Pressure-resistant pipe opening: High-tech "minimally invasive surgery" for building the "arteries" of industryPressure-resistant pipe opening: High-tech "minimally invasive surgery" for building the "arteries" of industryWithin the complex network of industrial pipelines, a seemingly impossible technology is quietly operating - pipeline pressure-opening. It is like a highly skilled surgeon performing precise "minimally invasive surgery" on a constantly flowing pipeline. In modern industrial production, energy transmission pipelines are like the blood vessels of the human body, maintaining the normal operation of the entire production system. And the pressure-bearing pipeline opening technology is a high-tech operation method that can process circular holes on the running pipeline while ensuring uninterrupted pipeline transportation. This technology has solved the problem that traditional pipeline renovations require shutdown, venting and purging, and has become a key technical support in modern industrial maintenance and renovation. I. Technical Essence: Precise Control of High-Risk Operations Pipeline pressure-bearing opening refers to a technical operation that, under a sealed condition, uses mechanical cutting to process a circular hole on an operating pipeline. When an in-service pipeline needs to be equipped with a branch pipe, this pipeline pressure-bearing opening technology can be adopted to complete the task, which not only does not affect the normal transportation of the pipeline but also ensures safe, efficient and environmentally friendly completion of the connection between the old and new pipelines. The core of this technology lies in the ability to carry out various construction or emergency repair operations at any point on the pipeline during the pressurized transportation process. The basic principle is to use the opening sealing equipment installed at both ends of the pipeline segment to cut off the flow of the medium in that pipeline segment. Then, a temporary bypass connection is established between the two ends of the pipeline being worked on, allowing the medium in the pipeline to continue to be transported through the temporary bypass. Compared with the traditional method of stopping the pipeline and then opening the hole, pressure-assisted hole opening has revolutionary advantages: The entire process takes place within a completely sealed cavity, and the cutting process of the tool is isolated from the air, eliminating the possibility of fire or explosion, and causing no pollution to the environment. These characteristics make it an indispensable maintenance technology in continuous production industries such as oil, gas, and chemical engineering. II. Technical Barriers: Professional壁垒 Built by Multiple Elements Opening holes under pressure on pipelines is by no means a simple mechanical operation; it is a highly technical task that requires a combination of multiple disciplines of knowledge and a wealth of accumulated experience. From equipment preparation to on-site operation, each step involves strict technical requirements. Strict application conditions The pressure-bearing hole opening technology is not a panacea. Its application requires strict boundary conditions to be met: · Pipe diameter range: Applicable to steel pipes, cast pipes, ductile iron pipes, PE/PVC pipes and other types of pipes with diameters ranging from φ22 to φ2000. · Medium type: Suitable for non-corrosive media such as oil, natural gas, water, ethylene, gas, aviation kerosene, etc. · Temperature range: The applicable temperature range of the pipeline medium is wide, ranging from -70℃ to +350℃. · Pressure range: The operating pressure of the pipeline is within the range of 0 to 10 MPa, which covers most of the pressure conditions for industrial pipelines. Precise equipment requirements The pressure-bearing hole-opening equipment is a sophisticated system consisting of a hole-opening machine, a connecting box, a clamp valve, and specialized tools. Each component of the equipment must meet strict technical standards: Take the hole-making machine as an example. The early manual hole-making machines had problems such as being time-consuming and labor-intensive, difficult to disassemble the cutting tools, and poor sealing performance. After technological improvements, modern hole-making machines have added an electric head. They drill holes with a diameter of φ6mm - φ8mm on the side of the cutting tool for easy disassembly, and add a taper and contact surface at the end of the flange plug to enhance alignment and sealing performance. Although these improvements are minor, they demonstrate the utmost attention to detail in the equipment design. Professional operation techniques Pressure-bearing hole opening operations require meticulous and precise operations by professional technicians. Technical standards such as SY/T 6554-2019 "Safety Regulations for Pressure-bearing Hole Opening Operations in the Petroleum Industry" have stipulated detailed operation procedures and safety requirements. Take the operation of advancing the tool as an example: Rotate the handwheel clockwise to advance the tool. When the center drill (drill bit) reaches the main pipeline, reverse the handwheel by half a turn (to prevent the drill bit from breaking). Start the motor, slowly turn the handwheel clockwise to advance the tool. When you feel that the drill has penetrated the pipe wall, cut off the power supply. After cutting off the power supply, you can manually advance the tool, which indicates that the drill has penetrated. This kind of operation that relies on tactile sensation and experience for judgment requires long-term training to be mastered proficiently. III. Technical Process: Precise and Interconnected Operations Pipeline pressure-bearing opening operations are a complex system project. They must be carried out strictly in accordance with the procedures. Any negligence at any stage could lead to serious consequences. Preparation stage Welding pipe fittings are the first crucial process. Taking the pressure-opening of a natural gas pipeline as an example, it is necessary to first measure the wall thickness of the pipeline at the position where the opening needs to be made on the main line, ensuring that the wall thickness is not less than 5mm and there are no corrosive cracks on the surface. Then, a three-way opening pipe is fabricated and welded. The three-way opening pipe consists of a base and a saddle short section. The length of the base is D (the diameter of the opening) + 500mm, and the length of the saddle short section is not less than 500mm. During the welding process, it is necessary to take into account the flowing process medium inside the pipeline and control the current size to prevent the pipe wall from being punctured. For welding on pipelines with special media and harsh operating conditions, the thickness of the section should be measured in advance. Equipment installation stage Installing the valve is a crucial step for ensuring safety. The perforated valve is installed at the top of the saddle short section, with its nominal pressure not less than 1.5 times the internal pressure of the natural gas pipeline. Then, the perforation device is installed at the top of the perforated valve. Before installing the opening equipment, a strong pressure and air tightness test must be conducted to prevent leakage. At the same time, nitrogen replacement should be carried out to avoid air mixing when opening the holes.