ATEX certification, pressure equipment and machinery

ATEX is Directive 2014/34/EU, the EU directive on equipment for potentially explosive atmospheres. IECEx is the IEC's voluntary certification system: a Certificate of Conformity backed by an ExTR test report and a QAR audit of the factory. Both test to the EN IEC 60079 series (60079-0, 60079-1 flameproof, 60079-11 intrinsic safety), so an ATEX notified body normally accepts an IECEx report as the technical basis for its EU-type examination certificate. The reverse does not hold, and neither document satisfies TR CU 012/2011 in the Eurasian Union, which needs its own EAC certificate.

Selling into several regions, do IECEx first and derive the regional certificates from it, because the ExTR is written to be reused. Start with ATEX at a laboratory that does not also issue IECEx test reports, and the gas-group and temperature-class testing may have to be repeated when a Gulf customer asks for IECEx.

The zone decides it, and the zone is set by the site operator under the workplace Directive 1999/92/EC. Zone 0 for gas or Zone 20 for dust, where an explosive atmosphere is present continuously, needs Category 1 equipment. Zone 1 or 21, present occasionally in normal operation, needs Category 2. Zone 2 or 22, present rarely and briefly, needs Category 3. A Category 3 motor installed in a Zone 1 pump house is an illegal installation however good its certificate.

The category sets the third-party involvement. Category 1 equipment, and Category 2 electrical equipment, need EU-type examination by a notified body under Annex III plus production surveillance. Category 2 non-electrical equipment is self-assessed, but the technical file must be lodged with a notified body under Annex VIII. Category 3 is internal production control only. A certificate without the full marking, II 2G Ex db IIC T4 Gb for example, tells a buyer nothing about where the equipment may go.

Directive 2014/68/EU applies to vessels, piping, safety accessories and pressure accessories with a maximum allowable pressure PS above 0.5 bar, and not at all below it. Above it, the nine charts in Annex II sort equipment into Categories I to IV by PS, volume (or nominal size for piping) and fluid group: Group 1 is the dangerous fluids (flammable, toxic, oxidising), Group 2 everything else. Below the Category I line, Article 4(3) applies, sound engineering practice: you follow a recognised code, mark it with your name, and do not CE mark it. From Category I up, CE marking is mandatory: Category I is self-declared under Module A, and from Category II a notified body takes part.

The most common error is assessing the vessel and forgetting the assembly. A skid combining vessels, piping and safety accessories is an assembly under Article 4(2) and needs its own global assessment on top of the component certificates. In the Eurasian Union the same threshold, 0.05 MPa, opens TR CU 032/2013 on equipment operating under excess pressure, with four hazard categories and an EAC certificate or declaration by category.

Machinery assessment under Directive 2006/42/EC is dominated by risk assessment and the technical file; testing is a small part of it. The file follows EN ISO 12100:2010, safety of machinery, general principles for design: identify each hazard, estimate and evaluate the risk, then reduce it in fixed order: inherently safe design, guarding and protective devices, information for use. For the 23 categories in Annex IV, presses for cold working of metals and devices lifting persons more than 3 metres among them, a notified body examines the type unless the machine is built fully to harmonised standards. Everything else is self-declared, and the file is kept for ten years after the last unit is made.

Regulation (EU) 2023/1230 replaces the directive on 20 January 2027 and keeps the structure, adding a short Annex I Part A list where third-party assessment is mandatory whatever standards were used, cybersecurity requirements and digital instructions. In the Eurasian Union machinery falls under TR CU 010/2011: 14 of its listed positions take certification only, and the rest may go by declaration.

For equipment also under ATEX or PED, the machinery file references the other certificates, is assembled last, and is the document that sets the delivery date.

Equipment meeting two or three of these needs all of them satisfied. They cannot be traded against each other, and the assessments cannot be merged into one document.