API 5L generally refers to the implementation standard for pipeline steel pipes, which include two main categories: seamless steel pipes and welded steel pipes. Currently, the commonly used welded steel pipe types in oil pipelines are spiral submerged arc welded pipes (SSAW PIPE), longitudinal submerged arc welded pipes (LSAW PIPE), and electric resistance welded pipes (ERW). Seamless steel pipes are typically selected when the pipeline diameter is less than 152mm.
The national standard GB/T 9711-2011, Steel Pipes for Pipeline Transportation Systems in Petroleum and Natural Gas Industries, was developed based on API 5L.
GB/T 9711-2011 specifies manufacturing requirements for seamless and welded steel pipes used in petroleum and natural gas pipeline transportation systems, covering two product specification levels (PSL1 and PSL2). Therefore, this standard applies only to seamless and welded steel pipes for oil and gas transmission and does not apply to cast iron pipes.
Steel Grades
API 5L steel pipes utilize various raw material grades including GR.B, X42, X46, X52, X56, X60, X70, X80, and others. Pipeline steels with grades X100 and X120 have now been developed. Different steel grades impose distinct requirements on raw materials and production processes.
Quality Levels
Within the API 5L standard, pipeline steel quality is categorized as PSL1 or PSL2. PSL stands for Product Specification Level.
PSL1 specifies general quality requirements for pipeline steel; PSL2 adds mandatory requirements for chemical composition, notch toughness, strength properties, and supplemental NDE testing.
Post time: Sep-01-2025
