Straight pipe pressure balance expansion joint for limited space

Abstract

The invention provides a straight pipe pressure balance expansion joint for space limitation, which comprises a working wave assembly, a first balance wave assembly, a second balance wave assembly and a pull rod assembly, one end of the working wave assembly is connected with an inlet pipe, the other end of the working wave assembly is connected with one end of the first balance wave assembly through an outlet pipe, and the other end of the second balance wave assembly is connected with the pull rod assembly. The other end of the first balance wave assembly is connected with the pull rod assembly, the second balance wave assembly is sleeved with the first balance wave assembly, one end of the second balance wave assembly is connected with the outlet pipe, the other end of the second balance wave assembly is connected with the third connecting pipe, and one end of the pull rod assembly is connected to the inlet pipe. The other end of the pull rod assembly is connected to the third connecting pipe, a through hole is formed in the outlet pipe, and the through hole enables a working medium to enter a cavity formed by the first balance wave assembly and the second balance wave assembly. According to the expansion joint, large axial displacement and transverse displacement can be compensated, and the structure is more compact.

Description

Technical Field

[0001] The invention relates to the technical field of application of metal bellows expansion joints, in particular to a straight pipe pressure balancing expansion joint for a space-constrained area. Background Art

[0002] The basic forms of displacement absorption by metal bellows expansion joints include axial displacement, lateral displacement and angular displacement. Different structural types of metal bellows expansion joints are selected according to different pipeline layout schemes to compensate for the displacement of the pipeline caused by temperature changes, thereby reducing pipeline stress.

[0003] The traditional internal pressure straight pipe pressure balance expansion joint structure is as follows Figure 1 As shown, it is composed of two working bellows at both ends and a balancing bellows in the middle, as well as structural parts such as tie rods and end plates. The tie rods are arranged outside the working bellows and the balancing bellows. The distance between a working bellows and a balancing bellows of the expansion joint is guaranteed to remain unchanged throughout the entire working process through the constraint of the tie rods. The ball, conical washers and nuts at the ends of the tie rods allow the tie rods to tilt while constraining the pressure thrust, so that the bellows absorbs lateral displacement. The tie rods are cross-arranged outside the working bellows and the balancing bellows, and can only compensate for small lateral displacements, and are mainly used to absorb axial displacements. That is, the expansion joints of the prior art not only cannot meet the large axial and lateral displacements at the same time, but also have the problems of large external dimensions and occupying a large space. Summary of the invention

[0004] In view of this, the present invention aims to propose a straight pipe pressure balancing expansion joint for space-constrained areas, so as to solve the problem that the expansion joint in the prior art not only cannot simultaneously meet the requirements of large axial and lateral displacements, but also has large external dimensions and occupies a large space.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A straight pipe pressure balancing expansion joint for space confined, comprising a working wave assembly, a first balancing wave assembly, a second balancing wave assembly, and a tie rod assembly, wherein one end of the working wave assembly is connected to an inlet pipe, and the other end of the working wave assembly is connected to one end of the first balancing wave assembly through an outlet pipe, and the other end of the first balancing wave assembly is connected to the tie rod assembly, the first balancing wave assembly is sleeved on the outside of the second balancing wave assembly, one end of the second balancing wave assembly is connected to the outlet pipe, and the other end of the second balancing wave assembly is connected to a third connecting pipe, one end of the tie rod assembly is connected to the inlet pipe, and the other end of the tie rod assembly is connected to the third connecting pipe, and a through hole is provided on the outlet pipe, and the through hole allows the working medium to enter the cavity formed by the first balancing wave assembly and the second balancing wave assembly.

[0007] This setting optimizes the arrangement of the balancing bellows so that the first balancing bellows assembly is in an internal pressure state and the second balancing bellows assembly is in an external pressure state. The two sets of balancing bellows are designed as an inner sleeve type, which can effectively reduce the installation length of the expansion joint, thereby making the spatial structure of the entire expansion joint more compact and reliable. In combination with the working wave assembly and the pull rod assembly, the expansion joint can compensate for both larger axial displacements and larger lateral displacements.

