What is ASTM A106 Schedule 80 Seamless Steel Pipe?
ASTM A106 Schedule 80
seamless steel pipe is a type of carbon steel seamless pipe conforming to the American Society for Testing and Materials (ASTM) standard
ASTM A106, with a wall thickness grade of SCH 80.
Material and Grade:
The ASTM A106 standard is suitable for high-temperature and high-pressure environments and is mainly divided into three grades: A106A, A106B, and A106C. Among them, A106B is the most commonly used grade, possessing good comprehensive mechanical properties. ASTM A106 Schedule 80 seamless pipe belongs to the ordinary carbon steel series, equivalent to #20 steel in China. It is manufactured through hot rolling or cold drawing processes and has no weld seams. The two differ in precision, surface quality, and mechanical properties.
Wall Thickness Grade:
Schedule 80 is abbreviated as SCH 80, indicating a wall thickness grade. SCH 80 is a thicker wall type, suitable for high-pressure applications. The wall thickness range for ASTM A106 Schedule 80 seamless steel pipes includes SCH20, SCH40, STD, XS, SCH80, SCH160, XXS, etc. The wall thickness value of SCH 80 needs to be determined based on the outer diameter and is usually thicker than SCH 40 pipe (standard wall thickness).
Core Features of ASTM A106 Schedule 80 Seamless Steel Pipes:
1. Excellent High-Temperature Strength: Strict chemical composition (especially carbon, manganese, silicon, and low phosphorus and sulfur) ensures high strength even at high temperatures (typically up to 400°C-450°C).
2. Ultra-High Pressure Bearing Capacity: The thicker wall of SCH 80 allows it to withstand extremely high internal pressures.
3. No Weld Risk: The seamless structure eliminates the potential weakness of welds.
Size Specifications:
ASTM A106 standard seamless tube dimensions follow ASME B36.10. Common sizes range from NPS 1/8″ to NPS 24″. For the same outer diameter, the inner diameter of SCH 80 is smaller than that of SCH 40.
Applications of ASTM A106 SCH 80 Seamless Tubes:
1. Power and Energy Industry
Power plant boiler systems: main steam piping, high-temperature reheat steam piping.
Thermal systems: main steam transmission lines for industrial boilers, high-temperature hot water piping.
Nuclear power: high-temperature and high-pressure auxiliary piping systems for some conventional islands.
2. Petrochemical and Refining Industry
Process piping: connecting reactors, cracking furnaces, and converters.
Heat exchange piping: shell-and-tube heat exchangers, high-temperature side tube bundles in steam generators.
Utilities: high-pressure steam transmission networks and thermal oil system piping within plants.
3. Other Industrial and Special Applications
High-temperature heating systems: district heating transmission piping.
Industrial furnace system: furnace tubes and outlet pipes.
Key equipment interfaces: inlet and outlet pipes for high-temperature and high-pressure vessels and pumps.
Read more: Seamless vs. welded pipe
