Continuous pipeline repair technology leads the way: "Minimally invasive surgery" for safeguarding the energy arteriesIn the operation of modern industries and cities, pipelines are like the blood vessels of the human body, continuously transporting media such as oil, natural gas, and tap water day and night. However, as the service life of pipelines increases, inevitable defects such as corrosion, cracks, and leaks will occur. In the past, repairing these defects often meant having to stop the pipeline operation, emptying the media, or even performing a "cutting and opening" excavation and replacement - this not only caused huge economic losses but also affected the normal lives of thousands of households. Now, the emergence of non-stop pipeline repair technology has completely changed this situation. This technology, known as "minimally invasive surgery for pipelines", is leading the way with its safety, efficiency, and environmental protection advantages, safeguarding the energy arteries and urban lifelines worldwide. 1. What is the non-stop pipeline repair technology? Continuous pipeline repair technology refers to the general term for online repair and reinforcement of pipeline body defects, leakage points, or structural damages under the condition that the pipeline is operating normally, the medium is continuously transported, and the system pressure does not decrease. Its core value lies in achieving "zero perception by users" for emergency repair operations, minimizing the social impact and economic losses caused by pipeline shutdowns to the greatest extent. From a technical classification perspective, the non-stop repair technology encompasses a variety of process paths: epoxy steel shell composite casing reinforcement for long-distance oil and gas pipelines, mechanical spiral-wound inner lining for urban drainage networks, online overlay welding repair for nuclear power pipeline welds, and pressure-sealing and clamp operations for sudden leakage points. Although these technologies have different application scenarios, they all follow a core concept: to rejuvenate old pipelines without interrupting their services. II. Oil and Gas Pipeline Field: Permanent Repair of Epoxy Steel Shell Composite Liners In the field of oil and gas transportation, the safe operation of pipelines directly affects national energy security and public safety. Traditional repair methods, such as directly welding steel sleeves, are not only operationally difficult and carry high risks, but also often ineffective for curved pipes and irregular pipe sections. In recent years, China has successfully developed the epoxy steel shell composite casing technology, which enables permanent and maintenance-free repair without interrupting the flow. The innovation of this technology lies in the fact that the steel shell does not closely adhere to the pipeline but is loosely fitted over the defective section of the pipe. Through the injection of epoxy resin in the annular space, the steel shell and the pipeline form a composite casing structure. This design brings multiple advantages: Firstly, the entire operation process does not require any welding with fire, thus avoiding the catastrophic risks associated with direct welding on flammable and explosive oil and gas pipelines. Secondly, the epoxy filler has excellent chemical resistance, not only strengthening the damaged sections of the pipe wall but also effectively inhibiting the intensification of the corrosion process inside the pipe. What's even more astonishing is that this technology has an extremely high tolerance for defects - it can repair pipe wall defects with an average depth of up to 80% of the wall thickness and a maximum depth of up to 90%, and even allows for a distortion of the pipe up to 9% of its diameter. From the perspective of application scope, this technology has covered various steel pipelines with diameters ranging from 100 to 1420 mm, with a maximum temperature tolerance of 3 to 100℃ and a maximum pressure capacity of 10 MPa. These pipelines include oil, natural gas, refined oil, liquefied gas transportation pipelines, as well as the piping systems of oil refining and petrochemical plants. The reliability of the repaired pipelines can be comparable to that of the original pipe bodies, and can fully meet the requirements of the pipeline's design lifespan. III. Urban Drainage Pipeline Network: The Water-Recovery Revolution of the Mechanical Spiral Winding Method If the repair of oil and gas pipelines focuses on "safety under high pressure", then the repair of urban drainage networks is more concerned with "convenience without interruption". The total length of the underground drainage system in Chinese cities has exceeded 1.2 million kilometers. The traditional "open and dismantle" repair method has caused significant disruptions to urban traffic and residents' lives. Against this backdrop, non-invasive repair technology has gradually become the mainstream, and the mechanical spiral winding method is one of the outstanding ones. The operation process of this technology is truly ingenious: The staff introduce the custom-made PVC-U sheet material into the underground, and through a specially designed pipe-making machine, wind it spirally inside the old pipe to form a new pipe. The sheet materials are closely connected by specific designed locks, forming a continuous and seamless inner lining pipe. Subsequently, special cement materials are filled in the gap between the new and old pipes - this cement can maintain a stable structure in water, not segregate, and solidify within a few hours, significantly enhancing the pressure-bearing capacity of the pipe. What is even more astonishing is that throughout the entire construction period, the pipeline did not cease operation. Domestic sewage from thousands of households continued to flow inside the pipeline. This "water-bearing operation" capability is attributed to two major technological breakthroughs: Firstly, the development of special cement materials has solved the problem of disintegration of ordinary cement when exposed to water; Secondly, the meticulous design of the construction process, including the provision of exhaust and observation holes to monitor the grouting process in real time. From an economic perspective, the advantages of this technology are equally remarkable. To repair a 2.4-meter-diameter and 60-meter-long sewage pipeline using the mechanical spiral winding construction method, the cost is only about one-third of that of the traditional stainless steel welding repair method. The repaired pipeline is expected to have a service life of up to 50 years, truly achieving "one-time investment, long-term benefits". It is worth noting that Chinese enterprises have achieved import substitution in this field. Through absorption, introduction and re-innovation, the mechanical winding technology developed domestically has evolved into four construction methods: steel-plastic composite reinforced type, self-propelled type, expansion type, and wall-clinging type. These methods can be flexibly selected according to different working conditions. For pipes with functional damage, the wall-clinging method can be used for rapid repair; for severely damaged structural damage, the steel-plastic composite reinforced method is adopted for comprehensive reinforcement. IV. Nuclear Power Pipeline Field: Independent Breakthrough in Welding Repair Technology The design lifespan of nuclear power plants is typically 40 to 60 years. There are a large number of pipeline systems connected by welding, and the service safety of weld seams is one of the key points in the operation and maintenance of nuclear power plants. In the past, when it came to the high-end repair of complex pipeline welds, China often relied on foreign suppliers. This not only involved high costs but also carried the risk of technical limitations. This situation was completely overturned in recent years. Our independently developed "Welding Repair Method and System for Weld Flaws of Stainless Steel Branch Pipes" won the China Patent Gold Award, achieving online welding repair of nuclear power pipeline welds without the need to remove the original defects inside the welds or to isolate or empty the internal medium of the pipeline. The leading nature of this technology is manifested in three aspects: First to introduce the online maintenance mode without eliminating defects: It can directly carry out repairs in an irradiation environment without emptying the medium or clearing internal defects, completely changing the cumbersome process of traditional techniques that required stopping the machine, emptying, and clearing defects first. Residual stress control and pressure-bearing boundary reconstruction: Through techniques such as residual stress control, pressure-bearing boundary reconstruction, and defect tolerance analysis, the long-term safety guarantee problems of complex branch pipe welds, tubular sealing welds, and other structures with defects have been effectively solved. A leap in maintenance efficiency: The duration of a single maintenance operation can be strictly controlled within 10 hours. Compared to foreign technical solutions, it saves at least 30 hours, significantly reducing the downtime for unit maintenance and lowering maintenance costs. At present, the complete set of technologies based on this patent have been successfully applied to the pipeline weld seams, valve sealing weld seams, and tubular weld seams of key parts in multiple domestic nuclear power units for maintenance. The cumulative economic benefits have exceeded 100 million yuan. With the steady advancement of the batch construction of China's independent third-generation nuclear power technology "Hualong One", the application scope of this technology will continue to expand.