Axial compound bellow compensator

Abstract

The utility model discloses an axial compound corrugated compensator, it includes two or more than series connection setting's bellows, and through series connection structure doubles increases axial compensation quantity. The outer periphery fixed sleeve of this inner connecting pipe is equipped with the guide plate, is used for providing axial direction guide and radial support for pull rod system, prevents instability. The both ends of bellows group are connected through outer connecting pipe, and the independent pull rod dress board is fixed on every outer connecting pipe and is equipped with, thereby will pull rod connection function and pipeline flange connection function separate, and the stress structure is optimized. The both ends of a plurality of parallel to axial's pull rod are detachably connected in the pull rod dress board of both ends, and pass through the corresponding guide hole on the guide plate. Two flanges are respectively set on the outer connecting pipe of both ends, are used for with pipeline connection. Through above -mentioned compound series connection, independent pull rod dress board and central direction's collaborative structure, provide greater compensation quantity while, the stability and work reliability of overall structure have been improved significantly.

Description

Technical Field

[0001] This utility model relates to a corrugated compensator, specifically an axial compound corrugated compensator. Background Technology

[0002] In pipeline engineering, axial bellows compensators (also known as axial expansion joints) are key components used to absorb axial displacement caused by factors such as thermal expansion and contraction and pressure differences in pipelines. Currently, conventional axial bellows compensators typically consist of a bellows and connecting pipes welded to both ends of the bellows, with a flange fixedly connected to the outer end of each connecting pipe. The two flanges are connected and axially limited by a tie rod. However, the above-mentioned traditional single-bellows structure has the following significant shortcomings in practical applications: First, its compensation capacity is limited, and its system dependence is high. Because it uses only a single bellows, its compensation amount (axial expansion capacity) is limited. When the pipeline experiences large displacement due to a large pressure or temperature difference, the single-bellows compensator cannot fully absorb the displacement, easily leading to its own overload failure and transferring excessive additional stress to adjacent pipeline supports, thus increasing the strength and rigidity requirements of the pipeline supports and shortening the service life of the compensator and the pipeline system. Second, there are defects in structural stability and reliability. In the traditional structure, the tie rod is directly connected to the flange used for pipeline connection. This causes the flange and its connection to the connecting pipe (usually the weld) to simultaneously bear the connection force from the pipe, the constraint reaction force from the tie rod, and the thrust generated by the deformation of the bellows, forming a complex composite stress state. This easily leads to stress concentration and increases the risk of fatigue failure. In addition, this structure lacks effective radial guidance and support for the bellows during the compensation process. The bellows is prone to lateral bending or instability during axial expansion and contraction, affecting normal operation and even causing structural damage.

[0003] Therefore, there is an urgent need for an axial corrugated compensator that can provide greater compensation and has higher structural stability and reliability. Utility Model Content

[0004] The technical problem this invention aims to solve is to overcome the limitations of existing single-wave axial compensators in terms of compensation capacity and structural reliability caused by the direct connection of the tie rod to the pipe connection flange. To this end, this invention provides an axial double-bellows compensator, which, through a structure with a tie rod mounting plate and a central guide plate independent of the pipe connection flange, provides a larger compensation capacity while effectively distributing the load and preventing instability, thereby significantly improving overall stability and reliability.

[0005] The technical problem of this utility model is solved by the following technical solution: An axial compound bellows compensator includes two or more bellows arranged in series; an inner connecting pipe, both ends of which are fixedly connected to one end of two adjacent bellows; two outer connecting pipes, each fixedly connected to the other end of the outermost bellows at both ends of the series bellows assembly; two tie rod mounting plates, each fixedly fitted onto the two outer connecting pipes; multiple tie rods, each tie rod having its two ends detachably connected to the two tie rod mounting plates, and all tie rods being arranged parallel to the axial direction of the bellows; a guide plate, fixedly fitted onto the outer periphery of the inner connecting pipe, having guide holes corresponding to the number and position of the tie rods, with the tie rods passing through the corresponding guide holes; and two flanges, each fitted onto the two outer connecting pipes.

[0006] The external connecting pipe is a straight connecting pipe, and the end of the flange is welded and fixed to the end of the straight connecting pipe.

