Seamless carbon steel pipe is one of the most widely used pipe materials in industrial and civil fields. Its manufacturing follows strict international, national and industry standards, which specify in detail the chemical composition, mechanical properties, dimensional tolerances, surface quality, non-destructive testing methods and uses of steel pipes.
American Standards (ASTM / ASME / API)
American standards have a great influence worldwide, especially in the oil and gas, electricity, petrochemical and other industries.
1. ASTM A53 / ASME SA-53: Steel pipe, black and hot-dip galvanized, welded and seamless
Uses: It is suitable for general mechanical and pressure applications and is also commonly used in steam, water, gas and air pipelines.
Features: It covers seamless and welded pipes, available in two grades, A and B. Grade B is the more commonly used grade with higher tensile strength and yield strength.
Chemical composition and mechanical properties: The standard has clear requirements on the content of elements such as carbon, manganese, phosphorus, sulfur, as well as tensile strength and yield strength.
2. ASTM A106 / ASME SA-106: Seamless carbon steel pipe for high temperature service
Application: It is specially designed for high temperature and high pressure environment and is widely used in refineries, chemical plants, power plants, boilers and ships, etc.
Features: Seamless pipes only, available in three grades: A, B, and C. Grade B (A106 Gr. B) is the most commonly used, with excellent high temperature performance.
Chemical composition and mechanical properties: There are stricter controls on elements such as carbon, manganese, and silicon, and the tensile strength and yield strength at high temperatures are specified, requiring tensile, bending, flattening, water pressure and other tests.
3. ASTM A333 / ASME SA-333: Seamless and welded steel pipes for low temperature service
Application: Suitable for low temperature pressure vessels and pipelines, such as liquefied gas, refrigeration equipment, etc.
Features: It covers seamless and welded pipes, has multiple grades (such as Grade 1, Grade 6), and requires impact testing to ensure toughness at low temperatures.
Chemical composition and mechanical properties: There are specific requirements for the content of elements such as carbon, manganese, silicon, and low-temperature impact performance.
4. ASTM A500 / A500M: Cold-formed welded and seamless carbon steel structural tube, round and shaped
Uses: It is mainly used in structural applications such as building frames, bridges, mechanical structures, etc.
Features: It covers cold-formed welded and seamless pipes, and has four grades of A, B, C, and D with different strength requirements.
Chemical composition and mechanical properties: It focuses on the yield strength and tensile strength of the structure.
5. API Spec 5L: Specification for Line Pipe
Uses: It is specially used in pipeline transportation systems in the oil and gas industry, covering from low pressure to high pressure, and is often used for long-distance transportation of crude oil, natural gas, etc.
Features: It covers seamless and welded pipes, providing a variety of strength grades (such as Grade B, X42, X46, X52, X56, X60, X65, X70).
Chemical composition and mechanical properties: There are strict controls on carbon equivalent, sulfur, phosphorus and other elements, and detailed regulations on yield strength, tensile strength, toughness, weldability, dimensional accuracy and surface quality. It is usually divided into PSL1 and PSL2 grades, and PSL2 requirements are more stringent.
Chinese National Standard (GB/T)
China's national standard system also subdivides seamless carbon steel pipes according to their uses.
1. GB/T 8162: Seamless Steel Tube for Structural Use
Use: For general structures and mechanical structures, not for conveying fluids.
Common materials: 10#, 20#, 45#, Q345 (formerly known as 16Mn), etc.
Features: It focuses on strength, toughness and processing performance.
2. GB/T 8163: Seamless steel pipe for conveying fluids
Application: used for conveying general fluids such as water, oil, and gas.
Common materials: 10#, 20#, Q345, etc.
Features: Compared with GB/T 8162, it has higher requirements for water pressure test and surface quality.
3. GB/T 3087: Seamless steel tube for low and medium pressure boilers
Purpose: It is used to manufacture superheated steam pipes, boiling water pipes and locomotive boiler pipes for low and medium pressure boilers of various structures.
Common materials: 10#, 20#, etc.
Features: There are requirements for the pressure resistance and temperature resistance of the material, and process tests such as flattening and expansion are usually carried out.
4. GB/T 5310: Seamless steel tube for high-pressure boilers
Purpose: It is used to manufacture water tube boiler heating surface tubes, economizers, superheaters, reheaters, petrochemical industry tubes, etc. with high pressure and above.
Common materials: 20G, 20MnG, 25MnG, etc. (carbon steel grades), and alloy steel.
Features: Strict requirements for high temperature strength, creep resistance, endurance strength and oxidation resistance.
5. GB/T 3639: Cold-drawn or cold-rolled precision seamless steel tube
Application: Occasions with high requirements for dimensional accuracy and surface finish, such as hydraulic systems, pneumatic systems, automotive parts, etc.
Common materials: 10#, 20#, 45#, etc.
Features: Small dimensional tolerance, high internal and external surface finish.
European Standards (EN)
European standards (especially the EN 10216 series) are widely used in European countries and in some international projects.
EN 10216-1: Seamless steel tubes for pressure purposes Part 1: Non-alloy steel tubes with specified room temperature properties
Application: general pressure-bearing applications, such as conveying water, steam, gas, etc.
Common grades: P195TR1, P235TR1, P265TR1, P195TR2, P235TR2, P265TR2, etc.
Features: It defines different grades of non-alloy steel pipes and their room temperature mechanical properties.
Japanese Standards (JIS)
Japanese Industrial Standards have a certain influence in Asia.
JIS G3444: Carbon steel pipe for general structural use
Application: general mechanical structures and civil engineering structures.
Common grades: STK30, STK41, STK50, STK51, STK55.
JIS G3454: Carbon steel pipe for pressure piping
Application: Suitable for medium and low pressure pipelines.
Common grades: STPG38, STPG42.
JIS G3456: Carbon steel pipe for high temperature piping
Application: Suitable for pipelines for conveying high temperature fluids.
Common grades: STPT38, STPT42, STPT49.
Conclusion
When selecting seamless carbon steel pipes, it is crucial to understand their end use, working environment (temperature, pressure, medium) and the standards they need to follow. Different standards and grades have clear provisions on the chemical composition, mechanical properties, dimensional tolerances, inspection methods and delivery status of steel pipes, ensuring that the selected products can meet the specific requirements and safety specifications of the engineering project.
Read more: American Standard Carbon Steel Seamless Pipe
