CN220416589U

CN220416589U - Novel bellows expansion joint for gas pipeline

Info

Publication number: CN220416589U
Application number: CN202322141257.6U
Authority: CN
Inventors: 张爱琴; 付贝贝; 张家铭; 张璐杨
Original assignee: CSSC Shuangrui Luoyang Special Equipment Co Ltd
Current assignee: CSSC Shuangrui Luoyang Special Equipment Co Ltd
Priority date: 2023-08-10
Filing date: 2023-08-10
Publication date: 2024-01-30
Anticipated expiration: 2033-08-10

Abstract

The utility model provides a novel corrugated pipe expansion joint for a gas pipeline, which comprises an external pressure corrugated pipe expansion joint assembly, a gas inlet pipe, a gas outlet pipe and a pull rod, wherein the gas inlet pipe is connected with the gas outlet pipe through an expansion joint outer pipe and an external pressure corrugated pipe in the expansion joint assembly, and support pieces on flanges at two ends of the gas inlet pipe and the gas outlet pipe far away from the expansion joint assembly are connected through the pull rod, so that the pull rod and a nut are used for limiting axial stretching, compression or transverse deflection displacement of the expansion joint assembly in the expansion stretching, compression or transverse deflection process of the expansion joint assembly, and meanwhile, the pull rod can bear pressure thrust of the corrugated pipe; the novel corrugated pipe expansion joint for the gas pipeline can improve the compensation capability of the expansion joint, has an anti-seismic protection function, can facilitate daily monitoring of the change of the expansion joint, and meets the requirement of daily use safety inspection.

Description

Novel bellows expansion joint for gas pipeline

Technical Field

The utility model relates to the field of metal corrugated pipe expansion joints, in particular to a novel corrugated pipe expansion joint for a gas pipeline.

Background

The gas pipeline which is synchronously laid with a large bridge or enters an underground pipe gallery is laid in an overhead manner, and the gas pipeline is easily influenced by expansion caused by heat and contraction caused by cold due to the existence of temperature difference and uneven settlement of a foundation, so that the straight pipe section of the gas pipeline with longer laying length needs to be flexibly compensated to reduce the stress of the pipeline; and when natural compensation cannot meet the requirement, the expansion joint of the metal corrugated pipe is generally adopted for compensation due to the limitation of space.

The compensation of the straight pipe section of the existing gas pipeline is generally carried out by selecting an internal pressure axial expansion joint, the structural form of the expansion joint is shown in figure 1, and the corrugated pipe expansion joint structure of the compensation mode commonly adopted by the existing gas pipeline has the following defects:

in the aspect of compensation capability, the expansion joint is of an internal pressure axial structure and is limited by the number of column instability, the compensation capability is smaller, the corresponding arrangement spacing is smaller, and the number is more.

In the aspect of use safety, the existing expansion joint structure cannot meet the national related anti-seismic safety requirements of bridges and underground pipe galleries, and meanwhile, the existing structure cannot meet the daily use safety inspection requirements, so that research on how to improve the compensation capability of the straight pipe section of the gas pipeline is of great significance in guaranteeing the safety of the expansion joint.

