Sealing protection structure for valve seat of metal sealing ball valve

Abstract

The utility model provides a valve seat sealing protection structure of a metal sealing ball valve, and relates to the field of ball valves. The sealing protection structure for the valve seat of the metal sealing ball valve comprises a connecting body, the valve seat, a pressing ring and a flexible graphite ring. The connector end is provided with an annular mounting area; the valve seat is provided with a first valve seat ring part and a second valve seat ring part which are different in diameter. The valve seat is arranged in the annular mounting area, an annular gap is formed between the circumferential side wall of the ring part of the first valve seat and part of the side wall of the corresponding annular mounting area, and the circumferential side wall of the ring part of the second valve seat is in fit contact with part of the side wall of the corresponding annular mounting area; the pressing ring is detachably arranged on the end face of the connecting body, presses the valve seat and seals the annular gap to form an annular cavity. The flexible graphite ring is arranged in the annular cavity in a matched mode, and the pressing ring abuts against the flexible graphite ring. By adopting the valve seat sealing and protecting structure of the metal sealing ball valve, the metal sealing ball valve has higher stability and longer service life.

Description

Technical Field

[0001] The utility model relates to the field of ball valves, in particular to a metal sealing ball valve seat sealing protection structure. Background Art

[0002] Ball valves that rely on metal-to-metal sealing, namely metal-sealed ball valves, have higher temperature and pressure limits, better regulating and throttling performance, quick opening and closing, and save operating space. They can also resist damage from solid particles, flash evaporation, cavitation, etc., and their sealing performance is also outstanding. Therefore, metal-sealed ball valves have a wide range of promotion and application prospects in petrochemical systems, power systems, urban construction systems, and metallurgical systems.

[0003] Existing metal-sealed ball valves usually use flexible graphite rings as sealing elements in the cavity between the valve seat and the connector. However, under high temperature conditions, the flexible graphite rings are prone to graphitization, which reduces or even fails the sealing performance; under high pressure conditions, the high-pressure medium directly erodes the flexible graphite rings, which easily leads to damage and failure. The above situation directly leads to the failure of the metal-sealed ball valve, reducing the stability and service life of the metal-sealed ball valve. Utility Model Content

[0004] The utility model aims to solve the problem in the prior art that flexible graphite rings are easily damaged and fail under high pressure conditions, thereby reducing the stability and service life of metal-sealed ball valves, and provides a metal-sealed ball valve seat sealing protection structure that prevents the flexible graphite rings from being directly eroded by media under high pressure conditions.

[0005] The technical solution adopted by the utility model is:

[0006] A metal-sealed ball valve seat sealing protection structure, comprising:

[0007] A connector, whose cylindrical end is located inside the valve body of the ball valve; the inner side of the end surface of the connector is cylindrically recessed along its own axial center direction to form an annular installation area;

[0008] The valve seat is annular and arranged in the annular installation area; the valve seat has a first valve seat ring portion and a second valve seat ring portion; the first valve seat ring portion is close to the ball of the ball valve, and the outer diameter of the second valve seat ring portion is consistent with the outer diameter of the annular installation area and is larger than the outer diameter of the first valve seat ring portion; the valve seat is arranged in the annular installation area, and there is an annular gap between the circumferential side wall of the first valve seat ring portion and the corresponding part of the side wall of the annular installation area, and the circumferential side wall of the second valve seat ring portion is in close contact with the corresponding part of the side wall of the annular installation area;

[0009] A pressure ring is detachably arranged on the end surface of the connector and presses the valve seat; at the same time, the pressure ring closes the annular gap to form an annular cavity;

[0010] A flexible graphite ring is arranged in the annular cavity, and the flexible graphite ring is pressed against by the pressure ring.

[0011] Furthermore, the valve seat has an arc-shaped front sealing surface on one side facing the sphere, and the front sealing surface is tightly fitted with the sphere to form a seal and does not overlap with the area where the pressure ring presses the valve seat.

[0012] Furthermore, the two edges of the front sealing surface are designed to be smooth and sharp to form sharp blades.

[0013] Furthermore, the valve seat has a rear sealing surface along its axial center direction facing the connector, and an annular boss is formed on the surface of the annular installation area opposite to the rear sealing surface, and the annular boss fits tightly with the rear sealing surface to form a seal.

[0014] Furthermore, an outer edge of a surface of the first valve seat ring portion facing the sphere has a positioning step that cooperates with the pressure ring.

[0015] Furthermore, the pressure ring has an annular extrusion protrusion on one side facing the connecting body along its axial center direction, and the annular extrusion protrusion extends into the annular cavity. Its annular inner and outer side walls are respectively in contact with the second valve seat ring portion and the annular mounting area, and the end face of the annular extrusion protrusion abuts against the flexible graphite ring.

