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AM processes, personnel and non-destructive testing

Question 4 of the AM route. The category is settled and the material route is known — then comes the question of who may build, with what, and how you show that what comes out is free of defects. This is the second big underestimation after the material: the testing.

PED-CheckGuide › AM processes and qualification

At a glance

Which AM process you use changes the legal question

Most of what is written about the PED and additive manufacturing tacitly concerns WAAM. That is not harmless: of the three process families, WAAM is the only one in which the part is unmistakably deposited weld metal. For a powder bed process or binder jetting that argument largely falls away, and your route then looks different.

Melting with feed wireDED-arc (WAAM)DED-LB with wireThe part is deposited weld metalpoint 3.1.2 strongestMelting from a powder bedPBF-LB (laser)PBF-EB (electron beam)A melting process, but no jointbetween partspoint 3.1.2 arguableWithout meltingBinder jetting + sinteringcold sprayA forming process, closer topowder metallurgypoint 3.1.2 weakestWhat stays the same for every AM processthe PED category does not change, and without a harmonised AM standard the material runs through a PMA
ProcessFeedstockWhat that does legallyOperator qualification
DED-arc
(WAAM)
Welding wire — a welding consumable within the meaning of Guideline G-10The part is entirely deposited weld metal. Point 3.1.2 on permanent joining is most obviously engaged here, and the wire trap below applies in fullISO/ASTM 52926-5
DED-LB
(laser, wire or powder)
Wire or powderThe same reasoning as DED-arc where wire is used. With powder the feedstock is not a welding consumable, but the result is still fused metalISO/ASTM 52926-4
PBF-LB
(laser powder bed)
Metal powderA melting process, but no two parts are joined. Point 3.1.2 is arguable and defensible, yet less self-evident; the guidelines on welding consumables do not applyISO/ASTM 52926-2
PBF-EB
(electron beam powder bed)
Metal powderAs PBF-LB. Note in addition the vacuum environment and the higher build temperature: those belong to the process window and therefore to the material dataISO/ASTM 52926-3
Binder jetting
+ debinding and sintering
Metal powder with a binderNot a melting process. This sits closer to powder metallurgy than to welding; point 3.1.2 is hardest to sustain here. Sintering shrinkage is a control question of its ownno dedicated part in the 52926 series
Cold sprayMetal powderA solid-state process without melting, usually building up on an existing part. Almost always a repair discussion, not a new-build discussionno dedicated part in the 52926 series
Why this matters. Everything on this page about the category, the material route and the file applies to each of these processes. Everything below about point 3.1.2 and about welding consumables is process-dependent. Assess a PBF part with WAAM reasoning and you defend more than you need to; do it the other way round and you defend too little.
References: ISO/ASTM 52926 series, “Additive manufacturing of metals — Qualification principles”, part 2 (PBF-LB), part 3 (PBF-EB), part 4 (DED-LB) and part 5 (DED-Arc), all 2023; PED Guidelines G-10 and G-12 (welding consumables); Annex I point 3.1.2. The grouping into process families and the consequence drawn per family are my reading, not the directive's.

Question 4: process, personnel and NDT

Does point 3.1.2 apply to the whole part?

Annex I point 3.1.2 requires permanent joints and the adjacent zones to be free from surface and internal defects, and requires both the joining procedures and the personnel to be approved. In WAAM the entire part is deposited weld metal. There is then no joint you can point at — there is only joint.

My reading: point 3.1.2 then applies to the whole part. That is the conservative and defensible reading, and it is the reading that will not get you into an argument with a notified body. It is expressly not legal text and not a guideline — the Working Group Pressure has not pronounced on this. Support for the direction comes from Guideline F-05: points 3.1.2 and 3.1.3 apply to permanent joints other than welded ones as well, including brazing, expansion, gluing and riveting. The criterion is the definition in Article 2(13), not the process.

There is no harmonised standard — and the directive has an answer for that

This is the part systematically skipped in AM discussions. PED Guideline F-06 describes exactly what you do when no harmonised standard exists for the approval of personnel carrying out permanent joining: the manufacturer refers to an existing document — a draft standard candidate for harmonisation, a professional document, a guide, a document from a recognised third-party organisation or notified body, or a company document — or draws up a specific document himself. That document must define at least four things:

For DED-arc that fits without strain: ISO/ASTM 52926-5:2023 deals specifically with the qualification of operators for DED-arc and is precisely the "existing document" F-06 has in mind. The degree of automatisation is not mentioned by accident — in WAAM the difference between an operator who adjusts a path plan and an operator who presses start is a difference in range of validity.

On the procedure side the counterpart is a build process qualification instead of a WPQR for a single joint: the same principle, but the range of validity is expressed in build parameters and build directions rather than in plate thickness and welding positions.

From category II the approval of procedures and personnel must come from a notified body or a recognised third-party organisation; from category III that also applies to the personnel carrying out non-destructive testing (point 3.1.3), and that approval can come only from a third-party organisation recognised by a member state.

References: Annex I point 3.1.2 (permanent joining: procedures and personnel) and point 3.1.3 (NDT personnel); Art. 2(13) (definition of permanent joint); Art. 20 (notification and recognition); PED Guidelines F-05 and F-06; ISO/ASTM 52926-5:2023, "Additive manufacturing of metals — Qualification principles — Part 5: Qualification of operators for DED-Arc".

NDT is the underestimated cost

Experience, not legal text. What follows comes from practice, not from the directive. It is, however, the point at which AM projects most often run over budget in my experience.

Frequently asked questions

Does point 3.1.2 on permanent joining apply to a fully printed part?

That is a question of interpretation; the Working Group Pressure has issued no guideline on it. My reading is that point 3.1.2 applies to the whole part, because in WAAM it consists entirely of deposited weld metal. Support for that direction comes from Guideline F-05, under which points 3.1.2 and 3.1.3 apply to non-welded permanent joints such as brazing, expansion and gluing as well: the criterion is the definition in Article 2(13), not the process.

Do I have to qualify my operators when no harmonised standard exists?

Yes. Annex I point 3.1.2 requires approval of both the procedures and the personnel for permanent joining, whether or not a standard exists for it. PED Guideline F-06 sets out what to do when it does not: you refer to an existing document or draw up a specific one yourself, covering at least the equipment, the degree of automation, the test-piece conditions and the range of validity. For DED-arc, ISO/ASTM 52926-5:2023 is such an existing document. From category II that approval must come from a notified body or a recognised third-party organisation.

Do you already know your category?

The qualification requirements hang off the category: from II a notified body or recognised third-party organisation, from III also for the NDT personnel. The free check gives you the category in a minute.

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Further reading