Patent CN2031056U mentions an expansion joint, which consists of a corrugated pipe, an inner sleeve pipe positioned in the corrugated pipe, and seamless steel pipes and flanges welded at two ends of the corrugated pipe. The corrugated pipe is formed by butt welding outer bearing end points of two telescopic single sheets, then the butt welding of the bearing end points in the two adjacent telescopic sheets is carried out to form a complete corrugated pipe, so that a welding seam is not positioned at a telescopic part, the service life of the expansion joint is prolonged, but the corrugated pipe and a steel pipe are connected in a connecting mode, which is not connected with the outer side, of the corrugated pipe, the shock resistance is poor, the situation of fracture easily occurs, the expansion joint for the fuel gas vertical pipe is disclosed in patent CN206802604U, the expansion joint comprises the corrugated pipe, an outer shield is sleeved outside the corrugated pipe, and two ends of the outer shield are respectively sealed and fixedly connected with a first straight pipe section and a second straight pipe section; the end parts of the first straight pipe section and the second straight pipe section are respectively provided with a transition joint; the outer walls of the first straight pipe section and the second straight pipe section are respectively fixed with a first sealing ring plate and a second sealing ring plate which are perpendicular to the corrugated pipe at two ends, the fixed end of the outer shield is fixedly connected with the first sealing ring plate in a sealing way along the circumferential direction, and the movable end of the outer shield is overlapped and extends outwards beyond the second sealing ring plate; the outer shield, the first sealing ring plate, the first straight pipe section, the corrugated pipe, the second straight pipe section and the second sealing ring plate sequentially surround to form a closed cavity; the movable end of the outer shield is provided with at least one group of inner limiting devices and outer limiting devices protruding towards the second straight pipe section at positions corresponding to the two sides of the second sealing ring plate, so that expansion caused by heat and contraction caused by cold of the vertical pipe can be avoided, but the structure is not suitable for a gas pipeline installed underground, the shock resistance requirement is not met, if the structure is installed underground, the shock resistance and the safety performance of the structure can be greatly changed, and the compensation requirement of the straight pipe section of the gas pipeline cannot be effectively met.

Disclosure of Invention

In view of the above, the utility model aims to provide a novel corrugated pipe expansion joint for a gas pipeline, so as to solve the problems that the existing corrugated pipe expansion joint for the gas pipeline in the prior art has smaller compensation capability, smaller corresponding arrangement space and excessive quantity, and the existing expansion joint structure can not meet the national related anti-seismic safety requirements of bridges and underground pipe galleries and can not meet the daily use safety inspection requirements; therefore, the compensation capability of the expansion joint is improved, the expansion joint has an anti-seismic protection function, the change of the expansion joint can be monitored conveniently in daily life, and the requirement of daily use safety inspection is met.

In order to achieve the above purpose, the technical scheme of the utility model is realized as follows:

the utility model relates to a novel corrugated pipe expansion joint for a gas pipeline, which comprises an expansion joint assembly, a gas inlet pipe, a gas outlet pipe and a pull rod, wherein the gas inlet pipe is connected with the gas outlet pipe through the expansion joint assembly, one ends of the gas inlet pipe and the gas outlet pipe, which are far away from the expansion joint assembly, are respectively connected with the pull rod through a supporting piece, and the pull rod is used for limiting the axial stretching, compression or transverse deflection displacement of the expansion joint assembly in the expansion stretching, compression or transverse deflection process of the expansion joint assembly.

Further, the gas inlet pipe is close to the one end bottom of expansion joint subassembly and sets up the draft tube, and the one end that the draft tube kept away from the gas inlet pipe has certain clearance with gas outlet pipe bottom for the gas pressure passes through in the course of the work of being convenient for.

Further, expansion joint subassembly includes limiting plate subassembly, outer bellows, export end ring subassembly, expansion joint outer tube and import end ring subassembly, and limiting plate subassembly, outer bellows, export end ring subassembly, expansion joint outer tube and import end ring subassembly connect gradually, and the one end that the limiting plate subassembly kept away from outer bellows is connected with the gas outlet pipe, and the one end that the expansion joint outer tube was kept away from to import end ring subassembly is connected with the gas import pipe.

Further, a cavity is formed among the limiting plate assembly, the outer corrugated pipe, the outlet end ring assembly, the expansion joint outer pipe, the inlet end ring assembly and the guide cylinder and is used for buffering the pressure of fuel gas.

Further, limiting plate subassembly includes spacing first board and spacing two boards, and spacing first board one end sets up perpendicularly and is close to the one end of draft tube at the gas outlet pipe, and spacing first board is kept away from and has certain clearance between the one end of gas outlet pipe and the expansion joint outer tube, and spacing two boards set up perpendicularly and are close to the one end of gas outlet pipe at spacing first board, and spacing two boards are kept away from the one end top of spacing first board and are connected with outer bellows bottom.