[0016] Furthermore, a conical inclined surface transition is adopted between the first valve seat ring portion and the second valve seat ring portion, and the flexible graphite ring also has a conical sealing surface that matches with each other.

[0017] Furthermore, the valve seat is integrally forged.

[0018] The beneficial effects of the utility model are:

[0019] 1. The utility model relies on the design of separating the flexible graphite ring from the high-pressure medium by the cooperation of the pressure ring, the valve seat and the connector, which solves the problem that the flexible graphite ring is easily damaged and fails under high temperature and high pressure conditions, so that the ball valve adopting the metal sealing ball valve seat sealing protection structure of the utility model has higher stability and longer service life.

[0020] 2. The utility model relies on the double-blade design of the front sealing surface of the valve seat to achieve self-cleaning and avoid dirt accumulation and clogging of the ball valve.

[0021] 3. The annular shoulder of the utility model is in close contact with the rear sealing surface, so that a static seal is formed between the valve seat and the annular installation area of ​​the connector, and the high-temperature and high-pressure medium is prevented from entering the annular cavity from the rear sealing surface of the valve seat to directly scour the flexible graphite ring, thereby ensuring the sealing performance. In addition, the circumferential side wall of the valve seat and the flexible graphite ring form a radial seal between the valve seat and the connector, and the rear sealing surface of the valve seat and the annular shoulder on the connector form an axial seal. Under the action of double sealing, the sealing performance of the metal sealing valve seat is more stable and reliable.

[0022] 4. The utility model relies on the positioning step design on the valve seat that cooperates with the pressure ring to enhance the sealing effect of the metal sealing ball valve seat sealing protection structure.

[0023] 5. The utility model increases the sealing pressure ratio at the static seal and enhances the sealing effect of the metal-sealed ball valve seat sealing protection structure by means of the design of the conical inclined surface transition between the first valve seat ring portion and the second valve seat ring portion.

[0024] 6. The utility model relies on the integral forging design of the valve seat to improve the mechanical properties of the utility model and enhance the stability, strength and durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a cross-sectional view of the metal sealing ball valve seat sealing protection structure of an embodiment of the utility model.

[0027] Figure 2 It is a cross-sectional view of a connector according to an embodiment of the present utility model.

[0028] Figure 3 It is a cross-sectional view of a connector, a valve seat and a pressure ring according to an embodiment of the utility model.

[0029] Figure 4 This is a cross-sectional view of a valve seat in a preferred embodiment of the present invention.

[0030] Figure 5 This is a cross-sectional view of a flexible graphite ring in a preferred embodiment of the present invention.

[0031] Figure 6 It is a cross-sectional view of a pressure ring according to an embodiment of the utility model.

[0032] Reference numerals:

[0033] 10-ball, 20-valve seat, 30-pressure ring, 40-flexible graphite ring, 50-screw, 60-spring washer, 70-connector, 80-valve body.

[0034] 21 - first valve seat ring portion, 22 - second valve seat ring portion.

[0035] 31- Annular extrusion protrusion.

[0036] 41 - inner sealing surface of the ring, 42 - outer sealing surface of the ring, 43 - conical sealing surface.

[0037] 71- annular mounting area, 72- annular boss.

[0038] 213 - positioning step, 221 - rear sealing surface, 212 - front sealing surface, 211 - annular cavity, 214 - conical inclined surface. DETAILED DESCRIPTION

[0039] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0040] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention.

[0041] The embodiments of the utility model are described in detail below with reference to the accompanying drawings.

[0042] In the prior art, a metal-sealed ball valve is generally composed of a valve body, a ball, a flexible graphite ring, a valve seat, a connector, and other components. In order to solve the problem that the flexible graphite ring in the existing metal-sealed ball valve is damaged by erosion of high-temperature and high-pressure media, resulting in sealing failure, a metal-sealed ball valve seat sealing protection structure is provided. Figure 1-Figure 4 .

