High external pressure pipeline zero leakage displacement compensation device

Abstract

This invention discloses a zero-leakage displacement compensation device for high external pressure pipelines. The device is welded to the pipelines on both sides via a straight pipe section of a ball joint and a straight pipe section of a cap II. Caps I and II are fixedly connected, covering the spherical portion of the ball joint. The ball joint can rotate around its center between caps I and II. High-pressure fluid outside the pipeline compresses the pressure-balanced self-tightening seal, achieving balanced compression under high pressure and ensuring sealing performance. The pre-compression force of the pre-compressed pre-pressure ring is applied to the hyperelastic pre-pressure seal, causing it to fit tightly against the ball joint and cap II, achieving pre-pressure sealing under high pressure. A variable-pitch bellows is installed inside the hyperelastic pre-pressure seal and the pre-pressure ring. This device achieves displacement compensation in different directions of the pipeline through the rotation of the ball joint around its center, and achieves displacement compensation in the axial direction of the pipeline through the elongation of the variable-pitch bellows.

Description

Technical Field

[0001] This invention relates to the field of pipeline displacement compensation technology, specifically to a zero-leakage displacement compensation device for high external pressure pipelines. Background Technology

[0002] Pipeline systems, as an important means of transporting fluids and energy, are widely used in industries such as power, chemical, aviation, and shipbuilding. When pipelines undergo large deformations under external loads or support displacements, it can cause serious hazards such as damage to connectors, pipeline rupture, and leakage.

[0003] To prevent pipeline failure due to large deformation, displacement compensators are typically installed to compensate for the deformation. Currently, commonly used compensators include square compensators, sleeve compensators, rotary compensators, spherical compensators, and corrugated compensators.

[0004] Square compensators offer advantages such as simple processing and convenient installation, but they have low compensation capacity, occupy a large space, and cause high local resistance to fluid flow. Sleeve compensators are characterized by small size and large compensation capacity, but their sealing performance is unreliable due to the reliance on bolt pre-tightening, requiring frequent maintenance and packing replacement, and they are unsuitable for high-pressure applications. Rotary compensators offer large compensation capacity and are suitable for high-temperature and high-pressure applications, but their sealing performance is reduced because the sealing rings cannot fit tightly together. Spherical compensators offer advantages such as convenient installation, small space occupation, and large compensation capacity, but their sealing performance is poor due to lateral offset, making them prone to leakage and unsuitable for high-pressure applications. Bellows compensators are advantageous due to their compact structure, large compensation capacity, and low leakage rate, making them suitable for high-pressure applications, but they are prone to corrosion failure and have a short service life. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention aims to provide a zero-leakage displacement compensation device for high-pressure pipelines. This device combines the structural forms of a spherical compensator and a corrugated compensator, employing multiple sealing devices to ensure pipeline sealing performance under high external pressure environments. It is suitable for deep-sea applications, high-pressure vessels, and other similar locations, and offers advantages such as high pressure resistance, zero leakage, reliable sealing performance, compact structure, and small footprint.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A zero-leakage displacement compensation device for high external pressure pipelines includes a ball joint 1, a pressure-balanced self-tightening seal 2, a cap I3, a cap II4, a super-elastic pre-pressure seal 5, a pre-pressure ring 6, and a variable-pitch bellows 7. The displacement compensation device is welded to the pipelines on both sides via straight pipe sections of the ball joint 1 and cap II4. Cap I3 and cap II4 are fixedly connected, covering the spherical portion of the ball joint 1. The ball joint 1 can rotate around its center between cap I3 and cap II4. A trapezoidal groove is cut on cap I3 at the contact point with the ball joint 1. The pressure-balanced self-tightening seal 2 is fixed to cap I3 via a matching trapezoidal section on one side, and its other side is engaged in the groove between the straight pipe section and the spherical section of the ball joint 1. High-pressure fluid outside the pipeline compresses the pressure-balanced self-tightening seal 2, causing it to fit tightly against the ball joint 1 and cap I3. 3. The pressure-balanced self-tightening seal 2 under high pressure is balanced and tightened to ensure sealing performance. Trapezoidal and rectangular grooves are opened on the cover II 4 where it contacts the ball joint 1. The superelastic pre-pressure seal 5 is fixed to the cover II 4 through its matching trapezoidal section on one side. The pre-pressure ring 6 is installed in the rectangular groove of the cover II 4. The main body of the superelastic pre-pressure seal 5 is snapped into the small cavity formed by the ball joint 1, the cover II 4, and the pre-pressure ring 6. The pre-compression force of the pre-pressure ring 6 is applied to the superelastic pre-pressure seal 5, making it tightly fit against the ball joint 1 and the cover II 4, achieving pre-pressure sealing of the superelastic pre-pressure seal 5 under high pressure. The variable pitch bellows 7 is set inside the superelastic pre-pressure seal 5 and the pre-pressure ring 6, with the large pitch side welded to the ball joint 1 and the small pitch side welded to the cover II 4. 4. As the third layer of sealing of the device; the displacement compensation device realizes displacement compensation of the pipeline in different directions by rotating the ball joint head 1 around the center of the ball in different directions, and realizes displacement compensation of the pipeline axis direction by extending the variable pitch bellows 7.

