30th July 2003 marked the end of the transition period of EC directive 94/9/EC on the use of protective systems according to national standards (flame arresters) for use in potentially explosive atmospheres.

Since that date, manufacturers and importers have no longer been permitted to circulate such “old” flame arresters in the EC. All “new” protective systems (flame arresters) put on the market after this date have to meet the EC directive 94/9/EC or later 2014/34/EC “Approximation of the laws of the Member States concerning equipment and protective systems intended for use in potentially explosive atmospheres” and the EN ISO 16852 standard without exception.

These changes apply to the field of application as well as to the testing and monitoring of the production quality.

Where fields of application are concerned a difference is made between protection against flame transmission in explosions (pipe deflagrations) on the one hand and detonations on the other hand. (The difference lies in the approach velocity of the flame front depending on the length of the run-up distance between the possible ignition point and the location of the flame arrester.)

All flame arresters newly put into circulation have to undergo a type-examination procedure with regard to their design and will receive a type examination certificate for their function as a protective system. In addition, manufacturers of flame arresters will either have to have their production process monitored in a quality assurance procedure or have every product undergo individual testing. Only on compliance with one of these two quality assurance procedures may the manufacturer issue the required declaration of conformity and affix the CE marking.

Another regulation on the use of flame arresters can be found in EC directive 1999/92/EC on “Minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres”.

Article 9 in this directive, “Special requirements for work equipment and workplaces”, regulates the periods required for adaptation to the new standards.

Annex II of this directive regulates the use of protective systems in potentially explosive atmospheres.

For further information please contact Mr Pfliegl (see our general contact details).