CN113883329B

CN113883329B - Method for resetting gas pipeline

Info

Publication number: CN113883329B
Application number: CN202111219690.6A
Authority: CN
Inventors: 朱伟; 唐磊; 单雪琴; 吴晟彦
Original assignee: Shanghai Energy Construction Group Co ltd
Current assignee: Shanghai Energy Construction Group Co ltd
Priority date: 2021-10-20
Filing date: 2021-10-20
Publication date: 2023-04-21
Anticipated expiration: 2041-10-20
Also published as: CN113883329A

Abstract

The invention discloses a method for moving and resetting a gas pipeline; firstly, installing valves on two reserved sections of a gas pipeline, which are close to two ends of the pipeline to be maintained, and cutting off the pipeline by using an electric climbing knife and a manual shaking knife after closing the valves; then, the two three-way side pipelines are respectively connected with the two ends of the temporary pipeline through corresponding flanges; ventilation through temporary tubing; maintaining the pipeline to be maintained; and cutting off the short joint pipe with the flange of each tee joint, and connecting the two ends of the maintained pipeline to be maintained with the short joint pipes with the two cut tee joints respectively. The invention solves the construction risk in welding caused by the fact that the gate valve cannot be completely closed and the pipeline leaks air in the prior art.

Description

Method for resetting gas pipeline

Technical Field

The invention relates to the technical field of gas pipeline transformation, in particular to a method for moving and resetting a gas pipeline.

Background

With the continuous expansion of urban scale, the urban in-service gas pipeline is transformed by the urban old gas pipe transformation planning, the construction of other important infrastructures of the city is avoided, the maintenance and repair of the pipeline are involved in temporary transportation of the pipeline, the maintenance of the pipeline and other matters.

At present, the city expansion speed is high, and a large amount of new construction, maintenance and improvement of infrastructure construction are likely to involve the movement of the original pipeline. As shown in fig. 1 to 3, when the existing pipeline is moved, the conventional construction method is to close the valve, release the valve to normal pressure, replace the residual air in the pipeline with nitrogen and break the pipeline. At the pipe breaking position, the pipe is connected with a new pipeline by adopting a mode of welding an elbow, and the new pipeline is parallel to the original pipeline.

The existing construction method has the following problems:

1. the newly built pipeline needs to borrow to the left or right side and changes, need occupy new pipe position when borrowing to change, but the underground pipeline below the urban road of present stage is densely distributed, and the pipe position is very tense, especially old urban area, hardly is at arranging new pipe position.

2. Because the original pipeline is laid according to the minimum burial depth requirement of national standards, the newly built pipeline cannot be laid in the area with shallower burial depth.

3. Laying the pipeline in the depths, can increasing the pipeline laying cost, should dig the depth increase for the pipeline simultaneously, increase construction area, can probably involve the operation of darker foundation ditch simultaneously (not deep foundation ditch, deep foundation ditch requires 5m and more), have certain potential safety hazard, and the buried depth is greater than former pipeline simultaneously, just can carry out new pipeline laying after need waiting for the broken pipe of former pipeline to tear down, this can lead to long-time outage, seriously influences the user.

4. The valve of current pipeline is mainly with the gate valve, and the gate valve can't close completely after long-time operation, even adopts nitrogen replacement's mode, still can have a lot of natural gas to get into the pipeline, after the mixed air, explodes at the welded part easily.

5. The traditional obstruction drainage device can only transversely enter and exit the pipeline, and can not be taken out after the pipeline splicing is completed.

Therefore, how to reduce the cost of the relocation and reconstruction of the old gas pipeline and improve the construction efficiency are technical problems which are needed to be solved by the technicians in the field.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention provides a method for relocation and resetting of a gas pipeline, which aims to reduce the cost of relocation and reconstruction of old gas pipelines and improve the construction efficiency.

In order to achieve the above purpose, the invention discloses a method for moving and resetting a gas pipeline; the method comprises the following steps:

step 1, laying a temporary pipeline and preparing a tee joint; each tee joint comprises a straight pipeline and a side pipeline which is arranged on the side wall of the straight pipeline and is perpendicular to the straight pipeline;

one end of each straight pipeline is provided with a short-joint pipe, and the tail end provided with one end of the short-joint pipe and the tail end of the corresponding side pipeline are provided with flanges;

step 2, finding out the nearest valves on an upstream pipeline and a downstream pipeline of the gas pipeline, which are close to the pipeline to be maintained;

after closing the two valves, diffusing the fuel gas in the pipeline to be maintained;

after the diffusion is finished, an electric climbing knife and a manual rocking knife are used for breaking the pipe, the pipe to be maintained is cut off, and a section of pipe with an intact pipe wall is reserved as a reserved section on one side of the two valves, which faces the pipe to be maintained, respectively;

step 3, after pipe breakage is completed, a barrier is plugged into the two reserved sections;

step 4, connecting the tee joint with the two retaining sections; the other end of each tee joint, which is not connected with the short joint pipe, is connected with the corresponding reserved section;