[0043] The metal sealing ball valve seat sealing protection structure comprises a connecting body 70 and a valve seat 20. The end of the connecting body 70 is cylindrical and is located in the valve body 80. The inner side of the end surface of the connecting body 70 is cylindrically concave along its own axial center direction to form a cylindrical shape. Figure 2 The valve seat 20 is generally annular and is integrally forged. The valve seat 20 is located in the valve body 80, between the ball 10 and the connector 70, and in the annular mounting area 71 of the connector 70. Figure 4 As shown, along the axial center direction of the valve seat 20, the valve seat 20 has a first valve seat ring portion 21 and a second valve seat ring portion 22. The first valve seat ring portion 21 is close to the ball 10, and its ring outer diameter is smaller than the ring outer diameter of the second valve seat ring portion 22. At the same time, the ring outer diameter of the second valve seat ring portion 22 is consistent with the ring outer diameter of the annular mounting area 71. Therefore, when the valve seat 20 is arranged in the annular mounting area 71, there is an annular gap between the circumferential side wall of the first valve seat ring portion 21 and the corresponding part of the side wall of the annular mounting area 71, and the circumferential side wall of the second valve seat ring portion 22 is in close contact with the corresponding part of the side wall of the annular mounting area 71. At the same time, the metal sealing ball valve seat sealing protection structure also includes a pressure ring 30 and a flexible graphite ring 40. The pressure ring 30 is located on the end face of the connector 70 and is fixedly connected to the connector 70 by a detachable method such as screws 50. Furthermore, the inner edge of the pressure ring 30 facing the connector 70 presses the outer edge of the first valve seat ring 21 facing the spherical body 10. Thus, the cooperation between the pressure ring 30 and the connector 70 enables the valve seat 20 to be reliably installed in the annular installation area 71. After the valve seat 20, the pressure ring 30 and the connector 70 are combined, the outer circumferential side wall of the first valve seat ring 21 forms a Figure 3 The closed annular cavity 211 is shown. The flexible graphite ring 40 is arranged in the annular cavity 211 and is supported by the pressure ring 30.

[0044] The metal-sealed ball valve seat sealing protection structure in this embodiment can prevent the flexible graphite ring 40 from being directly eroded by the high-temperature and high-pressure medium passing through the flow channel of the ball 10, the valve seat 20 and the connector 70 when the metal-sealed ball valve is opened, by arranging the flexible graphite ring 40 in the closed annular cavity 211 formed by the combination of the valve seat 20, the pressure ring 30 and the connector 70, and can reduce the directly transferred heat, thereby extending the service life of the flexible graphite ring and ensuring the sealing effect.

[0045] In this embodiment, Figure 4As shown, the first valve seat ring 21 also has a circle of front sealing surface 212 on the side facing the sphere 10, and the front sealing surface 212 is in an arc shape. The front sealing surface 212 does not overlap with the area where the pressure ring 30 presses the valve seat 20. The front sealing surface 212 of the first valve seat ring 21 fits tightly with the surface of the sphere 10 to form a seal. The movement displacement of the sphere 10 in the high-temperature and high-pressure medium applies an axial thrust to the valve body 2, and can also improve the sealing between the valve body 20 and the connector 70. Furthermore, the two edges of the front sealing surface 212 are designed to be smooth and sharp to form sharp blades. Therefore, during the opening or closing process of the metal-sealed ball valve, the two sharp blade edges of the front sealing surface scrape the spherical surface of the sphere to achieve self-cleaning, and the sharp blade has a smooth arc transition without dead angles to avoid medium accumulation.

[0046] In this embodiment, Figure 4 As shown, along the axial center direction of the valve seat 20, the side of the valve seat 20 facing the connector 70 is the rear sealing surface 221. An annular boss 72 is formed on one side of the annular installation area 71 opposite to the rear sealing surface 221. The annular boss 72 is in close contact with the rear sealing surface 221, so that a static seal is formed between the valve seat 20 and the annular installation area 71 of the connector 70, and the high-temperature and high-pressure medium is prevented from entering the annular cavity from the rear sealing surface of the valve seat to directly flush the flexible graphite ring, thereby ensuring the sealing performance. In addition, the circumferential side wall of the valve seat and the flexible graphite ring form a radial seal between the valve seat and the connector, and the rear sealing surface of the valve seat and the annular shoulder on the connector form an axial seal. Under the action of the double seal, the sealing performance of the metal sealing valve seat is more stable and reliable. Furthermore, in order to make the metal sealing ball valve seat sealing protection structure adapt to the needs of different media, the width of the annular boss 72 can also be adjusted according to the pressure and medium characteristics of the medium.

[0047] In this embodiment, Figure 4 As shown, in order to facilitate the rapid positioning and compression of the valve seat 20 when the pressure ring 30 is connected to the connecting body 70, the outer edge of the first valve seat ring portion 21 facing the ball 10 has a positioning step 213. When the pressure ring 30 is connected to the connecting body 70, the edge of the pressure ring 30 cooperates to extend into the positioning step 213 and compresses the valve body. At the same time, the pressure ring 30 cooperates with the positioning step 213 on the first valve seat ring portion 21, and the static sealing force of the rear sealing surface 221 can be further improved under the axial compression force of the pressure ring 30 and the axial thrust applied to the valve body 2 by the displacement of the ball 10 in the high temperature and high pressure medium, thereby further improving the sealing effect between the rear sealing surface 221 and the annular boss 72.

