High-pressure pipeline sealing technology: The core process safeguarding the energy arteriesOn the long and winding oil and gas pipeline, maintenance workers are conducting a non-sparking, non-stop-flow "minimally invasive surgery". This is the advanced technology of high-pressure pipeline sealing operation. In the field of energy transportation, high-pressure pipelines are like the "energy arteries" of a country, undertaking the task of transporting important resources such as oil and natural gas. During their long-term operation, these pipelines inevitably encounter risks such as corrosion, geological disasters, and damage caused by third parties. Once a leak occurs, it will not only cause economic losses, but also may lead to safety accidents, having a significant impact on the environment and society. The pressure-bearing pipeline opening and sealing operation is a special type of hot work, which is highly dangerous. The entire construction process must ensure absolute safety. This technology is an advanced process for conducting maintenance, renovation, and pipe replacement operations on pipelines without stopping production or affecting normal operation. It has become an indispensable core technology in modern pipeline operation and maintenance. 01 Technical Foundation: From Traditional Pipeline Shutdown to Modern Non-Shutdown Operation Looking back at the development history of pipeline maintenance technology, it has evolved from traditional stop-flow maintenance to modern non-stop-flow maintenance. The traditional methods required stopping the pipeline operation and purging the medium, which not only caused production disruptions but also led to energy waste and safety and environmental protection risks. The pressure-sealing technology enables maintenance operations to be carried out while the pipeline remains in normal operation, significantly reducing production losses and safety risks. The basic principle of modern high-pressure pipeline sealing operations is to use specialized equipment such as hole-making machines and sealing devices for emergency maintenance and repair. These devices are used to make holes on the running pipeline, and then sealing equipment is installed to temporarily block the flow of the medium, creating safe conditions for the maintenance work. According to the national standard "Technical Specification for Pressure-Resistant Sealing of Steel Pipelines" (GB/T 28055-2023), this technology is applicable to pressure-resistant opening operations of steel oil and gas transportation pipelines as well as various sealing operations. 02 Equipment Innovation: Hardware Support for Sealing Operations One must prepare thoroughly before undertaking a task; likewise, the successful completion of high-pressure pipeline sealing operations relies on the technical support of specialized equipment. The hole-making machine is the key equipment for completing pipe hole drilling. Its reliability directly affects the success or failure of the operation. Modern hole-making machines adopt a dual high-pressure balancing system. Even if one balancing system fails, it can promptly switch to the other system, ensuring the high reliability of the hole-making process. The performance of the hole-making tool is also of great significance. Given the high hardness characteristic of high-strength pipeline steel (such as X80 steel), the new type of hole-making tool adopts high-strength hard alloy materials. The tool angle is specially designed and has a segmented structure, ensuring the smoothness of the hole-making process. These tools also adopt the welding process used in military armored infantry combat vehicles, ensuring that the teeth of the knives will not fall off due to welding quality issues, and further enhancing the reliability of the holes. The sealing head is the core component for achieving sealing. The traditional lip seal method has been replaced by multi-line sealing, which has solved the problem of difficult sealing under high and low pressure conditions of the pipeline. Through fluid dynamics simulation (CFD) to optimize the structure of the sealing head and the rubber cup, and in combination with a specialized debris sweeping device, the damage to the rubber cup caused by iron filings generated from the opening holes was effectively prevented. 03 Process Progress: From Conventional to Special Operating Conditions With the development of pipeline construction, the sealing technology has continuously adapted to the requirements of various special working conditions, demonstrating strong adaptability. In the face of the special working conditions of high-altitude pipeline in mountainous areas, the static pressure inside the pipeline is far beyond the conventional construction pressure. The traditional sealing technology is difficult to cope with this situation. By adopting the "stepwise" pressure reduction method, by setting multiple sealing points, the high static pressure construction is first changed to conventional pressure construction, and then it is sealed step by step, effectively solving this problem. In the renovation of ultra-high pressure oil pipelines, the combined sealing technology has demonstrated unique value. The core process involves reasonably dividing a single ultra-high pressure sealing operation into two or multiple sealing operations, ensuring that the sealing pressure in each operation remains within the range of the ultra-high pressure sealing operation, thereby addressing the risks and safety hazards associated with ultra-high pressure sealing. For large-diameter high-strength thin-walled oil and gas pipelines, traditional sealing systems are facing new challenges. As high-strength pipelines are increasingly widely used, the wall thickness becomes thinner under the same pressure, and the inner diameter of the pipeline increases. The original pipeline sealing system is unable to achieve effective sealing. Through structural optimization analysis and on-site application verification, the original sealing heads and three-way valves were adaptively modified, successfully resolving this problem. 04 Safety Standards: Hard Constraints on Work Risks The operation of sealing high-pressure pipelines is highly risky and must adhere to strict safety regulations and technical standards. The "Guidelines for Safety Management of Pressure Sealing Operations in Chemical and Hazardous Chemical Enterprises in Shandong Province" clearly states that pressure sealing operations should not be carried out if the on-site conditions do not meet safety construction requirements or there is no safety guarantee. The safety measures include but are not limited to: accurately identifying safety risks, adhering to the principle of safety retreat (not conducting pressure-sealing operations unless absolutely necessary), and strictly limiting the circumstances under which pressure-sealing operations are carried out. For instance, situations where the wall thickness of the sealing area cannot be detected, leakage points that cannot effectively prevent the further expansion of material cracks, and where the strength and stiffness of the structure and materials fail to meet the requirements for pressure-sealing operations, should not undergo pressure-sealing operations. According to the regulations, for special operations, the requirements of the "Safety Specifications for Special Operations in Hazardous Chemical Enterprises" (GB 30871) should be followed. Corresponding safety operation tickets should be issued and risk control measures should be implemented. For the pressure-sealing operations on equipment involving flammable, explosive and highly toxic hazardous chemicals, approval from the enterprise's principal responsible person is mandatory. 05 Application Case: A Successful Example of Technological Practice The high-pressure pipeline sealing technology has accumulated numerous successful cases in practical applications. In April 2025, Xinyang Fudi Gas Company carried out non-stop gas pipeline operation at key nodes on National Highway 107 and Xitanghe South Road. This area is the main pipeline for gas supply from the Xitanghe River side. The gas shutdown would affect nearly 100,000 gas users. The maintenance team adopted a modular disassembly method combined with multi-point coordination tactics. Under a temperature of 32℃, they worked continuously for 10 hours and successfully completed the valve installation task on one 160-inch main pipe and another 250-inch main pipe, achieving the "zero outage and zero disturbance" dual-zero standards.