step 5, connecting the side pipelines of the two tee joints with two ends of the temporary pipeline through corresponding flanges respectively;

step 6, taking out the corresponding obstructers from the two retaining sections through the two tee joints; closing one end of each tee joint, where a flange is arranged, of the straight pipe through a flange blind plate;

step 7, ventilation is carried out through the temporary pipeline;

step 8, maintaining/replacing the pipeline to be maintained to form a new pipeline;

step 9, closing two valves after maintenance is completed, and diffusing at the valve until no obvious pressure exists in the pipeline;

step 10, removing the temporary pipelines, closing the side pipelines of each tee joint by using flange blind plates, and opening the flange blind plates at one end of the straight pipeline of each tee joint, which is provided with a flange;

step 11, plugging the baffle devices into the two retaining sections through the straight pipelines of the tee joint, and leading out the dragging rope and the drainage hose of each baffle device through the side pipeline;

step 12, cutting off the short section pipe provided with the flange of each tee joint, and respectively connecting two ends of the new pipeline which is maintained/replaced with the short section pipes of the two tee joints;

and 13, respectively taking out the corresponding obstructers from the side pipelines of the two tee joints, and closing the side pipeline of each tee joint by using a flange blind plate.

Preferably, in step 2, after pipe breakage, spraying is performed at the pipe breakage.

Preferably, in step 4, each of the short pipes is connected to the corresponding reserved section by welding.

The invention has the beneficial effects that:

the invention solves the construction risk in welding caused by the fact that the gate valve cannot be completely closed and the pipeline leaks air in the prior art.

The invention reduces the influence of pipeline maintenance and relocation on the gas consumption of users.

The invention uses the original pipe position laying, thereby reducing the use of new pipe positions which are originally very tense.

The invention avoids the cost of nitrogen replacement in the prior art.

The conception, specific structure, and technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, features, and effects of the present invention.

Drawings

Fig. 1 shows a top view of a prior art pipe relocation.

Figure 2 shows an elevation of a prior art new laying pipeline above an original pipeline.

Figure 3 shows an elevation of a prior art new laying pipeline below an original pipeline.

Fig. 4 shows a front view of the finished pipe in an embodiment of the invention.

Fig. 5 shows a top view of the completed pipe in an embodiment of the invention.

Figure 6 illustrates a front view of a completed barrier arrangement in an embodiment of the invention.

Figure 7 shows a top view of a completed barrier arrangement in an embodiment of the invention.

Fig. 8 shows a front view of a completed tee installation in an embodiment of the invention.

Fig. 9 shows a top view of a completed tee installation in an embodiment of the invention.

Figure 10 illustrates an elevation view of ventilation through temporary ducts in an embodiment of the invention.

Figure 11 illustrates a top view of ventilation through temporary ducts in an embodiment of the invention.

FIG. 12 illustrates an elevation view of a temporary pipeline removed to complete a repair requiring the repair of the pipeline in accordance with one embodiment of the present invention.

FIG. 13 illustrates a top view of a temporary pipeline removed to complete a repair of a pipeline in need of repair in accordance with an embodiment of the present invention.

Figure 14 shows an elevation view of the completion of a flanged sub pipe cut in an embodiment of the invention.

Figure 15 shows a top view of the completed pipe nipple with flange in an embodiment of the invention.

FIG. 16 shows an elevation view of a completed tee in connection with a pipe requiring repair in an embodiment of the invention.

FIG. 17 shows a top view of a completed tee in connection with a pipe requiring repair in an embodiment of the invention.

Figure 18 shows a front view of a flange blind closing a side duct with the obstructor removed in an embodiment of the present invention.

Figure 19 shows a top view of a flange blind closing a side duct with the obstructor removed in an embodiment of the present invention.

Detailed Description

Examples

As shown in fig. 4 to 19, the method for resetting the gas pipeline; the method comprises the following steps:

step 1, laying a temporary pipeline and preparing a tee joint 1; each tee joint 1 comprises a straight pipeline and a side pipeline 2 which is arranged on the side wall of the straight pipeline and is vertical to the straight pipeline;

one end of each straight pipeline is provided with a short-joint pipe 3, and the tail end of one end provided with the short-joint pipe 3 and the tail end of the corresponding side pipeline 2 are provided with flanges 4;

step 2, finding out the nearest valves 6 on an upstream pipeline and a downstream pipeline of the gas pipeline, which are close to the pipeline to be maintained;

after closing the two valves 6, diffusing the fuel gas in the pipeline to be maintained;

after the diffusion is completed, an electric climbing knife and a manual rocking knife are used for breaking the pipe, the pipe needing to be maintained is cut off, and a section of pipe wall-intact pipeline is reserved as a reserved section 5 on one side of the two valves 6 facing the pipe needing to be maintained;

step 3, after pipe breakage is completed, a barrier is plugged into the two retaining sections 5;

