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Pressure Equipment Directive 2014/68/EU: categories, modules, materials

14 September 2026 · Reading time approx. 8 min.

The Pressure Equipment Directive is not a document for the drawer. It decides whether a piping component has to carry a CE mark, which certificate belongs with it and whether a notified body gets involved. Settling that before the enquiry saves arguments later about documents that no longer exist.

What the directive covers

Directive 2014/68/EU – usually PED for short – applies to pressure equipment and assemblies with a maximum allowable pressure PS above 0.5 bar. Below that it does not apply. Piping, vessels, valves and pressure-bearing accessories are covered, as are safety devices.

Excluded are, among others, transmission pipeline networks, simple pressure vessels covered by their own directive, equipment within the scope of other legislation and equipment for nuclear use. For plant engineering that means in practice: almost everything carrying steam, compressed air, gas or hot water falls under it.

Fluid group 1 or 2

Before a category can be determined, the medium has to be classified.

GroupFluidsExamples
Group 1hazardous fluids – flammable, oxidising, toxic, corrosive and further hazard classes under the CLP Regulationnatural gas, hydrogen, oxygen, chlorine, many solvents
Group 2all other fluidswater, steam, compressed air, nitrogen, thermal oil

A further distinction is made between liquids and gases – a fluid held above its boiling point in service counts as a gas.

The four categories

Pressure, nominal size or volume and fluid group give the category via the charts in Annex II. The category determines the effort – not the quality of the part, but the amount of proof required.

CategoryRiskUsual conformity assessmentNotified body
IlowModule A (internal production control)no
IImediumModule A2, D1 or E1yes, surveillance
IIIhighModule B + D, B + F, Hyes
IVvery highModule B + D, B + F, G, H1yes, with design examination

From category I the equipment carries the CE mark; from category II the identification number of the notified body follows it.

Article 4(3): sound engineering practice

Frequently misunderstood: equipment below the category I limits must be designed and manufactured in accordance with sound engineering practice. It carries no CE mark for the Pressure Equipment Directive – a CE mark would in fact be wrong here. It still needs operating instructions and the manufacturer's marking.

What this means for materials

The directive prescribes no list of materials, but it does require evidence of suitability. There are three admissible routes:

An alternative, and a common one, is the route via the AD 2000 code, whose W data sheets address exactly this question of suitability.

And for certificates

For the main pressure-bearing parts of equipment in categories II, III and IV, Annex I of the directive requires specific product control. In practice that means an inspection certificate 3.1 to EN 10204. A test report 2.2 is not enough here.

CategoryCertificate for main pressure-bearing parts
Article 4(3) (sound engineering practice)2.1 or 2.2 is normally sufficient
Category I2.2, 3.1 often agreed
Categories II, III, IV3.1 required, 3.2 where third-party witnessing applies

What this means for your enquiry

Three details are usually enough for us to supply the right thing: medium and fluid group, PS and nominal size, and the category or a reference to Article 4(3). Everything else follows from that – proof of material, certificate type and marking.

We supply pipes, flanges, fittings and gaskets, valves and boiler and power plant parts with the matching documentation. The basics on pressure rating and nominal size are in DN, PN and schedule explained.

Frequently Asked Questions

When does the Pressure Equipment Directive 2014/68/EU apply?

It applies to pressure equipment and assemblies with a maximum allowable pressure PS greater than 0.5 bar. Below that it does not apply. Whether a CE mark is then needed additionally depends on fluid group, pressure and nominal size or volume.

What is the difference between fluid group 1 and 2?

Group 1 covers hazardous fluids – flammable, oxidising, toxic, corrosive and further hazard classes. Group 2 covers all the rest, such as water, steam, compressed air and nitrogen. At the same size and pressure, group 1 leads to a higher category.

What does “sound engineering practice” under Article 4(3) mean?

Equipment below the category I limits is designed and manufactured to recognised practice but without a conformity assessment procedure. It carries no CE mark for the Pressure Equipment Directive; the manufacturer's marking and operating instructions are still required.

Which material certificate does the Pressure Equipment Directive require?

For the main pressure-bearing parts of equipment in categories II, III and IV, specific product control is required – in practice an inspection certificate 3.1 to EN 10204. For category I and for sound engineering practice, 2.2 is normally sufficient.

Does AD 2000 replace the Pressure Equipment Directive?

No. The directive is binding law; AD 2000 is a technical code by which its requirements can be met. Alternatives are harmonised standards such as EN 13480 for industrial piping or EN 13445 for pressure vessels.

Do you need exactly these parts?

Grade, size, pressure rating and quantity are enough – you usually receive your quote the same day, with an inspection certificate 3.1 on request.

Request a quote