[0008] Furthermore, the first balancing wave assembly includes a first connecting pipe, a first balancing bellows, and a second connecting pipe which are connected in sequence, the first connecting pipe is connected to the outlet pipe through a second ring plate, the second connecting pipe is connected to the pull rod assembly, and the through hole is located between the second ring plate and the second balancing wave assembly.

[0009] Furthermore, the second balancing wave assembly includes a fourth connecting pipe and a second balancing bellows which are connected in sequence, the fourth connecting pipe is connected to the outlet pipe through a fourth ring plate, the second balancing bellows is connected to the third connecting pipe, and the through hole is located between the second ring plate and the fourth ring plate.

[0010] Furthermore, a guide block is provided on the outlet pipe, and the guide block is located on the inner side of the third connecting pipe.

[0011] This arrangement not only serves the function of supporting the tie rod assembly, the first balancing wave assembly, and the second balancing wave assembly, but also enables the first / second working bellows to drive the first balancing bellows and the second balancing bellows to produce tensile displacement through the tie rod, the third ring plate and other structures when the pipeline undergoes compressive displacement due to thermal expansion, thereby realizing the axial displacement compensation function of the expansion joint.

[0012] Furthermore, a plurality of through holes are provided.

[0013] The purpose of this arrangement is to achieve a state in which the first balancing bellows is subjected to internal pressure and the second balancing bellows is subjected to external pressure.

[0014] Furthermore, the number of the through holes is 6 to 10.

[0015] Furthermore, the working bellows assembly includes a first working bellows and a second working bellows, the inlet pipe is connected to the first working bellows, the first working bellows and the second working bellows are connected through a connecting pipe, and the second working bellows is connected to the outlet pipe.

[0016] Furthermore, the tie rod assembly comprises a first ring plate, a tie rod, and a third ring plate which are connected in sequence, the first ring plate is connected to the inlet pipe, and the third ring plate is connected to the third connecting pipe.

[0017] Furthermore, spherical cone surface washers are provided at both ends of the pull rod, and the spherical cone surface washers are in close contact with the first ring plate and the third ring plate.

[0018] This arrangement can improve the lateral displacement compensation capability of the expansion joint.

[0019] Furthermore, the tie rod assembly further comprises a rib plate, and the rib plate is connected to the third ring plate and / or the first ring plate.

[0020] This setting is used to improve the strength of the tie rod assembly, ensuring that the expansion joint has a compact structure while being able to compensate for larger axial displacements and larger lateral displacements.

[0021] Furthermore, a guide tube is arranged inside the working wave assembly.

[0022] Compared with the prior art, the straight pipe pressure balancing expansion joint for space-constrained use described in the present invention has the following advantages:

[0023] 1) The present invention optimizes the arrangement of the balancing bellows so that the first balancing bellows is in an internal pressure state and the second balancing bellows is in an external pressure state. The two sets of balancing bellows are designed as inner sleeves to achieve the balance of the pressure thrust of the working bellows and the balancing bellows. At the same time, the installation length of the expansion joint can be effectively reduced, so that the spatial structure of the entire expansion joint is more compact and reliable. In combination with the working bellows assembly and the tie rod assembly, the expansion joint can compensate for both large axial displacement and large lateral displacement.

[0024] 2) A gap is provided between the outlet pipe and the third connecting pipe of the present invention, so that when the outlet pipe is axially extended, the working bellows is compressed and the balancing bellows is stretched, thereby realizing the function of compensating for the axial displacement of the pipeline;

[0025] 3) The tie rod of the present invention is arranged outside the working bellows and the balancing bellows, and spherical cone washers are provided at both ends of the tie rod. One end of the tie rod is connected to the third ring plate, and the other end of the tie rod is connected to the first ring plate outside the inlet end pipe. The distance between the working bellows and the balancing bellows connected to the inlet pipe is ensured to remain unchanged during the entire working process by the constraint of the tie rod;

[0026] 4) The expansion joint of the present invention can be applied to fields such as petrochemical equipment and large-scale test equipment, and is suitable for occasions that require both a large axial displacement compensation capability and a large lateral displacement compensation capability and a compact installation space. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of a traditional internal pressure straight pipe pressure balance expansion joint;

[0028] Figure 2 The present invention is a schematic diagram of the overall structure of a straight pipe pressure balancing expansion joint for a space-constrained environment.

