Pressure Equipment Directive PED 2014/68/EU: categories, modules and CE for refrigeration
PED 2014/68/EU for refrigeration and heat pumps: PS, fluid groups 1 and 2, categories I–IV from PS·V and PS·DN, modules, notified body, CE marking, assemblies, EN 378-2.
Key points
- The PED (2014/68/EU) covers the design, manufacture and conformity assessment of pressure equipment and assemblies with PS above 0.5 bar [1][2].
- The category (I–IV) depends on the fluid group and on PS·V for vessels or PS and DN for piping. Flammable and toxic refrigerants fall into group 1 and give a higher category [1].
- Equipment below the limits in Article 4(1) must follow sound engineering practice under Article 4(3) and must not carry the CE marking under the PED [1].
- A refrigerating system built from several items of pressure equipment is usually an assembly. It is assessed as a whole, and safety accessories such as relief valves are category IV [1].
- EN 378-2:2016 is a harmonised standard and gives a presumption of conformity. EN 13136 is replaced by EN ISO 24664:2024 and its presumption ends on 2 April 2028 [3][4][5].
What the directive covers
The Pressure Equipment Directive (PED) 2014/68/EU covers the design, manufacture and conformity assessment of pressure equipment (vessels, piping, safety accessories and pressure accessories) and assemblies with a maximum allowable pressure PS above 0.5 bar [1]. It governs what may be placed on the market, not operation. It replaced 97/23/EC and has applied in full since 19 July 2016 [1][2].
Article 1 exclusions relevant to refrigeration
- At most category I and covered by another directive, such as the Machinery or Low Voltage Directive (Art. 1(2)(f)) [1].
- Casings where pressure is not a significant design factor, including compressors and pumps (Art. 1(2)(j)). Assessed case by case [1].
- Ships and equipment for installation on board, such as marine refrigeration (Art. 1(2)(n)) [1].
- Simple pressure vessels (2014/29/EU), vehicle equipment, and radiators and pipes in warm water heating (Art. 1(2)(c), (e), (t)) [1].
PS and other definitions
- PS: maximum pressure the equipment is designed for, given by the manufacturer as gauge pressure in bar [1].
- TS: maximum and minimum allowable temperature [1].
- V: internal volume of a chamber in litres, including nozzles to the first connection or weld [1].
- DN: nominal size of piping components. Components designated by outside diameter, such as copper tube, are excluded from the definition, so agree how DN is set [1].
Fluid groups 1 and 2
Article 13 sets two fluid groups. Group 1 covers substances classified under the CLP Regulation (EC) No 1272/2008 as, among others, flammable gases of category 1 or 2, or acutely toxic by inhalation in category 1–3. Group 2 is the rest [1]. Group 1 gives a higher category.
| Refrigerant | Safety class (ISO 817) | Usual fluid group (PED) |
|---|---|---|
| R134a, R404A, R410A, R513A | A1 | Group 2 |
| R744 (CO2) | A1 | Group 2 |
| R32, R1234yf, R454B | A2L | Group 1 |
| R290, R600a, R1270 | A3 | Group 1 |
| R717 (ammonia) | B2L | Group 1 (flammable and toxic) |
Categories I–IV
Article 4(1) sets when vessels and piping are in scope, and Annex II places them in category I–IV by ascending hazard [1]. For refrigerants, tables 1 and 2 apply to vessels and tables 6 and 7 to piping. Vessels depend on PS·V, piping on DN and PS·DN:
| Equipment | In scope when | Cat. I | Cat. II | Cat. III | Cat. IV |
|---|---|---|---|---|---|
| Vessels, group 1 (table 1) | V > 1 L and PS·V > 25 bar·L | PS·V ≤ 50 | PS·V ≤ 200 | PS·V ≤ 1,000 | PS·V > 1,000 |
| Vessels, group 2 (table 2) | V > 1 L and PS·V > 50 bar·L | PS·V ≤ 200 | PS·V ≤ 1,000 | PS·V ≤ 3,000 | PS·V > 3,000 and PS > 4 bar |
| Piping, group 1 (table 6) | DN > 25 | DN ≤ 100 and PS·DN ≤ 1,000 | DN ≤ 100, or DN ≤ 350 and PS·DN ≤ 3,500 | Larger | – |
| Piping, group 2 (table 7) | DN > 32 and PS·DN > 1,000 | DN ≤ 100 or PS·DN ≤ 3,500 | DN ≤ 250 or PS·DN ≤ 5,000 | Larger | – |
Piping is at most category III. Vessels with V ≤ 1 L are only in scope above 200 bar (group 1) or 1,000 bar (group 2). Pressure accessories such as valves use the vessel or piping table, and the higher category applies [1].