Further, the outlet end ring assembly comprises an outlet end plate and an outlet end ring plate, the top of the outlet end plate is connected with the bottom of one end of the outer pressure corrugated pipe, which is far away from the limiting two plates, the end of the outlet end plate, which is far away from the outer pressure corrugated pipe, is vertically arranged at the bottom of the inner side of the outlet end ring plate, the top of the outlet end ring plate is connected with the inlet end ring assembly through an expansion joint outer pipe, the outlet end plate is arranged in parallel with the gas outlet pipe, and the outlet end ring plate is vertically arranged above the gas outlet pipe.

Further, a monitoring gap is formed between the outlet end plate and the outer side wall of the gas outlet pipe and is used for simultaneously meeting the passing of an external pressure corrugated pipe inner wall detection endoscope probe or a gas micro-leakage monitoring probe.

Further, the inlet end ring component comprises an inlet ring plate and an inlet end connecting block, the top of the inlet ring plate is connected with the outer tube of the expansion joint, and the bottom of the inlet ring plate is connected with one end, close to the guide cylinder, of the gas inlet tube through the inlet end connecting block.

Further, the support piece comprises a support first piece and a support second piece, the top of one end of the gas inlet pipe, which is far away from the guide cylinder, is connected with the pull rod through the support first piece, and the top of one end of the gas outlet pipe, which is far away from the guide cylinder, is connected with the pull rod through the support second piece.

Further, the top ends of the first support piece and the second support piece are respectively provided with a through hole, and the left end and the right end of the pull rod are respectively arranged in the first support piece and the second support piece through the through holes.

Compared with the prior art, the novel corrugated pipe expansion joint for the gas pipeline has the following beneficial effects:

by the arrangement of the expansion joint, the compensation capability of the expansion joint can be improved, so that the expansion joint has an anti-seismic protection function, the change of the expansion joint can be monitored conveniently in daily life, and the requirement of daily use safety inspection is met; through changing the bellows pressure-bearing state and setting up of spacing atress pull rod, improved the compensation ability of expansion joint, satisfied the antidetonation demand, improved the security and the monitoring detection convenience of product.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the utility model. In the drawings:

FIG. 1 is a schematic diagram of a bellows expansion joint commonly used in a gas pipeline in the prior art;

fig. 2 is a schematic diagram of a novel bellows expansion joint structure for a gas pipeline.

Reference numerals illustrate: 1. an expansion joint assembly; 11. a limiting plate assembly; 111. a limiting plate; 112. limiting two plates; 12. an outer crimp tube; 13. an outlet end ring assembly; 131. an outlet end plate; 132. an outlet ring plate; 14. an expansion joint outer tube; 15. an inlet end ring assembly; 151. an inlet ring plate; 152. an inlet end connecting block; 16. a cavity; 2. a gas inlet pipe; 3. a gas outlet pipe; 4. a pull rod; 5. a support; 51. supporting a piece; 52. supporting two pieces; 6. a guide cylinder; 7. monitoring the gap; 8. installing a nut; 9. a gasket; 10. and (5) limiting the nut.

Detailed Description

The inventive concepts of the present disclosure will be described below using terms commonly used by those skilled in the art to convey the substance of their work to others skilled in the art. These inventive concepts may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

It should be noted that, without conflict, the embodiments of the present utility model and features of the embodiments may be combined with each other.

In the description of the present utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present utility model and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

The utility model will be described in detail below with reference to the drawings in connection with embodiments.

The embodiment is directed to a metal corrugated pipe expansion joint, and the same as a conventional metal corrugated pipe expansion joint, and the whole structure consists of the expansion joint and a nut.

In the prior art, the compensation of the straight pipe section of the gas pipeline is generally carried out by selecting an internal pressure axial expansion joint, but the corrugated pipe expansion joint has the following defects: 1. in the aspect of compensation capability, the expansion joint is of an internal pressure axial structure, is limited by the number of column instability, has smaller compensation capability, and has smaller corresponding arrangement space and more quantity; 2. in the aspect of use safety, the existing expansion joint structure cannot meet the national related anti-seismic safety requirements of bridges and underground pipe galleries, and meanwhile, the existing structure cannot meet the daily use safety inspection requirements, so that research on how to improve the compensation capability of the straight pipe section of the gas pipeline is of great significance in guaranteeing the safety of the expansion joint.

