Leak-proof metal compensator

Abstract

The utility model discloses a leakproof metal compensator, which belongs to the technical field of metal compensators and comprises a plurality of layers of metal corrugated pipes arranged concentrically, flanges are welded at the upper end and the lower end of each metal corrugated pipe, and a flexible sealing material layer is filled between the adjacent metal corrugated pipes to form a radial multi-layer buffer structure. A dynamic adjusting sealing structure is arranged at the upper end of the flange and comprises an annular sealing groove formed in the upper end of the inner side of the flange, an annular hollow rubber bag is arranged in the sealing groove and filled with a compressible medium, and a sealing ring is fixedly connected to the top of the annular hollow rubber bag; a plurality of mounting lugs are fixedly arranged on the side of the flange; the annular pressure sensor is arranged at the joint of the flange and the metal corrugated pipe, the synergistic effect of dynamic sealing, graded pressure relief, intelligent corrosion prevention and real-time monitoring is achieved, the safety and reliability of the metal compensator are remarkably improved, and the metal compensator is suitable for high-pressure and high-temperature working conditions of petroleum, chemical engineering, heat supply pipe networks and the like.

Description

Technical Field

[0001] This utility model relates to the field of metal compensator technology, specifically to a metal compensator with anti-leakage, dynamic sealing adjustment and multiple safety protections. Background Technology

[0002] Metal compensators are widely used in piping systems to absorb displacement changes caused by thermal expansion and contraction, mechanical vibration, etc. Existing metal compensators mostly employ single-layer or multi-layer metal bellows structures, but these present the following problems in practical applications:

[0003] 1. Insufficient sealing performance: Traditional sealing structures are mostly static designs, which cannot dynamically adjust the sealing force according to changes in pipeline pressure, making them prone to leakage under high pressure.

[0004] 2. Limited compressive strength: The lack of buffer material between the multi-layered corrugated pipes makes them prone to deformation or rupture due to stress concentration.

[0005] 3. Lack of pressure relief mechanism: The lack of a staged pressure relief structure under overpressure or high temperature conditions can easily lead to overall rupture accidents;

[0006] 4. Delayed leakage monitoring: Traditional structures rely on manual inspections, making it difficult to detect sealing failures or minor leaks in a timely manner.

[0007] While existing technologies attempt to improve performance by increasing the thickness of the sealing ring or modifying the bellows material, they cannot fundamentally solve problems such as dynamic sealing, safe pressure relief, and self-healing corrosion prevention. Therefore, there is an urgent need for a metal compensator with adaptive sealing, multiple pressure relief protections, and intelligent monitoring functions. Utility Model Content

[0008] 1. Technical problem to be solved:

[0009] To address the problems existing in the prior art, the purpose of this utility model is to provide a leak-proof metal compensator that achieves the synergistic effects of dynamic sealing, graded pressure relief, intelligent corrosion prevention and real-time monitoring, significantly improving the safety and reliability of the metal compensator. It is suitable for high-pressure and high-temperature working conditions such as petroleum, chemical and heating pipeline networks.

[0010] 2. Technical Solution:

[0011] To solve the above problems, the present invention adopts the following technical solution.

[0012] A leak-proof metal compensator includes multiple layers of concentrically arranged metal bellows, with flanges welded to both the upper and lower ends of the metal bellows.

[0013] A flexible sealing material layer is filled between adjacent metal bellows to form a radial multi-layer buffer structure;

[0014] The upper end of the flange is provided with a dynamic adjustment sealing structure. The dynamic adjustment sealing structure includes an annular sealing groove opened at the upper end of the inner side of the flange. An annular hollow rubber bladder is provided in the sealing groove. The annular hollow rubber bladder is filled with a compressible medium, and a sealing ring is fixedly connected to its top.

[0015] The flange is fixedly provided with multiple mounting lugs on its side;

[0016] An annular pressure sensor is installed at the connection between the flange and the metal bellows, and the annular pressure sensor is connected to an external monitoring system via a wireless transmission module.