[0008] The caps I 3 and II 4 are connected by bolts or welding, with a sealing gasket between them.

[0009] The ball joint head 1, cover I 3, cover II 4 and variable pitch bellows 7 are made of TA2 material.

[0010] Both the pressure-balanced self-tightening seal 2 and the ultra-elastic pre-pressure seal 5 are made of corrosion-resistant rubber.

[0011] The corrosion-resistant rubber is polyurethane rubber, butyl rubber, or fluororubber.

[0012] The preload ring 6 is made of superelastic porous carbon material.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1) The high external pressure pipeline zero leakage displacement compensation device of the present invention combines the advantages of corrugated compensator and spherical compensator. The ball joint head can rotate around its center. One or more compensation devices can be used to perform displacement compensation in multiple directions. At the same time, the corrugated pipe can also perform axial displacement compensation. Therefore, the device has good multi-directional displacement compensation capability.

[0015] 2) The high external pressure pipeline zero-leakage displacement compensation device of the present invention adopts three parts for sealing: pressure balance self-tightening seal, ultra-elastic pre-pressure seal and variable pitch bellows, to ensure that the compensation device has good sealing performance during displacement compensation under high external pressure environment and will not cause leakage accidents.

[0016] 3) The main body of the high external pressure pipeline zero leakage displacement compensation device of the present invention is specifically a ball joint head, a cover and a variable pitch corrugated pipe. It is made of TA2 material and has the advantages of high strength and toughness, low density, corrosion resistance and strong high temperature creep resistance. It has a compact structure, occupies little space and has a wide range of applications. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the zero-leakage displacement compensation device for high external pressure pipelines according to the present invention.

[0018] Figure 2 This is a schematic cross-sectional view of the pressure-balanced self-tightening seal of the present invention.

[0019] Figure 3 This is a schematic cross-sectional view of the superelastic pre-compression seal of the present invention.

[0020] Figure 4 This is a schematic cross-sectional view of the titanium alloy variable pitch bellows of the present invention.

[0021] Figure 5 A schematic diagram for installing a compensation device.

[0022] Figure 6 This is a schematic diagram for installing three compensation devices.

