5.3 Welding Procedures, Qualification & API 1104
Key Takeaways
- Every production weld must be made using a qualified WPS backed by a PQR, and by a welder qualified for the process, position, diameter, and grade of the joint
- API 1104, 22nd Edition (July 2021, Errata 1 September 2023) Sections 3–11 is the testable welding scope; CSA Z662:23 is the Canadian parallel
- Essential variables (base metal grade, thickness, diameter, process, filler, joint design, position, preheat, travel speed, shielding gas) must be within the PQR range for the WPS to apply
- If any essential variable of the joint is outside the WPS or welder-qualification range, the inspector places a HOLD
5.3 Welding Procedures, Qualification & API 1104
Quick Answer: Every production weld on a pipeline must be made using a qualified Welding Procedure Specification (WPS) backed by a Procedure Qualification Record (PQR), and by a welder qualified for the process, position, diameter, and grade of that joint. The API 1169 inspector verifies that the WPS at the weld station is current and approved, that welder qualification records are on site, that welders are working within their essential variables, and that the work follows API 1104 (22nd Edition, July 2021, Errata 1 September 2023) or CSA Z662:23 as the governing code.
The Governing Code
For U.S. pipelines the welding code is API 1104, 22nd Edition, July 2021 (with Errata 1, September 2023). API 1169 BOK questions on welding draw from Sections 3 through 11 of API 1104 — procedure and welder qualification, production welding, inspection, and repair. For Canadian projects the parallel body is CSA Z662:23, which addresses welding qualification across Chapters 1, 2, 4, and 6–10. The inspector must know which code governs the project and apply the corresponding essential-variable and qualification rules; the two codes are similar in structure but not identical in limits.
WPS and PQR
A Welding Procedure Specification (WPS) is the written instruction for how a production weld is to be made — process, filler, joint design, preheat, travel speed, shielding gas, and so on. A Procedure Qualification Record (PQR) is the record of a test weld that proved the WPS can produce a sound joint. The WPS is only valid if it is supported by a qualified PQR. The inspector's first welding check at a weld station is to confirm the approved WPS is physically present and that the crew is following it.
Essential Variables
API 1104 defines essential variables — changes that require requalification. If a production joint falls outside the qualified range of any essential variable, the WPS is not valid for that joint. The inspector verifies each variable against the joint in front of the welder:
| Essential Variable | What the Inspector Verifies | Effect of Changing |
|---|---|---|
| Base metal grade (SMYS) | Pipe grade (X52, X65, etc.) within PQR range | Requalify |
| Wall thickness / diameter | Joint WT and OD within qualified range | Requalify outside range |
| Welding process | SMAW, FCAW, GMAW, etc. matches PQR | Change of process = new qualification |
| Filler metal | Electrode/wire classification within PQR | Requalify |
| Joint design | Bevel angle, root face, land within PQR | Requalify |
| Position | 1G, 2G, 5G, 6G within qualified range | Requalify |
| Preheat / interpass temperature | Measured temp within WPS range | Lower preheat risks cracking = requalify |
| Travel speed / heat input | Within WPS limits | Affects mechanical properties |
| Shielding gas (gas-shielded processes) | Gas composition and flow within WPS | Requalify |
The rule: if the joint's essential variables are within the PQR ranges, the WPS applies; if any is outside, the WPS does not apply and the joint cannot be welded under that procedure.
Welder Qualification
A qualified WPS is necessary but not sufficient — the welder must also be qualified. API 1104 requires each welder to pass a qualification test for the process, position, diameter, and grade they will use in production. Key inspector checks:
- Qualification records on site — the welder's qualification card or record must be available at the spread; "back at the office" is not acceptable.
- Welder identification — each welder has an ID (stencil stamp or assigned code) used on the weld map so every weld is traceable to its maker.
- Qualified for the production joint — a welder qualified for 5G on X52 is not automatically qualified for 6G on X70; the inspector confirms the welder's qualified ranges cover the joint's essential variables.
- Currency (continuity) — qualification has a continuity requirement (a welder must have used the process within a defined period, or requalify); the inspector checks the last-use date.
Ensuring the Welder Matches the Joint
The inspector's field routine:
- Identify the joint — pipe grade, WT, diameter, and position required.
- Pull the WPS — confirm it is approved and that the joint's essential variables are within its PQR ranges.
- Pull the welder's qualification — confirm the welder is qualified for the process, position, diameter, and grade of this joint.
- Confirm welder ID — verify the stencil or ID matches the record and that it will be recorded on the weld map.
- Clear to weld only if all three line up; otherwise place a HOLD.
API 1104 Sections 3–11 at a Glance
| Section | Scope (API 1104, 22nd Ed.) | Inspector Focus |
|---|---|---|
| 3 | Terms, Definitions, Acronyms, and Abbreviations | Know the vocabulary the acceptance clauses use |
| 4 | Specifications | What the WPS must contain and cover |
| 5 | Qualification of Welding Procedures with Filler Metal Additions | Verify the PQR supports the WPS |
| 6 | Qualification of Welders | Verify the welder's card covers the joint |
| 7 | Design and Preparation of a Joint for Production Welding | Bevel, alignment/hi-lo, lineup clamps, weather, cleaning |
| 8 | Inspection and Testing of Production Welds | Rights of inspection, methods, who may examine |
| 9 | Acceptance Standards for Nondestructive Testing | The pass/fail limits for every indication |
| 10 | Repair and Removal of Weld Defects | Repair authorization, removal, re-examination |
| 11 | Procedures for Nondestructive Testing | RT/UT/MT/PT procedure and technique requirements |
Numbering trap: candidates routinely put acceptance standards in Section 8. Section 8 governs who inspects and by what method; Section 9 holds the acceptance criteria. All nine of these sections (3 through 11) are in scope — in-service welding lives in an annex, not in Section 11.
Key Takeaways Recap
- The WPS must be present at the weld station and supported by a PQR; essential variables must cover the joint.
- Welders must be qualified per API 1104 for the process/position/diameter/grade, with records on site.
- API 1104 22nd Ed. (Jul 2021, Errata 1 Sep 2023) §3–11 is the testable scope; CSA Z662:23 is the Canadian parallel.
- If any essential variable of the joint is outside the WPS or welder range, place a HOLD.
What document must be present at the weld station and supported by a PQR before production welding begins?
Which edition and errata of API 1104 is the current governing welding code referenced in the API 1169 Body of Knowledge?
A welder qualified for 5G on X52 pipe is assigned to a 6G X70 production tie-in weld. What is the correct inspector action?
A production joint's wall thickness falls outside the range qualified in the PQR. What does this essential-variable change require?