[0029] Description of reference numerals:

[0030] 1-inlet pipe; 2-first ring plate; 3-first working bellows; 4-guide tube; 5-connecting pipe; 6-second working bellows; 7-second ring plate; 8-first connecting pipe; 9-first balancing bellows; 10-second balancing bellows; 11-pull rod; 12-second connecting pipe; 13-spherical cone washer; 14-rib plate; 15-third ring plate; 16-third connecting pipe; 17-guide block; 18-outlet pipe; 181-through hole, 19-fourth connecting pipe; 20-fourth ring plate. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail in conjunction with the accompanying drawings. In addition, the directions involved in the following specific implementation methods are briefly described: the directions or positional relationships indicated by "up", "down", "left" and "right" mentioned in the embodiments refer to the directions or positional relationships shown in the accompanying drawings; the "axial" mentioned in this embodiment refers to the left and right movement direction, "lateral" refers to the up and down movement direction, "inside" refers to the direction close to the expansion joint axis, and "outside" refers to the direction away from the expansion joint axis.

[0032] like Figure 2 As shown, the present invention proposes a straight pipe pressure balancing expansion joint for limited space, including a working wave component, a first balancing wave component, a second balancing wave component, and a tie rod component, one end of the working wave component is connected to the inlet pipe 1, the other end of the working wave component is connected to one end of the first balancing wave component through the outlet pipe 18, the other end of the first balancing wave component is connected to the tie rod component, the first balancing wave component is sleeved on the outside of the second balancing wave component, one end of the second balancing wave component is connected to the outlet pipe 18, the other end of the second balancing wave component is connected to the third connecting pipe 16, one end of the tie rod assembly is connected to the inlet pipe 1, the other end of the tie rod assembly is connected to the third connecting pipe 16, and the outlet pipe 18 is provided with a through hole 181, and the through hole 181 allows the working medium to enter the cavity formed by the first balancing wave component and the second balancing wave component.

[0033] The present invention optimizes the arrangement of the balancing bellows, and designs the two groups of balancing bellows as an inner-sheath type, and cooperates with the pull rod assembly and the working bellows assembly, so that one group of balancing bellows is located inside the other group of balancing bellows, the inner balancing bellows is in an external pressure state, and the outer balancing bellows is in an internal pressure state, and the inner cavity area of ​​the two groups of balancing bellows is the same as the effective area of ​​the working bellows, thereby achieving the balance of pressure thrust of the working bellows and the balancing bellows of the expansion joint.

[0034] Specifically, the first balancing wave assembly includes a first connecting pipe 8, a first balancing bellows 9, and a second connecting pipe 12 which are connected in sequence. The first connecting pipe 8 is connected to the outlet pipe 18 through a second ring plate 7. The second connecting pipe 12 is connected to the pull rod assembly. The through hole 181 is located between the second ring plate 7 and the second balancing wave assembly.

[0035] Preferably, the left side of the first connecting pipe 8 is welded to the right side of the second ring plate 7, and the inner diameter of the first connecting pipe is equal to the outer diameter of the second ring plate.

[0036] Specifically, the second balancing wave assembly includes a fourth connecting pipe 19 and a second balancing bellows 10 which are connected in sequence. The fourth connecting pipe 19 is connected to the outlet pipe 18 through a fourth ring plate 20. The second balancing bellows 10 is located on the inner side of the first balancing bellows 9. The second balancing bellows 10 is connected to the third connecting pipe 16.

[0037] In this setting, the two sets of balancing bellows are designed with an inner sleeve to achieve a balance between the pressure thrust of the working bellows and the balancing bellows, thereby achieving the expansion joint's function of compensating for axial and lateral displacements while effectively reducing the installation length of the expansion joint.

[0038] Preferably, the second ring plate and the fourth ring plate are respectively sleeved on the outside of the outlet pipe and fixed by welding, and the outer diameter of the second ring plate is larger than the outer diameter of the fourth ring plate. This arrangement improves the connection firmness of the first / second balancing wave assembly.

