Printed is not standardised – why an additively manufactured part is no standard part

Rule of thumb

An additively manufactured part is not a standard part, even when dimensions and material number match – the product standard does not know the product form. Whoever orders a "flange to EN 1092-1" receives a forged or cast part; a printed one must not be certified as such.

Where does the rule come from?

From the product standards themselves. EN 1092-1 refers for steel flanges to forgings (EN 10222), castings (EN 10213) and plate (EN 10028); EN 10253 makes elbows, tees and reducers from pipe or plate; EN 10216 and EN 10217 are pipe standards. None of these standards contains an additively manufactured product form. The rule is therefore not an opinion about 3D printing but a reading of the standards that exist.

What is technically correct?

The material number describes the chemical composition, not the condition. A 1.4404 melted in the powder bed has the same analysis as a forged one, but a different microstructure: solidified layer by layer, direction-dependent in strength and toughness, with residual stresses and residual porosity. The product standard – EN 10222 for the forging, EN 10216 for the pipe – fixes exactly this condition together with heat treatment and scope of testing. For the printed part there is no such standard; an inspection certificate 3.1 to EN 10204 can be issued, but it certifies only the agreed tests with no standard behind them. For pressure retaining parts the Pressure Equipment Directive (Annex I No. 4) therefore requires the particular material appraisal (PMA) today, because harmonised material standards for metal powder do not exist; the pre-standard DIN/TS 17026 and the draft E EN 13445-14 (2025) set the additional requirements.

Where does the rule end?

• It applies to parts that have a product standard. Impellers, valve trims, manifolds to drawing have none – nothing can be "not standardised" there; the manufacturer's qualification counts.
• It says nothing about quality: a printed valve body from a certified manufacturer may be better tested than a catalogue part. It is just not a standard part.
• Once EN 13445-14 is published as a harmonised standard, additively manufactured pressure parts will have a standard – the product standards for piping components remain unchanged.
• Build-up welding on an existing part falls under the rules of welding, not under this rule.

What does the standard say?

EN 1092-1 (flanges: materials from forgings, castings, plate), EN 10253-2/-4 (fittings from pipe or plate), EN 10216-2 / EN 10217-1 (pipes), EN 10204 (inspection documents, independent of product form), Directive 2014/68/EU Annex I No. 4 (harmonised standard, European material approval or particular material appraisal), DIN/TS 17026:2020-10 and E EN 13445-14:2025-01 (additional requirements for additively manufactured pressure equipment).

DIN/EN versus ASME/ASTM

In the ASME world it is the same logic under different names: ASME B16.5 refers to ASTM material standards for forgings (A105, A182) and castings; a printed flange is no B16.5 flange. The route for printed pressure parts is written by PTB-13 (2021), Code Case 3020 (wire arc additive manufacturing) and, for oil and gas, API Std 20S – as qualification per part, not as a product standard.

Worked example

Enquiry: "Flange DN 80 PN 16, type 11, 1.4404 – can you have it printed, our service provider has capacity?" Answer: yes, technically that works up to about DN 100 in the powder bed. But the flange would not be a flange to EN 1092-1, would need a material appraisal as a pressure retaining part and would cost a multiple of the welding-neck flange that is forged, certified and available from stock. The enquiry ends with the standard part.

Zickwolff reference

Zickwolff does not print. We carry flanges, fittings, pipes and valves to product standard, forged, rolled or cast, with certificate to EN 10204 – from stock or to order. The rule of thumb is the short answer to the most frequent question about additive manufacturing in piping; the long one is in our topic cluster on additive manufacturing, for now in German.

Checked today

Traffic light: applies (class A). The product standards of piping know no additively manufactured product form; the rule is a reading of the standards, not an assessment of the process. It will have to be reviewed when EN 13445-14 appears – for pressure parts, not for flanges and fittings.

Further reading

• EN 10204 explained: 2.1, 2.2, 3.1 and 3.2 inspection certificates – what a 3.1 certificate certifies
• Flange standards explained: EN 1092-1, DN, PN, types & sealing faces – flanges to EN 1092-1 from stock
• Repair yes, buy the standard part – build-up welding is regulated, the standard part is in stock – the sister rule
• Additive manufacturing in piping: what can be printed, what cannot – and why – overview: what works, what does not
• Additive manufacturing and the rules: product standard, Pressure Equipment Directive, material appraisal, ASME, drinking water – product standard, PED, appraisal
• Suitability matrix additive manufacturing: component against process – technically and normatively – suitability matrix