What EN 13445 is — and what it is not
EN 13445 is a design standard. It is a set of technical rules for the design, materials, fabrication, inspection and testing of unfired pressure vessels. It is not a law, not a conformity assessment procedure, not a marking, and not a certificate. A vessel is designed to EN 13445; it is placed on the EU market under the Pressure Equipment Directive. Keeping those two roles separate is the starting point for reading any Chinese factory’s quotation for an EU-bound tank.
The standard is published by CEN and covers vessels not exposed to flame — which includes cryogenic storage tanks, whose inner vessels are pressure vessels in the ordinary sense. Its core parts divide the work: Part 1 general requirements, Part 2 materials, Part 3 design, Part 4 fabrication, Part 5 inspection and testing, Part 6 vessels of spheroidal graphite cast iron, with further parts for aluminium and nickel alloys. A vessel built to EN 13445 is built to all applicable parts together, not to Part 3 alone.
EN 13445 and the Pressure Equipment Directive (PED)
EN 13445 is a harmonized standard cited under the PED. Designing and building to it gives a presumption of conformity with the essential safety requirements the standard covers. The presumption simplifies the conformity assessment; it does not replace it. Conformity assessment still runs through a PED module, and CE marking still follows the module, not the standard. A factory can also demonstrate PED conformity by other means, but EN 13445 is typically the route notified bodies review most efficiently.
For vacuum-insulated cryogenic vessels specifically, a dedicated European standard family (EN 13458 for static vessels) exists and refers back to EN 13445 rules for much of the pressure design. Which standard a factory quotes for a given tank is a design decision, confirmed at order stage.
EN 13445 design by formula and design by analysis
Part 3 offers two paths to a compliant design. Design by formula (DBF) uses closed-form rules to set wall thickness or maximum allowable pressure for standard geometries — shells, heads, nozzles, flanges. Most cryogenic storage tanks are DBF designs. Design by analysis (DBA) uses numerical methods, typically finite element analysis, either as a direct route or through stress categorization. DBA suits non-standard geometry, high cycle counts, or cases where formula rules are conservative enough to matter commercially. For a routine liquid oxygen or nitrogen tank, DBF is the expected route; DBA appears in quotations for unusual configurations, not standard ones.
EN 13445 materials, welding and NDT requirements
An EN 13445 design is built from EN material grades — austenitic stainless steels for cryogenic inner vessels, carbon and fine-grain steels for outer jackets and frames — with each pressure-bearing item traceable to an EN 10204 type 3.1 inspection certificate. Welding is executed to qualified procedures: WPQR and WPS records, with welders qualified to the corresponding EN ISO standards. Inspection and testing follow Part 5, where the vessel’s testing group sets the extent of radiographic or ultrasonic examination of welds. The testing group is a design choice with cost consequences: fuller NDT permits higher joint efficiency and thinner walls, reduced NDT does the opposite. It is settled in the design specification, not on the shop floor.
EN 13445 vs ASME Section VIII in procurement
EN 13445 and ASME Section VIII address the same equipment with different mechanics. EN 13445 works with EN materials, characteristic strength values and its own safety factors; ASME works with its listed materials, allowable stresses and the U-stamp shop authorization system. Neither is generally thinner, cheaper or safer; the comparison shifts with geometry, material and testing group. In procurement the deciding factor is rarely the engineering — it is the destination. An EU-bound vessel needs PED conformity, for which EN 13445 is the natural design basis; a vessel bound for a jurisdiction that recognizes ASME is more simply built to ASME. Selecting the factory whose design office and documentation practice match the destination standard is usually cheaper than converting a design after the fact.
EN 13445 acceptance outside the EU
EN 13445 travels reasonably well. In Australia and New Zealand, AS/NZS 1200 lists EN 13445 among the international vessel standards accepted alongside AS 1210, so an EN 13445 design can support supply into Australia and New Zealand, subject to the verification and registration steps those markets apply — steps that sit with the buyer as the party placing the equipment into service. Other jurisdictions accept EN designs case by case. Acceptance in any market is checked against the local regime for the specific order, not assumed.
What an EN 13445 order from a Chinese factory looks like
Several factories in our network quote EN 13445 design for export orders. When an EU-bound storage tank is quoted on an EN 13445 basis, the documentation package typically includes:
- design calculations to EN 13445-3, with drawings;
- material certificates, EN 10204 type 3.1, for pressure-bearing parts;
- WPQR and WPS welding records, with welder qualifications;
- NDT reports to the agreed testing group;
- pressure test records;
- the manufacturer’s EU Declaration of Conformity, with the notified-body certificates required by the applicable PED module (categories II–IV), followed by CE marking.
Transportable tanks follow a different regime. Cryogenic ISO tanks and road tankers fall outside the PED: they are approved under the transport-of-dangerous-goods rules (ADR/RID/IMDG, with pi marking under TPED where applicable) to standards such as EN 13530 or ISO 20421, not CE marked under the PED.
The design standard is one input to factory selection, alongside duty, media and destination-country registration steps — the buyer’s statutory obligations in the destination country remain the buyer’s, with Cryofor arranging the supporting manufacturer documentation. Our notes on export certification and factory vetting cover the surrounding process.
Availability and applicability of any standard, certificate, marking or registration procedure is confirmed for the specific manufacturer, model and order before production.
Next step
Send a rough duty description — medium, working pressure, capacity and destination country — and we will indicate whether an EN 13445 design basis fits the order, and which documentation set would accompany it.