Coded Welder (EN ISO 9606)

You are given a test piece to prepare and weld, usually to a qualified welding procedure, under supervision. The assembly is then examined visually and sectioned or bent for destructive testing. Some schemes add a written or oral assessment. The sequence, materials and positions are set by the examining body, not chosen by you.

It depends on the certification scheme. EN ISO 9606 is fundamentally a practical standard, but many examining bodies and employer schemes add a theoretical or oral assessment covering process knowledge, consumables, defects and safety. Confirm with your examining body whether theory forms part of your assessment.

Validity periods and the conditions for confirmation are set by the standard and, in detail, by the certification scheme and employer quality system. Rather than relying on a remembered number, check the current requirements with your examining or certifying body, and diarise the confirmation dates so the qualification does not lapse.

Failed pieces are usually reported with the specific defects found, and retake arrangements, waiting periods and any additional training requirements are set by the examining body. Ask for the defect report - it tells you precisely which variable to fix, whether root fusion, penetration, profile or stop/start technique.

Test in the position you actually weld in production, because the qualification range extends from the position tested in defined ways. Testing in a more difficult position broadens your range but raises the risk of failure. Discuss the intended production positions with your employer before booking.

Thickness qualification follows the essential variable rules of the standard, and a test piece above a certain thickness typically covers a range below it, with limits on the minimum. The exact ranges depend on the process and joint, so read the relevant table in the standard and confirm your intended production thickness before choosing a test piece.

Start with the essential variables you need covered, then choose the process, position and joint that give that range. Practise the exact configuration repeatedly, including root and capping, and have someone inspect your practice pieces against the acceptance criteria. Leave administrative booking and documentation until the welding is repeatable.

Lack of root fusion and incomplete penetration, porosity from poor gas coverage or contaminated material, slag inclusions in multi-pass work, and poor stop/start or cap profile. Preparation errors - wrong gap, root face or fit-up, or dirty plate - cause many failures before the arc is even struck.

Only within the procedure and the examiner's instructions. Parameters such as current range, consumable, preparation and position are part of what is being assessed. Deviating from the qualified procedure can invalidate the test even if the weld looks acceptable.

Those are administrative details that change and are specific to each certifying body and country. The official body responsible for your scheme publishes current fees, schedules and requirements on its website - check there rather than relying on second-hand information.