API 5L General Information The API SPEC 5L specification provides standards for pipe suitable for use in conveying gas, water, and oil in the natural gas and oil industries. The API SPEC 5L covers seamless and welded steel line pipe. It includes plain-end, threaded-end, and belled-end pipe, as well as through-the-flowline (TFL) pipe, and pipe with ends prepared for use with special couplings. Pipe manufactured to ASTM106 Grade A or B are not interchangable with API 5L. Requirements to API 5L X grades are more stringent; rolled grades are not acceptable and rework is not allowed. Moreover, particular attention is given to toughness and toughness tests for sour services and higher pressure & temperature classes. Strength Levels & Desulphurization Manganese sulphides are typical inclusions in all manganese alloyed steels. Because they tend to segregate resulting in reduced impact strength, sulphure content needs to be minimized. We specify maximum 0.007%. API 5L Benefits & Applications Gas, water and oil transportation – preferred in long pipelines due to inexpensiveness Pipeline steel – resistance to crack propogation Line Pipe / Sour Service Line Pipes