Hot tapping plugging construction method of long natural gas delivery pipeline

Abstract

The invention discloses a hot tapping plugging construction method of a long natural gas delivery pipeline. The method specifically comprises the following implementation steps of: performing non-stop tapping operation; performing non-stop plugging operation; disassembling a pipeline of a cutting section; performing end connecting operation; restoring; and performing anti-corrosive backfill. The construction process of the method has the characteristics of reliability, economy, safety, simplicity in operation of an entire construction process, light labor intensity, no influence on downstream gas utilization, short working period, cost saving, suitability for various environments and the like, so that the method is increasingly generalized and applied in natural gas reconstruction and expansion projects.

Description

technical field [0001] The invention relates to a construction method for opening and plugging holes under pressure in long-distance natural gas pipelines. Background technique [0002] As people's demand for natural gas in production and life continues to increase, small and medium-sized cities around the world have also begun to connect to natural gas. This requires the reconstruction, expansion and emergency repair of the operating natural gas pipelines, and the natural gas pipeline plugging construction accordingly. Natural gas pipeline hot-press operation is essential, and there is no relatively mature method for hot-press maintenance and connection at present, and natural gas is flammable and explosive, and once a leak occurs, it will directly endanger the safety of people's lives and property. Because this process has the characteristics of not affecting downstream gas consumption, short construction period, cost saving, and applicable to various environments, it has ...

AI Technical Summary

Problems solved by technology

[0005] A long-distance natural gas pipeline construction method with pressure opening and sealing. The method is to install instruments, valves and other equipment under pressure under the maximum allowable sealing pressure that does not affect the needs of downstream pipeline users; , damaged or even fractured, seriously affecting medium transportation, holes can be opened under pressure in the intact parts and sections on both sides of the damaged pipe section, and bypass tee holes can be opened before and after the plugging point, and the bypass pipe can be installed and pressure tested and tested. Nitrogen replacement, so that the medium to be transported is temporarily transported through the bypass branch, and the damaged or need to be replaced pipe section is blocked. After the hole is opened, the plugging device is installed to start the plugging operation. Downstream, use a balance valve to balance the air pressure on both sides of the occluder, and slowly block; after confirming that the blockage is successful by observing the pipeline pressure in the isolation section, empty the waste section pipeline and replace it, cut it with a non-fired cutting tool, and connect the ends Operation: After the connection of the old and new pipelines is completed, nitrogen replacement is carried out, the blockage is removed, the upstream and downstream blockers are removed successively, the bypass pipe is removed, and the original equipment and pipeline transportation medium are restored to prevent the leakage of the transportation medium and pipeline transportation interruption;

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