[0007] The external connecting pipe is a flange connecting pipe, and the end of the flange connecting pipe forms a port flange face; the flange is rotatably fitted onto the outer periphery of the flange connecting pipe and forms a sealing fit with the port flange face.

[0008] The multiple tie rods are arranged uniformly and symmetrically along the circumference of the bellows.

[0009] The end of the pull rod passes through the pull rod mounting plate and is secured and its axial length adjusted by a nut.

[0010] The guide hole on the guide plate is a light hole, and its inner diameter is clearance-fitted with the outer diameter of the pull rod.

[0011] The fixed connections between the corrugated pipe, the inner connecting pipe, and the outer connecting pipe are all welded.

[0012] The maximum distance between the two tie rod plates is greater than the total length of the series bellows assembly in its free state.

[0013] The corrugated pipe, inner connecting pipe, and outer connecting pipe are all made of stainless steel.

[0014] Both the tie rod mounting plate and the guide plate are rectangular plates, and their planar shapes and dimensions are the same.

[0015] Compared with the prior art, the beneficial effect of this utility model is that it provides an axial compound bellows compensator, which is achieved through the following technical solution. Its structure includes two or more bellows arranged in series; an inner connecting pipe, whose two ends are respectively fixedly connected to one end of two adjacent bellows; two outer connecting pipes, respectively fixedly connected to the other end of the outermost bellows at both ends of the series bellows group; two tie rod mounting plates, respectively fixedly fitted onto the two outer connecting pipes; multiple tie rods, the two ends of each tie rod being detachably connected to the two tie rod mounting plates, and all tie rods being arranged parallel to the axial direction of the bellows; and a guide plate, fixedly fitted onto the outer periphery of the inner connecting pipe, on which are provided the number and position of the tie rods. The corresponding guide holes are provided, and the tie rods are inserted into the corresponding guide holes; two flanges are respectively fitted onto the two external connecting pipes; by adopting the above technical solution, this utility model has the following beneficial effects: by setting two or more bellows connected in series, the axial compensation amount of the compensator is significantly increased; by setting an independent tie rod mounting plate, the constraint function of the tie rod is separated from the flange connection function of the pipeline, optimizing the load distribution and improving the connection reliability; at the same time, by setting a guide plate with guide holes on the inner connecting pipe, axial guidance and radial support are provided for the tie rod, effectively preventing the bellows from becoming laterally unstable during the compensation process, thereby improving the overall structural stability and operational reliability of the compensator. Attached Figure Description

[0016] Figure 1 This is a half-sectional view of the structure of this utility model (using a straight connecting pipe).

[0017] Figure 2 This is a half-sectional view of the present invention (using a flanged connecting pipe).

[0018] Figure 3 This is a cross-sectional view of the internal connecting pipe.

[0019] Figure 4 This is a cross-sectional view of the straight connecting pipe.

[0020] Figure 5 This is a cross-sectional view of the flanged pipe connection.

[0021] Figure 6 A schematic diagram of the structure for mounting a plate on a tie rod.

[0022] Figure 7 This is a schematic diagram of the guide plate. Detailed Implementation

[0023] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0024] like Figures 1-7As shown, 1. Bellows, 2. Inner connecting pipe, 3. Outer connecting pipe, 31. Port flange face, 4. Tie rod mounting plate, 41. Mounting hole, 5. Tie rod, 6. Guide plate, 61. Guide hole, 7. Flange, 8. Nut, 9. Connecting step. The same labels in each figure represent the same parts.

[0025] An axial compound bellows compensator, such as Figure 1 , Figure 2 As shown, it has structural advantages such as simple design, convenient processing and low investment, and can be widely used in high and low temperature gas and liquid applications. Its structure mainly includes a corrugated pipe 1, an inner connecting pipe 2, an outer connecting pipe 3, a tie rod plate 4, a tie rod 5 and a guide plate 6, etc. The corrugated pipe 1, the inner connecting pipe 2 and the outer connecting pipe 3 are all made of stainless steel.

[0026] The external connecting pipe 3 used in this utility model is... Figure 4 The straight connecting pipe shown and Figure 5 The flange connection pipes shown are used as examples. Therefore, two corrugated compensator structures are designed based on the differences between these two types of external connection pipes.

