Category
Piping & Fittings
Subcategory
Pipeline
Applicable standards
5
Issuing bodies
4
Description
ASME B31.8 cross-country pipeline for natural gas transmission & distribution.
Applicable Standards (5)
API — 2 standards
API 1104
Welding of Pipelines and Related Facilities
Welding procedures, welder qualification and NDE for cross-country pipelines.
Key requirements (7)
- Welding of pipelines and related facilities.
- Procedure qualification: PQR with mechanical tests (tensile, bend, nick break, Charpy where required).
- Welder qualification by destructive bend tests OR radiography.
- Acceptance criteria (Section 9): undercut, porosity, slag, lack of fusion limits.
- RT acceptance: porosity max 1/8" diameter, max 4 in 6" weld length (general).
- Automated UT (AUT) increasingly used for offshore / large diameter.
- Annex A: alternative acceptance via fitness-for-purpose (ECA).
API 5L / ISO 3183
Specification for Line Pipe
Line pipe for pipeline transportation systems (PSL 1 / PSL 2).
Key requirements (7)
- Line pipe specification — PSL 1 (basic) and PSL 2 (more stringent toughness, hydrostatic, NDT).
- Grades: B, X42, X46, X52, X56, X60, X65, X70, X80 (number = SMYS in ksi).
- Manufacturing: SMLS (seamless), HFW (high-frequency welded ERW), SAWL (submerged arc longitudinal), SAWH (helical SAW).
- Hydrotest: per pipe (each length) — 75% SMYS minimum × 10 sec.
- Charpy impact for PSL 2: minimum average 27 J at 0 °C body, 40 J for ≥ X65.
- DWTT (drop weight tear test) for ≥ X70 in PSL 2.
- Heat treatment: hot rolled, normalized, Q&T per grade.
ASME — 1 standard
ASME B31.8
Gas Transmission and Distribution Piping Systems
Pipelines transporting natural and other gases.
Key requirements (7)
- Gas transmission and distribution piping.
- Class locations 1–4 based on population density within 1/4-mile (200 ft typical x 1 mi each side of pipeline).
- Design factor F: 0.72 (Class 1 Div 2), 0.60 (Class 2), 0.50 (Class 3), 0.40 (Class 4).
- Hydrotest: typical 1.25 × MAOP for 8 hours minimum.
- MAOP = 2·S·t·F·E·T/D — basis for design.
- Compressor stations covered per Chapter VIII (B31.8); offshore per B31.8.S.
- Pipeline integrity management per ASME B31.8S (gas) — covers HCAs (high consequence areas).
ISO — 1 standard
ISO 13623
Petroleum and natural gas industries — Pipeline transportation systems
Pipeline transportation system design (liquid and gas).
NACE/AMPP — 1 standard
NACE SP0169
Control of External Corrosion on Underground or Submerged Metallic Piping Systems
Cathodic protection design and operation for buried/submerged piping.