With so many seamless steel pipes, how should one choose?

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Seamless steel pipes are steel pipes without welds, manufactured using hot processing methods such as piercing and hot rolling. If necessary, the heat-treated tubes can be further cold-worked to achieve the desired shape, size, and properties. Currently, seamless steel pipes (DN15–600) are the most widely used pipes in petrochemical production facilities. 01 Carbon steel seamless pipes: There are 4 material grades – 10, 20, 09MnV, and 16Mn. Standards applicable: GB8163 \"Seamless pipes for fluid transport\", GB/T9711 \"Technical requirements for pipes used in the oil and gas industry\", GB6479 \"High-pressure seamless pipes for fertilizer equipment\", GB9948 \"Seamless pipes for petroleum cracking\", GB3087 \"Seamless pipes for low- and medium-pressure boilers\", GB/T5310 \"Seamless pipes for high-pressure boilers\". 1. GB/T8163: Material grades include 10, 20, Q345, etc. Application range: Oils, oil-gases, and utility fluids with a design temperature of less than 350°C and a pressure of below 10 MPa. 2. GB6479: Material grades: 10, 20G, 16Mn, etc. Application range: oils and oil-gas with a design temperature of -40 to 400°C and a design pressure of 10.0 to 32.0 MPa. 3. GB9948: Material grades: 10, 20, etc. Scope of application: Situations where GB/T8163 steel pipes are not suitable. 4. GB3087: Material grades: 10, 20, etc. Application range: superheated steam, boiling water, etc., in low and medium pressure boilers. 5. GB5310: Material grade: 20G, etc. Application range: Superheated steam media in high-pressure boilers. Inspection: Steel pipes used for general fluid transportation must undergo chemical composition analysis, tensile testing, flattening testing, and hydrostatic testing. For steel pipes governed by the GB5310, GB6479, and GB9948 standards, in addition to the tests required for pipes used in fluid transportation, flaring tests and impact tests are also mandated ； The manufacturing and inspection requirements for these three types of steel pipes are quite strict. Standard GB6479 also sets specific requirements for the low-temperature impact toughness of materials. For steel pipes in accordance with GB3087 standard, in addition to the general test requirements for steel pipes used in fluid transport, a cold bending test is also required. For steel pipes in accordance with the GB/T8163 standard, in addition to the general test requirements for steel pipes used in fluid transport, flaring tests and cold bending tests are carried out as specified by the agreement. The manufacturing requirements for these two types of pipes are not as strict as those for the first three types. Manufacturing: Steel pipes conforming to the GB/T 8163 and GB3087 standards are mostly produced using open-hearth or converter smelting methods; consequently, they contain relatively more impurity components and internal defects. GB9948 is mostly smelted using electric furnaces. Most have adopted the off-ferrous refining process, resulting in relatively fewer compositional impurities and internal defects. The GB6479 and GB5310 standards specify the requirements for off-ferment refining, resulting in the lowest levels of impurities and internal defects as well as the highest quality of the material. The manufacturing quality grades of the aforementioned steel pipe standards, from lowest to highest: GB/T8163