[0017] A further improvement is that a positioning bracket is fixedly provided between the central inner walls of the sealing groove, the bottom of the positioning bracket is arc-shaped and a channel is opened in the center; multiple air inlets communicating with the sealing groove are opened on the side end of the flange, and the bottom of the annular hollow rubber bladder is fixed to the bottom of the positioning bracket.

[0018] A further improvement is that the outer end of the bottom metal bellows is provided with a pressure relief hole, and a weak ring is installed on the inner wall. The outer side of the pressure relief hole is covered with a fusible alloy sheet.

[0019] A further improvement is that the outer surface of the metal bellows is coated with an anti-corrosion layer, which is a composite coating containing microcapsules, and the microcapsules are encapsulated with corrosion inhibitors.

[0020] A further improvement is that a high-temperature resistant adhesive is coated between the sealing ring and the top of the annular hollow rubber bladder. The high-temperature resistant adhesive is a silicone sealant or epoxy resin that can withstand temperatures above 200°C.

[0021] A further improvement is that the compressible medium is nitrogen.

[0022] 3. Beneficial effects:

[0023] Compared with the prior art, the technical solution provided by this utility model has the following advantages:

[0024] (1) High reliability of dynamic sealing: Through the synergistic effect of the annular hollow rubber bladder and the compressible medium, the clamping force of the sealing ring automatically increases with the increase of pipeline pressure, realizing "pressure adaptive sealing" and effectively preventing high pressure leakage;

[0025] (2) Optimization of pressure resistance and buffering performance: The flexible sealing material layer between the multi-layer bellows can absorb radial stress, reduce the risk of fatigue damage to the bellows, and extend the service life;

[0026] (3) Dual pressure relief safety guarantee: The weak ring and the fusible alloy sheet form a staged pressure relief mechanism. When the pressure is over-pressured, the weak ring will break first to release the pressure. Under high temperature conditions, the alloy sheet will melt to further relieve pressure and avoid the overall structure from bursting.

[0027] (4) Intelligent corrosion prevention and self-repair: The microcapsule composite coating automatically releases corrosion inhibitors when local corrosion occurs, inhibiting corrosion spread and reducing maintenance costs;

[0028] (5) Real-time leakage monitoring: The ring pressure sensor combined with wireless transmission technology can monitor the sealing status in real time, provide early warning of leakage risks, and improve system safety;

[0029] (6) Ease of installation: The multiple mounting ears on the flange side simplify the fixing process of the compensator and adapt to the rapid deployment needs under complex working conditions.

[0030] It should be noted that the structures not described in this utility model are the same as or can be implemented using existing technology, and will not be elaborated here, as they do not involve the design points and improvement directions of this utility model. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0032] Figure 2 This is a schematic diagram of the dynamic adjustment sealing structure of this utility model.

[0033] Explanation of the labels in the diagram:

[0034] 1. Metal bellows; 2. Flange; 3. Mounting lug; 4. Ring pressure sensor;

[0035] 5. Dynamically adjustable sealing structure; 51. Sealing groove; 52. Positioning bracket; 53. Channel; 54. Annular hollow rubber bladder; 55. Air inlet; 56. Sealing ring;

[0036] 6. Pressure relief hole; 7. Fusible alloy sheet. Detailed Implementation

[0037] To facilitate understanding of this utility model, a more comprehensive description of the utility model will be given below with reference to the accompanying drawings, which show several embodiments of the utility model. However, the utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the utility model will be more thorough and complete.

[0038] I. Component Installation Steps

[0039] 1. Assembly of multi-layer metal corrugated pipe and buffer layer

[0040] Multiple metal bellows 1 are stacked concentrically, and the annular gaps between adjacent bellows are uniformly filled with flexible sealing material such as silicone rubber or polytetrafluoroethylene to form a radial multi-layer buffer structure. Figure 1 When filling, ensure the material is evenly distributed to avoid creating air bubbles or voids.

[0041] After aligning the two ends of the multi-layer corrugated pipe, it is fixedly connected to the upper and lower flanges 2 by welding. The weld must meet the airtightness requirements.

[0042] 2. Installation of dynamically adjustable sealing structure

[0043] An annular sealing groove 51 is machined on the upper inner side of flange 2. The groove depth is 5-8mm, and the width matches the outer diameter of the annular hollow rubber bladder 54. Figure 2 ).

