Certified welding and DS/EN-ISO 9606

In many industries, welding on load-bearing or pressure-bearing structures may only be performed by certified welders. The certification documents that the welder masters a particular welding method on a particular type of joint and material.

The standard DS/EN ISO 9606-1 deals with the qualification of welders for fusion welding of steel. It describes how a welding test is carried out and assessed, and which parameters the certification applies to — for example process, material group, material thickness, pipe or plate material and welding position. The other parts cover aluminium (-2), copper (-3), nickel (-4) and titanium and zirconium (-5). ISO is working on combining the five parts into one standard. As of October 2026 it is still a draft (ISO/DIS 9606, stage 40.60 at ISO), and it does not apply yet.

• 01Welding method (e.g. TIG, MAG, manual arc)
• 02Material type and group
• 03Joint type: plate or tube
• 04Welding position

To become certified, you weld a test piece under controlled conditions. The piece is typically assessed both visually and by non-destructive testing, and depending on requirements also by destructive testing, where the piece is cut up and examined.

The certificate is valid from the day the test was welded. Every 6 months, the person responsible for the welding work (or the examiner or the certification body) must confirm that you have welded within the certificate's range. Otherwise it lapses. When the certificate is issued, one of three routes for extending it is chosen:

• 01a) A new test every 3 years
• 02b) Extension every 2 years if two of your welds from the last 6 months have been tested: butt welds by radiography, ultrasound or a destructive test, fillet welds by fracture test or macro examination
• 03c) No end date, as long as you work for the same company and it has a quality system according to ISO 3834-2 or ISO 3834-3

The route is stated on the certificate. If you change route later, it requires a new test. The rules are quoted from a public working draft of the new ISO 9606 (June 2024). The current DS/EN ISO 9606-1:2017 is a paid standard that we have not read ourselves.

At AMU SYD the certificate is valid for 3 years after issue. It is stored digitally on svejsepas.dk and in the Svejsepas app, where you can ask for a reminder when it needs to be renewed.

The draft of the new ISO 9606 uses new group names, e.g. FE1-FE5 for steel and AL1-AL5 for aluminium. It does not apply yet, but you will meet the names when the standard is adopted.

Pressure equipment

For pressure equipment in categories II, III and IV, the welding procedures and the personnel who weld must be approved by a competent third party (Pressure Equipment Directive, Annex I point 3.1.2). For equipment in categories III and IV, the same applies to the personnel carrying out non-destructive testing (point 3.1.3).

Certification is about safety and quality. On structures that must bear load or contain pressure an incorrect weld can have serious consequences. The certification is documentation to customers and authorities that the work is performed by a qualified person.