[0039] Preferably, the left side of the fourth connecting pipe 19 is welded to the right side of the fourth ring plate.

[0040] Specifically, a guide block 17 is provided between the outlet pipe 18 and the third connecting pipe 16. The guide block is made of low-friction material, which not only supports the tie rod assembly, the first balancing wave assembly, and the second balancing wave assembly, but also enables the first / second working bellows to drive the first balancing bellows and the second balancing bellows to generate tensile displacement through the tie rod, the third ring plate and other structures when the pipeline is thermally elongated to generate compression displacement, thereby realizing the axial displacement compensation function of the expansion joint.

[0041] Preferably, the third connecting pipe 16 is located outside the outlet pipe, and there is a radial gap between the third connecting pipe 16 and the outlet pipe 18, so that not only can the guide block be placed, but there will also be a certain gap after the guide block is placed, so that the third connecting pipe can float, thereby realizing the axial displacement and lateral displacement compensation function of the expansion joint.

[0042] Specifically, the working bellows assembly includes a first working bellows 3 and a second working bellows 6 , the inlet pipe 1 is connected to the first working bellows 3 , the first working bellows 3 and the second working bellows 6 are connected through a connecting pipe 5 , and the second working bellows 6 is connected to the outlet pipe 18 .

[0043] Preferably, the inlet pipe and the first working bellows, the first working bellows and the connecting pipe, the connecting pipe and the second working bellows, and the second working bellows and the outlet pipe are connected by welding.

[0044] Specifically, the tie rod assembly includes a first ring plate 2, a tie rod 11, and a third ring plate 15 connected in sequence. The first ring plate 2 is connected to the inlet pipe 1, the third ring plate 15 is connected to the third connecting pipe 16, and the third ring plate 15 is connected to the second connecting pipe 12.

[0045] Preferably, through holes are arranged at the same radial dimension of the first ring plate and the third ring plate, and the number of through holes is consistent with the number of tie rods, which is determined according to the magnitude of the pressure thrust and the diameter of the tie rods. The tie rods pass through the first ring plate and the third ring plate respectively.

[0046] Preferably, the first ring plate is sleeved on the outside of the inlet pipe and welded.

[0047] Specifically, spherical cone washers 13 are provided at both ends of the pull rod 11, and the spherical cone washers 13 are in close contact with the first ring plate 2 and the third ring plate 15. The pull rod plays a role in bearing the pressure thrust of the bellows, and the spherical cone washers assist the lateral deformation of the working bellows, thereby achieving the function of compensating for lateral displacement. Preferably, the left and right sides of the first ring plate 2 and the third ring plate 15 are in close contact with spherical cone washers.

[0048] Preferably, the second pipe 12 is welded to the side of the third ring plate 15, and the outer diameter of the third ring plate 15 is the same as the outer diameter of the first ring plate 2 and is larger than the outer diameter of the second pipe 12. The third ring plate 15 is sleeved on the outside of the third pipe 16 and fixed by welding, and the inner diameter of the third pipe 16 is larger than the outer diameter of the outlet pipe 18.

[0049] Specifically, the tie rod assembly further includes a rib plate 14, the rib plate 14 is connected to the third ring plate and / or the first ring plate, and the rib plate is used to strengthen the rigidity of the third ring plate / the first ring plate.

[0050] Specifically, the second ring plate, the first connecting pipe, the first balancing bellows, the second connecting pipe, the third ring plate, the third connecting pipe, the second balancing bellows, the fourth connecting pipe, the fourth ring plate, and the outlet pipe together form a cavity, and the through hole allows the working medium to enter the cavity to achieve the internal pressure of the first balancing bellows and the external pressure of the second balancing bellows. The left side of the second ring plate and the left side of the outlet pipe can be set at the same cross-section, thereby shortening the total length of the expansion joint.