In order to solve the problems that the existing common corrugated expansion joint of the gas pipeline in the prior art has smaller compensation capability, smaller corresponding arrangement space and excessive quantity, and the existing expansion joint structure can not meet the national related anti-seismic safety requirements of bridges and underground pipe galleries and the daily use safety inspection requirements; the embodiment provides a novel bellows expansion joint for gas pipeline, including expansion joint subassembly 1, gas inlet pipe 2, gas outlet pipe 3 and pull rod 4, gas inlet pipe 2 is connected with gas outlet pipe 3 through expansion joint subassembly 1, gas inlet pipe 2, gas outlet pipe 3 are kept away from the one end of expansion joint subassembly 1 and are connected with pull rod 4 through support piece 5 respectively, be used for in expansion joint subassembly 1 expansion stretching, compression or lateral deflection in-process, pull rod 4 plays the axial stretching of restriction expansion joint subassembly 1, compression or lateral deflection displacement, wherein, gas inlet pipe 2 is close to expansion joint subassembly 1's one end bottom sets up guide cylinder 6, guide cylinder 6 is kept away from gas inlet pipe 2's one end and has certain clearance with gas outlet pipe 3 bottom, guide cylinder 6 and gas outlet pipe 3 bottom parallel arrangement, be used for the gas pressure to pass through in the course of being convenient for, in this embodiment, expansion joint subassembly 1 is the expansion joint subassembly including external pressure bellows 12.

Through the cooperation setting between expansion joint subassembly 1, gas inlet pipe 2, gas outlet pipe 3 and the pull rod 4, can effectually improve the compensation ability of expansion joint, make the expansion joint have antidetonation safeguard function, and can be convenient for daily monitoring expansion joint's change, satisfy the requirement that daily use safety patrolled and examined.

The expansion joint assembly 1 comprises a limiting plate assembly 11, an outer corrugated pipe 12, an outlet end ring assembly 13, an expansion joint outer pipe 14 and an inlet end ring assembly 15, wherein the limiting plate assembly 11, the outer corrugated pipe 12, the outlet end ring assembly 13, the expansion joint outer pipe 14 and the inlet end ring assembly 15 are sequentially connected, one end of the limiting plate assembly 11, which is far away from the outer corrugated pipe 12, is connected with the gas outlet pipe 3, and one end of the inlet end ring assembly 15, which is far away from the expansion joint outer pipe 14, is connected with the gas inlet pipe 2; a cavity 16 is formed among the limiting plate assembly 11, the outer corrugated pipe 12, the outlet end ring assembly 13, the expansion joint outer pipe 14, the inlet end ring assembly 15 and the guide cylinder 6 and is used for buffering gas pressure, the cavity 16 is an annular space, two ends of the outer corrugated pipe 12 are respectively welded with the limiting plate assembly 11 and the outlet end ring assembly 13, and in the working process, the gas pressure enters the annular space between the expansion joint outer pipe 14 and the outer corrugated pipe 12, namely the cavity 16 through a gap between the guide cylinder 6 and the inner wall of the gas outlet pipe 3; the limiting plate assembly 11 comprises a limiting first plate 111 and a limiting second plate 112, one end of the limiting first plate 111 is vertically arranged at one end of the gas outlet pipe 3, which is close to the guide cylinder 6, a certain gap is reserved between one end of the limiting first plate 111, which is far away from the gas outlet pipe 3, and the outer tube 14 of the expansion joint, the limiting second plate 112 is vertically arranged at one end of the limiting first plate 111, which is close to the gas outlet pipe 3, and one end top of the limiting second plate 112, which is far away from the limiting first plate 111, is welded and connected with the bottom of the outer corrugated tube 12; the outlet end ring assembly 13 comprises an outlet end plate 131 and an outlet ring plate 132, the top of the outlet end plate 131 is welded with the bottom of one end, far away from the limiting two plates 112, of the outer corrugated pipe 12, one end, far away from the outer corrugated pipe 12, of the outlet end plate 131 is vertically arranged at the bottom end of the inner side of the outlet ring plate 132, the top end of the outlet ring plate 132 is connected with the inlet end ring assembly 15 through an expansion joint outer pipe 14, the outlet end plate 131 is arranged in parallel with the gas outlet pipe 3, and the outlet ring plate 132 is vertically arranged above the gas outlet pipe 3; a monitoring gap 7 is formed between the outlet end plate 131 and the outer side wall of the gas outlet pipe 3 and is used for simultaneously meeting the passing of an endoscope probe or a gas micro-leakage monitoring probe for detecting the inner wall of the external pressure corrugated pipe 12; the inlet end ring assembly 15 includes an inlet ring plate 151 and an inlet end connecting block 152, the top of the inlet ring plate 151 is connected with the outer tube 14 of the expansion joint, the bottom of the inlet ring plate 151 is connected with one end of the gas inlet tube 2, which is close to the guide cylinder 6, through the inlet end connecting block 152, in this embodiment, the bottom refers to the lower part as shown in the figure, and the top refers to the upper part as shown in the figure, in this embodiment, the size of the monitoring gap 7 between the right side outlet ring plate 132 of the outlet end ring assembly 13 and the outer side wall of the gas outlet tube 3 is set, so that the requirements of detecting the passage of an endoscope probe or a micro leakage monitoring probe by the inner wall of the external pressure corrugated tube 12 and daily safety inspection operation are met.

