Welder qualification and procedure qualification are not the same thing

Two completely different things get called a welding qualification. One qualifies a person. One qualifies a method. Confusing them is the most common reason welding documentation gets rejected on an Australian job, and it costs real money because it is usually discovered after the welding is finished.

The two documents

Strip everything else away and there are two separate questions a client needs answered before they accept a weld.

Question one: is this method capable of producing a sound weld? That is answered by qualifying the welding procedure. Somebody welds a test coupon under controlled, recorded conditions. The coupon is examined and then destroyed: bent, pulled, sectioned, hardness tested, impact tested depending on the requirement. If it passes, you hold a welding procedure qualification record, and that record defines the range of production welding the procedure covers.

Question two: can this particular person execute that method? That is answered by qualifying, or certifying, the welder. A named individual welds a test piece, it is examined and tested, and if it passes, that person holds a qualification covering a defined range of process, material, position and thickness.

Two questions, two documents, two pieces of evidence. Holding one tells you nothing about the other.

Why both are needed

A qualified procedure with an unqualified welder is a good recipe handed to somebody who has never cooked. A qualified welder with an unqualified procedure is a good cook told to improvise on something structural.

The second case is the one people underrate, because a skilled welder producing a visually excellent weld feels like a safe outcome. It is not, and the reason is metallurgical rather than a matter of skill. Heat input, preheat, interpass temperature, consumable selection and post weld heat treatment change the properties of the joint in ways nobody can see. A perfect looking weld made with the wrong preheat on the wrong material can crack days later. The procedure exists to control the things the welder cannot judge by eye.

How this goes wrong on a job

The sequence is almost always the same.

1. The specification says welders shall be certified to AS 1796, and separately requires qualified welding procedures.
2. The fabricator collects welder certificates, because those are easy to collect and everybody understands them.
3. Welding proceeds. The welds look fine, because the welders are good.
4. At the documentation review, the client asks for the welding procedure qualification records that support the welding procedure specifications the welders were working to.
5. There are welding procedure specifications, and behind them there is nothing. Or there is a qualification record that does not cover the thickness, the material grade or the position that was actually welded.

At that point the options are all expensive. Qualify the procedure retrospectively and argue that production work fell inside it. Cut out and replace. Or negotiate a concession, which means the client now owns a documented deviation on your job and will remember it at the next tender.

The reverse failure happens too, and is faster to spot: excellent procedure documentation, and a welder whose certificate covers plate when the work was 3 mm wall pipe.

Range is where both fail quietly

Both documents look like permissions and behave like boundaries. Each one covers a defined range and says nothing outside it.

For a welder, the range typically covers the welding process, the material group, the product form of plate or pipe, the joint type, the welding position, the thickness band and, for pipe, the diameter band. A certificate covering manual metal arc welding on alloy steel pipe in one position range does not cover gas tungsten arc welding on stainless plate, and it is not intended to.

For a procedure, the range comes from the essential variables recorded in the qualification: parent material group, process, consumable classification, thickness, diameter, position, heat input limits, preheat and interpass temperature, and whether post weld heat treatment was applied. Change one beyond its permitted limit and you are outside the qualification.

The practical discipline is unglamorous and it works. Before anybody strikes an arc, put three things side by side: the joints on the drawing, the range on the procedure qualification record, and the range on each welder’s certificate. Every production joint has to sit inside both ranges. Doing that takes an hour. Discovering a gap afterwards takes weeks.

The document set on a job

Six documents, six different claims. A complete set answers every question a client can reasonably ask. A partial set invites the question you least want.

Where each standard family sits

• Structural steel. AS/NZS 1554 allows prequalified welding procedures inside defined limits, so a great deal of routine structural work never needs a procedure test at all. You still have to write the procedure and be able to show that it sits inside the prequalified conditions. Welder qualification is a separate requirement, and AS 1796 certification is the usual Australian evidence.
• Pressure equipment. AS 1210 and AS 4041 both point to the pressure equipment welding qualification standard for procedures and welders alike. There is no prequalification shortcut of the structural kind.
• International specifications. ISO 15614 qualifies the procedure and ISO 9606 qualifies the welder. Same split, different rules and different ranges.
• Company level. AS/NZS ISO 3834 does not qualify either one. It requires that both exist, that the records are controlled, and that somebody competent is coordinating the lot.

A procedure or a welder qualified under one of these families is not automatically acceptable under another. On projects with mixed requirements, get the acceptance position agreed in writing before fabrication starts.

A checklist worth pinning up

1. Which standard governs the welding on this job? Name it, with the part number.
2. Is every production joint covered by a welding procedure specification?
3. Does every welding procedure specification trace back to a qualification record, or to a documented prequalification?
4. Does the range on that record cover the material grade, thickness, diameter and position actually being welded?
5. Does every welder hold a current qualification covering the joints they are being given?
6. Is each welder’s qualification still valid, with the continuity evidence to show it?
7. Does the material in the rack match what the procedure was qualified on?
8. Is there a named, competent person coordinating all of the above?

If you cannot answer all eight before welding starts, the gap is already there. It is only a question of who finds it and when.