[0048] In this embodiment, Figure 6As shown, in order to enable the pressure ring 30 to better exert its extrusion effect on the flexible graphite ring 40 after being installed in place, the pressure ring 30 has an annular extrusion protrusion 31 on one side facing the connector 70 along its axial center direction. The annular extrusion protrusion 31 extends into the annular cavity 211, and its annular inner and outer side walls are respectively in contact with the circumferential side wall of the second valve seat ring portion 22 and a portion of the side wall of the corresponding annular installation area 71. The end face of the annular extrusion protrusion 31 abuts against the flexible graphite ring 40. Therefore, when the pressure ring 30 is installed, the annular extrusion protrusion 31 can exert a certain extrusion force on the flexible graphite ring 40 along the axial center direction, further improving the sealing effect. And as Figure 5 As shown, the circumferential side wall of the first valve seat ring portion 21 and the circumferential side wall of the second valve seat ring portion 22 are transitioned by a conical inclined surface 214, and the flexible graphite ring 40 matched with the annular cavity 211 also has an inner ring sealing surface 41, an outer ring sealing surface 42 and a conical sealing surface 43. When the pressure ring 30 presses the flexible graphite 40, the flexible graphite ring 40 is more easily squeezed and deformed to achieve sealing. In addition, the axial pressing force of the pressure ring 30 at the conical sealing surface 43 will generate an oblique extrusion component force, increase the sealing specific pressure of the conical sealing surface 43, and further improve the sealing performance.

[0049] In this embodiment, Figure 1 As shown, in order to improve the reliability of the screws 50 used to fix the pressure ring 30 and the connecting body 70 , a spring washer 60 is sleeved on the screws 50 .

Claims

1. A metal-sealed ball valve seat sealing protection structure, characterized in that: Include: A connector, whose cylindrical end is located inside the valve body of the ball valve; the inner side of the end surface of the connector is cylindrically recessed along its own axial center direction to form an annular installation area; The valve seat is annular and arranged in the annular installation area; the valve seat has a first valve seat ring portion and a second valve seat ring portion; the first valve seat ring portion is close to the ball of the ball valve, and the outer diameter of the second valve seat ring portion is consistent with the outer diameter of the annular installation area and is larger than the outer diameter of the first valve seat ring portion; the valve seat is arranged in the annular installation area, and there is an annular gap between the circumferential side wall of the first valve seat ring portion and the corresponding part of the side wall of the annular installation area, and the circumferential side wall of the second valve seat ring portion is in close contact with the corresponding part of the side wall of the annular installation area; A pressure ring is detachably arranged on the end surface of the connector and presses the valve seat; at the same time, the pressure ring closes the annular gap to form an annular cavity; A flexible graphite ring is arranged in the annular cavity, and the flexible graphite ring is pressed against by the pressure ring.

2. The metal sealing ball valve seat sealing protection structure according to claim 1, characterized in that: The valve seat has an arc-shaped front sealing surface on one side facing the sphere, and the front sealing surface is tightly fitted with the spherical surface of the sphere to form a seal, and does not overlap with the area where the pressure ring presses the valve seat.

3. The metal sealing ball valve seat sealing protection structure according to claim 2, characterized in that: The two edges of the front sealing surface are designed to be rounded and sharp to form sharp blades.

4. The metal sealing ball valve seat sealing protection structure according to claim 1, characterized in that: The valve seat has a rear sealing surface along its axial center direction facing the connector. An annular boss is formed on the surface of the annular installation area opposite to the rear sealing surface. The annular boss fits tightly with the rear sealing surface to form a seal.

5. The metal sealing ball valve seat sealing protection structure according to claim 1, characterized in that: An outer edge of a surface of the first valve seat ring portion facing the sphere has a positioning step that cooperates with the pressure ring.

6. The metal sealing ball valve seat sealing protection structure according to claim 1, characterized in that: The pressure ring has an annular extrusion protrusion on one side facing the connecting body along its axial center direction, and the annular extrusion protrusion extends into the annular cavity. Its annular inner and outer side walls are respectively in contact with the second valve seat ring portion and the annular mounting area, and the end face of the annular extrusion protrusion abuts against the flexible graphite ring.

7. The metal sealing ball valve seat sealing protection structure according to claim 6, characterized in that: A conical inclined surface transition is adopted between the first valve seat ring portion and the second valve seat ring portion, and the flexible graphite ring also has a conical sealing surface that matches with each other.

8. The metal sealing ball valve seat sealing protection structure according to any one of claims 1 to 7, characterized in that: The valve seat is integrally forged.

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