The outer corrugated pipe 12 is changed into an outer corrugated pipe 12 in a connection mode of the left end and the right end, namely the bottoms of the left end and the right end of the outer corrugated pipe 12 are respectively connected with the limiting plate assembly 11 and the top of the device in the outlet end ring assembly 13, the inner diameter of the outer corrugated pipe 12 is respectively larger than the outer diameter of the gas inlet pipe 2 and the outer diameter of the gas outlet pipe 3, the axial displacement compensation capacity of the expansion joint of the outer corrugated pipe 12 is improved, the transverse displacement compensation capacity of the expansion joint of the outer corrugated pipe 12 is guaranteed, in addition, the safety of a product is improved due to the arrangement of the outer expansion joint pipe 14, in addition, compared with the inner pressure axial expansion joint, the outer corrugated pipe 12 is not limited by the number of column instability, the outer corrugated pipe 12 bearing the outer pressure is arranged in the application, the larger axial compensation amount can be realized, meanwhile, the inner diameter of the outer corrugated pipe 12 can be set according to the requirements of shock-resistant transverse displacement, the monitoring gap 7 between the right outlet end ring plate 132 of the outlet end ring assembly 13 and the outer side wall of the gas outlet pipe 3 is guaranteed, the outer corrugated pipe 12 is also provided with the expansion joint 14, the abnormal outer corrugated pipe 12 is avoided, and the abnormal outer corrugated pipe is prevented from being collided, and the abnormal phenomenon is avoided.