[0044] The positioning bracket 52 is fixed between the center inner wall of the sealing groove 51. The bottom of the bracket is designed to be arc-shaped, and a channel 53 is opened in the center.

[0045] The bottom of the pre-formed annular hollow rubber bladder 54 is embedded into the arc-shaped bottom surface of the positioning bracket 52. The cavity of the rubber bladder is filled with a compressible medium (such as nitrogen), with a preset pressure of 0.5-1.0 MPa.

[0046] Apply a high-temperature resistant adhesive to the top of the rubber bladder and press and bond the sealing ring 56 to its top to ensure that the sealing ring fits tightly against the flange end face.

[0047] Multiple air inlets 55 with a diameter of 2-3 mm are opened on the side end of flange 2 so that the air inlets are connected to the bottom of the sealing groove 51.

[0048] 3. Setting of pressure relief structure

[0049] A weak ring 6 is processed at the trough of the bottom metal bellows 1. The thickness of the weak ring is 50%-70% of that of the adjacent area, and multiple pressure relief holes with a diameter of 3-5mm are opened along the circumference of the ring.

[0050] A fusible alloy sheet 7, with a melting point set at 150-200℃, is placed over the outside of the pressure relief hole and secured by welding or riveting. Figure 1 ).

[0051] 4. Spraying of anti-corrosion coating

[0052] A composite coating containing microcapsules is sprayed onto the outer surface of the metal bellows 1. The microcapsules have a diameter of 10-50 μm and encapsulate a corrosion inhibitor (such as zinc phosphate) inside. The coating thickness is 0.2-0.5 mm, and it is sprayed in two coats and then cured.

[0053] 5. Integration of sensor and mounting ear

[0054] An annular pressure sensor 4 is embedded at the connection between flange 2 and metal bellows 1. The sensor signal line is led out through the side wall of the flange and connected to a wireless transmission module (such as a LoRa module).

[0055] Multiple mounting ears 3 are symmetrically welded on the sides of flange 2. Bolt holes are made on the mounting ears, and the hole diameter matches the pipe support.

[0056] II. Operation Process and Technical Effects

[0057] 1. Dynamic sealing adjustment

[0058] Low pressure state: When the pressure of the medium in the pipeline is low, the nitrogen in the annular hollow rubber bladder 54 maintains the initial pressure, and the sealing ring 56 relies on the pre-tightening force to fit with the flange contact surface to form a basic seal.

[0059] High pressure state: When the medium pressure increases, the pressure enters the bottom of the sealing groove 51 through the air inlet 55, pushing the annular hollow rubber bladder 54 to expand upward, increasing the clamping force between the sealing ring (56) and the flange contact surface, thus achieving "pressure self-reinforcing seal" ( Figure 2 This process can adapt to pressure fluctuations of 0-5 MPa, reducing the leakage rate to less than 0.1%.

[0060] 2. Staged pressure relief protection

[0061] Structural integration: Both the weak ring and the fusible alloy sheet 7 are formed by processing thinned areas on the bellows body (e.g., cutting annular grooves). Furthermore, compared to the pre-fracture pull tab of a can, the weak ring is part of the bellows' own structure.

[0062] Overpressure relief (pressure trigger): When the pipeline pressure rises abnormally to 120% of the design threshold, the weak ring breaks first, and the medium is quickly released through the pressure relief hole 6 to avoid the entire bellows from breaking.

[0063] Fracture location: The annular groove of the weak ring has the thinnest wall thickness. When the pressure exceeds the design threshold (e.g., 1.2 times), cracks will form at the root of the groove and propagate rapidly, eventually leading to the overall fracture along the annular groove.

[0064] Fracture principle:

[0065] When the bellows is subjected to internal pressure, the stress concentration factor at the weak ring reaches 3 to 5 times, and it preferentially reaches the material yield strength; after fracture, the pressure relief hole 6 is exposed, forming a pressure relief channel.

[0066] High-temperature relief (temperature trigger): If the temperature continues to rise above 150°C after pressure relief, the fusible alloy sheet 7 will melt, further expanding the pressure relief channel and preventing the risk of secondary overpressure.

