1. What is the corresponding relationship between API 5L X56 welded pipe and Chinese standard welded pipe, and what are their application scenarios in oil and gas pipelines?
Answer: API 5L X56 welded pipe corresponds to GB/T 9711.1 L415 welded pipe in Chinese standard. Both are used in medium-pressure oil and gas transportation pipelines, and their application scenarios are as follows: API 5L X56 has a minimum tensile strength of 560 MPa, a yield strength of not less than 380 MPa, good weldability and toughness, and is suitable for medium-pressure oil and gas transmission pipelines (working pressure 6-10 MPa) in plain and hilly areas; GB/T 9711.1 L415 has basically the same mechanical properties as API 5L X56 (tensile strength 510-655 MPa, yield strength ≥415 MPa), and is suitable for medium-pressure oil and gas pipelines in domestic complex terrain (such as mountainous areas, plateaus), with better adaptability to geological changes. In addition, both are widely used in branch pipelines of oil and gas fields and urban gas transmission pipelines.
2. Does GB/T 8163 20G welded pipe have a corresponding American Standard grade, and what are their differences in high-temperature steam resistance?
Answer: GB/T 8163 20G welded pipe (boiler pressure vessel pipe) corresponds to ASTM A106 Grade B welded pipe in American Standard. In terms of high-temperature steam resistance, the two have differences: ASTM A106 Grade B can be used in high-temperature steam environments up to 450℃, and has good high-temperature strength and oxidation resistance, which is suitable for boiler steam pipelines and superheated steam pipelines; GB/T 8163 20G can be used in high-temperature steam environments up to 420℃, and its high-temperature steam resistance is slightly lower than that of ASTM A106 Grade B, but it has better fatigue resistance, which is more suitable for domestic boiler water wall pipes and low-temperature superheater pipes. In addition, 20G has stricter requirements on the purity of the material, ensuring the safety of boiler operation.
3. What is the corresponding Chinese standard grade for ASTM A269 Grade TP304H welded stainless steel pipe, and what are their differences in high-temperature strength?
Answer: ASTM A269 Grade TP304H welded stainless steel pipe (high-temperature austenitic stainless steel pipe) corresponds to GB/T 12771 06Cr19Ni10H welded stainless steel pipe in Chinese standard. In terms of high-temperature strength, the two have obvious differences: ASTM A269 TP304H has a carbon content of 0.04-0.10%, and the high-temperature strength at 870℃ is not less than 150 MPa, which is suitable for high-temperature pipelines with high strength requirements; GB/T 12771 06Cr19Ni10H has a carbon content of 0.04-0.10%, and the high-temperature strength at 870℃ is not less than 145 MPa, which is slightly lower than that of TP304H. TP304H is more suitable for high-temperature and high-pressure pipelines in international petrochemical and thermal power projects, while 06Cr19Ni10H is more commonly used in domestic high-temperature pipelines with medium strength requirements.
4. Which American Standard welded pipe grade corresponds to GB/T 3091 Q390B welded pipe, and what are their differences in impact toughness?
Answer: GB/T 3091 Q390B welded pipe (high-strength low-pressure pipe) corresponds to ASTM A53 Grade X52 welded pipe in American Standard. In terms of impact toughness, the two have differences: GB/T 3091 Q390B has impact toughness requirements at 20℃, and the impact energy is not less than 34 J, which has good toughness and can withstand certain impact loads; ASTM A53 X52 does not have mandatory impact toughness requirements, but its elongation is not less than 30%, which has good ductility. Q390B is suitable for low-pressure pipelines and structural parts that require impact resistance, such as bridge supports, industrial plant pipelines; ASTM A53 X52 is suitable for pipelines that need to withstand deformation but have no strict impact requirements.
5. What is the corresponding relationship between API 5L X90 welded pipe and Chinese standard welded pipe, and what are their development prospects in high-pressure oil and gas transportation?
Answer: API 5L X90 welded pipe corresponds to GB/T 9711.1 L830 welded pipe in Chinese standard. Both are high-strength, high-toughness welded pipes with broad development prospects in high-pressure oil and gas transportation: API 5L X90 has a minimum tensile strength of 900 MPa, a yield strength of not less than 630 MPa, excellent weldability and corrosion resistance, which can meet the requirements of ultra-high pressure (＞14 MPa) long-distance oil and gas transportation, and is the key material for future international ultra-high pressure pipeline projects; GB/T 9711.1 L830 is independently developed in China, with basically the same mechanical properties as API 5L X90 (tensile strength 830-980 MPa, yield strength ≥830 MPa), and has better adaptability to domestic geological and environmental conditions, which is of great significance for promoting the localization of ultra-high pressure oil and gas pipelines in China. With the continuous development of ultra-high pressure oil and gas transportation technology, both will play an increasingly important role in the global oil and gas industry.
