Can an engineer of record (EOR) or owner supply a WPS to the fabricator?

Yes. Nothing in AWS D1.1 prohibits an owner from providing welding procedures. However, the code places the obligation to produce acceptable welds on the contractor/fabricator. Using an owner-supplied WPS does not relieve the fabricator of that obligation.

If we use an owner-supplied WPS and a weld fails, who is liable?

This is a contract law question, not a code question. AWS D1.1 makes the contractor responsible for weld quality regardless of WPS source. Contractual indemnification provisions may shift some risk, but a fabricator cannot escape production responsibility by pointing to a client-furnished document.

What should we check before accepting an owner-supplied WPS?

Verify it is complete per AWS D1.1 Annex M, that it covers the joint configurations you will actually weld, that the PQR (if tested) has been properly qualified, and that the supporting test records are available. A WPS with no traceable PQR or no valid prequalification basis is not a valid WPS.

Can we modify an owner-supplied WPS?

Only with the owner's approval and proper re-authorization. Unilateral changes to a furnished procedure — even small ones — create a new document that the original review and signature no longer cover. Always get written approval before modifying a client-furnished WPS.

Owner-Supplied WPS vs Fabricator-Developed: Who Owns Responsibility?

When an owner or EOR furnishes welding procedures, who is responsible if a weld fails? AWS D1.1:2025 is clear — and most fabricators get this wrong.

Owner-supplied welding procedures are more common than fabricators realize. An EPC contractor furnishes a package of standardized WPS documents for all subs. An owner's welding engineer has already qualified procedures and wants them used across multiple shops. A structural engineer of record (EOR) attached a WPS to the project specification.

Each scenario raises the same question: when the client hands you the procedure, who is responsible if the weld does not meet the acceptance criteria?

The answer under AWS D1.1:2025 is unambiguous, and most fabricators misread it.

What AWS D1.1:2025 Actually Says

AWS D1.1 places fabrication and weld quality responsibility squarely on the contractor. The standard is structured as a document between the owner (who sets requirements) and the contractor (who performs the work). The contractor's obligation is to produce welds that conform to the WPS and to the code — regardless of who authored the WPS.

This means that accepting a client-furnished WPS is not a risk transfer. The fabricator remains responsible for:

Welding to the parameter ranges specified in the WPS (amperage, voltage, travel speed, preheat, interpass limits)
Assigning only qualified welders per the process and position
Performing required NDE at the specified sampling rates
Ensuring the WPS actually covers the joint configurations being welded

If you execute a client-supplied WPS and a weld fails a bend test or fails UT acceptance, the weld failure is yours. The CWI must determine whether the weld was made to the WPS and whether the WPS was adequate for the joint. Both failures land on the contractor.

The Hidden Risk: An Inadequate WPS You Did Not Write

The real danger in a client-furnished WPS is that the fabricator has no visibility into whether it was properly developed. A complete, valid WPS under AWS D1.1 either:

Is written to the prequalified conditions of Clause 5 — in which case you can verify it by comparing the document to the code requirements, or
Is supported by a Procedure Qualification Record (PQR) from a test conducted per Clause 6 — in which case the PQR test records must be available and traceable.

A WPS without a valid basis is not a WPS in any meaningful sense. It is a document that looks like a WPS.

Before accepting an owner-supplied WPS into your quality system, your CWI should perform a document review. At minimum:

Check the prequalification basis. If the WPS claims prequalified status, walk through AWS D1.1 Clause 5. Is the base metal on the prequalified list? Does the joint geometry conform to Annex B? Is the filler metal an approved classification per Table 5.2? Does preheat meet Table 5.3? Are the pass parameters within Clause 5 limits? One failure on any of these means the WPS is not prequalified and must be supported by a PQR.

