B31.4 is the ASME code for liquid pipeline transportation systems. This guide decodes inspection scope, NDE methods, weld acceptance, and code-specific gotchas.
\nASME B31.4, Pipeline Transportation Systems for Liquids and Slurries, covers pipelines transporting liquids such as crude oil, refined products, natural gas liquids, liquid anhydrous ammonia, liquid alcohol and carbon dioxide, including pump stations, tank farms and terminals. In the United States, hazardous liquid and CO2 pipelines are regulated by PHMSA under 49 CFR Part 195, which sets the legal requirements.
\nNew and replaced pipelines are pressure tested before service under 49 CFR Part 195 Subpart E and B31.4's requirements.
\nIntegrity management for hazardous liquid pipelines that could affect high consequence areas is required by 49 CFR 195.452, using in-line inspection, pressure testing or other assessment methods. Breakout tanks are inspected per API 653 under 49 CFR 195.432; API 510 and 570 do not apply to the pipeline itself. Atlantis NDT does not run pipeline in-line inspection.
\n| Concern | Common method | Reference |
|---|---|---|
| Girth weld volumetric examination | RT or automated UT | API 1104; 49 CFR 195.234 |
| Surface cracking at welds and fittings | MT or PT | Operator procedures |
| Wall loss at digs | UT thickness and corrosion mapping | Operator integrity program |
| Breakout tank floors and shells | MFL floor scanning with UT prove-up; shell UT | API 653 via 49 CFR 195.432 |
A: API 1104 Section 9 (or Appendix A where qualified), as referenced by 49 CFR 195.228 and B31.4.
\nA: Yes. 49 CFR 195.222 and B31.4 allow qualification under API 1104 or ASME Section IX.
\nA: Only to breakout tanks, through 49 CFR 195.432. The pipeline itself follows Part 195 and B31.4; API 510 and 570 do not apply.
\nA: NDT personnel are qualified under the employer's written practice (commonly ASNT SNT-TC-1A) and the requirements of API 1104 and the operator's program.
\nA: With ASNT Level III consulting on NDE procedures, ASNT SNT-TC-1A training, tank-floor MFL and UT for breakout tanks, and inspection software. Atlantis does not run in-line inspection.
\nRecommended practices and guides inform an inspection programme; binding requirements come from the in-service codes (API 510, API 570, API 653), the construction codes and the regulations that apply to the asset. NDE personnel are qualified under the employer's written practice (commonly ASNT SNT-TC-1A, ANSI/ASNT CP-189 or ISO 9712), and NDE procedures are approved by the employer's NDT Level III. Acceptance of indications follows the governing code; damage beyond its rules may be referred for an engineering fitness-for-service assessment (API 579-1/ASME FFS-1), which Atlantis NDT does not perform. Keep procedure revisions, calibration records and personnel certifications traceable; Atlantis ERP can hold these records.
\nUse the edition required by the contract, governing requirements and applicable jurisdiction. Record that edition in the procedure and evaluate changes before adopting a later publication.
\nA: 4-20 weeks depending on team size + scope. SMB: 4 weeks. Mid-size: 8-12 weeks. Enterprise multi-region: 12-20 weeks. Atlantis NDT delivers phased rollout with clear milestone gates.
\nA: Atlantis ERP has an open REST API, so it connects to SAP, Maximo, NetSuite or any other system that accepts API connections; each integration is scoped with you during implementation. Free integration scoping consultation.
\nA: Request a free 30-min consultation at /contact. We reply within one business day. We scope your asset class + damage mechanisms + code requirements + delivery model preference + integration needs in a single call.
\nAtlantis NDT — led by Anoop Rayavarapu (ASNT NDT Level III in UT, RT, MT, PT and VT). Free consultation. request a free consultation. Pricing varies by region and scope.
","order":0,"createdAt":"2026-06-24","updatedAt":"2026-10-18","quickAnswer":{"question":"What does B31.4 cover and how is inspection done in 2026?","answer":"ASME B31.4 covers pipelines for liquids and slurries, including crude, products, NGLs and CO2. In the US, 49 CFR Part 195 sets the legal requirements: welding qualified to API 1104 or ASME IX, weld acceptance per API 1104, pressure testing per Subpart E, integrity management per 195.452, and API 653 for breakout tanks.","bullets":["B31.4 = liquid and slurry pipelines","Weld acceptance: API 1104 (49 CFR 195.228)","Integrity management: 49 CFR 195.452"]}}