Pre-tightening structure for valve seat of ultrahigh-pressure ball valve

Abstract

The utility model belongs to the technical field of ball valves, and discloses an ultrahigh pressure ball valve seat pre-tightening structure which comprises a supporting seat a and a supporting seat b which are connected with each other, a sealing ball seat a and a sealing ball seat b are arranged at the adjacent ends of the supporting seat a and the supporting seat b respectively, and a ball body is movably connected between the sealing ball seat a and the sealing ball seat b. A wave-shaped spring providing pre-tightening force is arranged at the end, away from the ball body, of the sealing ball seat a, and a stabilizing structure used for supporting the sealing ball seat a is further arranged in the supporting seat a. The service life of the ball valve is prolonged, deviation of the center of the ball body is avoided, and normal operation is guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of petroleum and natural gas downhole operation equipment, and in particular relates to a valve seat pre-tightening structure for an ultra-high pressure ball valve. Background Art

[0002] The existing two-way sealing ball valve is preloaded mainly by cylindrical compression springs and disc springs. The cylindrical compression spring requires a large installation space, while the downhole tool is limited by the external dimensions and has very little available space, which often cannot meet the design requirements. In addition, this type of ball valve is often used to open under high pressure difference conditions. In this state, the extrusion force between the ball and the ball seat of the ball valve is large, so the operating force required to open the ball valve is large, and the greater the operating force, the higher the design requirements for the downhole tool to which it belongs. In addition, the excessive extrusion force when the high pressure difference is opened will cause the sealing surface of the ball and the ball seat to wear during rotation, reducing the service life of the ball valve. Therefore, the preload force of the ball valve should be as high as possible while meeting the preload force requirements of the ball valve itself. However, due to its own characteristics, the disc spring has low processing and manufacturing precision and poor stiffness consistency, which results in a large deviation in the preload force and cannot meet the use requirements of downhole tools well.

[0003] In addition, the spring test compression state of the existing structure is pre-tightened state and working state. When the pressure difference direction at both ends of the ball valve changes, the spring will be compressed from the pre-tightened state to the working state. Due to the occurrence of compression distance, the pre-tightened end ball seat will move axially, causing the ball center to easily shift, resulting in abnormal fluctuations in the high-pressure end pressure, making the pressure monitoring curve of the operation process abnormal. The pressure curve is an important factor in judging the downhole conditions. This abnormal curve will not be able to determine whether it is due to abnormal downhole pressure or pressure leakage caused by ball valve leakage or other reasons. Inappropriate treatment measures may be taken due to misjudgment, resulting in repeated adjustments and implementation of treatment measures, resulting in increased operation cycle, cost and other unpredictable risks, and even well control risks. Utility Model Content

[0004] The utility model aims to provide a pre-tightening structure for an ultra-high pressure ball valve seat, which can improve the service life of the ball valve and prevent the center of the ball from shifting, thereby ensuring normal operation.

[0005] The technical solution adopted by the utility model is a pre-tightening structure for an ultra-high pressure ball valve seat, comprising a support seat a and a support seat b connected to each other, a sealing ball seat a and a sealing ball seat b are respectively arranged at adjacent ends of the support seat a and the support seat b, a ball is movably connected between the sealing ball seat a and the sealing ball seat b, a wave spring for providing a pre-tightening force is arranged at the end of the sealing ball seat a away from the ball, and a stabilizing structure for supporting the sealing ball seat a is also arranged in the support seat a.

[0006] The utility model is also characterized in that:

[0007] The stabilizing structure includes a step surface located on the inner side of the support seat a and milled out axially along the support seat a. A step block is vertically fixedly connected to the step surface close to the inner side of the support seat a, and an annular groove is formed between the step block and the support seat a.

[0008] The wave spring is arranged in the annular groove, and one side of the wave spring abuts against the sealing ball seat a, and the other side abuts against the supporting seat a.

[0009] The sealing ball seat a is arranged inside the supporting seat a, and an O-ring is sleeved outside the sealing ball seat a. The sealing ball seat a is sealingly connected to the supporting seat a through the O-ring.

[0010] A supporting ring for auxiliary sealing is also arranged on one side of the O-ring, and the supporting ring is sleeved on the outer side of the sealing ball seat a.

[0011] The sealing ball seat b is located inside the supporting seat b, and one end of the sealing ball seat b abuts against the ball body, and the other end abuts against the supporting seat b.

[0012] The beneficial effects of the utility model are:

[0013] (1) The utility model adopts a wave spring, which takes advantage of the small size and high rigidity consistency of the wave spring. It only occupies a very small space to improve the consistency of the preload force of the ball valve, so that the sealing performance between the valve seat and the ball of the ball valve meets the requirements. At the same time, it reduces the wear between the ball seat of the ball valve when it is opened with a pressure difference, prolongs its service life, reduces the operating force of the tool for opening the ball valve under pressure, and thus reduces the difficulty of tool design.

