At a glance
- Additive manufacturing does not change your category. Annex II contains no process parameter — what changes is the burden of proof within the category, not the category itself.
- A repair — replacing a part inside equipment already in service — is not covered by the PED but by national law (Guideline A-03, point 2); replacing the whole item with a new one is covered by the PED (point 1). In the Netherlands the repair route runs through Article 26 of the WBDA 2016, for equipment subject to inspection under Article 21(1). That is a considerably lighter route than most customers fear.
- No AM standard is harmonised under the PED. Without a presumption of conformity the material route runs unavoidably through a particular material appraisal (Annex I point 4.2(b), third indent) or a European approval for materials (Art. 15).
- The underestimated cost is not the printing but the NDT: an as-built surface is poorly suited to ultrasonic testing, and critical surfaces are machined in practice to make them inspectable.
The AM route across four pages — what is where
This guide is split over four pages, in the order in which the questions arise in a project. Starting from scratch, work through them top to bottom. Looking for one answer, go straight in.
- This page — why, which method, which regime. The route wizard · why additive, and what it costs · which AM method suits pressure equipment · what “may I print this” actually consists of · question 1: new product or replacement · question 2: does AM change the category · question 3: the material, in brief
- Material and PMA — question 3 in full. Which of the three material routes applies, what belongs in a particular material appraisal, test directions and anisotropy, the material manufacturer's quality system, and whether your DNV or API qualification counts.
- Processes, personnel and NDT — question 4. Which process family you use and what that changes legally, point 3.1.2 on a fully printed part, qualification without a harmonised standard under Guideline F-06, and non-destructive testing.
- Technical file and sector frameworks. What the notified body wants to see on the table, and how DNV-ST-B203, API 20S and the ISO/ASTM 52926 series relate to the PED.
Two in-depth pages sit alongside that route, for anyone looking beyond one project: European approval for materials and your PMA library — material evidence you reuse · Standards in development — EN 13445-14 and what harmonisation takes.
Then: the feasibility check — your part put through the same route, with the outcome on paper.
What do I have to do to have this part made additively?
Six choices. The outcome is your complete route: which regime applies, how you demonstrate the material, what qualification and NDT you need, and which documents belong in the file. Free, and you leave nothing behind.
Why have a part made additively?
Rarely because it is cheaper. Per kilogram of deposited metal, additive manufacturing costs more than plate, pipe or a casting from an existing mould — and that will not change in the next few years. AM wins on three other axes: lead time, geometry and availability. Anyone who starts by comparing cost per kilogram always ends up at “better not”, and so misses the cases where it is the cheapest solution in the whole project.
When additive is the better choice
- The original is no longer available. A casting whose mould is gone, an accessory from a manufacturer that no longer exists, a part with a twenty-week lead time while the plant stands still. Here the comparison is not “print or cast” but “print or stand still”.
- One part, or a handful. No mould, no pattern, no minimum order. Below roughly ten pieces tooling seldom pays for itself; above a hundred, conventional almost always wins.
- The shape cannot be made any other way. Internal channels a drill cannot reach, wall thicknesses that follow the load, a transition piece between two flange sizes in one body.
- Fewer joints. An assembly of six welded parts becomes one built part. That removes joints, and a joint that does not exist need not be qualified, examined and assessed (Annex I point 3.1.2). Under the PED this is the argument that pays back fastest.
- Expensive material. With nickel alloys, duplex or titanium the ratio between bought and remaining material weighs heavily; machining from solid throws most of it away.
- Repair and build-up. Rebuilding worn surfaces on an existing part is a standard DED application — but note: repair of equipment in service falls under national law, not the PED (see question 1).
What it gives you
- weeks instead of months, with no tooling cost
- freedom of shape and consolidation of parts: fewer joints, fewer leak paths
- material only where it carries load
- a digital inventory: the file sits on the shelf, not the part
- local production, a short chain
What it costs you
- no harmonised standard, so a particular material appraisal per material and process window
- anisotropy: properties perpendicular to the layers differ
- residual stress and distortion; usually a heat treatment afterwards
- an as-built surface is rougher; how much depends on process and parameters — critical faces are often machined to make them ultrasonically inspectable
- qualification of the procedure and the personnel, from category II by a body
- traceability to batch and build, not merely to the delivery note
When not to do it
A plain cylindrical shell from plate, a standard flange from stock, a batch of a thousand: there additive manufacturing is more expensive, slower and harder to substantiate. And for a part that falls entirely within an existing harmonised standard, going additive trades a presumption of conformity for a burden of proof. Do that only when you get something in return.