[0027] The first structure is as follows Figure 1 As shown, it mainly includes two corrugated pipes 1 connected in series, one inner connecting pipe 2, two outer connecting pipes 3, two tie rod mounting plates 4, four tie rods 5, one guide plate 6, two flanges 7, and multiple nuts 8.

[0028] Specifically, the two ends of the inner connecting pipe 2 are respectively connected to one end of the two adjacent corrugated pipes 1 through the connecting steps 9 formed at their ends, and then fixedly connected by circumferential welding, thereby connecting the two corrugated pipes 1 in series into a whole. Its core function is to realize the double series connection of the corrugated pipes 1, so that the total compensation amount is more than twice the compensation amount of a single corrugated pipe, effectively solving the problem of insufficient compensation amount of a single corrugated pipe.

[0029] Both external connecting pipes 3 are straight connecting pipes. The inner ends of these two straight connecting pipes are respectively inserted into the other ends of the outermost corrugated pipes 1 at both ends of the series corrugated pipe group through the connecting steps 9 formed at their ends, and then fixed by circumferential welding. The outer ends of the two straight connecting pipes are used for external pipe connections. The end of the flange 7 is fixed to the end of the straight connecting pipe (i.e., the external connecting pipe 3) by welding to form a whole, and can be used to connect to an external pipe flange (not shown in the figure).

[0030] One of the key improvements in this structure is that the two tie rod mounting plates 4 are welded and fixedly fitted onto the outer circumference of the two external connecting pipes 3, respectively. This design makes the tie rod mounting plates 4 a dedicated load-bearing structure independent of the flange 7. Four tie rods 5, serving as rigid reinforcing rods, are evenly and symmetrically arranged along the circumference of the bellows 1 and are all parallel to the axial direction of the bellows. The two ends of each tie rod 5 pass through the corresponding mounting holes 41 on the tie rod mounting plates 4 at both ends, and are locked and finely adjusted in axial length by a pair of nuts 8. This structure transfers the main mechanical load (tie rod constraint force) that constrains excessive deformation of the bellows from the flange 7 and its welds to the dedicated tie rod mounting plates 4, optimizing the load distribution, significantly reducing the risk of fatigue fracture at the flange connection, and improving reliability. The fit between the tie rods 5 and the nuts 8 also facilitates length adjustment and hoisting before product installation.

[0031] The second key improvement of this structure lies in the fact that the guide plate 6 is welded and fixedly fitted onto the outer periphery of the inner connecting pipe 2. Both the guide plate 6 and the tie rod mounting plate 4 are preferably rectangular plates, and their planar shapes and dimensions are identical. The guide plate 6 has four guide holes 61 corresponding one-to-one with the positions of the tie rods 5. These guide holes 61 are smooth holes, and their inner diameter is precisely clearance-fitted with the outer diameter of the tie rod 5. All tie rods 5 pass through their corresponding guide holes 61. During the operation of the compensator, the guide plate 6 provides precise axial guidance and radial support constraint to the tie rods 5 through its guide holes 61, essentially setting a stable "track" in the middle of the entire compensator. This effectively prevents lateral bending or instability that may occur during the axial expansion and contraction of the series bellows, greatly improving the structural stability of the product. The maximum distance between the two tie rod mounting plates 4 is set to be greater than the total length of the two bellows 1 and their connecting pipes in their free state, ensuring that the bellows have sufficient space for tensile compensation.

[0032] The working principle and beneficial effects are as follows: When the pipeline experiences axial displacement due to temperature or pressure changes, the two stainless steel bellows 1 connected in series can expand and contract collaboratively, providing a larger compensation amount than a single-wave compensator, thereby more effectively absorbing displacement and reducing the thrust requirements on the pipeline supports. The constraint system composed of tie rod 5, nut 8, and tie rod mounting plates 4 at both ends limits the maximum tensile and compressive amounts of the bellows 1, providing protection. Throughout the process, tie rod 5 maintains linear motion under the constraint of guide plate 6, ensuring smooth movement and preventing instability.

[0033] In summary, this embodiment achieves the core objective of providing greater compensation, higher structural stability, and higher reliability through the synergistic effect of three structural improvements: "increasing the compensation amount with a double-layered series bellows", "optimizing the load path with an independent tie rod plate", and "preventing lateral instability with a central guide plate".

