Coded Welders: What to Check Before You Hire One

A coded welder is one who holds a current qualification certificate for the process, material, thickness and position of the job, issued after a test to a recognised standard. In the UK that is usually BS EN ISO 9606-1 for steels, or part 2 for aluminium. In Spain the same European standard is cited as UNE-EN ISO 9606-1, so the idea carries across. What goes wrong is the detail: a welder is coded for something, never for “welding” in general. This article sets out what to check before a welder starts on your plant in Spain or Portugal.

What “coded” means

The qualification belongs to the welder, not to the company. The welder makes a test piece, an examiner or examining body witnesses it, and the weld is examined to the requirements of the standard. If it passes, the welder gets a certificate for a stated range of work.

That is different from qualifying a welding procedure. The welding procedure specification (WPS) and its qualification record (WPQR) cover the method. The welder certificate covers the person. A company certificate such as EN ISO 3834 covers how the company manages its welding. You may need all three, and none replaces another. Our welding certification page explains what each one covers.

A certificate covers a range

Read the certificate against the job, line by line. The main variables are:

• Process. Certificates name it by its ISO 4063 number: 141 is TIG, 135 is MAG and 111 is manual metal arc.
• Plate or pipe, and whether the joint is a butt weld or a fillet weld.
• Parent material group. EN ISO 9606-1 covers steels, with carbon and stainless steel in separate groups. Aluminium is EN ISO 9606-2 and titanium ISO 9606-5, so check the certificate is the right part.
• Filler material.
• Thickness, and the outside diameter for pipe.
• Position, for example a pipe fixed in place that has to be welded from every angle.
• Joint details, such as welding from one side with or without backing.

A welder tested with TIG on thin stainless pipe is not qualified for MAG on thick carbon steel plate, however good the welder is. That is why many welders hold several certificates.

How long a certificate lasts

Under EN ISO 9606-1 a certificate has to be revalidated, usually every two or three years depending on the route the employer uses. In every case the employer or welding coordinator confirms every six months that the welder has kept welding within the range it covers. Look for those confirmations. They should be signed and dated, and a gap in them is worth a question. If the welder has not been welding in the range for six months or more, the qualification may no longer stand, so ask when they last welded this type of joint.

After three years the certificate has to be renewed, or the welder re-tested.

Who issued it

The test is witnessed by an examiner or examining body. Ask who it was and whether your project accepts them. Some jobs only take certificates from a body that is independent of the welder’s employer, and for pressure equipment and CE-marked structural steelwork the rules are stricter. Ask your inspection body what it requires before you shortlist anyone.

Certificates from Spain or Portugal may not be in English. Ask early for the key fields, that is the process, material, thickness, position and dates, to be listed in a form your inspector can read.

Six checks before a welder starts

1. The certificate is in the welder’s name, with an issue date and the six-monthly confirmations.
2. The range matches your job. Compare each variable with the WPS or the drawing.
3. The standard matches your specification. If your specification names ASME IX, say so in your first message. A European certificate does not automatically satisfy it.
4. The examiner or body is one your inspector accepts.
5. The site requirements are covered. In Spain, many metal-sector sites ask for occupational risk prevention training, often shown through the Tarjeta Profesional del Metal (TPM). Ask your site what it expects and give the contractor notice.
6. Recent experience on this kind of joint. A certificate shows the welder passed a test. It does not show speed or neatness on your job. If the range is borderline, agree a trial weld on your own material first.

Plan for the narrow certificates

Welders with a narrow range cannot be swapped at the last minute. If the job needs, for example, stainless pipework welded in a fixed position, say so in the first message and allow time. The same applies to a job that asks for a particular standard.

What to send us

Send the process, material, thickness range, position and the standard that applies, and we will tell you what we can supply. Tell us about the job. You can also read about our welding contractors service.