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Development of Lightweight Design and Manufacture of Heavy-Duty Pressure Vessels in China

In recent years, with the gradual expansion of units scale for energy industries such as oil refining, chemical and natural gas, etc. in China, pressure vessels are developing toward the large and heavy direction with the maximum wall thickness reaching hundreds of millimeters and weight exceeding one thousand tons. It not only causes huge material consumption, difficulty in manufacture and processing (even beyond current capability), but probably also lead to new failure modes and mechanisms, and significant safety risks thereby. Therefore, the lightweight design and manufacture under the premise of inherent safety has become an urgent need to break through the bottleneck of manufacturing capability and realize the material and energy conservation. In this paper, the progress of lightweight design and manufacturing technology of heavy-duty pressure vessels in recent years in China is introduced from the aspects of adjustment of material allowable strength, application of high strength steel and matching of strength and toughness, cold stretch of austenitic stainless steel, structure optimization design with multi-parameter coupling, and application of composite materials. Application cases in the construction of pressure equipments such as large hydrogenating reactors, low-temperature ethylene spherical tanks, austenitic stainless steel cryogenic vessels, butyl octanol heat exchangers, etc. are also included. Finally, some suggestions on the future research are proposed including composite pressure vessels in cryogenic environment, materials genome and additive manufacturing technologies for pressure vessels.