This Standard specifies requirements for the manufacture of two product specification levels (PSL 1 and PSL 2) of seamless and welded steel pipes for use in pipeline transportation systems in the petroleum and natural gas industries.

This editon of API Spec 5L is the modified national adoption of ISO 3183: 2007 Petroleum and natural gas industries Steel pipe for pipeline transportation systems. This specification contains the API Monogram Annex as part of the U.S. national adoption.