Understand pipeline welding qualification requirements: API 1104 (paywalled) governs the welding procedure/welder qualification itself, while PHMSA's Operator Qualification rule governs who's allowed to perform the covered task.

Steps

1. Confirm API Standard 1104 (Welding of Pipelines and Related Facilities, 22nd edition) is a paid, DRM-protected publication co-distributed via api.org and AWS's pubs.aws.org — there is no free full-text version; budget for purchase if your shop performs pipeline welding.
2. Separately, pull 49 CFR 192 Subpart E (Welding of Steel in Pipelines) from eCFR — welders/welding operators must be qualified per API 1104 Section 6, Section 12, Appendix A, or Appendix B, or ASME BPVC Section IX; this is the free regulatory cross-reference to the paid standard.
3. Pull PHMSA's Operator Qualification overview (phmsa.dot.gov/pipeline/operator-qualifications) and 49 CFR 192 Subpart N — OQ is a separate, task-based qualification system layered on top of welder qualification, documenting that specific individuals are trained to recognize and react to abnormal operating conditions for covered tasks.
4. Note the specific restriction that welders/welding operators qualified only by nondestructive testing (rather than destructive testing) may not weld compressor station pipe and components, per 49 CFR 192.
5. Don't conflate an AWS CWI credential, an API 1104 welder qualification, and PHMSA Operator Qualification — a pipeline welder may need all three depending on the specific operator's program and task.