Rising stem ball valve with reverse self-sealing structure

Abstract

The utility model discloses a valve equipment technical field's a kind of stem-up ball valve with reverse self-sealing structure, including valve body, the ball body and the flow passage are arranged in the above-mentioned valve body, the sealing structure is arranged in the position of the above-mentioned ball body and the above-mentioned flow passage junction;Its characterized in that, the sealing structure includes the installation groove being arranged in the inner wall of the above-mentioned valve body, the valve seat is arranged in the above-mentioned installation groove, the section of the above-mentioned valve seat is L shape, the above-mentioned valve seat is provided with fixed surface and the sealing surface for being sealed with the above-mentioned ball body cooperation;The above-mentioned installation surface is connected to the above-mentioned valve body, and the above-mentioned sealing surface is located at the one end of the above-mentioned valve seat away from the above-mentioned valve body;By setting L shape valve seat, the rigidity of sealing surface is reduced and its elasticity is improved, and the cooperation compensation ability of sealing pair between valve seat body sealing surface and ball body sealing surface is improved.

Description

Technical Field

[0001] This utility model relates to the field of valve equipment technology, and in particular to a rising rod ball valve with a reverse self-sealing structure. Background Technology

[0002] Metal-sealed riser ball valves are widely used in molecular sieve dewatering applications in the oil, gas, and chemical industries. A key characteristic of molecular sieve applications is that even after the valve is closed, a high-pressure medium remains downstream, while there is no medium upstream. To avoid affecting the dewatering process performance, the valve must possess excellent reverse sealing performance.

[0003] Existing valve seats have the following characteristics: a large interference fit is required between the outer circle of the valve seat and the valve body to achieve a seal. The specific assembly method involves pressing a metal valve seat, after being frozen with liquid nitrogen, into the valve seat hole on the valve body, maintaining this state until the valve seat temperature returns to room temperature. The advantage of this integral valve seat over a modular one is that it avoids the multiple sealing pairs found in modular valve seats, reducing leakage points and thus reducing the probability of leakage. Its disadvantage is that the rigidity of this integral valve seat is too high; for a good seal between the ball and the valve seat, the center of the ball's sealing surface must be strictly aligned with the center of the valve seat's sealing surface, with minimal deviation. Although current parts manufacturing techniques are sufficient to meet this requirement, after a period of use, wear inevitably occurs at the contact points between the ball trunnion and the ball support, leading to significant misalignment between the center of the ball's sealing surface and the center of the valve seat's sealing surface, resulting in valve leakage. In this case, leakage due to reverse sealing is particularly severe. Utility Model Content

[0004] To overcome the shortcomings of the prior art, the technical problem to be solved by this utility model is: how to improve the problem of short valve reverse sealing life caused by wear at the contact part of the ball trunnion and ball support seat in the prior art.

[0005] The technical solution adopted by this utility model to solve its technical problem is: A rising stem ball valve with a reverse self-sealing structure includes a valve body, a ball and a flow channel disposed within the valve body, and a sealing structure disposed at the junction of the ball and the flow channel; characterized in that the sealing structure includes a mounting groove disposed on the inner wall of the valve body, a valve seat disposed within the mounting groove, the valve seat having an L-shaped cross-section, and the valve seat having a fixing surface and a sealing surface for sealingly engaging with the ball; the fixing surface is connected to the valve body, and the sealing surface is located at the end of the valve seat away from the valve body.

[0006] Furthermore, the two inner sidewalls of the valve seat, which are distributed at right angles, form a support groove, and the inner wall of the mounting groove is provided with a support ring for supporting the support groove.

[0007] Furthermore, the aforementioned support ring and the aforementioned support groove are in clearance fit.

[0008] Furthermore, the cross-section of the aforementioned support ring is rectangular, and the length and width of the cross-section of the aforementioned support ring are respectively adapted to the width dimensions of the two inner walls of the support groove.

[0009] Furthermore, the end of the support ring furthest from the valve seat is flush with the inner wall of the flow channel.

[0010] Furthermore, the two intersecting edges of the inner walls of the aforementioned support groove are provided with elastic grooves extending along the aforementioned valve seat.

[0011] Furthermore, the valve seat and the inner wall of the valve body are interference fit.

[0012] Furthermore, the two rectangular extensions of the L-shaped end face of the valve seat have the same width.

[0013] The beneficial effects of this utility model are: By setting an L-shaped valve seat, the rigidity of the valve seat body sealing surface is reduced and its elasticity is increased, thereby improving the matching compensation capability of the sealing pair between the valve seat body sealing surface and the ball sealing surface. When the support part wears, due to the high elasticity of the valve seat body sealing surface, under the action of reverse pressure P1, the valve seat body sealing surface will more easily and actively conform to the ball sealing surface during reverse sealing, improving the matching compensation capability and thus extending the service life of the valve seat reverse seal.