[0014] (2) The valve seat pre-tightening structure of the ultra-high pressure ball valve of the utility model is in a state where there is only surface contact between the sealing ball seats on both sides and the corresponding support seats without axial clamping force when there is no pressure differential in the ball valve. Therefore, the ball center of the ball valve will never move when there is a two-way pressure differential in the ball valve. By placing the wave spring in the annular groove inside the support seat a and abutting against one end of the sealing ball seat a, it is ensured that the wave spring is always in a working state. When the ball valve is subjected to a two-way pressure differential, the pre-tightening force of the wave spring on the ball valve remains unchanged, thereby avoiding abnormal pressure fluctuations caused by the change in the direction of the pressure differential. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the valve seat pre-tightening structure of the ultra-high pressure ball valve of the utility model;

[0016] Figure 2 yes Figure 1 Schematic diagram of the enlarged structure at point A in the middle.

[0017] In the figure, 1. sphere, 2. support seat a, 3. wave spring, 4. sealing ball seat a, 5. annular groove, 6. step block, 7. sealing ball seat b, 8. support seat b, 9. O-ring, 10. support ring. DETAILED DESCRIPTION

[0018] The utility model is described in detail below with reference to the accompanying drawings and specific implementation modes.

[0019] Example 1

[0020] like Figure 1 As shown, the novel ultra-high pressure ball valve seat pre-tightening structure disclosed in the utility model comprises a supporting seat a2 and a supporting seat b8 connected to each other, and a sealing ball seat a4 and a sealing ball seat b7 are respectively arranged at the adjacent ends of the supporting seat a2 and the supporting seat b8, and a ball 1 is movably connected between the sealing ball seat a4 and the sealing ball seat b7, and the ball 1 is clamped in the middle position by the supporting seat a2 and the supporting seat b8, and the ball 1 is in a suspended state as a whole, and is fixed by different shaft rods, etc., which improves the flexibility of the ball 1 when rotating, and also reduces the overall size of the ball valve. The sealing ball seat a4 is provided with a wave spring 3 providing pre-tightening force at one end away from the ball 1. Through the characteristics of the wave spring 3 with small external dimensions and high consistency of rigidity, it only occupies a very small space to improve the consistency of the pre-tightening force of the ball valve, so that the sealing between the valve seat of the ball valve and the ball 1 meets the requirements, and at the same time reduces the project wear between the ball seat of the ball valve when opening with pressure difference, prolongs the service life, reduces the operating force of the tool to open the ball valve with pressure, and thus reduces the difficulty of tool design.

[0021] The support seat a2 is also provided with a stabilizing structure for supporting the sealing ball seat a4. The stabilizing mechanism ensures that when a pressure difference is generated in both directions at both ends of the ball 1, the preload force of the wave spring 3 on the ball valve remains unchanged, thereby avoiding abnormal pressure fluctuations caused by the change in the direction of the pressure difference.

[0022] Example 2

[0023] The novel ultra-high pressure ball valve seat pre-tightening structure disclosed in the utility model comprises a supporting seat a2 and a supporting seat b8 which are connected to each other, a sealing ball seat a4 and a sealing ball seat b7 are respectively arranged at adjacent ends of the supporting seat a2 and the supporting seat b8, a ball 1 is movably connected between the sealing ball seat a4 and the sealing ball seat b7, a wave spring 3 for providing pre-tightening force is arranged at the end of the sealing ball seat a4 away from the ball 1, and a stabilizing structure for supporting the sealing ball seat a4 is also arranged in the supporting seat a2.

[0024] like Figure 2As shown, the stable structure includes a step surface located on the inner side of the support seat a2 and milled along the axial direction of the support seat a2, and a step block 6 is vertically fixedly connected to the step surface near the inner side of the support seat a2, and an annular groove 5 is formed between the step block 6 and the support seat a2. The wave spring 3 is arranged in the annular groove 5, and one side of the wave spring 3 abuts against the sealing ball seat a4, and the other side abuts against the support seat a2. That is, the step block 6 abuts against one end of the support seat a2, and the wave spring 3 applies a pre-tightening force to the support seat a2, so that even if a high pressure difference is generated on both sides of the ball 1, since the support seat a2 is limited by the step block 6, and the wave spring 3 is placed in the annular groove 5, the wave spring 3 is difficult to be subjected to the axial extrusion force caused by the high pressure difference, and the pre-tightening force of the wave spring 3 on the support seat a2 remains unchanged, ensuring the sealing between the ball 1 and the sealing ball seats on both sides.

[0025] Example 3

[0026] The novel ultra-high pressure ball valve seat pre-tightening structure disclosed in the utility model comprises a supporting seat a2 and a supporting seat b8 connected to each other, and a sealing ball seat a4 and a sealing ball seat b7 are respectively arranged at adjacent ends of the supporting seat a2 and the supporting seat b8, and the sealing ball seat a4 is arranged inside the supporting seat a2, and an O-ring 9 is sleeved on the outside of the sealing ball seat a4, and the sealing ball seat a4 is sealed and connected to the supporting seat a2 through the O-ring 9. A supporting ring 10 for auxiliary sealing is also arranged on one side of the O-ring 9, and the supporting ring 10 is sleeved on the outside of the sealing ball seat a4 to reduce the sealing gap.

