Pressure-sealing operation: An extremely sophisticated industrial safety guarantee artIn the industrial site with numerous pipelines, a seemingly simple yet highly technical operation is safeguarding our safety. In the energy industries such as petroleum, chemical engineering, and natural gas, pipelines are like the blood vessels of the human body, continuously transporting various media day and night. However, these pipelines are bound to experience leaks or require maintenance during their long-term operation. How can sealing or maintenance be carried out safely without stopping the transportation? The pressure-bearing sealing technology emerged as a result. Pressure-sealing technology refers to a special technique that seals or isolates leakage points or sections requiring maintenance during the continuous operation of pipelines or equipment. It is not merely a technical method but also an art form, requiring operators to possess extensive professional knowledge, proficient operational skills, and acute judgment abilities. 01 Industry Status: The Extensive Application Areas of Pressure-Resistant Sealing Technology The pressure-sealing technology originated in the middle of the last century. With the rapid development of the energy industry, this technology has been widely applied and rapidly improved worldwide. From the initial simple mechanical sealing to the current intelligent sealing, the technology has been evolving rapidly. According to the definition in the national standard GB/T28055-2011, pressure-sealing technology is applicable to the opening operations of steel oil and gas pipelines and sealing operations such as plug type, folding type, cylindrical type, and bag type. This technology can also be applied to other media in accordance with the standard. This technology plays an irreplaceable role in the fields of petroleum, natural gas, chemical industry, metallurgy, and urban gas. In the petrochemical industry, the pressure-sealing technology has resolved the contradiction between continuous production and equipment maintenance. The emergency cooling water pipeline of the cracking unit at Liaoyang Petrochemical Company once solved the production problem through the pressure-opening technology. The main gas pipeline network of the first phase of the Anshan Steel Company's blast furnace also safely withdrew from operation without interrupting the gas supply by adopting the pressure-opening and sealing technology. With the continuous advancement of technology, China's pipeline non-flow sealing and blocking business, based on the introduction of foreign technologies, has achieved independent innovation in multiple technical processes through scientific research. The sealing equipment has become increasingly sophisticated, the sealing capacity, specifications and types have been continuously improved, and the business scope has also expanded. Nowadays, the pressure-sealing technology is applicable to a wide range of media, including oil, natural gas, water, ethylene, gas, medium-quality oil, aviation fuel, and other non-corrosive media with no strong corrosiveness. Different media, different pressure levels, and different pipe diameters all require corresponding sealing technologies and equipment, which further demonstrates the professionalism and complexity of this technology. 02 Technical Complexity: The Multi-Dimensional Technical Requirements for Pressure-Resistant Sealing Operations Pressure sealing operation is a systematic project that involves professional knowledge and technical skills from multiple disciplines. At first glance, it may seem like a simple mechanical operation, but in reality, it encompasses rich technical connotations. Mechanical knowledge forms the basis of pressure sealing operations. Operators must have a thorough understanding of materials mechanics, fluid mechanics and related knowledge, and be able to calculate the stress state of the pipeline under internal and external pressure, and determine the pipeline's load-bearing capacity. Especially when working on high-pressure pipelines, any negligence can lead to serious consequences. Materials science is also the core of pressure-sealing technology. For different pipe materials and different conveying media, different sealing equipment and sealing materials need to be selected. Operators need to understand the performance characteristics of metal materials and sealing materials, and choose the appropriate materials based on factors such as temperature, pressure, and medium properties. Understanding the principles of machinery is of vital importance. Equipment for pressure sealing, such as hole opening machines and sealing devices, are all highly specialized and precise machines. Operators need to master their structural principles, performance characteristics, be able to operate them proficiently, and be capable of diagnosing and resolving common faults. The application of automation control technology in modern pressure-sealing operations is becoming increasingly widespread. With the improvement of intelligence levels, many sealing equipment have achieved automatic control. Operators need to possess corresponding automation knowledge and be capable of programming, debugging and maintaining these systems. The pressure-sealing operation also involves multiple fields such as welding technology, measurement technology, and safety protection technology. When performing pressure-sealing on a three-way pipe joint, before welding, a welding process instruction manual must be compiled based on the pipe material, operating parameters, and the material of the weldment. After welding, a welding process assessment must be conducted according to the welding process instruction manual. Only a qualified welding process can be used for actual operations. 03 Professional Requirements: Qualifications and Skills of Personnel Engaged in Pressure Sealing Operations The professionalism of pressure sealing operations is primarily reflected in the strict requirements for the operators. According to relevant regulations, personnel engaged in pressure sealing operations must undergo specialized training. Only those who pass the theoretical and practical operation examinations can start working. Professional training is the first step towards becoming a qualified operator for pressure sealing operations. Institutions such as the China Special Equipment Inspection Association regularly hold "Safety and Skill Enhancement Training Courses for Personnel Engaged in Pressure Sealing of Pressure Vessels and Pressure Pipelines", covering topics such as the safety status and development trends of pressure sealing technology, relevant laws, regulations and standards, as well as on-site investigation and safety risk assessment of leakage accidents. Qualification certification is a necessary condition for engaging in pressure-sealing operations. The China Occupational Safety and Health Association recommends that relevant personnel participate in the training for pressure-sealing operation staff organized by professional institutions. Those who pass the comprehensive ability assessment after the training can obtain the "Position Training Qualification Certificate". The ability to continuously learn is equally important. The technology of pressure sealing is constantly evolving, with new equipment, new processes, and new standards emerging all the time. Operators need to constantly update their knowledge and master the latest technologies. Standards such as GB/T26467-2011 "Technical Specifications for Pressure Sealing of Pressure-bearing Equipment" are also being revised and updated continuously, and operators need to keep abreast of the latest content in a timely manner. In addition to professional technical knowledge, personnel engaged in pressure sealing operations also need to have rich practical experience. Judging the on-site situation, handling unexpected problems, and assessing safety risks all require reliance on accumulated experience. In complex working conditions, experience is often the key factor to ensure safety.