[0023] Among them: 1. Ball joint; 2. Pressure balanced self-tightening seal; 3. Cover I; 4. Cover II; 5. Super-elastic pre-pressure seal; 6. Pre-pressure ring; 7. Variable pitch bellows. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] like Figure 1As shown, the high external pressure pipeline zero-leakage displacement compensation device of the present invention includes a ball joint 1, a pressure-balanced self-tightening seal 2, a cap I 3, a cap II 4, a super-elastic pre-pressure seal 5, a pre-pressure ring 6, and a variable-pitch bellows 7. The device is welded to the pipelines on both sides via straight pipe sections of the ball joint 1 and cap II 4. Cap I 3 and cap II 4 are connected by bolts or welding, with a sealing gasket between them. The ball joint 1 can rotate around its center between cap I 3 and cap II 4. A cross-sectional schematic diagram of the pressure-balanced self-tightening seal 2 is shown below. Figure 2 As shown, a trapezoidal groove is made on the sealing cap I 3 at the contact point with the ball joint head 1. The pressure-balanced self-tightening seal 2, made of corrosion-resistant rubber, is fixed to the sealing cap I 3 through a matching trapezoidal section on one side, and the other side is engaged in the groove between the straight pipe section and the spherical section of the ball joint head 1. The corrosion-resistant rubber material of the pressure-balanced self-tightening seal 2 can be polyurethane rubber, butyl rubber, or fluororubber, etc. A cross-sectional schematic diagram of the superelastic pre-pressure seal 5 is shown below. Figure 3 As shown, trapezoidal and rectangular grooves are made on the sealing cap II 4 where it contacts the ball joint 1. A corrosion-resistant rubber superelastic pre-pressure seal 5 is fixed to the sealing cap II 4 via a matching trapezoidal section on one side. A pre-pressure ring 6 made of superelastic porous carbon material is installed in the rectangular groove of the sealing cap II 4. The main body of the superelastic pre-pressure seal 5 is snapped into the small cavity formed by the ball joint 1, the sealing cap II 4, and the pre-pressure ring 6. The corrosion-resistant rubber material of the superelastic pre-pressure seal 5 can be polyurethane rubber, butyl rubber, or fluororubber, etc. A cross-sectional schematic diagram of the bellows 7 is shown below. Figure 4 As shown, the variable pitch bellows 7 is installed inside the superelastic pre-pressure seal 5 and the pre-pressure ring 6. The large pitch side is welded to the ball joint head 1, and the small pitch side is welded to the cover II 4.

[0026] The working principle of the high external pressure pipeline zero-leakage displacement compensation device of the present invention is as follows:

[0027] If the pipeline requires displacement compensation, the high external pressure pipeline zero-leakage displacement compensation device of this invention should be installed at the connection between the two pipeline sections. When installing one compensation device, such as... Figure 5 As shown, when the ball joint 1 deflects at a certain angle around the Y-axis passing through the center of the ball, the axial distance between the straight tubes on the left and right sides can be changed. When the ball joint 1 deflects at a certain angle around the Z-axis passing through the center of the ball and perpendicular to the plane of the paper, small displacement compensation in the Y-direction can be achieved. When three compensation devices are installed, as shown... Figure 6As shown, when the ball joint head 1 of the three compensation devices deflects a certain angle around the center of the ball and perpendicular to the Z-axis of the paper, and the rotation angles of the left and right compensators are opposite (one clockwise and the other counterclockwise), large displacement compensation of the pipeline in the X direction can be achieved. When the rotation angles of the left and right compensators are in the same direction (clockwise or counterclockwise at the same time), displacement compensation of the pipeline in the Y direction can be achieved. When the ball joint head 1 deflects a certain angle around the center of the ball on the X-axis, displacement compensation of the pipeline in the Z direction can be achieved. At the same time, the extension of the variable pitch bellows 7 can also achieve displacement compensation in the axial direction of the pipeline.

[0028] For the pressure-balanced self-tightening seal 2, the high-pressure fluid flowing into the groove drilled on the ball joint 1 and the gap between the ball joint 1 and the cover I 3 compresses the pressure-balanced self-tightening seal 2, making the corrosion-resistant rubber material of the pressure-balanced self-tightening seal 2 tightly fit onto the ball joint 1 and the cover I 3, thereby achieving balanced compression of the pressure-balanced self-tightening seal 2 under high pressure and ensuring sealing performance; for the superelastic pre-pressure seal 5, the pre-compression ring 6 is pre-compressed and then cooperates with the corrosion-resistant rubber material of the superelastic pre-pressure seal 5. The pre-compression force of the pre-compressed ring 6 is applied to the superelastic pre-pressure seal 5, making the superelastic pre-pressure seal 5 tightly fit onto the ball joint 1 and the cover II 4, thereby achieving pre-pressure sealing of the superelastic pre-pressure seal 5 under high pressure; for the titanium alloy variable pitch bellows 7, the large pitch side is welded to the ball joint 1, which can ensure reliable welding under large deformation when the ball joint 1 rotates, and the small pitch side is welded to the cover II 4. It can ensure sufficient strength under multiple operations. The titanium alloy variable pitch bellows 7 is welded to the ball joint head 1 and the cover II 4 on both sides respectively. The good sealing performance of the bellows itself can ensure excellent sealing performance at this seal.