[0014] The support ring and the valve seat body cooperate with each other. The function of the support ring is to support the sealing surface of the valve seat body to prevent it from shifting and affecting the sealing performance during positive sealing (when there is medium pressure in the upstream flow channel of the valve, but no medium pressure in the downstream flow channel), so as to ensure the positive sealing performance of the valve. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the sealing structure between the ball and the valve seat of this utility model; Figure 2 This is a schematic diagram of the overall structure of this utility model; Figure 3 This is a utility model Figure 2 Schematic diagram of the structure at point A in the middle; Figure 4 This is a schematic diagram of the valve seat interface of this utility model; Figure 5 This is a schematic diagram of the existing valve seat structure; Figure 6 This is a schematic diagram of the calculation model for membrane stress and elastic deformation; Figure 7 This is a schematic diagram of the stress model of the existing valve seat structure; Figure 8 Schematic diagram of the force model of the valve seat structure of this utility model; The markings in the diagram are: 1-valve body, 2-ball, 3-flow channel, 4-valve seat, 5-mounting groove, 6-support groove, 7-elastic groove, 8-support ring. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] like Figures 1-4 As shown in the figure, this application proposes a rising stem ball valve with a reverse self-sealing structure, including a valve body 1, a ball 2 and a flow channel 3 disposed within the valve body 1, and a sealing structure disposed at the junction of the ball 2 and the flow channel 3; the sealing structure includes a mounting groove 5 disposed on the inner wall of the valve body 1, a valve seat 4 disposed within the mounting groove 5, the valve seat 4 having an L-shaped cross-section, and the valve seat 4 having a fixing surface and a sealing surface for sealing and engaging with the ball 2; the fixing surface is connected to the valve body 1, and the sealing surface is located at the end of the valve seat 4 away from the valve body 1. By setting the valve seat 4 in an L-shape, the rigidity of the sealing surface is reduced and its elasticity is increased, thereby improving the compensating ability of the sealing pair between the sealing surface of the valve seat 4 body and the sealing surface of the ball 2.

[0018] Specifically, in existing technologies, such as Figure 5 As shown, the valve seat 4 has high rigidity, which also causes two factors affecting the sealing performance: (1) During reverse sealing, the elastic deformation of the valve seat 4 caused by the reverse medium pressure P1 in the direction of the flow channel 3 is very small, and it cannot form an effective sealing specific pressure generated by the medium pressure P1 on the sealing surface, resulting in poor reverse sealing performance of the valve; (2) In the short term after the valve is used, wear will cause the center of the ball of the sealing surface of the ball 2 and the center of the ball of the sealing surface of the valve seat 4 to not completely overlap, which will cause valve leakage (whether it is forward sealing or reverse sealing). The L-shaped valve seat 4 ensures that the valve seat 4 has sufficient elastic performance, improves the adaptability of the sealing surface of the valve seat 4 to the sealing surface of the ball 2, thereby making up for the above two shortcomings and improving the valve sealing performance. Moreover, the width of the two rectangular extensions of the L-shaped end face of the valve seat 4 is the same, ensuring the balance of the overall elastic performance of the valve seat 4. To further improve the sealing performance during the forward sealing process, the two inner sidewalls of the valve seat 4, which are distributed at right angles, form a support groove 6. The inner wall of the mounting groove 5 is provided with a support ring 8 for supporting the support groove 6. In other words, during the forward sealing process, the valve seat 4 undergoes elastic deformation under force, and the support ring 8 provides stable support for the valve seat 4, preventing the relative displacement of the valve seat 4 and the sealing surface, and ensuring high sealing performance during forward sealing.

[0019] This can be proven from the perspective of stress-strain elastic deformation theory: under the same reverse medium pressure P1, Figure 6 This is a model for calculating membrane stress and elastic deformation applicable to the ROARK stress-strain formula. Where Δ y Elastic deformation; p Single axial load per unit length N / mm ; y : p The length of action, mm ; E The elastic modulus of the material. GPa ; t : p The thickness of the effect.

[0020] For existing valve seats, such as Figure 7 As shown, its elastic deformation amount The calculation process is as follows: Then it is concluded that: Regarding the structural valve seat in this embodiment, as follows: Figure 8 As shown, its elastic deformation is due to and Superimposed structure, It is the elastic deformation of the ring between ΦD1 and ΦD2 under the action of medium pressure P1. It is the elastic deformation of the ring between ΦD2 and ΦD3 under the action of medium pressure P1, and its total elastic deformation ( The calculation process for ) is as follows: Then it is concluded that: Then it is concluded that: The total elastic deformation is: The above calculations demonstrate that the valve seat structure in this application has a larger elastic deformation than existing valve seat structures, resulting in greater sealing adaptability to the ball sealing surface.

