Pipeline non-stop transportation pressure-sealing equipment: The core equipment for ensuring the smooth operation of energy arteries In the underground of modern cities, the complex network of pipelines is like the blood vessels in the human body, continuously transporting various media such as natural gas, oil, and water, ensuring the normal operation of the city. However, as the service life of the pipelines increases, problems such as corrosion and aging, as well as third-party damage, are inevitable. The traditional pipeline shutdown for maintenance means large-scale power outages for users and production halts, resulting in economic losses and social impacts that are difficult to estimate. Against this backdrop, the non-stop pipeline pressure-sealing equipment emerged, becoming the "special forces" for ensuring the safe operation of the energy arteries. This article will systematically analyze this core emergency repair equipment from four dimensions: technical principle, equipment composition, application scenarios, and development trends. I. The Birth and Significance of the Continuous Drainage Blocking Technology The pressure-sealing technology for continuous pipeline non-delivery is a specialized technique used to carry out maintenance, renovation, and replacement of pipeline sections while keeping the pipeline in a normal operating state. Its core value lies in: it neither affects the normal transportation of the pipeline nor hinders the safe, efficient, and environmentally friendly connection of new and old pipelines. The emergence of this technology is driven by profound practical needs. Take urban gas pipelines as an example. As of 2020, the total mileage of urban gas pipelines across the country has reached 864,000 kilometers. With the increase in operating time, the daily maintenance, repair, and technical renovation projects caused by the corrosion and aging of pipeline equipment have gradually increased, and the frequency of operations in conjunction with the construction or expansion of buildings has become more frequent. To reduce the impact of gas pipeline maintenance and repair operations, higher requirements have been put forward for pipeline operations in terms of no gas interruption, no pressure reduction, and rapid repair. At the same time, national policies are also promoting the application of this technology. The "Notice on Further Clarifying the Requirements for Aging Update and Renovation of Urban Gas Pipelines and Other Pipelines" jointly issued by the General Office of the Ministry of Housing and Urban-Rural Development and the General Office of the National Development and Reform Commission clearly requires the promotion and application of new equipment, new technologies, and new processes, aiming to enhance the inherent safety of gas pipelines and facilities from the source. At present, the pipeline non-flow blocking technology in our country has formed a complete system. The blocking diameter ranges from 25 millimeters to 1020 millimeters, the maximum blocking pressure reaches 10 megapascals, and the applicable media include petroleum, natural gas, water, ethylene, gas, aviation fuel, and other non-corrosive media. The medium temperature ranges from -60℃ to 350℃. II. Classification and Technical Principles of Sealing Equipment The pressure-sealing equipment for continuous pipeline shutdown is mainly classified into the following categories based on its sealing principle and structural form: Classified according to the blocking principle The cup-shaped sealing technology is widely adopted in developed countries around the world. Its principle is to use a cutting machine to make a saddle-shaped hole on the pipeline, then use the sealing device to push the rubber cup-shaped sealing ring into the pipe through hydraulic transmission, moving it in the opposite direction of gas supply to achieve the purpose of sealing the gas source. The cup-shaped sealing requires a short time for hole making, and the rubber cup-shaped sealing ring experiences a large thrust when moving in the pipeline, resulting in good sealing effect and wide application pressure range. However, when encountering pipes with large roundness deviations or threaded pipes, the effect is not ideal; moreover, for urban gas pipelines, since impurities such as iron filings cannot be removed from the pipeline, it will affect the sealing effect of the cup-shaped sealing. The expansion barrel type sealing method is mainly designed for more severe pipeline conditions and is widely used in high and medium-pressure urban gas pipelines in China. Its principle is to first, under pressure, use a perforating machine to completely cut the pipe section that needs to be renovated or repaired. Then, the sealing barrel (with a high-pressure-resistant rubber sheet on the outer surface) is sent into the center of the pipeline along the cut hole using the sealing device. Through the transmission device of the sealing device, the barrel expands, thereby sealing the gas source. Since the sealing hole is the entire pipe diameter, it will not affect the sealing effect regardless of whether there are impurities or deformations in the pipeline. However, this method requires complete pipe cutting, so it takes a long time, has a high cost, and also affects traffic. The folding type plug-in is a relatively new technology. By using a non-uniform diameter hole, a folded plug-in head is inserted into the pipeline. Once in place, it unfolds to achieve the sealing effect. This technology combines the advantages of a small opening size and high sealing reliability. The spherical plug device is a significant breakthrough in recent years. The Shenzhen Urban Rail Transit Line 13 Sub-high Pressure Gas Pipeline Relocation Project, undertaken by the Emergency Rescue Center of the Pipeline Bureau, is the first pipeline project in China to successfully apply the spherical plug technology. This technology reduces the double-side double-plug process from the traditional 16 holes to 8 holes, increasing the construction efficiency by 50%; it upgrades from judging the sealing condition based on experience to real-time "displaying on the screen" through sensors; it expands from being limited to land use to "water and land amphibious", and can be used in both crude oil pipelines and natural gas pipelines. 2. Classified by sealing method The plug-type sealing method involves inserting a plug-shaped sealing head into the pipeline to achieve sealing. It is suitable for medium and small-sized diameter pipelines. The tubular sealing method achieves sealing by expanding a tubular sealing element within the pipeline. It is suitable for medium to large diameter pipelines. The bag-type sealing device uses an inflated bag to seal the cross-section of the pipeline. It is suitable for low-pressure pipelines. III. Composition of the core system of the blocking equipment A complete pipeline non-stop flow pressure-sealing blocking equipment consists of a complex equipment system composed of multiple subsystems. Drilling machine system The hole-making machine is the core equipment for performing pressure-bearing pipe hole drilling. Its working principle is to drill the required-sized holes on the pipe wall while the pipe is in operation. This is achieved through a special sealing structure and cutting tools. During the hole-making process, the center drill first penetrates the pipe wall for positioning, followed by the ring cutter for circular cutting. The saddle-shaped plates cut off must be completely removed to prevent them from falling into the pipe and causing an accident. Modern hole-making machines are required to have precise feed control and reliable sealing performance. Before the hole-making operation, it is necessary to check whether the center drill and the cylinder cutter are installed perpendicularly to the centerline of the pipeline. During the hole-making process, the rotational speed and feed rate are judged through the equipment operation procedures and the cutting sound to ensure the quality of the hole-making. 2. Occluder System The plugger is the actuating mechanism that performs the plugging operation.