[0029] In summary, this invention can effectively compensate for pipeline deformation by using angle compensation displacement, and the triple sealing measures adopted can ensure good sealing performance of the pipeline under high external pressure environment.

Claims

1. A zero-leakage displacement compensation device for high external pressure pipelines, characterized in that: The device includes a ball joint (1), a pressure-balanced self-tightening seal (2), a cap I (3), a cap II (4), a super-elastic pre-pressure seal (5), a pre-pressure ring (6), and a variable pitch bellows (7). This displacement compensation device is welded to the pipes on both sides via the straight pipe sections of the ball joint (1) and the cap II (4). The caps I (3) and II (4) are fixedly connected, covering the spherical portion of the ball joint (1). The ball joint (1) can rotate around the center of the ball joint between the caps I (3) and II (4). A trapezoidal groove is opened at the contact point between I(3) and the ball joint (1). The pressure-balanced self-tightening seal (2) is fixed to the cover I(3) by a trapezoidal section that matches one side of it, and the other side is snapped into the groove between the straight pipe section and the spherical section of the ball joint (1). The high-pressure fluid outside the pipeline presses the pressure-balanced self-tightening seal (2) so that the pressure-balanced self-tightening seal (2) fits tightly against the ball joint (1) and the cover I(3), realizing the balanced pressing of the pressure-balanced self-tightening seal (2) under high pressure and ensuring the sealing performance; at the cover II(4) Trapezoidal and rectangular grooves are opened at the contact point between the ball joint head (1) and the superelastic pre-pressure seal (5). The superelastic pre-pressure seal (5) is fixed on the cover II (4) through the trapezoidal section that matches one side of it. The pre-pressure ring (6) is installed in the rectangular groove of the cover II (4). The main body of the superelastic pre-pressure seal (5) is snapped into the small cavity formed by the ball joint head (1), the cover II (4), and the pre-pressure ring (6). The pre-compression force of the pre-pressure ring (6) is applied to the superelastic pre-pressure seal (5), so that the superelastic pre-pressure seal (5) fits tightly against the ball joint head. (1) and the cap II (4) are used to achieve the pre-pressure sealing of the super-elastic pre-pressure seal (5) under high pressure; the variable pitch bellows (7) is set inside the super-elastic pre-pressure seal (5) and the pre-pressure ring (6), with the large pitch side welded to the ball joint head (1) and the small pitch side welded to the cap II (4), serving as the third seal of the device; the displacement compensation device achieves displacement compensation in different directions of the pipeline by rotating the ball joint head (1) around the center of the ball in different directions, and achieves displacement compensation in the axial direction of the pipeline by extending the variable pitch bellows (7).

2. The zero-leakage displacement compensation device for high external pressure pipelines according to claim 1, characterized in that: The caps I (3) and II (4) are connected by bolts or welding, with a sealing gasket between them.

3. The zero-leakage displacement compensation device for high external pressure pipelines according to claim 1, characterized in that: The ball joint (1), cover I (3), cover II (4) and variable pitch bellows (7) are made of TA2 material.

4. The zero-leakage displacement compensation device for high external pressure pipelines according to claim 1, characterized in that: Both the pressure-balanced self-tightening seal (2) and the ultra-elastic pre-pressure seal (5) are made of corrosion-resistant rubber.

5. A zero-leakage displacement compensation device for high external pressure pipelines according to claim 4, characterized in that: The corrosion-resistant rubber is polyurethane rubber, butyl rubber, or fluororubber.

6. The zero-leakage displacement compensation device for high external pressure pipelines according to claim 1, characterized in that: The preload ring (6) is made of superelastic porous carbon material.

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