| Example | Calculation | Category |
|---|---|---|
| R32 receiver, PS 42 bar, 10 L | Group 1, PS·V = 420 bar·L | III |
| CO2 receiver, PS 60 bar, 100 L | Group 2, PS·V = 6,000 bar·L | IV |
| R32 pipe, PS 42 bar, DN 32 | Group 1, PS·DN = 1,344 | II |
| CO2 pipe, PS 120 bar, DN 25 | Group 2, DN ≤ 32 | Article 4(3) |
Sound engineering practice, Article 4(3)
Equipment and assemblies at or below the limits in Article 4(1) and 4(2) must be designed and made to the sound engineering practice of a Member State and come with adequate instructions. They must not carry the CE marking under the PED [1].
Modules, notified body and CE marking
| Category | Modules the manufacturer chooses from | Notified body |
|---|---|---|
| I | A (internal production control) | No |
| II | A2, D1, E1 | Yes |
| III | B (design type) + D or F, B (production type) + E or C2, H | Yes |
| IV | B (production type) + D or F, G, H1 | Yes |
A module from a higher category may always be used. After assessment, an EU declaration of conformity is drawn up and the CE marking affixed, followed by the notified body number where it is involved in production control. Documentation is kept for 10 years [1]. In categories II–IV, brazing and welding procedures and personnel must be third-party approved (Annex I, 3.1.2) [1].
Assemblies: why a refrigerating system usually is one
An assembly is several items of pressure equipment put together by a manufacturer into an integrated, functional whole [1]. A refrigerating system with compressor, receiver, heat exchangers, piping and relief valves fits the definition. It is an assembly under Article 4(2)(b) when the manufacturer intends it to be made available and put into service as one. Whoever builds it, also on site, becomes the manufacturer, and so does anyone who uses it for his own purposes (Article 2(18)) [1]. It is assessed under Article 14(6):
- items without their own CE marking by their own category,
- the integration by the highest category among the items, excluding safety accessories,
- protection against exceeding limits by the highest category of the protected items [1].
Essential safety requirements in Annex I
- Design for all reasonably foreseeable loads, with a risk analysis [1].
- Protection against exceeding PS. A short surge may be at most 10% above PS [1].
- Pressure test at final assessment. For vessels at least the higher of 1.43 × PS and 1.25 × the maximum operating load [1].
- For assemblies, the safety devices are checked at final assessment [1].
- Marking with year of manufacture, identification and allowable limits [1].
- Instructions in a language the user understands [1].
Safety accessories are category IV
Safety accessories, such as safety valves, bursting discs and pressure switches with a safety function, protect against allowable limits being exceeded [1]. They are category IV, but if made for specific equipment they may take that equipment's category [1].
EN 378-2, EN 13136 and other harmonised standards
Equipment that meets a harmonised standard published in the Official Journal is presumed to meet the requirements it covers (Article 12) [1]. For refrigerating systems, EN 378-2:2016 is harmonised for design, construction, testing, marking and documentation [3][5]. The list also includes EN 14276-1/-2 (vessels, piping), EN ISO 21922 (valves) and EN 12735 (copper tube) [3]. For brazing, (EU) 2026/2211 adds EN ISO 17779:2025 (approval of brazing procedures) and EN ISO 13585:2024 (testing of brazers); EN 13134:2000 and EN ISO 13585:2012 lose the presumption of conformity on 2 April 2028 [4].
Practical checklist
- Set PS for each pressure zone and the fluid group from the safety data sheet.
- Classify each vessel and pipe size and note the highest category.
- Check that bought components are CE marked for the right refrigerant and PS.
- Choose the module for the assembly and book a notified body early for categories II–IV.
- Use approved brazing procedures and brazers from category II.
- Pressure test and document to EN 378-2, and keep the documentation for 10 years.
- Size relief to EN ISO 24664:2024 in new projects.
Calculate it yourself
Terms in this article
Sources
- Directive 2014/68/EU on pressure equipment (PED) – EUR-Lex
- European Commission – Pressure Equipment Directive
- European Commission – Harmonised standards for pressure equipment (summary list)
- Commission Implementing Decision (EU) 2026/2211 – harmonised standards for refrigerating systems and heat pumps under 2014/68/EU – EUR-Lex
- EN 378-2:2016 – Part 2: Design, construction, testing, marking and documentation