Precise control of the pressure-sealing operation process: Full-process management from preparation to acceptance inspectionCarrying out pressure-sealing operations while the pipeline is still in operation is like a surgeon performing an operation on a beating heart. The precise control of every operation step is crucial for the safety of the entire system. Pressure-sealing technology is an important method in modern pipeline maintenance. It enables pipeline replacement, relocation, valve replacement, and the addition of branch lines to be carried out without interrupting the continuous pipeline medium flow. It can also quickly and safely repair the accident pipeline when a leak occurs. This technology requires operators to precisely control the operation process. Any negligence could lead to a serious accident. This article will comprehensively analyze the control points in the pressure-sealing operation process, helping practitioners master this highly technical operation procedure. 01 Preparations before homework: The foundation of precise control On-site investigation and risk assessment are the first steps in pressure sealing operations and form the basis for precise control. Before the operation, relevant personnel must be organized to carry out on-site investigation, risk identification and control, scheme preparation and approval, as well as safety technical briefing in accordance with the prescribed standards. The survey content includes: pipe material, operating parameters, leakage point conditions, surrounding environment, etc. Based on the survey data, the operation team needs to accurately identify the safety risks of pressure-sealing operations and formulate corresponding control measures. The preparation of the construction plan serves as the guiding document for operation control. The plan should detail the operation steps, personnel division, equipment configuration, emergency measures, etc. For the implementation of pressure-sealing operations on equipment involving flammable and explosive, as well as highly toxic hazardous chemicals, approval from the main person in charge of the enterprise is required. Equipment inspection and debugging are equally indispensable. Before the operation, a comprehensive inspection of key equipment such as the opening machine, plugger, clamp valve, and sealing components is required to ensure they are in good working condition. Selecting appropriate sealing technologies and equipment configurations based on pipeline parameters and medium characteristics is an important guarantee for successfully completing the operation. 02 Excavation and Sealing of the Work Pit: The Starting Point of Safety Control The excavation of the operation pit is the first substantive operation in the pressure sealing operation. The quality control of this step directly affects the safety of the subsequent operations. When excavating and sealing the operation pit, the construction team leader should uniformly command the excavator, and other personnel should stay away from the site. To prevent slope failure in the excavation pit during the sealing operation, there must be a certain slope around the pit. In case of slope failure, it is necessary to immediately organize the cleanup. The size of the excavation pit should be determined reasonably based on the pipe diameter, operation content and on-site environment, taking into account both operational convenience and safety protection requirements. During the excavation of the work pit, it is necessary to continuously monitor the stability of the pit wall. Especially in soft strata or under rainy conditions, necessary support measures should be taken to prevent collapse accidents. At the same time, warning lines and safety signs should be set up around the work pit to prevent irrelevant personnel from entering. Pressure welding: The most risky control step Pressure welding is the most risky part in pipeline operation and also the operation with the strictest technical requirements. Before welding, a welding process instruction manual must be compiled based on the pipeline material, operating parameters, and the material of the weldment. After welding in accordance with the welding process specification, a welding process assessment must be conducted. Based on the qualified welding process assessment, a welding process procedure should be compiled. In actual operation, welding must be carried out strictly in accordance with the welding process procedure. During the welding process, it is essential to strictly control the welding parameters, including current, voltage, and welding speed, to prevent the pipe wall from being completely welded through, which could lead to accidents. If a weld-through phenomenon occurs, it should be immediately blocked with a welding rod and welded firmly. Ensure safety. During welding, welders must wear protective equipment to avoid eye injuries from arc light. In case of fire, the emergency plan should be activated immediately. 04 Sealed Opening: A Key Step in Precision Control The sealing opening is the most critical step in the operation of pressure sealing. Before the opening, strict adherence to the safety operation procedures for pressure testing must be followed. Only after the test is successful can the opening operation be carried out. During the hole-making process, the cutting tool should be advanced evenly. Pay close attention to the working condition and cutting situation of the hole-making machine. If oil leakage occurs during the hole-making process, immediate measures should be taken to identify the leakage point and eliminate it. During the operation, there may be a situation where the cutting tool gets stuck. In such cases, you should immediately move the reversing valve, stop the machine, analyze the cause, and then restart it. If the cutting tool is damaged, you should decisively lift the cutter disc, close the clamping valve, and replace it with a spare tool. After the hole is drilled, the drill should be slowly withdrawn to ensure that the cut-off pipe wall material (saddle block) is smoothly extracted and to prevent it from falling into the pipeline and causing blockage. After withdrawing the drill, the clamp valve should be promptly closed to create conditions for the subsequent sealing operation. 05 Blocking Operation: The Core Part of Process Control The sealing operation is the core part of the pressure-sealing operation, and its success directly determines the effectiveness of the entire operation. During the sealing process, it should be carried out in accordance with the principle of "first high pressure then low pressure, first the inner side then the outer side". Specifically, the high-pressure end should be sealed first, followed by the low-pressure end. This sequence ensures the safety of the sealing operation and prevents the medium from being pushed against the sealing equipment due to the pressure difference. When lowering the plug, the lowering speed should be controlled to ensure that the plug is placed accurately. <span data-v-472c13df="" class="tgt color_text_0" data-section="0" data-sentence="124" data-group="0-124" style="box-sizing: border-box; color: rgb(16, 18, 20); font-size: 14px; line-height: 1.78; display: inline; font-family: "PingFang SC", "Segoe UI", Arial, "Microsoft YaHei", 微软