[0067] When the temperature continues to rise above 150°C after pressure relief, the fusible alloy sheet 7 melts, and the flow area of ​​the pressure relief hole 6 expands to 2 to 3 times the original hole diameter.

[0068] If residual pressure is not completely released, the enlarged pressure relief hole can accelerate pressure relief and prevent secondary overpressure.

[0069] Among them, the dual functions of the fusible alloy sheet are: (1) mechanical breaking is the main function: the strength of the alloy sheet is designed to be lower than the fracture pressure of the weak ring (for example, the fracture of the weak ring requires 6MPa, and the tensile strength of the alloy sheet corresponds to 5.5MPa), so as to ensure that it is broken first when the pressure is triggered; (2) high temperature melting is the auxiliary function: the alloy sheet is a redundant design and only takes effect at extreme temperatures.

[0070] 3. Self-healing corrosion prevention and real-time monitoring

[0071] Corrosion protection: When the coating on the surface of the corrugated pipe cracks due to mechanical damage or corrosion, the microcapsules rupture and release corrosion inhibitors, forming a protective film in the damaged area, delaying the spread of corrosion and extending the anti-corrosion life by 2-3 times.

[0072] Leakage warning: The ring pressure sensor 4 monitors the pressure difference at the flange connection in real time. If the difference exceeds the set threshold (e.g., 0.2MPa), the wireless module immediately sends an alarm signal to the monitoring system to realize leakage prediction with a response time of less than 10 seconds.

[0073] 4. Stress buffering and ease of installation

[0074] The flexible sealing material layer between the multi-layered bellows can absorb more than 80% of the radial stress, reduce the fatigue damage of the bellows, and extend the service life to 8-10 years.

[0075] The flexible sealing material layer is filled with silicone rubber or polytetrafluoroethylene, with a filling thickness of 2-5mm, to ensure uniform distribution of radial stress.

[0076] Mounting ear 3 is fixed to the pipe support with bolts, simplifying the installation process and making it suitable for rapid deployment in confined spaces or complex pipelines.

[0077] The above-described embodiments are merely illustrative of certain implementations of this utility model, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A leak-proof metal compensator, comprising multiple layers of concentrically arranged metal bellows (1), wherein flanges (2) are welded to the upper and lower ends of the metal bellows (1), characterized in that: A flexible sealing material layer is filled between adjacent metal bellows (1) to form a radial multi-layer buffer structure; The upper end of the flange (2) is provided with a dynamic adjustment sealing structure (5). The dynamic adjustment sealing structure (5) includes an annular sealing groove (51) opened on the upper inner side of the flange (2). An annular hollow rubber bladder (54) is provided in the sealing groove (51). The annular hollow rubber bladder (54) is filled with a compressible medium, and a sealing ring (56) is fixedly connected to its top. The flange (2) is fixedly provided with multiple mounting ears (3) on its side; An annular pressure sensor (4) is provided at the connection between the flange (2) and the metal bellows (1). The annular pressure sensor (4) is connected to an external monitoring system through a wireless transmission module. The bottom metal bellows (1) has a pressure relief hole (6) at its outer end and a weak ring installed on its inner wall. The pressure relief hole (6) is covered with a fusible alloy sheet (7).

2. The leak-proof metal compensator according to claim 1, characterized in that: A positioning bracket (52) is fixed between the inner walls of the center of the sealing groove (51). The bottom of the positioning bracket (52) is arc-shaped and a channel (53) is opened in the center. The side end of the flange (2) is provided with multiple air inlets (55) that communicate with the sealing groove (51). The bottom of the annular hollow rubber bladder (54) is fixed to the bottom of the positioning bracket (52).

3. A leak-proof metal compensator according to claim 1, characterized in that: A high-temperature resistant adhesive is applied between the sealing ring (56) and the top of the annular hollow rubber bladder (54), and the high-temperature resistant adhesive has a temperature resistance of not less than 200°C.

4. A leak-proof metal compensator according to claim 1, characterized in that: The compressible medium is nitrogen.

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