Which AM method suits pressure equipment?
“3D printing” is not a process but a collection of processes with little in common. For pressure-bearing parts the field narrows in practice to two families: DED (material is melted as it is laid down) and PBF (a bed of powder is melted locally). The rest is an edge case.
| Method | How it works | Build rate | Size | What it comes down to for pressure equipment |
|---|---|---|---|---|
| DED-arc (WAAM) | arc welding with wire, layer on layer | high: order of 1–4 kg/h, more with high-deposition variants | metres; limited only by the robot | The one family in which the part is unmistakably deposited weld metal. Welding standards, welder qualification and NDT thinking map onto it well. Coarse build-up, so machine generously. |
| DED-LB, wire | laser melts fed wire | medium: order of 0.5–2 kg/h | large, machine dependent | Finer than DED-arc, lower heat input, more expensive equipment. The material evidence runs along the same route. |
| DED-LB, powder | laser melts blown powder | low to medium: order of 0.2–1 kg/h | large; also onto existing parts | Strong for build-up and repair on an existing surface. Powder efficiency is a loss item and re-use has to be substantiated. |
| PBF-LB | laser melts a powder bed | low: order of 0.05–0.3 kg/h | build chamber, in practice up to a few decimetres | Fine detail and internal channels, but size confines it to accessories and small pressure parts. Supports and powder trapped in channels are a risk of their own. |
| PBF-EB | electron beam in vacuum | low, slightly above PBF-LB | build chamber, small | Less residual stress thanks to the hot chamber, rougher surface, limited choice of materials. Rarely seen in pressure equipment. |
| Binder jetting with sintering | binder onto powder, then sintering | fast to print, slow to sinter | small to medium | Shrinkage of order 15–20 % and residual porosity make the strength case heavy going. For pressure-bearing work an exception. |
| Cold spray | particles bond in the solid state | high | large, onto an existing surface | No melt pool, so no weld metallurgy — but also limited toughness and bond strength. Coating and repair, not pressure-bearing structure. |
The rule of thumb: large, thick-walled, pressure-bearing parts go DED; small, fine parts go PBF. If your part sits in between, wall thickness decides — from a few millimetres upwards a powder bed is rarely the cheapest route.
What your choice changes legally — which qualification framework you can point to and what it means for NDT — is on Processes, personnel and NDT.
What "may I print this" actually consists of
Customers ask one question. It contains four, and they are almost always conflated:
- Is this a new product or a repair? This decides whether the PED applies at all.
- Does additive manufacturing change the category? No — and that helps less than you hope.
- How do you demonstrate the material? This is where the work is, and where projects stall.
- How do you qualify process, personnel and NDT? This is where the money is that nobody budgets.
Four words that get conflated
A directive, national regulations, guidelines and standards all appear on this page. They do not carry equal weight, and that difference decides how firmly you can make a statement. So, the hierarchy first:
The directive is the European law: Directive 2014/68/EU, the PED. Regulations here means the Dutch track for the in-service phase, the Pressure Equipment Decree and Regulation 2016. A guideline is something else: the interpretation the European Working Group “Pressure” gives at difficult points in the directive. That interpretation is not legally binding — the set says so itself — but notified bodies and market surveillance authorities follow it in practice, so you rarely win an argument by contradicting it. A standard, finally, is always voluntary; only a harmonised standard delivers the presumption of conformity.
Question 1: new product or replacement?
This is the most important split and the most frequently overlooked one. It decides whether you run a full conformity assessment or a considerably lighter route.
The Working Group Pressure answered this explicitly in PED Guideline A-03. Three situations, three outcomes:
| Situation | Regime | Consequence |
|---|---|---|
| The part is placed on the market as pressure equipment, an assembly or an accessory — or the entire item is replaced by a new one | Full conformity assessment under the PED | Category under Annex II, module under Art. 14, CE marking, notified body from category II |
| The part repairs or replaces a component of equipment already in service | Not the PED, but national law — in the Netherlands the WBDA 2016 | Article 26 WBDA, for equipment subject to inspection (Art. 21(1)): Annex I applies mutatis mutandis except for affixing the CE marking (paragraph 1); the user notifies the Dutch conformity assessment body or user inspectorate without delay (paragraph 2), and no new CE marking |
| The part brings a substantial modification that changes the original characteristics, purpose and/or type | Placing on the market anew: the PED, as a new product | Full route. Where the line lies is assessed case by case — the guideline says so in as many words |
Most "our casting is no longer available" questions fall in the second row. Your supplier will not tell you that, because he would rather sell you a new item. Your inspection body will not volunteer it either, because it only receives the question once the decision has been made.
