Three questions before every enquiry: drawing, material, approval – how every special part sorts itself

Rule of thumb

Is there a drawing or a sample? Which material in which condition? Does the part have to pass an assessment under the Pressure Equipment Directive, AD 2000 or ASME? Whoever has the three answers knows whether the part is a standard part from stock, a special fabrication – or a case for additive manufacturing with an appraisal.

Where does the rule come from?

From the everyday enquiry. The question "Can you print this?" almost always arrives without a drawing, without a material condition and without saying whether the part is pressure retaining – and cannot be answered that way. The three questions sort every enquiry in a few minutes: they are the same ones a forge, a turner or a notified body would ask.

What is technically correct?

The drawing decides the route: if a product standard describes the part, it is a standard part from stock; if there is a drawing with a geometry that can be turned, forged or welded, it is special fabrication; if there is only an old part, the work begins with measuring, material identification and a new drawing. The material decides feasibility: available as powder or wire? Which condition – normalised, quenched and tempered, solution annealed – is needed, and does the process deliver it after heat treatment? The approval decides the effort: a non-pressure part needs only the manufacturer's qualification; a pressure retaining part under the Pressure Equipment Directive needs a material appraisal to Annex I No. 4 and the conformity assessment of the equipment – today the only route, because harmonised material standards for metal powder do not exist. In the ASME world, qualification to PTB-13, Code Case 3020 or API 20S takes that place.

Where does the rule end?

• The three questions sort, they do not decide: whether a special part is made additively or conventionally is a question of geometry, quantity and costing.
• Quantity and date are the fourth and fifth questions an offer needs – for sorting, the first three suffice.
• For spare parts of pumps and valves the route leads to the manufacturer who has qualified his part; he then answers the three questions.
• Drinking water: for printed components there is currently no approval and no route we could recommend – the third question ends there.

What does the standard say?

Directive 2014/68/EU Annex I No. 4 (material evidence: harmonised standard, European material approval, particular material appraisal), DIN/TS 17026:2020-10 (additional requirements, material and process qualification), E EN 13445-14:2025-01 (draft), EN 10204 (inspection documents), AD 2000 (material testing by analogy), ISO/ASTM 52900 (terms).

DIN/EN versus ASME/ASTM

The same three questions, different answers to the third: in the ASME world acceptance is a matter of the code and the Authorized Inspector; for printed parts PTB-13, Code Case 3020 (wire arc additive manufacturing) and API Std 20S (qualification levels by criticality) give the rules. Whoever works for an operator with an ASME specification asks for API 20S before asking for EN 13445-14.

Worked example

Enquiry: "Manifold with four outlets, internal channels, 1.4404, small series of 20, service 16 bar / 120 °C." Drawing: yes, with internal geometry that cannot be drilled – no standard part. Material: 1.4404 available as powder, solution annealed after heat treatment. Approval: pressure retaining, Pressure Equipment Directive – material appraisal and conformity assessment required. Result: a case for additive manufacturing with appraisal at the manufacturer or a certified producer; the alternative would be a welded manifold from standard pipe and standard nozzles from stock, if the channels may run outside.

Zickwolff reference

The three questions are the start of every special-part enquiry with us – and the enquiry helper in the additive manufacturing cluster asks them in this order. In nine cases out of ten the first question already ends at the standard part from stock. Zickwolff does not print and does not broker printing services; we show the route and deliver the standard part.

Checked today

Traffic light: applies (class A). The three questions are the sorting questions of every notified body and every producer; they are valid regardless of the process.

Further reading

• EN 10204 explained: 2.1, 2.2, 3.1 and 3.2 inspection certificates – certificates
• Enquiry helper for special parts: standard part, special manufacture, additive manufacturing or repair? – the five questions as a tool
• 3D printing of flanges, fittings, pipes, valves and spare parts in steel: what is technically possible – what works technically
• Additive manufacturing and the rules: product standard, Pressure Equipment Directive, material appraisal, ASME, drinking water – what the rules require