AWS API 1104 Endorsement cheat sheet

Pipeline (API 1104)

• API 1104 governs field girth welding of pipelines and related facilities; it covers butt, fillet, and sleeve welds in carbon and low-alloy steel pipe.

• Welder qualification tests are typically made on pipe of the same nominal diameter and wall thickness group; a change in welding process, position, or essential variable requires requalification.

• Acceptance for butt welds is by radiographic or destructive testing; common acceptance criteria include crack prohibition, and limits on porosity, slag, incomplete fusion, and incomplete penetration.

• For girth welds, incomplete penetration and incomplete fusion are generally unacceptable in the root and sidewall, while isolated porosity and slag are judged against size and length limits.

• The qualification coupon is usually 6 in (168 mm) nominal diameter or larger for full-size tests; smaller pipe may require a special small-diameter procedure.

• Welder performance qualification remains valid unless the welder has not welded with the qualified process for a defined period (commonly 6 months) or a qualified essential variable changes.

• Preheat and interpass temperatures are procedure variables; minimum preheat increases with carbon equivalent and wall thickness to reduce hydrogen cracking risk.

• Visual acceptance covers undercut depth, cap height, misalignment (hi-lo), and surface porosity; limits are stated as fractions of wall thickness or fixed dimensions.