[0034] The second structure is as follows: Figure 2As shown, the main difference between this structure and the first one is the connection method between the outer connecting pipe 3 and the flange 7. The core structures and connection relationships of the rest, such as the double-layered corrugated pipe 1, the inner connecting pipe 2, the guide plate 6, the tie rod mounting plate 4, and the tie rod 5, are all the same.

[0035] In this embodiment, the external connecting pipe 3 is a flange connecting pipe. Specifically, the outer end of the flange connecting pipe is directly machined to form a port flange face 31, which can be used for sealing. The flange 7 is a loose flange, which is rotatably fitted onto the outer circumference of the flange connecting pipe (i.e., the external connecting pipe 3). During installation, the loose flange can rotate freely to facilitate alignment with the bolt holes of the external pipe flange (not shown in the figure). After alignment, the loose flange can be pressed onto the port flange face 31 by tightening the bolts to form a sealed connection.

[0036] The key advantage of this design is that it greatly facilitates the alignment of flange bolt holes when there is misalignment during pipeline installation or when replacing compensators, thus improving installation efficiency and making it particularly suitable for complex installation environments. Although the flange connection method has been changed to a rotatable loose-fitting structure, the constraint function of the tie rod 5 is entirely undertaken by the independent tie rod mounting plate 4, and is unrelated to the flange 7. Therefore, all the core beneficial effects of the first structure, such as "optimized load path and improved reliability" and "central guidance to prevent instability", are also fully retained and realized in the second structure.

[0037] The above description is merely a preferred embodiment of this utility model and is not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An axial compound bellows compensator, characterized in that, Including two or more bellows arranged in series (1); The inner connecting pipe (2) is fixedly connected at both ends to one end of the two adjacent corrugated pipes (1); Two external connecting pipes (3) are fixedly connected to the other end of the outermost corrugated pipe (1) at both ends of the series corrugated pipe group; Two tie rod mounting plates (4) are respectively fixedly fitted onto the two external connecting pipes (3); Multiple tie rods (5), each tie rod having its two ends detachably connected to two tie rod mounting plates (4), and all tie rods being arranged parallel to the axial direction of the bellows (1); The guide plate (6) is fixedly fitted on the outer periphery of the inner connecting tube (2), and has guide holes (61) corresponding to the number and position of the pull rods (5). The pull rods (5) pass through the corresponding guide holes (61). Two flanges (7) are respectively fitted onto the two external connecting pipes (3).

2. An axial compound bellows compensator according to claim 1, characterized in that, The external connecting pipe (3) is a straight connecting pipe, and the end of the flange (7) is welded and fixed to the end of the straight connecting pipe.

3. An axial compound bellows compensator according to claim 1, characterized in that, The external connecting pipe (3) is a flange connecting pipe, and the end of the flange connecting pipe forms a port flange face (31); the flange (7) is rotatably fitted on the outer periphery of the flange connecting pipe and forms a sealing fit with the port flange face (31).

4. An axial compound bellows compensator according to claim 1, characterized in that, The multiple tie rods (5) are arranged uniformly and symmetrically along the circumference of the corrugated pipe (1).

5. An axial compound bellows compensator according to claim 1, characterized in that, The end of the pull rod (5) passes through the pull rod mounting plate (4) and is fastened and its axial length is adjusted by a nut (8).

6. An axial compound bellows compensator according to claim 1, characterized in that, The guide hole (61) on the guide plate (6) is a light hole, and its inner diameter is in clearance fit with the outer diameter of the pull rod (5).

7. An axial compound bellows compensator according to claim 1, characterized in that, The fixed connections between the corrugated pipe (1), the inner connecting pipe (2) and the outer connecting pipe (3) are all welded.

8. An axial compound bellows compensator according to claim 1, characterized in that, The maximum distance between the two tie rod plates (4) is greater than the total length of the series bellows assembly in the free state.

9. An axial compound bellows compensator according to claim 1, characterized in that, The corrugated pipe (1), inner connecting pipe (2) and outer connecting pipe (3) are all made of stainless steel.

10. An axial compound bellows compensator according to claim 1, characterized in that, The tie rod mounting plate (4) and the guide plate (6) are both rectangular plates, and their planar shapes and dimensions are the same.

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