[0051] Specifically, the through holes are arranged on the outer wall of the outlet pipe in a circumferential arrangement, and a plurality of through holes are arranged. Preferably, the number of through holes arranged is 6 to 10. The through hole 181 is located between the second ring plate 7 and the fourth ring plate 20, and the medium in the pipeline flows into the above-mentioned cavity through this through hole, thereby realizing the state where the first balancing bellows is subjected to internal pressure and the second balancing bellows is subjected to external pressure. The diameter and waveform parameter design of the first balancing bellows and the second balancing bellows need to meet the requirement that the effective area of ​​the first balancing bellows minus the effective area of ​​the second balancing bellows is equal to the effective area of ​​the working bellows, thereby achieving the balance of pressure thrust.

[0052] Specifically, when the flow rate of the pipeline medium is high, a guide tube 4 is arranged inside the first / second working bellows, and the guide tube is welded to the inner wall of the inlet pipe and the connecting pipe respectively. The guide tube can be a flange structure or a straight tube structure with a gasket. In addition, a protective cover structure can be arranged outside the working bellows to avoid bumps during transportation and installation of the expansion joint.

[0053] Specifically, there is a gap between the first working bellows, the second working bellows and the guide tube, so as to achieve an internal pressure state of the first working bellows and the second working bellows.

[0054] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A straight pipe pressure balancing expansion joint for space-constrained applications, characterized in that: The invention comprises a working wave component, a first balanced wave component, a second balanced wave component and a pull rod component, wherein one end of the working wave component is connected to an inlet pipe (1), the other end of the working wave component is connected to one end of the first balanced wave component via an outlet pipe (18), the other end of the first balanced wave component is connected to the pull rod component, the first balanced wave component is sleeved on the outside of the second balanced wave component, one end of the second balanced wave component is connected to the outlet pipe (18), the other end of the second balanced wave component is connected to a third connecting pipe (16), one end of the pull rod component is connected to the inlet pipe (1), the other end of the pull rod component is connected to the third connecting pipe (16), and a through hole (181) is provided on the outlet pipe (18), and the through hole (181) allows the working medium to enter the cavity formed by the first balanced wave component and the second balanced wave component.

2. The expansion joint according to claim 1, characterized in that: The first balancing wave assembly comprises a first connecting pipe (8), a first balancing bellows (9), and a second connecting pipe (12) which are connected in sequence; the first connecting pipe (8) is connected to an outlet pipe (18) via a second ring plate (7); the second connecting pipe (12) is connected to a pull rod assembly; and the through hole (181) is located between the second ring plate (7) and the second balancing wave assembly.

3. The expansion joint according to claim 2, characterized in that: The second balancing wave assembly comprises a fourth connecting pipe (19) and a second balancing bellows (10) which are connected in sequence; the fourth connecting pipe (19) is connected to the outlet pipe (18) via a fourth ring plate (20); the second balancing bellows (10) is connected to the third connecting pipe (16); and the through hole (181) is located between the second ring plate (7) and the fourth ring plate (20).

4. The expansion joint according to claim 1, characterized in that: A guide block (17) is provided between the outlet pipe (18) and the third connecting pipe (16).

5. The expansion joint according to claim 1, characterized in that: A plurality of through holes (181) are provided.

6. The expansion joint according to claim 1, characterized in that: The working bellows assembly comprises a first working bellows (3) and a second working bellows (6); the inlet pipe (1) is connected to the first working bellows (3); the first working bellows (3) and the second working bellows (6) are connected via a connecting pipe (5); and the second working bellows (6) is connected to an outlet pipe (18).

7. The expansion joint according to claim 1, characterized in that: The tie rod assembly comprises a first ring plate (2), a tie rod (11), and a third ring plate (15) which are connected in sequence; the first ring plate (2) is connected to the inlet pipe (1), and the third ring plate (15) is connected to the third connecting pipe (16).

8. The expansion joint according to claim 7, characterized in that: Spherical cone surface washers (13) are provided at both ends of the pull rod (11), and the spherical cone surface washers (13) are in close contact with the first ring plate (2) and the third ring plate (15).

9. The expansion joint according to claim 7, characterized in that: The tie rod assembly further comprises a rib plate (14), wherein the rib plate (14) is connected to the third ring plate (15) and / or the first ring plate (2).

10. The expansion joint according to claim 1, characterized in that: A guide tube (4) is arranged inside the working wave assembly.

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