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Design considerations 1. The structure of high-pressure vessels must ensure reliability in terms of strength. To ensure strength and prevent the container from being damaged or undergoing excessive plastic deformation under operating pressure, it is necessary to conduct a detailed stress analysis of the container’s stress-bearing components. This analysis must be combined with considerations related to material selection, manufacturing, and inspection, in order to determine a suitable structure and dimensions for the container shell. 2. The joints between the nozzles (flanges) of pressure vessels and the vessel shell should be designed with a fully penetrated weld structure. 3. A reinforcement method involving overall reinforcement or local overall reinforcement should be adopted. 4. Perform full non-destructive testing (radiographic testing or ultrasonic testing) on the Class A and Class B butt joints of the containers. 5. Carbon steel and low-alloy steel sheets with a thickness of 12 mm or more (excluding the plates of multi-layer pressure vessels) shall be subjected to ultrasonic testing on a sheet-by-sheet basis when used to manufacture pressure vessel shells. 6. High-pressure vessel bolts shall be double-ended fine-thread bolts with a thinner middle section. 7. Specify the hardness requirements for forgings, gaskets, and bolts; the hardness of metal gaskets should be lower than that of the flanges. Manufacturing precautions: 1. For the openings and nozzles on high-pressure vessels, as well as at the fillet joints and at the corners of the inner diameter, the radius of the transition fillet R must be ≥5 mm, or as specified in the drawings. The formed surfaces should be smooth and uniform, without any cracks, burrs, or sharp edges. 2. Grade IV forgings of Category III containers shall be retested. 3. For the steel tubes used in the shells of high-pressure vessels, the equipment manufacturer shall conduct hydraulic tests on each tube at the pressure specified for the vessel’s hydraulic testing. 4. Low-hydrogen electrodes should be used. 5. All butt weld joints shall be inspected by radiography or ultrasonic testing. 6. Material substitution. In manufacturing, substitute materials may be used; since the materials selected in the design are those considered optimal for use, various parameters in the container design must be taken into account when substituting materials, and changes should not be made arbitrarily. 7. Develop detailed manufacturing processes and quality plans, strengthen process inspections, and pay attention to details. Due to the high pressures, as well as the complex variations in operating temperatures and media, high-pressure vessels can lead to severe consequences in the event of an accident. Therefore, strict quality control is necessary during the design and manufacturing stages to ensure the quality of these products.