Question 2: does additive manufacturing change the category?
No. Annex II classifies on equipment type, phase, fluid group and the figures PS and V or DN. There is no process parameter in it. An additively manufactured vessel of 11 bar and 500 litres holding compressed air lands in exactly the same category as the same vessel made from plate. You can verify that yourself with the free check.
That is the reassuring part. The difficult part is the sentence behind it: what changes is the burden of proof within that category. For a cast or rolled part you take a harmonised material standard and you are done with Annex I point 4.2. For an additively manufactured part that standard does not exist, and then the work described in the rest of this page begins.
Practical consequence: work out where you sit before you commit to an AM route. If you land in category I there is no notified body and no approval requirement for joining procedures — the route is far shorter than the literature suggests. If you land in III or IV, the specific assessment of the material by the notified body is unavoidable and it sets the lead time of your entire project.
Question 3: the material — in brief
This is the centre of gravity of the whole project and therefore has its own page. The short version: there is no harmonised AM material standard, so the presumption of conformity falls away and the route runs through a particular material appraisal (Annex I point 4.2(b), third indent) or, rarely, a European approval for materials (Article 15). From category III the notified body appraises that document separately (point 4.2(c)).
The four steps are worked out on Material and the particular material appraisal: which route, what you fix, how you test and who appraises.
AM–PED feasibility check — € 450 excl. VAT
The page above answers the general question. The question that costs money is the specific one: will this part pass, along which route, and what will the testing cost? That is what this is for.
What you get: a memo of four to six pages on one specific part, within five working days of receiving the data. Fixed price, no hourly billing afterwards.
- Regime determination — new on the market or replacement under Art. 26 WBDA, with the reasoning behind it.
- Category and module — calculated with the same engine as the free check, with the table and the limit values around it.
- Material route — which PMA evidence is needed, which tests, in which directions, and which harmonised standard for a similar grade you have to weigh in.
- Qualification plan — build procedure and operator, who approves what, and from which category that has to be a notified body or a recognised third-party organisation.
- NDT plan — method per surface, acceptance criterion with justification, and the machining question priced explicitly.
- File list and bottlenecks — what the technical file must contain, plus a realistic estimate of lead time and where it goes wrong.
What I need: a drawing or 3D model, the intended material and process, PS and V or DN, the medium and operating temperature, and whether the equipment is new or already in service. The request form asks for that in four steps; you receive a file number and a link to come back to it.
The request itself is free and without obligation: within two working days you hear whether the part lends itself to this and what the check would cost in your case. Already have a file? Open it on the file page.
This is advice on the route and the evidence, not a conformity assessment. The assessment itself remains with the manufacturer and, where the directive requires it, with a notified body. The in-service part of the memo covers Dutch law; for equipment operated elsewhere it identifies what to check in the member state of use.
Frequently asked questions
Does additive manufacturing change my PED category?
No. Annex II classifies on equipment type, phase, fluid group and the figures PS and V or DN; there is no process parameter in it. What changes is the burden of proof within the category: without a harmonised material standard the material route runs through a particular material appraisal or a European approval for materials.
May I replace a casting with a printed part?
If it stays a repair — the same item, one part replaced — Guideline A-03 point 2 puts it outside the PED and inside national law. In the Netherlands Article 26 of the Pressure Equipment Decree 2016 then applies, and only to equipment subject to inspection under Article 21(1): Annex I of the directive applies mutatis mutandis except for affixing the CE marking (paragraph 1), and the user notifies the Dutch conformity assessment body or user inspectorate without delay (paragraph 2). Replacing the whole item with a new one is covered by the PED (A-03 point 1). If the replacement changes the original characteristics, purpose or type, it counts as placing on the market anew and you run the full PED route. Outside the Netherlands the split follows the same guideline, but the in-service obligations are those of the member state of use.
Is there a harmonised standard for additive manufacturing under the PED?
No. The list of harmonised standards under Directive 2014/68/EU as compiled on 13-01-2026, following Commission Implementing Decision (EU) 2026/79, contains no AM standard: not the ISO/ASTM 52900 series, not AWS D20.1, no EN part on additive manufacturing. There is therefore no presumption of conformity along that route.
First find out which category your part falls in
The free check gives the table, the category and the permitted modules — identical for a printed and a cast part. After that you know which evidence you have to build.
Run the free check or see the full report