top portion (92) is in the shape of an arc surface with a middle portion protruding inward, and the right side surface (93) matches the surface of the sphere (20); The cross section of the joint (14) between the liquid outlet hole (13) and the matching cavity (12) is in the shape of an arc surface with the middle portion convex inwards; The inner cavity of the liquid passage hole (21) comprises a left section (211) and a right section (212), the left section (211) being in the shape of an arc surface with a middle portion protruding inwards, and the right section (212) being in the shape of an arc surface with a middle portion recessed outwards; and The outer surface of the valve body (10) is coated with a WC coating (50); The inner surface of the liquid inlet (11) and the inner surface of the liquid outlet (13) are both coated with a WC coating (50) and a CrN coating (60) located outside the WC coating (50); The outer surface of the joint portion (14) is coated with a WC coating (50); The left side surface (91) of the matching step (90) is coated with a composite ceramic coating (70), and the pointed top (92) and the right side surface (93) are coated with three layers of strengthening films (80); The sphere (20) is made of stainless steel, and its surface is provided with a hot-dip aluminum coating (201), a micro-arc oxidation coating (202), an acrylate coating (203), and a polyurethane coating (204) in sequence from the inside to the outside. The thickness of the WC coating (50) on the inner surface of the liquid inlet hole (11) and the inner surface of the liquid outlet hole (13) is smaller than the thickness of the WC coating (50) on the outer surface of the valve body (10).

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