Is it easier to install when opening holes on a pressurized pipeline? In-depth analysis of the entire installation process of this "minimally invasive pipeline surgery" In the field of pipeline maintenance, repair and renovation projects, the pipeline pressure-bearing opening technology is hailed as "a minimally invasive surgery for pipelines without interrupting the flow". It can precisely create circular holes under the condition that the pipeline maintains its normal operating pressure and the medium continues to be transported, thereby enabling the connection of new pipelines or the installation of equipment. However, for many engineers who are new to this technology, a core question has always lingered in their minds: Is the pipeline pressure-bearing opening easy to install? This article will comprehensively analyze the entire installation process of pipeline pressure-bearing opening from multiple aspects such as installation procedures, technical key points, pre-requisites, safety requirements, and actual engineering cases, helping readers objectively understand the implementation difficulty and safeguard measures of this technology. I. Objective assessment of installation difficulty: Rigorous system engineering It is essential to clarify that the installation of pressure-bearing pipe perforation is not a simple "plug-and-play" operation, but rather a meticulous systematic project. Unlike ordinary mechanical installations that can be disassembled and assembled at will, this operation is carried out in a high-pressure and high-risk environment and is a precise task. The industry metaphorically refers to pressure-assisted hole-making as "dancing on the tip of a knife". This metaphor vividly conveys its core characteristics: on the one hand, the operation must be precise and error-free, just like a dancer maintaining balance on the tip of a knife; on the other hand, the entire process involves risks and requires comprehensive safety guarantees. For instance, pressure-assisted hole-making on high-temperature blast furnace gas pipelines is classified as a first-level safety operation, which demands high professional knowledge, operational skills, and safety awareness from the operators. However, this does not mean that installation is uncontrollable. On the contrary, through scientific and standardized procedures, precise and reliable equipment, and well-trained personnel, the installation of pressure-bearing openings can be carried out safely, precisely, and efficiently. Shaanxi Coal Construction Northwest Branch successfully completed the pressure-opening of the DN1800 blast furnace gas pipeline in the Jiu'an Steel project. The 9-hour operation was ultimately completed 2 hours ahead of schedule. Subsequently, in the same project, they completed the pressure-opening of the DN2400 super-large diameter pipeline, with continuous 8-hour operations successfully completed. These cases strongly prove that as long as the norms are followed, the installation work can be smoothly accomplished. II. Key Preparations Before Installation "Preparation before action leads to success." For the successful installation of pressure-bearing holes, 50% of the outcome depends on the preparatory work carried out before the installation. On-site investigation and plan formulation Before installation, a comprehensive inspection of the work site must be conducted. This includes: confirming the pipeline route, burial depth, and height difference; confirming the position of the straight weld seam, ensuring that the opening point avoids the weld seam; measuring the ellipticity of the pipeline, requiring it to be no more than 1% of the outer diameter of the pipe; measuring the wall thickness of the pipeline, avoiding severely corroded areas as much as possible. Based on the survey results, a detailed construction plan was formulated. Before drilling the DN2400 hole, the Northwest Branch of Shaanxi Coal Construction Company made meticulous preparations from the aspects of technology, safety and coordination. They organized management personnel to conduct plan briefings, and provided technical and safety technical briefings and training to the workers to ensure that every aspect was flawless. 2. Precise selection of the location of the opening point The opening position should be selected on the straight pipe section and should avoid the pipeline welds as much as possible. When it is impossible to avoid, effective measures must be taken. The center point of the drill for the opening tool should not fall on the weld. This requirement is to prevent the stress concentration and material inhomogeneity in the weld area from affecting the quality and safety of the opening. 3. Recheck and debugging of equipment and materials Before the construction, it is necessary to conduct a comprehensive review and inspection of the construction pipes, fittings, sealing materials, etc., and also to debug the construction machinery and equipment. The drilling equipment needs to undergo factory size verification, airtightness test, and operational performance inspection. For construction units conducting the drilling operation for the first time, a simulation test should be carried out. III. Detailed Explanation of Core Installation Steps The installation of pressure-bearing pipe openings follows a well-established standard procedure, which mainly consists of the following key steps: Step 1: Welding of pipe fittings (short sections / tees) This forms the basis of the entire installation process. Firstly, remove the anti-corrosion coating from the pipeline at the welding site, thoroughly clean the pipeline surface, and remove oil stains and primer. Based on the opening position and valve model, calculate the length of the short section and manufacture it. Ensure the stroke of the cutting tool through precise calculation. The prefabricated perforated short section (or "encapsulated three-way junction") is welded onto the existing pipeline. During the welding process, strict control of the welding technique is required: the welding rods should be dried (between 250-300℃), and those not used within 1 hour after being taken out of the drying oven need to be re-dried; before welding, anti-static grounding wires must be properly installed; the weld seams must have no pores or slag inclusions, and ensure the successful completion of the subsequent pressure test. When welding on a steel pipeline under pressure, the medium pressure inside the pipeline should not exceed 1.0 MPa. Step 2: Install the valve Install the valve for the opening on the end face of the opening short section. Before installation, the valve must have a pressure test report and must be inspected to ensure there is no leakage. During installation, place the sealing gasket into the already welded base, then screw in the specially made ball valve. Pay attention to pressing the sealing gasket tightly to prevent medium leakage. Three steps: Installation of the drilling machine and overall tightness test