Pressure-sealing technology: The "uninterrupted production lifeline" in modern industry and an analysis of its core application fields Deep within oil and gas wells that reach depths of several kilometers, the electrical control instructions are precisely triggered, and the plug is instantly set in place, successfully preventing the gushing of high-pressure fluids. In urban gas pipelines, a non-sparking "minimally invasive surgery" is being carried out intensively, ensuring that the gas supply to millions of households does not cease for a moment - this is the modern industrial wonder created by the technology of pressure-sealing. When there is a leakage in a pipeline or container, traditional repair methods usually entail the shutdown of the entire system, the emptying of the medium, and significant economic losses. However, the pressure-retaining sealing technology has completely changed this situation. It enables the safe and rapid completion of leakage sealing or pipeline modification while keeping the system in a normal operating state and allowing the internal medium to flow under pressure. From the high-temperature and high-pressure petrochemical plants to the complex urban pipeline networks, this technology has become an indispensable key support for ensuring the safe production, continuous operation and environmental protection of modern industries. 01 Technical Foundation: Principles, Methods and Security Boundaries Pressure-sealing operation is commonly referred to as "pressure-sealing" or "pressure-sealing while production is ongoing" in professional terms. Its core objective is to completely cut off or reliably isolate the channels through which the medium is leaking, without disrupting the normal operation of the system. Since this technology was introduced to China in the early 1980s and successfully developed, it has evolved into a variety of mature manufacturing methods. According to different principles, the main technical methods can be classified into several categories. The adjustment leakage elimination method eliminates leakage by fine-tuning operation parameters or fastening components, which is the simplest and most direct approach. The mechanical leakage sealing method uses external mechanical devices such as clamps, pressure application, and supports to forcibly seal the leakage points, and is suitable for various leakage locations. The plug-and-seal method is similar to "patching up", using specially made wedges, plugs, etc. to directly fill the leakage holes. While the adhesive patching and sealing method utilizes high-performance adhesives or sealants to form a new sealing layer at the leakage site, which is particularly suitable for complex environments where firework operations are not allowed. For major renovations or replacement of pipe sections in the pipeline system, more complex pipeline pressure-sealing technologies need to be employed. This technology achieves partial or complete isolation of the pipeline through a series of procedures such as sealing the opening, blocking, and bypassing. It enables operations such as cutting, replacing valves, or connecting new pipelines, and the entire process ensures uninterrupted system operation. Any technology has its safety boundaries. Although the pressure sealing technology is powerful, it is explicitly prohibited from being used for high-toxicity media, pipelines with cracked components or those with severely corroded walls whose thickness is unknown. At the same time, hazardous chemical pipelines and boilers have also been explicitly prohibited from conducting pressure sealing operations. Safety has always been the unbreakable prerequisite for the application of this technology. 02 The Guardians of the Energy Corridor: Oil and Gas Extraction and Long-Distance Pipeline Transmission In the backbone of the national economy - the energy industry, the pressure-sealing technology plays a crucial "guardian" role, and its application covers every aspect from oil and gas extraction to long-distance transportation. At the oil and gas field extraction sites, traditional well repair operations require well pressure control. This not only involves complex procedures but also causes damage to the formation and affects production capacity. Nowadays, advanced pressure-holding operation technologies, combined with high-performance downhole tools such as electrically controlled blockers, have completely transformed this situation. The operator simply presses the electronic control button on the ground, and the tools at a depth of over a thousand meters underground can precisely complete the well sealing operation. This reduces the construction period by an average of 20%, and the one-time success rate is increased to over 98%, achieving the maximum protection of the oil and gas layers. For the long-distance oil and gas pipelines that are crisscrossed and continuously operating, any unplanned shutdown would result in huge economic losses and disruption of downstream supply. The pressure-sealing technology is the only option for dealing with pipeline emergencies, conducting planned rerouting, or installing additional diversion valves. This technology can handle pipelines with diameters ranging from 25 millimeters to 1020 millimeters and a maximum pressure of up to 10 megapascals. It is applicable to various media such as petroleum, natural gas, and refined oil. The domestic technical team has successfully completed the sealing and connection operations for high-pressure and high-risk pipelines in major projects in places like Xiong'an New Area and Shenzhen, achieving the safety goal of zero leakage. 03 Stabilizers in the Process Industry: Petrochemicals and Electricity The characteristics of process industries such as petrochemicals and power include the large-scale of equipment and the continuous nature of the processes. A non-planned shutdown of one link may cause the entire production line to come to a standstill, resulting in losses often amounting to tens of millions. Here, the pressure-sealing technology is one of the core technologies for ensuring that the equipment operates in a safe, stable, long-term, full, and efficient manner. In oil refining and chemical production facilities, flanges, valves, reactors and various process pipelines are prone to "leaking, spilling, dripping and spewing" under the harsh conditions of high temperature, high pressure and strong corrosion. The pressure-sealing technology can quickly eliminate these leakage points under extreme conditions with a maximum temperature of 900℃ and a pressure of 30 MPa. It not only prevents material loss and environmental pollution, but more importantly, avoids the huge cost of having the entire large-scale equipment stop operation just to deal with one leakage point. In power plants, whether it is a traditional coal-fired power station or a nuclear power plant, the steam pipelines, circulating water pipelines, fuel oil and chemical water systems are like the blood vessels of the human body, and must remain unobstructed and leak-free. Leakage of high-temperature and high-pressure steam pipelines is particularly dangerous. Pressure-sealing technology can repair these critical parts without stopping the machine, and has become an important guarantee for power plants to achieve long-term operation. 04 The Invisible Shield for Urban Operations: Municipal Public Utilities When the pressure-sealing technology moves from the factory to the city, it transforms into an "invisible shield" that ensures the normal operation of society and the safety of people's livelihoods. The urban gas pipelines are buried deep underground and the network is complex. They directly affect the gas supply safety for thousands of households and public safety. In case of leakage, the traditional repair methods require large-scale gas shutdowns, resulting in an extremely wide impact area. By adopting the non-hot-work pressure-sealing technology, pipeline maintenance, replacement or connection for new users can be carried out quickly and safely without affecting the users' gas supply. This approach minimizes risks and social impacts. Similarly, for water supply and heating pipelines, if the heating pipes or main water supply pipes leak during winter, the shutdown for maintenance will cause significant inconvenience to a large number of residents. The pressure-sealing technology makes the maintenance and renovation of the pipelines flexible and rapid, ensuring the continuity and reliability of municipal services. 05 Cutting-edge Developments: Intelligence, Integration and Material Innovation With the increasing demands for safety, efficiency and environmental protection in industrial development, the technology of pressure sealing