step 4, connecting a tee joint 1 with two retaining sections 5; the other end of the straight pipeline of each tee joint 1, which is not connected with the short-joint pipe 3, is connected with a corresponding reserved section 5;

step 5, connecting the side pipelines 2 of the two tee joints 1 with two ends of the temporary pipeline through corresponding flanges 4 respectively;

step 6, taking out the corresponding barrier from the two retaining sections 5 through the two tee joints 1; sealing one end of each tee joint 1, where a flange 4 is arranged, of a straight pipe by using a flange blind plate;

step 7, ventilation is carried out through a temporary pipeline;

step 9, after maintenance is completed, closing the two valves 6, and diffusing at the valve 6 until no obvious pressure exists in the pipeline;

step 10, removing temporary pipelines, closing the side pipelines 2 of each tee joint 1 by using flange blind plates, and opening the flange blind plates at one end of the straight pipeline provided with the flange 4 of each tee joint 1;

step 11, plugging the baffle devices into the two retaining sections 5 through the straight pipeline of the tee joint 1, and leading out the dragging rope and the drainage hose of each baffle device through the side pipeline 2;

step 12, cutting off the short-joint pipe 3 with the flange 4 of each tee joint 1, and respectively connecting two ends of a new pipeline which is maintained/replaced with the short-joint pipes 3 of the two tee joints 1;

and 13, respectively taking out the corresponding obstructers from the side pipelines 2 of the two tee joints 1, and closing the side pipeline 2 of each tee joint 1 by using a flange blind plate.

Please briefly describe herein the principle of the present invention to achieve the technical effects

In certain embodiments, in step 2, after the pipe break, a shower is performed at the pipe break.

In certain embodiments, in step 4, each short tube 3 is connected to the corresponding reserved section 5 by welding.

The foregoing describes in detail preferred embodiments of the present invention. It should be understood that numerous modifications and variations can be made in accordance with the concepts of the invention by one of ordinary skill in the art without undue burden. Therefore, all technical solutions which can be obtained by logic analysis, reasoning or limited experiments based on the prior art by the person skilled in the art according to the inventive concept shall be within the scope of protection defined by the claims.

Claims

1. The method for resetting the gas pipeline comprises the following steps:

step 1, laying a temporary pipeline and preparing a tee joint (1); each tee joint (1) comprises a straight pipeline and a side pipeline (2) which is arranged on the side wall of the straight pipeline and is perpendicular to the straight pipeline;

one end of each straight pipeline is provided with a short-joint pipe (3), and the tail end provided with one end of the short-joint pipe (3) and the tail end of the corresponding side pipeline (2) are provided with flanges (4);

step 2, finding out the nearest valves (6) on an upstream pipeline and a downstream pipeline of the gas pipeline, which are close to the pipeline to be maintained, respectively;

after closing the two valves (6), diffusing the fuel gas in the pipeline to be maintained;

after the diffusion is finished, an electric climbing knife and a manual rocking knife are used for breaking pipes, the pipe needing to be maintained is cut off, and a section of pipe wall-perfect pipe is reserved as a reserved section (5) on one side of the two valves (6) facing the pipe needing to be maintained;

step 3, after pipe breaking is completed, a blocking device is plugged into the two reserved sections (5);

step 4, connecting the tee joint (1) at two retaining sections (5); the other end of the straight pipe of each tee joint (1) which is not connected with the short pipe joint (3) is connected with the corresponding reserved section (5);

step 5, connecting the side pipelines (2) of the two tee joints (1) with two ends of the temporary pipeline through the corresponding flanges (4) respectively;

step 6, taking out the corresponding barrier from the two retaining sections (5) through the two tee joints (1); closing one end of the straight pipe provided with a flange (4) of each tee joint (1) by using a flange blind plate;

step 7, ventilation is carried out through the temporary pipeline;

step 9, after maintenance is completed, closing the two valves (6), and diffusing at the positions of the valves (6) until no obvious pressure exists in the pipeline;

step 10, removing the temporary pipelines, closing the side pipelines (2) of each tee joint (1) by using flange blind plates, and opening the flange blind plates at one end of the straight pipeline provided with the flange (4) of each tee joint (1);

step 11, plugging the baffle devices into the two retaining sections (5) through the straight pipe of the tee joint (1), and leading out the dragging rope and the drainage hose of each baffle device through the side pipe (2);

step 12, cutting off the short-section pipe (3) provided with the flange (4) of each tee joint (1), and respectively connecting two ends of the new pipeline which is completed to repair/replace with the short-section pipes (3) of the two tee joints (1) which are cut off;

and 13, respectively taking out the corresponding obstructers from the side pipelines (2) of the two tee joints (1), and closing the side pipelines (2) of each tee joint (1) by using a flange blind plate.

2. The method for relocation of a gas pipeline according to claim 1, wherein in step 2, after pipe breakage, spraying is performed at the pipe breakage.

3. A method of resetting a gas pipeline according to claim 1, wherein in step 4 each of the sub-pipes (3) is connected to the respective retaining segment (5) by welding.