Request the PQR. If the WPS is tested (Clause 6), ask for the PQR. Verify the test was conducted per the essential variable requirements of AWS D1.1:2025 Table 6.6. Check that the test thicknesses, positions, and base metal groupings cover the production joints you are about to weld. For CVN requirements, confirm Table 6.8 supplementary essential variables were captured if demand-critical welds are involved. See AWS D1.1 Table 6.6 essential variables explained for a full rundown of what must be documented in the PQR.

Confirm joint configuration coverage. Run the owner-supplied WPS through the same gap analysis you would run on your own library. Does it cover every joint type on the project drawings? What if the drawings show fillet welds in the overhead position (4F) and the WPS was only tested flat (1F)? The fabricator executing that joint without a qualified position is producing an unqualified weld — even if the WPS number came from the client.

For a broader discussion of who is responsible for what at each stage, see WPS responsibility: fabricator, contractor, and EOR roles.

What Your QC Documentation Should Show

Once you accept a client-furnished WPS, it becomes part of your quality system. Treat it exactly as you would treat a WPS you developed.

Your project quality file should show:

Receipt of the owner-supplied WPS (document log entry, revision and date)
Your internal review sign-off by the CWI or QC manager, with noted findings
Resolution of any coverage gaps (additional WPS written for uncovered joint types, or written agreement with the owner on the scope of the furnished procedures)
Pre-job briefing records showing welders were given the WPS and understood its requirements
Production parameter log entries showing welding was performed within the WPS ranges

If a third-party auditor or the owner's inspection team asks to trace a weld back to a procedure, you must be able to show: this joint was welded under WPS-042 Rev 2 (owner-furnished), which covers this process, position, thickness, and base metal. See weld map and WPS traceability in production for how that traceability chain should be built.

When to Push Back on a Client-Furnished WPS

There are situations where a fabricator should refuse an owner-furnished WPS or escalate before accepting it:

It has no valid basis. If the WPS claims prequalification but does not meet Clause 5, and no PQR is produced, you cannot validate it. Using an invalid WPS is not the owner's problem to solve after the fact — it is your weld.

It does not cover your joints. If the furnished WPS qualifies only the flat and horizontal positions and your shop will weld vertical connections in the field, the procedure does not cover your scope. Either obtain an amended WPS from the owner or write supplemental procedures for the uncovered positions.

It specifies equipment or consumables you do not have. A WPS specifying a particular shielding gas blend (e.g., 75Ar/25CO2) is not covered if your shop uses 90Ar/10CO2. Under AWS D1.1:2025 Table 6.6, shielding gas composition is an essential variable for GMAW and FCAW-G. Proceeding with the wrong gas means welding out of the WPS range — a production nonconformance.

The signature authority is wrong. AWS D1.1 specifies who may sign a WPS — it must be a responsible welding engineer, a CWI, or other qualified personnel as defined by the governing contract. A WPS signed by a project manager or field superintendent with no welding credentials has a documentation problem that may surface in audit.

For a full discussion of who holds signing authority under the code, see who can sign a WPS: CWI and engineer requirements.

Contractual Protections

While AWS D1.1 assigns weld quality responsibility to the contractor, contracts can — and often do — shift risk for procedure adequacy. If an owner furnishes WPS documents as part of a contract, a well-drafted indemnification clause may protect the fabricator from liability if the procedure itself is the root cause of a defect (as opposed to the fabricator failing to follow it).

This is a contract review matter, not a code matter. Review furnished WPS packages with your QC manager and legal counsel before accepting scope on projects where client-furnished procedures represent a significant portion of the work.

The practical takeaway: if you are working under a client-furnished WPS, confirm it is valid, document your verification, and execute it exactly as written. If you have questions about whether your WPS library covers your project scope or if you need tools to manage procedure documents across multiple projects, WPS Welding's platform keeps everything in one place, whether procedures are self-developed or client-furnished.

Rule library based on AWS D1.1:2025; verify against your governing edition (the AHJ or contract may specify 2020 or earlier).