Pressure-sealing and emergency repair technology: The "heart-lung bypass surgery" for pipeline safety Introduction: A Revolutionary Breakthrough in Pipeline Maintenance Technology In modern industrial and urban lifeline systems, oil and gas pipelines, chemical pipelines, and water and heating supply networks are like the vascular network of the human body, undertaking the heavy responsibility of transporting energy and resources. Traditional pipeline maintenance requires complete shutdown and emptying of the medium, which not only causes huge economic losses but also may trigger chain reactions such as supply chain disruptions and urban functional paralysis. The technology of pressure sealing and pressure emergency repair has emerged as a revolutionary solution under this background - it is like a non-stop heart surgery in the medical field, allowing pipelines to complete maintenance, renovation or emergency rescue operations while maintaining normal operating pressure. This technology integrates mechanical engineering, materials science, fluid mechanics and safety engineering, representing the highest technical level in the field of pipeline maintenance. From the initial simple clamp for leak sealing to the current highly intelligent complete operation system, the pressure-bearing sealing and emergency repair technology has developed into a mature, standardized and efficient professional field, playing an irreplaceable role in ensuring energy security, maintaining urban operation and protecting the ecological environment. I. Technical Principle: The Artistic Precision Work under Pressure Pressure-sealing technology system The core of pressure sealing is to establish a temporary bypass on the pipeline using specialized equipment without affecting the normal transportation of the pipeline. This allows for the isolation of the faulty section and enables safe maintenance. Depending on the sealing method and application scenario, it is mainly divided into the following categories: Suspended plugging: Suitable for medium and low pressure, and clean medium pipelines. By using a dedicated hole-making machine to drill holes on the pipeline, insert the plugging device (plug handle), and utilize mechanical force or hydraulic expansion of the sealing element (such as a rubber bag) to form a reliable seal. This technology is relatively simple to operate, but it has certain requirements for the ellipticity of the pipeline and the uniformity of the wall thickness. Bucket-type sealing (double sealing and double blocking): This is the most advanced and safest sealing method at present, especially suitable for high-pressure, large-diameter, and hazardous medium pipelines. During the operation, qualified short joints and valves are first welded onto the pipeline. The operation hole is completed using a drilling equipment. Then, using the manifold equipment, two sealing buckets are successively sent in, located upstream and downstream of the maintenance point respectively, forming a double isolation barrier. The cavity between the two sealing buckets can be monitored for pressure or the medium discharged through the drainage holes to ensure absolute safety. Foldable sealing: Suitable for small-diameter pipelines or special scenarios with limited space. The sealing head is in a folded state before being inserted into the pipeline. Once in place, it is mechanically expanded to fit the pipe wall and form a seal. This technology has small requirements for the opening size, but the design and manufacturing are quite challenging. 2. Types of Pressure-Resistant Emergency Repair Techniques Pressure-resistance emergency repair focuses on rapid response and temporary restoration. The main techniques include: Fixture glue injection repair: For pipeline corrosion perforation, sand holes or small cracks leakage. Wrap the leakage point with the specially designed fixture, and inject the special sealant (such as carbon fiber sealant, oil-resistant and high-temperature resistant sealant) under high pressure into the cavity through the glue injection hole to form a dense filling layer, stopping the leakage. This method is fast and efficient, but is usually used as a temporary or semi-permanent repair. Steel band binding technology: Suitable for perforations or circumferential cracks in straight pipe sections. Using high-strength stainless steel bands combined with sealing rubber strips, it is mechanically bound by a dedicated tensioning tool to quickly control the leakage. Its advantage is that the operation is extremely rapid and is often used for the initial control in emergency rescue situations. Epoxy steel sleeve repair: For pipe sections with a large area of corrosion but not yet penetrating, the surface is cleaned and then a special epoxy material is applied. The steel sleeve is mechanically fixed externally to restore the structural strength. This is a semi-permanent repair method. Composite material winding repair: Using carbon fiber or glass fiber strips impregnated with resin, multiple layers are wound around the leaking point of the pipeline. After curing, a high-strength "repair sleeve" is formed. This technology does not require welding and is highly safe. Moreover, the strength of the repaired part often exceeds that of the original pipeline. II. Application Scenarios: From Daily Maintenance to Emergency Response The application of pressure-sealing and emergency repair technologies has spread to various industrial sectors, and its value is particularly prominent in the following scenarios: Pipeline modification and branching connection: This is the most common application. When additional branch lines need to be added to an operating pipeline, valves need to be replaced, or corroded sections need to be replaced, a temporary bypass is established through pressure sealing to isolate the operation section, enabling zero-stop pipeline modification. For example, in a city's main gas pipeline valve replacement project, the use of pressure sealing technology prevented the impact on the gas supply to tens of thousands of households downstream. Crossing projects and pipeline relocation: When the expansion of highways or railways or the renovation of rivers requires pipeline relocation, the original pipeline can be sealed at both ends to cut off the flow of the medium. The pipeline can then be safely cut, the new sections welded, and reconnected, all while not affecting the normal operation of the upstream and downstream areas. Emergency rescue and leak control: This is the highest manifestation of technical value. When a pipeline leaks due to corrosion, third-party damage, or natural disasters, the rescue team can quickly arrive at the scene and, based on the leakage situation, select the most appropriate pressure-bearing emergency repair technology to control the crisis within the shortest time and prevent the accident from escalating. Especially in scenarios involving flammable, explosive, and toxic hazardous media leaks, rapid pressure-bearing emergency repair is the key to preventing catastrophic consequences. Maintenance of offshore platforms and underwater pipelines: In harsh environmental conditions and with short maintenance windows, pressure-bearing technology is almost the only option. Professional underwater pressure-sealing equipment can be operated by divers or ROVs (remotely operated underwater robots) to achieve non-destructive maintenance of underwater pipelines. III. Standardized Work Procedures: Safeguarding Safety and Success Under pressure operations are like "dancing on the edge of a knife". Any negligence could lead to serious consequences. Therefore, extremely strict standardized operation procedures must be followed: Phase 1: Preliminary Evaluation and Scheme Design (accounting for 60% of the success factors) Field investigation and data collection: Precisely measure the outer diameter, wall thickness, material, operating pressure, temperature, and medium properties of the pipeline. Use ultrasonic thickness gauges, anti-corrosion layer detectors, and other equipment to assess the current condition of the pipeline. 2. Condition Analysis and Risk Identification: Determine whether the ellipticity and straightness of the pipeline meet the sealing requirements of the plug; assess the welding performance (if welding splices are required);