The support piece 5 comprises a first support piece 51 and a second support piece 52, the top of one end of the gas inlet pipe 2, which is far away from the guide cylinder 6, is connected with the pull rod 4 through the first support piece 51, and the top of one end of the gas outlet pipe 3, which is far away from the guide cylinder 6, is connected with the pull rod 4 through the second support piece 52; the left and right ends of the pull rod 4 are respectively arranged in the first support piece 51 and the second support piece 52 through the through holes, when the pull rod is connected with the first support piece 51, the left and right sides of the first support piece 51 are sequentially provided with the mounting nut 8 and the gasket 9 on the outer side wall of the pull rod 4 from outside to inside, the gasket 9 is a ball conical surface gasket used for guaranteeing flexibility when the expansion joint of the outer bellows 12 compensates transverse displacement, the mounting nut 8 is used for fastening the pull rod 4 with the first support piece 51 through the gasket 9, the left and right sides of the second support piece 52 are provided with the double limiting nuts 10 on the outer side wall of the pull rod 4, so that on one hand, the failure caused by the over-displacement compensation of the expansion joint can be prevented, on the other hand, the arrangement of the pull rod 4 can bear the pressure thrust of the outer bellows 12, the expansion joint of the outer bellows 12 is prevented from being failed due to the failure of a gas pipeline fixing pipe frame under earthquake or extreme working conditions, and the safety of products is improved; preferably, the support piece 5 is a flange, the left end and the right end of the pull rod 4 are respectively and fixedly arranged on the flange through the mounting nuts 8, the mounting nuts 8 are respectively arranged on the left side and the right side of the flange connected with the left end or the right end of the pull rod 4, and the mounting nuts 8 are preferably arranged for 4, but the actual number is set according to the required number, the arrangement of the pull rod 4 can bear the pressure thrust of the external pressure corrugated pipe 12, the pull-out failure of the external pressure corrugated pipe 12 caused by the failure of a gas pipeline fixing support under the extreme working condition of an earthquake is prevented, the pull rod 4 is close to one end of the support piece 51, and the spherical conical washers 9 are respectively arranged at the left side and the right side of the support piece 51, so that the flexibility of the expansion joint of the external pressure corrugated pipe 12 in the process of compensating the transverse displacement can be ensured; and the limit nuts 10 are arranged on the left side and/or the right side of the two support pieces 52 at one end, close to the two support pieces 52, of the pull rod 4, so that the limit of the pull rod 4 is realized, wherein the number of the limit nuts 10 is determined according to the small compensation amount set by the expansion joint, and preferably, the limit nuts 10 are respectively arranged on the left side and the right side of the two support pieces 52, so that the bidirectional limit of the pull rod 4 is realized.

The stress pull rods 4 are arranged on the outer sides of the supporting pieces 5 at the two ends of the expansion joint, the limit nuts 10 are arranged on the two sides of the supporting piece 5 at one end of the pull rod 4, so that the axial stretching and compression displacement of the expansion joint is limited, and meanwhile, the arrangement of the pull rods 4 can bear the pressure thrust of the external pressure corrugated pipe 12, so that the failure of the corrugated pipe expansion joint caused by the failure of the fixed pipe frame under the extreme working condition of an earthquake is prevented; the monitoring gap 7 is reserved at the right end of the expansion joint, and is used for providing a monitoring operation space for a probe for monitoring leakage of the outer bellows 12 of the expansion joint, so that daily inspection is facilitated, the service life of the device can be prolonged, the stable operation of the gas channel under the conditions of thermal expansion and contraction or stratum change is enhanced, and the safety of personnel is ensured.

In the present utility model, for any expansion joint of the metal external pressure bellows 12, the novel expansion joint structure for a gas pipeline described in this embodiment may be included, and on the basis of the related structures and the assembly relationships of the pull rod 4 and the limiting plate assembly 11 provided in this embodiment, the expansion joint of the metal external pressure bellows 12 further includes conventional components including expansion joints, nuts, etc., which are not described herein in detail in view of the prior art.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the utility model.

Claims

1. The utility model provides a novel bellows expansion joint for gas pipeline, a serial communication port, including expansion joint subassembly (1), gas inlet pipe (2), gas outlet pipe (3) and pull rod (4), gas inlet pipe (2) are connected with gas outlet pipe (3) through expansion joint subassembly (1), one end that expansion joint subassembly (1) was kept away from to gas inlet pipe (2), gas outlet pipe (3) is connected with pull rod (4) through support piece (5) respectively, be used for in expansion joint subassembly (1) expansion stretching, compression or lateral deflection in-process, pull rod (4) play restriction expansion joint subassembly (1) axial stretching, compression or lateral deflection displacement.

2. The novel corrugated pipe expansion joint for the gas pipeline according to claim 1, wherein a guide cylinder (6) is arranged at the bottom of one end, close to the expansion joint assembly (1), of the gas inlet pipe (2), and a certain gap is formed between one end, far away from the gas inlet pipe (2), of the guide cylinder (6) and the bottom of the gas outlet pipe (3) so as to facilitate gas pressure passing in the working process.

