High-pressure check valve

Abstract

The utility model discloses a high-pressure check valve, and relates to the technical field of valves. The check ring is arranged on the outer wall of the valve cover in a sleeving mode, the check ring is provided with a boss extending outwards in the radial direction, the inner wall of the valve body is provided with a clamping part matched with the boss, the boss and the clamping part are clamped by rotating the check ring, and the check block is inserted to limit rotation of the check ring; a first sealing cavity and a second sealing cavity are axially formed between the outer wall of the extending end of the valve cover and the inner wall of the valve body; the sealing assembly comprises an elastic sealing piece arranged in the first sealing cavity and a wedge-shaped metal sealing ring arranged in the second sealing cavity, and the wedge-shaped metal sealing ring is located above the elastic sealing piece. When the medium pressure rises, the axial force acting on the valve cover is converted into the radial pressing force on the wedge-shaped metal sealing ring through the check ring, the self-tightening effect that the higher the pressure is, the larger the sealing specific pressure is, is formed, and therefore the defect that leakage is likely to be caused by thermal cycle attenuation due to the fact that traditional oval pad forced sealing depends on bolt pre-tightening force is overcome.

Description

Technical Field

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

[0002] High-pressure check valves (nominal pressure PN≥320) are widely used in industrial pipelines in petroleum, chemical, and power industries to prevent backflow of media and ensure system safety. Currently, common high-pressure check valves typically use an elliptical gasket for forced sealing between the valve body and the valve cover.

[0003] This sealing method relies on the preload of high-strength bolts to maintain the sealing pressure, which has the following obvious defects: First, the sealing reliability is low. During the operation of the pipeline system, thermal expansion and contraction caused by changes in the medium temperature will cause fluctuations in the load of the connecting bolts and the preload will gradually decrease. Once the bolt load is insufficient to resist the internal pressure, leakage is very likely to occur at the sealing surface, especially under conditions of frequent start-stop or large temperature difference. Utility Model Content

[0004] This application provides a high-pressure check valve, which solves the problems mentioned in the background art.

[0005] This application provides a high-pressure check valve, including a valve body, a valve cover, a valve disc, a sealing assembly, and a locking structure. One end of the valve cover extends into the valve body, and the inner wall of the valve cover and the inner wall of the valve body together form an inner cavity for accommodating the valve disc. The flange of the valve cover and the top wall of the valve body are initially axially connected by fasteners. The locking structure is disposed between the outer wall of the valve cover and the inner wall of the valve body. The locking structure includes a retaining ring and a retaining block. The retaining ring is fitted onto the outer wall of the valve cover and has a radially outwardly extending boss. The inner wall of the valve body has a locking portion adapted to the boss. The boss engages with the engaging portion by rotating the retaining ring, and a stop block is inserted to restrict the rotation of the retaining ring. A first sealing cavity and a second sealing cavity are formed axially between the outer wall of the valve cover extension end and the inner wall of the valve body. The sealing assembly includes an elastic sealing element disposed in the first sealing cavity and a wedge-shaped metal sealing ring disposed in the second sealing cavity. The wedge-shaped metal sealing ring is located above the elastic sealing element, and the bottom wall of the retaining ring presses against the top wall of the wedge-shaped metal sealing ring axially, so that the wedge-shaped metal sealing ring can achieve radial self-tightening sealing as the medium pressure increases.

[0006] In one possible implementation, the resilient seal includes a Y-ring and an O-ring arranged sequentially along the medium pressure direction, wherein the Y-ring is located at the bottom of the O-ring and its lip faces the inner cavity of the valve body.

[0007] In one possible implementation, the cross-section of the wedge-shaped metal sealing ring is wedge-shaped, wider at the top and narrower at the bottom.

[0008] In one possible implementation, the outer wall of the valve disc is provided with a plurality of guide protrusions along the circumferential direction; the outer wall of the guide protrusions is clearance-fitted with the guide holes correspondingly provided in the valve body.

[0009] In one possible implementation, the top of the valve disc is a conical structure.

[0010] In one possible implementation, the stop is located between adjacent bosses.

