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Which welding code is more common in the Middle East?

Both are used extensively. AWS D1.1 is common in structural and refinery construction, while API 1104 is used for pipeline projects. Aramco and ADNOC projects often require both depending on the scope.

Do I need separate certifications for AWS D1.1 and API 1104?

The CWI (Certified Welding Inspector) certification from AWS covers both codes, but you need specific training on each code's acceptance criteria. Some employers require code-specific endorsements.

What is the main difference in acceptance criteria?

AWS D1.1 classifies welds as fatigue-critical (Table 6.1) or non-critical with different acceptance levels. API 1104 uses a single acceptance standard based on weld type (stringer vs fill) and pipe diameter.

QC · Certification Comparison

AWS D1.1 vs API 1104

AWS D1.1 and API 1104 are the two primary welding codes used in industrial construction. AWS D1.1 (Structural Welding Code – Steel) governs welding for buildings, bridges, and structural steel. API 1104 governs welding of pipelines and related facilities. QC welding inspectors must know which code applies to their project.

Criterion	AWS D1.1	API 1104
Application	Structural steel (buildings, bridges)	Cross-country pipelines and piping
Welding Processes	SMAW, GMAW, FCAW, SAW	SMAW, GMAW, FCAW (pipeline-specific)
Inspection Focus	Visual, UT, RT, MT, PT	Visual, RT, UT (pipeline welds)
Acceptance Criteria	Clause 6 — fatigue-critical vs non-critical	Section 9 — based on weld type and pipe diameter
Certification	CWI (Certified Welding Inspector)	API 1104 CWI or pipeline-specific
Typical Projects	Refineries, plants, structural fabrication	Pipeline construction, tie-ins, repairs

The Verdict

If you inspect structural steel fabrication, AWS D1.1 is your code. If you work on pipeline construction or maintenance, API 1104 is essential. Many senior CWIs hold both to work across structural and pipeline projects.

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