5.4 Consumable Control, Weld Docs & Repairs

5.4 Consumable Control, Weld Docs & Repairs

Quick Answer: Consumable control keeps electrodes, wire, and shielding gas traceable and dry so hydrogen cracking is prevented — low-hydrogen electrodes must be baked, held in heated quivers, and reconditioned per the manufacturer. The API 1169 inspector verifies filler-lot traceability, the root/hot/fill/cap weld sequence, lineup and preheat, hi-lo alignment, weather protection, and the daily weld documentation (weld map). When a defect is found, repairs follow API 1104 — grind-and-repair or cut-out-and-reweld within repair limits, with re-NDE to the same acceptance standard.

Consumable Control

Welding consumables — electrodes, wire, flux, and shielding gas — directly affect weld quality. The inspector verifies a controlled consumable program:

Low-Hydrogen Electrode Storage

Hydrogen in the weld metal causes delayed cracking in the heat-affected zone. Low-hydrogen electrodes (e.g., E7018) are the most tightly controlled:

The inspector checks: ovens are at temperature (verified with a thermometer, not just "on"), electrodes are in the oven (not sitting on the pipe), and the exposure log is current. An E7018 electrode sitting on the pipe in humid weather is a hydrogen-cracking risk and a finding.

Filler Lot Traceability

Every weld must be traceable to the lot of filler used. The inspector confirms:

• Lot numbers recorded on the weld map for each weld.
• Electrodes/wire in the quiver match the lot recorded — no uncontrolled mixing of lots in a single quiver.
• Lot control documents retained so a problem with a lot can be traced to the affected welds.

Wire and Gas Control

• Wire — spool identity, classification (e.g., ER70S-6), and diameter match the WPS; wire kept clean and dry.
• Shielding gas — gas type (e.g., 75% Ar/25% CO2) and flow rate match the WPS; cylinders identified; mixed gas verified at the source.

Production Welding: The Root-to-Cap Sequence

A pipeline girth weld is built in passes:

Lineup, Clamps, Bevel Prep, and Preheat

• Lineup — pipe ends aligned with an internal clamp (or external) so the bevels match; the inspector checks for hi-lo (mismatch) across the joint — excessive hi-lo causes incomplete fusion and must be corrected before welding.
• Bevel prep — bevel angle, root face, and land per the WPS; clean, dry, free of rust, oil, and moisture.
• Preheat — measured and within the WPS range before the root pass; removes moisture and slows cooling to prevent hydrogen cracking; verified with temp sticks or a pyrometer.
• Interpass temperature — kept within the WPS range between passes; not too low (cracking) or too high (excessive heat input).

Weather Protection

• Wind screens for gas-shielded processes (GMAW, FCAW-G) — wind displaces shielding gas and causes porosity; the inspector verifies screens are in place above the wind-speed limit in the WPS.
• No welding over moisture or ice — the pipe must be dry; rain or snow stops the weld or requires cover.
• Ambient cold — preheat must overcome ambient cold per the WPS.

Daily Weld Documentation

The inspector verifies the weld map (weld log) is kept current:

• Weld number / station tied to the alignment sheet.
• Joint numbers of the two pipes joined (closing the material-traceability loop).
• Welder IDs for each pass (root, hot, fill, cap may be different welders).
• WPS used and lot numbers of filler.
• NDE status (pending, passed, failed) — NDE itself is covered in ch6.
• Repair status and re-NDE.

A missing or incomplete weld map is a documentation finding; without it, traceability of the finished pipeline is broken.

Defect Repair per API 1104

When NDE or visual inspection finds a defect, repair follows API 1104 — Section 9 sets the accept/reject limits and Section 10, Repair and Removal of Weld Defects, governs the repair itself:

Repair Options

Repair Limits and Re-NDE

• Repair limits — under API 1104 Section 10 every repair requires the company's authorization, and a repair of a previously repaired area is not permitted unless the company specifically authorizes it. Most project specifications tighten this to one repair attempt per area; beyond the authorized limit, cut-out is required.
• Repair welder — the repair must be made by a welder qualified for the repair procedure; the original welder is not automatically barred but the project may require it.
• Re-NDE — the repair area must be re-examined by the same NDE method and to the same acceptance standard as the original; a repair that still fails goes to cut-out.
• Documentation — the repair is recorded on the weld map with defect type, location, repair method, welder ID, and re-NDE result.

Inspector's Documentation Checklist

1. WPS at station and PQR coverage verified.
2. Welder qualifications on site and qualified for the joint.
3. Consumables: ovens at temperature, lot traceability, gas and wire correct.
4. Lineup hi-lo, preheat, and interpass within WPS.
5. Weather protection in place.
6. Weld map current: weld number, joint numbers, welder IDs, WPS, filler lots.
7. Defects repaired per API 1104; re-NDE passed; records updated.

Key Takeaways Recap

• Low-hydrogen electrodes must be baked, held in heated quivers, and exposure-tracked.
• Filler lot, wire, and gas are traceable and match the WPS.
• The root/hot/fill/cap sequence, hi-lo lineup, preheat, and weather protection are the production weld watch-points.
• Repairs follow API 1104 grind-repair or cut-out within repair limits, with re-NDE and full documentation.