[0027] The sealing ball seat b7 is located inside the support seat b8, and one end of the sealing ball seat b7 abuts against the ball 1, and the other end abuts against the support seat b8.

[0028] A ball 1 is movably connected between the sealing ball seat a4 and the sealing ball seat b7. A wave spring 3 for providing pre-tightening force is arranged at one end of the sealing ball seat a4 away from the ball 1. A stable structure for supporting the sealing ball seat a4 is also arranged in the support seat a2.

[0029] The stabilizing structure includes a step surface located inside the support seat a2 and milled along the axial direction of the support seat a2, and a step block 6 is vertically fixedly connected to the step surface near the inside of the support seat a2, and an annular groove 5 is formed between the step block 6 and the support seat a2. The step block 6 and the support seat a2 can be integrally formed or the annular groove 5 can be directly milled. The wave spring 3 is arranged in the annular groove 5, and one side of the wave spring 3 abuts against the sealing ball seat a4, and the other side abuts against the support seat a2.

[0030] When the utility model ultra-high pressure ball valve seat pre-tightening structure is used, the ball valve needs to be sealed by the O-ring 9 to seal the outer circumference of the sealing ball seat a4, and at the same time, the contact surface between the sealing ball seat a4 and the ball 1 has sufficient extrusion force to achieve the sealing of the ball valve. Among them, the supporting ball seat b7 only plays a supporting role but no sealing role. Its working state and process are as follows:

[0031] Sealing of initial pressure: The wave spring 3 provides extrusion force for the contact surface between the sealing ball seat a4 and the ball 1 in the working (compression) state, thereby achieving sealing and establishing initial pressure.

[0032] Sealing after initial pressure is established: After the initial pressure is established, a certain pressure difference is formed on both sides of the ball 1. When the pressure difference gradually increases, the extrusion force provided by the wave spring 3 for the contact surface between the sealing ball seat a4 and the ball 1 will be insufficient. At this time, the extrusion force relies on the extrusion force formed by the pressure difference on both sides of the ball 1.

[0033] The pressure on the left side of the ball valve is high: When the pressure on the left side of the ball valve is high, the sealing ball seat a4 is squeezed on the ball 1 due to the pressure difference, and the ball 1 is squeezed on the sealing ball seat b7. The sealing ball seat b7 is fixed by the support seat b8. Therefore, the center of the ball 1 cannot move, and the space on the left side of the ball 1 will not change. Even if the pressure on the left side continues to rise, the ball 1 will not fluctuate abnormally.

[0034] The pressure on the right side of the ball valve is high: when the pressure on the right side of the ball valve is high, the ball 1 is squeezed on the sealing ball seat a4 due to the pressure difference, and the sealing ball seat a is fixed by the support seat a2. Therefore, the center of the ball 1 cannot move horizontally, and the space on the left side of the ball 1 will not change. Even if the pressure on the left side continues to rise, the ball 1 will not fluctuate abnormally.

Claims

1. Ultra-high pressure ball valve seat pre-tightening structure, characterized in that: The invention comprises a supporting seat a (2) and a supporting seat b (8) which are connected to each other. A sealing ball seat a (4) and a sealing ball seat b (7) are respectively arranged at adjacent ends of the supporting seat a (2) and the supporting seat b (8). A ball (1) is movably connected between the sealing ball seat a (4) and the sealing ball seat b (7). A wave spring (3) for providing a pre-tightening force is arranged at the end of the sealing ball seat a (4) away from the ball (1). A stabilizing structure for supporting the sealing ball seat a (4) is also arranged inside the supporting seat a (2).

2. The ultra-high pressure ball valve seat pre-tightening structure according to claim 1 is characterized in that: The stabilizing structure comprises a step surface located on the inner side of the support seat a (2) and milled out along the axial direction of the support seat a (2), a step block (6) being vertically fixedly connected to the step surface near the inner side of the support seat a (2), and an annular groove (5) is formed between the step block (6) and the support seat a (2).

3. The ultra-high pressure ball valve seat pre-tightening structure according to claim 2 is characterized in that: The wave spring (3) is arranged in the annular groove (5), and one side of the wave spring (3) abuts against the sealing ball seat a (4), and the other side abuts against the support seat a (2).

4. The ultra-high pressure ball valve seat pre-tightening structure according to any one of claims 1 to 3, characterized in that: The sealing ball seat a (4) is arranged on the inner side of the supporting seat a (2), and an O-ring (9) is sleeved on the outer side of the sealing ball seat a (4). The sealing ball seat a (4) is sealingly connected to the supporting seat a (2) via the O-ring (9).

5. The ultra-high pressure ball valve seat pre-tightening structure according to claim 4, characterized in that: A supporting ring (10) for auxiliary sealing is also provided on one side of the O-ring (9), and the supporting ring (10) is sleeved on the outside of the sealing ball seat a (4).

6. The ultra-high pressure ball valve seat pre-tightening structure according to any one of claims 1 to 3, characterized in that: The sealing ball seat b (7) is located inside the support seat b (8), and one end of the sealing ball seat b (7) abuts against the ball body (1), and the other end abuts against the support seat b (8).

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