3. The corrugated pipe expansion joint for the novel gas pipeline according to claim 2, wherein the expansion joint assembly (1) comprises a limiting plate assembly (11), an external pressure corrugated pipe (12), an outlet end ring assembly (13), an expansion joint outer pipe (14) and an inlet end ring assembly (15), the limiting plate assembly (11), the external pressure corrugated pipe (12), the outlet end ring assembly (13), the expansion joint outer pipe (14) and the inlet end ring assembly (15) are sequentially connected, one end, far away from the external pressure corrugated pipe (12), of the limiting plate assembly (11) is connected with the gas outlet pipe (3), and one end, far away from the expansion joint outer pipe (14), of the inlet end ring assembly (15) is connected with the gas inlet pipe (2).

4. A novel corrugated expansion joint for a gas pipeline according to claim 3, wherein a cavity (16) is formed between the limiting plate assembly (11), the external pressure corrugated pipe (12), the outlet end ring assembly (13), the expansion joint outer pipe (14), the inlet end ring assembly (15) and the guide cylinder (6) for buffering the gas pressure.

5. The novel corrugated pipe expansion joint for the gas pipeline according to claim 4, wherein the limiting plate assembly (11) comprises a limiting first plate (111) and a limiting second plate (112), one end of the limiting first plate (111) is vertically arranged at one end of the gas outlet pipe (3) close to the guide cylinder (6), a certain gap is reserved between one end of the limiting first plate (111) far away from the gas outlet pipe (3) and the outer pipe (14) of the expansion joint, the limiting second plate (112) is vertically arranged at one end of the limiting first plate (111) close to the gas outlet pipe (3), and the top of one end of the limiting second plate (112) far away from the limiting first plate (111) is connected with the bottom of the outer corrugated pipe (12).

6. The novel corrugated pipe expansion joint for the gas pipeline according to claim 5, wherein the outlet end ring assembly (13) comprises an outlet end plate (131) and an outlet end ring plate (132), the top of the outlet end plate (131) is connected with the bottom of one end of the external pressure corrugated pipe (12) far away from the limiting two plates (112), one end of the outlet end plate (131) far away from the external pressure corrugated pipe (12) is vertically arranged at the bottom of the inner side of the outlet end ring plate (132), the top of the outlet end ring plate (132) is connected with the inlet end ring assembly (15) through an expansion joint outer pipe (14), the outlet end plate (131) is arranged in parallel with the gas outlet pipe (3), and the outlet end ring plate (132) is vertically arranged above the gas outlet pipe (3).

7. The novel corrugated pipe expansion joint for the gas pipeline according to claim 6, wherein a monitoring gap (7) is formed between the outlet end plate (131) and the outer side wall of the gas outlet pipe (3) and is used for simultaneously meeting the passing of an endoscope probe or a gas micro-leakage monitoring probe for detecting the inner wall of the external pressure corrugated pipe (12).

8. The corrugated expansion joint for the novel gas pipeline according to claim 6, wherein the inlet end ring assembly (15) comprises an inlet ring plate (151) and an inlet end connecting block (152), the top of the inlet ring plate (151) is connected with the outer pipe (14) of the expansion joint, and the bottom of the inlet ring plate (151) is connected with one end, close to the guide cylinder (6), of the gas inlet pipe (2) through the inlet end connecting block (152).

9. The novel corrugated pipe expansion joint for the gas pipeline according to claim 8, wherein the supporting piece (5) comprises a first supporting piece (51) and a second supporting piece (52), one end top of the gas inlet pipe (2) far away from the guide cylinder (6) is connected with the pull rod (4) through the first supporting piece (51), and one end top of the gas outlet pipe (3) far away from the guide cylinder (6) is connected with the pull rod (4) through the second supporting piece (52).

10. The novel corrugated pipe expansion joint for the gas pipeline according to claim 9, wherein through holes are formed in the top ends of the first supporting piece (51) and the second supporting piece (52), and the left end and the right end of the pull rod (4) are respectively arranged in the first supporting piece (51) and the second supporting piece (52) through the through holes.