[0021] like Figures 2-4As shown, in order to further improve the sealing performance during the forward sealing process, the two inner sidewalls of the valve seat that are distributed at right angles form a support groove, and the inner wall of the mounting groove is provided with a support ring for supporting the support groove; that is, during the forward sealing process, the valve seat undergoes elastic deformation under force, and the support ring provides stable support for the valve seat, avoiding relative displacement between the valve seat and the sealing surface, and ensuring high sealing performance during forward sealing.

[0022] Furthermore, the aforementioned support ring 8 and the aforementioned support groove 6 are in clearance fit, which can ensure that the valve body 1 has a certain elastic deformation space for support by the back support ring 8, ensuring that the valve body 1 has sufficient elastic performance.

[0023] The cross-section of the aforementioned support ring 8 is rectangular, and the length and width of the cross-section of the support ring 8 are respectively adapted to the width dimensions of the two inner walls of the support groove 6, ensuring that the support surface of the support ring 8 and the inner wall of the support groove 6 are in complete contact, further improving the support performance of the support ring 8. Moreover, the end of the aforementioned support ring 8 away from the aforementioned valve seat 4 is flush with the inner wall of the aforementioned flow channel 3, ensuring that the support ring 8 will not affect the unobstructed flow of the flow channel 3.

[0024] Furthermore, the two intersecting edges of the inner walls of the support groove 6 are provided with elastic grooves 7 extending along the valve seat 4. The presence of elastic grooves 7 further enhances the elasticity of the valve seat 4. In other words, under the action of elastic grooves 7, the sealing adaptability of the sealing surface to the sealing surface of the ball 2 is further improved, making it easier to achieve reverse self-sealing capability. Moreover, the presence of elastic grooves 7 also greatly eliminates the stress concentration problem that may exist in this part.

[0025] The outer wall of the valve seat 4 and the inner wall of the mounting groove 5 on the valve body 1 are interference fit. The interference should be greater than the maximum elastic deformation of the valve seat 4 hole in the circumferential direction when the valve body 1 is subjected to 1.1 times the design pressure, so as to ensure that the interference between the outer wall of the valve seat 4 and the inner wall of the mounting groove 5 is still sufficient to achieve the sealing performance between them under the most severe conditions.

[0026] In summary, this application proposes a rising stem ball valve with a reverse self-sealing structure. The L-shaped valve seat 4 improves the elasticity of the valve seat 4 structure, enabling it to have a reverse self-sealing capability. At the same time, the design of the support ring 8 ensures that the stiffness of the sealing surface of the valve seat 4 is sufficient to withstand the requirements of the forward sealing force when the valve is sealing in the forward direction.

Claims

1. A rising stem ball valve with a reverse self-sealing structure, comprising a valve body (1), wherein a ball (2) and a flow channel (3) are disposed within the valve body (1), and a sealing structure is provided at the contact position between the ball (2) and the flow channel (3); characterized in that, The sealing structure includes an installation groove (5) disposed on the inner wall of the valve body (1), a valve seat (4) disposed in the installation groove (5), the valve seat (4) having an L-shaped cross section, the valve seat (4) having a fixing surface and a sealing surface for sealing cooperation with the ball (2); the fixing surface is connected to the valve body (1), and the sealing surface is located at the end of the valve seat (4) away from the valve body (1).

2. A rising stem ball valve with a reverse self-sealing structure according to claim 1, characterized in that, The valve seat (4) has two inner sidewalls that are distributed at right angles to form a support groove (6), and the inner wall of the mounting groove (5) is provided with a support ring (8) for supporting the support groove (6).

3. A rising stem ball valve with a reverse self-sealing structure according to claim 2, characterized in that, The support ring (8) and the support groove (6) are in clearance fit.

4. A rising stem ball valve with a reverse self-sealing structure according to claim 3, characterized in that, The cross-section of the support ring (8) is rectangular, and the length and width of the cross-section of the support ring (8) are adapted to the width dimensions of the two inner walls of the support groove (6).

5. A rising stem ball valve with a reverse self-sealing structure according to claim 4, characterized in that, The end of the support ring (8) away from the valve seat (4) is flush with the inner wall of the flow channel (3).

6. A rising stem ball valve with a reverse self-sealing structure according to claim 2, characterized in that, The two intersecting edges of the inner walls of the support groove (6) are provided with elastic grooves (7) extending along the valve seat (4).

7. A rising stem ball valve with a reverse self-sealing structure according to claim 1, characterized in that, The valve seat (4) and the inner wall of the valve body (1) are interference fit.

8. A rising stem ball valve with a reverse self-sealing structure according to claim 1, characterized in that, The two rectangular extensions of the L-shaped end face of the valve seat (4) have the same width.

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