API 5L piping is usually used for both seamless steel pipes and welded steel pipes, but ASTM A106 is particularly for carbon seamless steel pipes which can be used for high-temperature and high-pressures service.
API 5L steel pipes are attained from API Spec 5L specification for line pipe, and they are suitable for the transportation of gas, oil and water. It is divided into two product levels i.e. API 5L PSL1 and API 5L PSL2. API 5L PSL1 is a standard quality for line pipe whereas API 5L PSL2 contains additional chemical, mechanical properties, and testing requirements.
API 5L Grades specification are A25, A, B and “X” Grades X42, X46, X52, X56, X60, X65, X70, X80. The two digit number following the “X” shows Minimum Yield Strength of pipe formed to this grade.
ASTM A106/ ASME SA 106 steel pipes are the standard specification for carbon seamless steel pipe for high-pressures and high-temperature service, such as power generation. ASTM A106 pipes contain three grades i.e. ASTM A106 Grade A, Grade B, and Grade C.
API 5L is comparatively broad specification, mainly developing line pipes for the oil and gas industry; the range of strength levels is much broad. While the lower strength grades A & B are comparable to ASTM A106, the strength of other grades are comparatively much higher. In addition, the quality rating is more demanding when API 5L line pipe PSL2 is applied, the rolling rating is not acceptable and rework is not acknowledge. Moreover, accurate consideration is given to toughness and toughness tests for sour services and higher pressure and temperature classes