Specification for Line Pipe, API Specification 5L

API Specification 5L is the American Petroleum Institute's standard for line pipe used in the transportation of oil, gas, and water in the petroleum and natural gas industries. This specification covers seamless and welded steel line pipe, outlining requirements for manufacturing processes, chemical composition, mechanical properties, and testing to ensure strength, toughness, and resistance to corrosion and environmental stress. API 5L includes various product specification levels (PSL1 and PSL2) that define stricter quality and performance standards, particularly for critical applications. The specification also addresses pipe dimensions, tolerances, and surface conditions to ensure compatibility and safety in pipeline systems.