What is a coded welder?
A coded welder is a welder who has passed a practical test to a recognised welding standard, on a named process, material, thickness and welding position. The resulting certificate covers that range of work and nothing outside it. So the useful question is never "are your welders coded?" It is which code, and what range the certificate covers.
What does coded welding actually mean?
“Coded” means tested and certified against a published welding standard, not simply experienced. A welder welds a test piece under controlled conditions. An independent examiner then checks that test piece visually, and usually by destructive or non-destructive testing as well. If it passes, the welder receives a certificate recording exactly what was tested.
Most buyers read more into the word than it holds. It is neither a rank nor a general licence. A time-served welder with thirty years on the tools is not coded unless they have sat the test, and a welder who passed a test on thin-wall stainless pipe is not thereby qualified to weld heavy carbon steel structural sections.
Which welding codes will you see in South Africa?
Two families of standard cover most industrial work in South Africa: the ISO 9606 series and the ASME Boiler and Pressure Vessel Code. Which one applies is usually decided by the plant, the insurer or the equipment being worked on, not by the fabricator.
ISO 9606-1 is titled Qualification testing of welders: Fusion welding, Part 1: Steels, and covers manual and partly mechanised welding of steels. ISO's own technical committee has confirmed the 2012 edition is under revision, so if you are writing it into a specification, check which edition your plant requires. ASME Section IX is the equivalent most often encountered on pressure equipment.
Locally, the Southern African Institute of Welding is the reference point. SAIW is an Authorised National Body of the International Institute of Welding, certifies companies to ISO 3834, and runs an accredited laboratory that does the mechanical and non-destructive testing behind welder and procedure qualification.
What is the difference between a WPS, a PQR and a welder's certificate?
Three separate documents do three separate jobs, and having one does not give you the others. This is where most misunderstandings on site start: a contractor produces one document when the specification asked for another.
| Document | What it is | What it proves |
|---|---|---|
| WPS Welding Procedure Specification |
The written recipe for a weld: process, consumable, joint preparation, position, heat input and the rest. | That a method exists and has been written down, so the same weld can be repeated. |
| PQR Procedure Qualification Record |
The record of a test weld made to that procedure, and the test results from it. | That the method itself produces a sound weld. It qualifies the procedure, not a person. |
| Welder certificate Welder qualification test |
A named individual's test result, recording the range they were tested across. | That this particular person can work to that procedure. It qualifies a person, not a method. |
The ranges on a WPS and on a welder's certificate are set separately and are often different. A procedure qualified across one thickness band does not stretch because the welder happens to be certified more widely, and the reverse is equally true.
What does a welder's certificate actually cover?
A welder's certificate records a range, not a blanket permission. Read it and you will find the specific conditions the test was carried out under, together with the span of work the result extends to.
The variables that normally appear on the certificate include:
- Welding process: TIG, MIG, manual arc and so on, each tested separately.
- Material group: a certificate on stainless does not automatically cover carbon steel.
- Product type: plate or pipe, which behave differently and are tested differently.
- Thickness and diameter range: expressed as a band either side of the test piece.
- Welding position: a test welded flat proves very little about overhead work.
- Joint and weld type: butt or fillet, and whether it was welded from one side or both.
Certificates also run for a limited period and have to be kept current. How long, and what is required to maintain them, depends on the standard and the edition in force, so treat the date on the certificate as something to check rather than something to assume.
Why does any of this matter on a plant?
On production plant, the cost of a failed weld is almost never the weld itself. It is the line that stops, the batch that is scrapped, the permit that has to be reissued and the shutdown window that closes before the work is finished.
That is why certification matters. It does not make a weld good on its own: a certificate is evidence that someone was tested, not a guarantee of what they did on your site last Tuesday. But it moves the conversation from a claim to a document, and it means the person who signs off the work has something to point at.
What should you ask a fabricator for?
Ask for the certificates that apply to your job, and read the ranges against your scope. A fabricator who works to code will have them to hand and will not be troubled by the question. One who cannot produce them, or who answers the question with how many years they have been trading, has told you something useful.
Worth asking, in this order:
- Which code applies here, and is that the code my plant or insurer requires?
- Can I see the certificates for the welders who will actually be on my site?
- Do the ranges on those certificates cover my material, thickness and position?
- Is there a WPS for this joint, and has it been qualified?
- Are the certificates current?
If the answer to any of these is no, that is not automatically a reason to walk away. Plenty of good general fabrication does not need coded work at all. It is a reason to be clear about which category your job falls into before anyone strikes an arc.
Austek Engineering works with coded welders on stainless and carbon steel, for process pipework, hygienic plant installation, boilermaking and structural work across Gauteng. Which certificates apply depends on the job and the code your plant works to. Ask us for the ones relevant to your scope and we will send them with the quote.
Related reading
If you are specifying stainless for a process line, the companion question is usually which grade to use. See 304 vs 316 stainless: how to choose for plant work. If the work is going into a planned outage, see how to prepare for a plant shutdown. Shorter answers to common questions are on the frequently asked questions page.
Sources
- ISO/TC 44 (Welding and allied processes), ISO 9606-1:2012, Qualification testing of welders: Fusion welding, Part 1: Steels (revision under preparation). committee.iso.org, checked 23 September 2026.
- Southern African Institute of Welding, SAIW Certification. saiw.co.za, checked 23 September 2026.