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I. The horizontal directional drilling pipeline installation technique is generally used in the peripheral areas of cities where the density of pipelines is low, and it requires a large working area. In today’s era of rapid urbanization, this technique has certain limitations. II. Pipe splitting and replacement technique: This method involves using a cutting roller to cut the old pipe into pieces while pulling in a new pipe; it is suitable for ductile iron and plastic pipes. New pipes can be plastic pipes or steel pipes. It has limitations for old steel pipes. Additionally, this technology cannot navigate curves, and it requires a relatively large construction area. III. PE pipe insertion repair technique: Since inserting a new pipe into the existing one results in a significant reduction of the pipe’s inner diameter, which affects the gas flow rate, this method requires a large working area during installation and cannot accommodate bends greater than 15 degrees; as a result, it has limitations in many urban areas, with an operating pressure not exceeding 0.4 MPa. IV. U-shaped insertion repair technique for HDPE pipes in old pipelines: The pressure of the pipes repaired using this technique is below 0.4 MPa; their ability to bend is less than 15 degrees, and the inner diameter of the pipes decreases by several dozen millimeters, which affects the flow rate of gas. V. CIPP repair technology: This technique uses compressed air as a driving force to push a membrane-covered hose made of polymer fibers impregnated with adhesive curing agents into old gas pipelines; after pressure is applied and curing takes place, a composite pipeline that bonds tightly to the inner wall of the original pipeline is formed. This process requires a small construction area ； Can pass through 90-degree elbows ； It can repair gas pipelines with a design capacity of 5.0 MPa or less ； A single pipeline repair can cover a length of up to eight hundred meters.