[0011] One or more technical solutions provided in the embodiments of this application have at least the following technical effects:

[0012] The high-pressure check valve provided in this application embodiment achieves improved sealing reliability and optimized overall structure through a multi-stage sealing assembly disposed in an axially distributed first and second sealing cavities. The sealing assembly includes an elastic seal disposed in the first sealing cavity and a wedge-shaped metal sealing ring disposed in the second sealing cavity. The elastic seal provides an initial seal through pre-compression and has the ability to achieve auxiliary self-tightening under low pressure using the medium pressure, together forming the initial sealing barrier. The wedge-shaped metal sealing ring is located above the elastic seal, and the bottom wall of the retaining ring presses against its top wall axially, forming the main sealing structure. Its technical advantages are mainly reflected in the following aspects: First, the elastic seal and the wedge-shaped metal sealing ring work together to form a full-condition coverage system from initial pre-tightening and low-pressure self-sealing to high-pressure self-tightening sealing. The two-stage sealing functions complement each other and enhance each other step by step, providing a more reliable continuous sealing barrier. Especially when the medium pressure increases, the axial force acting on the valve cover is converted into radial clamping force on the wedge-shaped metal sealing ring through the retaining ring, forming a self-tightening effect of "the higher the pressure, the greater the sealing specific pressure". This overcomes the defect of traditional elliptical gasket forced sealing, which relies on bolt pre-tightening force and is prone to leakage due to thermal cycling decay. Second, the locking structure undertakes the main load-bearing and anti-rotation functions, so that the connection between the valve cover flange and the valve body top wall does not rely on the continuous pre-tightening of a large number of high-strength bolts in the traditional solution. Only a small number of fasteners are needed to achieve initial pre-tightening and positioning, simplifying the connection structure, reducing the overall weight, and effectively reducing material consumption and manufacturing costs. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of a high-pressure check valve in the prior art;

[0015] Figure 2 This is a schematic diagram of the high-pressure check valve provided in the embodiments of this application;

[0016] Figure 3 for Figure 2 Enlarged view of section A in the image;

[0017] Figure 4 This is a schematic diagram of the valve disc structure provided in an embodiment of this application.

[0018] Icons: 1-Valve body; 2-Valve cover; 21-Flange; 3-Valve disc; 31-Guide protrusion; 4-Sealing assembly; 41-Elastic seal; 411-Y-ring seal; 412-O-ring seal; 42-Wedge-shaped metal sealing ring; 5-Lock structure; 51-Retaining ring; 52-Stop block; 6-Oval gasket; 7-First sealing cavity; 8-Second sealing cavity. Detailed Implementation

[0019] 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, not all, of the embodiments of this application. 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.

[0020] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, 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 connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0021] This application provides a high-pressure check valve, such as... Figures 2 to 4As shown. This high-pressure check valve includes a valve body 1, a valve cover 2, a valve disc 3, a sealing assembly 4, and a locking structure 5. One end of the valve cover 2 extends into the valve body 1, and the inner wall of the valve cover 2 and the inner wall of the valve body 1 together form an inner cavity to accommodate the valve disc 3. The flange 21 of the valve cover 2 is initially axially connected to the top wall of the valve body 1 by fasteners.

[0022] Because this application employs the aforementioned locking structure 5 to bear the main axial force and prevent rotation of the valve under pressure, the connecting bolts between the flange 21 of the valve cover 2 and the top wall of the valve body 1 do not need to rely on a large number of high-strength bolts to provide a huge continuous preload to maintain the seal, as is the case with traditional elliptical gasket 6 sealing schemes. The fasteners used in this application are bolts, whose diameter and number can be significantly reduced, only needing to meet the initial preload and component positioning requirements during assembly. This design simplifies the connection structure, reduces the overall weight, and effectively lowers manufacturing costs and material consumption.

[0023] A locking structure 5 is disposed between the outer wall of the valve cover 2 and the inner wall of the valve body 1. The locking structure 5 includes a retaining ring 51 and a stop block 52. The retaining ring 51 is fitted onto the outer wall of the valve cover 2 and has a radially outwardly extending boss. The inner wall of the valve body 1 has a locking part that matches the boss. By rotating the retaining ring 51, the boss engages with the locking part, and the stop block 52 is inserted to restrict the rotation of the retaining ring 51. A first sealing cavity 7 and a second sealing cavity 8 are formed axially between the outer wall of the valve cover 2 at the extended end and the inner wall of the valve body 1. The sealing assembly 4 includes an elastic sealing element 41 disposed in the first sealing cavity 7 and a wedge-shaped metal sealing ring 42 disposed in the second sealing cavity 8. The wedge-shaped metal sealing ring 42 is located above the elastic sealing element 41, and the bottom wall of the retaining ring 51 presses against the top wall of the wedge-shaped metal sealing ring 42 axially, so that the wedge-shaped metal sealing ring 42 can achieve radial self-tightening sealing as the medium pressure increases.

