API
API 1104
Welding of Pipelines and Related Facilities
The welding code for cross-country pipelines and related facilities - the piping of ASME B31.4 and B31.8. It carries its own qualification route, its own radiographic acceptance criteria and its own destructive test regime, and it does NOT apply to process plant piping, which B31.3 sends to ASME Section IX instead. The two are confused often enough that knowing which one governs the line in front of you is itself a competence.
This is an explanation, not the standard. PipingInspector is not affiliated with API and reproduces no part of the document. Always work to the current edition of the standard itself and to your project specification.