[0024] Specifically, the engaging part is a groove.

[0025] The high-pressure check valve provided in this application embodiment achieves improved sealing reliability and optimized overall structure through a multi-stage sealing assembly 4 disposed in the first sealing cavity 7 and the second sealing cavity 8, which are distributed axially. The sealing assembly 4 includes an elastic seal 41 disposed in the first sealing cavity 7 and a wedge-shaped metal sealing ring 42 disposed in the second sealing cavity 8. The elastic seal 41 provides an initial seal by pre-compression and has the ability to achieve auxiliary self-tightening by means of medium pressure under low pressure, together forming an initial sealing barrier; the wedge-shaped metal sealing ring 42 is located above the elastic seal 41, and the bottom wall of the retaining ring 51 presses against its top wall axially, forming the main sealing structure. Its technical effects are mainly reflected in the following aspects: First, the elastic sealing element 41 and the wedge-shaped metal sealing ring 42 work together to form a full-condition coverage system from initial pre-tightening and low-pressure self-sealing to high-pressure self-tightening sealing. The two-stage sealing functions complement each other and are enhanced step by step, providing a more reliable continuous sealing barrier. Especially when the medium pressure increases, the axial force acting on the valve cover 2 is converted into radial clamping force on the wedge-shaped metal sealing ring 42 through the retaining ring 51, forming a self-tightening effect of "the higher the pressure, the greater the sealing specific pressure", thereby overcoming the defect of traditional elliptical gasket 6 forced sealing relying on bolt pre-tightening force and easily causing leakage due to thermal cycling decay. Second, the locking structure 5 undertakes the main load-bearing and anti-rotation functions, so that the connection between the flange 21 of the valve cover 2 and the top wall of the valve body 1 does not need to rely on the continuous pre-tightening of a large number of high-strength bolts in the traditional solution. Only a small number of fasteners are needed to achieve initial pre-tightening and positioning, simplifying the connection structure, reducing the overall weight, and effectively reducing material consumption and manufacturing costs.

[0026] like Figure 1 As shown, in the prior art, the valve body 1 and valve cover 2 are typically connected using a wafer-type or flange 21 connection structure. Specifically, the valve cover 2 and valve body 1 are flanged together using multiple circumferentially distributed high-strength bolts. For sealing, an elliptical gasket 6 is typically used for forced sealing between the valve body 1 and valve cover 2; that is, an elliptical metal gasket (elliptical gasket 6) is placed between the sealing surfaces of the flanges 21. This sealing method relies on the preload applied by the high-strength bolts to cause the elliptical gasket 6 to undergo plastic deformation, filling the microscopic unevenness of the sealing surface, thereby forming an initial seal. The establishment and maintenance of its sealing pressure depend entirely on the preload of the high-strength bolts.

[0027] In this embodiment, the elastic seal 41 includes a Y-shaped sealing ring 411 and an O-shaped sealing ring 412 arranged sequentially along the medium pressure direction. The Y-shaped sealing ring 411 is located at the bottom of the O-shaped sealing ring 412, and its lip faces the inner cavity of the valve body 1.

[0028] It should be noted that the elastic seal 41 formed by the combination of the Y-ring 411 and the O-ring 412 constitutes the first line of defense. Pre-compression during installation allows the O-ring 412 to provide a uniform and reliable initial static seal; simultaneously, the Y-ring 411 maintains initial contact due to its pre-compression. When a low-pressure medium is present in the valve, the medium pressure acting on the lip of the Y-ring 411 causes its lip to further tighten against the sealing surface, generating a preliminary self-tightening effect; while the O-ring 412 also enhances its sealing effect with the assistance of system pressure. Together, they improve sealing reliability during low-pressure or pressure-fluctuating phases. This elastic seal 41 combines the dual functions of pre-tightening sealing and low-pressure self-tightening, providing strong protection for the sealing integrity of the valve under critical operating conditions such as opening and closing, and low-pressure operation.

[0029] In this embodiment, the cross-section of the wedge-shaped metal sealing ring 42 is wedge-shaped, wider at the top and narrower at the bottom, which allows the wedge-shaped metal sealing ring 42 to undergo radial compression deformation under the action of medium pressure, forming a unique "pressure self-tightening" effect, and achieving a reliable sealing effect where the higher the medium pressure, the greater the sealing pressure.

[0030] In this embodiment, the outer wall of the valve disc 3 is provided with a plurality of guide protrusions 31 along the circumferential direction. The outer wall of the guide protrusions 31 is clearance-fitted with the corresponding guide holes provided in the valve body 1. In comparison, as Figure 1 The existing high-pressure check valve shown typically uses a valve disc 3 rod guide, that is, the slender rod extending from the top of the valve disc 3 cooperates with an independent guide cylinder. This existing guiding method has the disadvantages of small contact area and insufficient centering. It is easy for the slender rod to bend under force, causing the valve disc 3 to deviate from the center position, affecting its precise fit with the valve seat and the sealing effect.

[0031] The guiding method adopted in this application, in which multiple guide protrusions 31 directly engage with the guide holes of the valve body 1, increases the guiding contact area and improves the stability and centering of the valve disc 3. This structure can effectively withstand higher lateral forces and impacts, ensuring that the valve disc 3 can maintain stable movement and accurately reseat for sealing under high pressure, high flow rate, and frequent opening and closing conditions, thereby improving the guiding reliability, sealing performance, and overall service life of the valve.

[0032] In this embodiment, the top of the valve disc 3 is a conical structure. This structure can effectively guide the flow of the medium, reduce eddies and resistance during the opening and closing process of the valve disc 3, making its movement smoother and its response faster.

[0033] In this embodiment, the stop block 52 is located between adjacent bosses. This position design allows the stop block 52 to directly and reliably limit the rotation tendency of the retaining ring 51 after engagement, ensuring that the locking structure 5 remains locked when subjected to medium pressure and vibration impact, effectively distributing the shear force acting on the bosses, thereby improving the mechanical stability and anti-loosening reliability of the overall connection.

[0034] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0035] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A high-pressure check valve, characterized in that, It includes a valve body (1), a valve cover (2), a valve disc (3), a sealing assembly (4), and a locking structure (5); One end of the valve cover (2) extends into the interior of the valve body (1), and the inner wall of the valve cover (2) and the inner wall of the valve body (1) together form an inner cavity for accommodating the valve disc (3); the flange (21) of the valve cover (2) and the top wall of the valve body (1) are initially axially connected by fasteners. The locking structure (5) is disposed between the outer wall of the valve cover (2) and the inner wall of the valve body (1); the locking structure (5) includes a retaining ring (51) and a stop block (52); the retaining ring (51) is fitted onto the outer wall of the valve cover (2), the retaining ring (51) is provided with a radially outwardly extending boss, the inner wall of the valve body (1) is provided with a locking part adapted to the boss, the boss is locked with the locking part by rotating the retaining ring (51), and the stop block (52) is inserted to restrict the rotation of the retaining ring (51); A first sealing cavity (7) and a second sealing cavity (8) are formed axially between the outer wall of the valve cover (2) extending into the valve body (1). The sealing assembly (4) includes an elastic seal (41) disposed in the first sealing cavity (7) and a wedge-shaped metal sealing ring (42) disposed in the second sealing cavity (8). The wedge-shaped metal sealing ring (42) is located above the elastic seal (41), and the bottom wall of the retaining ring (51) presses against the top wall of the wedge-shaped metal sealing ring (42) in the axial direction, so that the wedge-shaped metal sealing ring (42) can achieve radial self-tightening sealing as the medium pressure increases.

2. The high pressure check valve of claim 1, wherein, The elastic seal (41) includes a Y-type sealing ring (411) and an O-type sealing ring (412) arranged sequentially along the medium pressure direction. The Y-type sealing ring (411) is located at the bottom of the O-type sealing ring (412), and its lip is arranged facing the inner cavity of the valve body (1).

3. The high pressure check valve of claim 1, wherein, The cross-section of the wedge-shaped metal sealing ring (42) is wedge-shaped, wider at the top and narrower at the bottom.

4. The high pressure check valve of claim 1, wherein, The outer wall of the valve disc (3) is provided with a plurality of guide protrusions (31) along the circumferential direction; the outer wall of the guide protrusions (31) is in clearance fit with the guide holes correspondingly provided in the valve body (1).

5. The high pressure check valve of claim 4, wherein, The top of the valve disc (3) is a conical structure.

6. The high pressure check valve of claim 1, wherein, The stop (52) is located between adjacent bosses.

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