NON ELECTRICAL EQUIPMENT

The need for non electrical apparatus to be assessed, tested, rated, labelled and certified for use in potentially explosive atmospheres was introduced for the first time as part of the implementation of the ATEX Directives 94/9/EC & 1999/92/EC. Here is a summary of the standards that have been established against which the non electrical apparatus should be tested.
EN 13463-1:2001 Non electrical equipment for use in potentially explosive atmospheres – Basic method and requirements
EN 13463-2:2004 Non electrical equipment for use in potentially explosive atmospheres – Protection by flow restricting enclosure (symbol: fr) - The explosive atmosphere is prevented from reaching the ignition source by the tight seals of the enclosure. The seals restrict the breathing of the enclosure as internal air heats and cools through operation of the equipment.
EN 13463-3:2005 Non electrical equipment for use in potentially explosive atmospheres – Protection by flemeproof enclosure (symbol: d) - An ignition inside the equipment does not propagate the external atmosphere. This type of protection relies on closely machined joints and a robust enclosure.
prEN 13463-4 Non electrical equipment for use in potentially explosive atmospheres – Protection by inherent safety
(symbol: g) - low potential energy
EN 13463-5:2003 Non electrical equipment for use in potentially explosive atmospheres – Protection by by constructional safety (symbol: c) - Ignition hazards are eliminated by the specification of the equipment.
EN 13463-6:2005 Non electrical equipment for use in potentially explosive atmospheres – Protection by control of ignition sources (symbol: b) - sources of ignition are only present in the event of a malfunction. The equipment is fitted with control equipment to detect malfunctions and prevent ignition sources arising.
prEN 13463-7 Non electrical equipment for use in potentially explosive atmospheres – Protection by pressurisation (symbol: p) - draft not yet available. In general, the enclosure is purged with a protective gas (air) and pressurised to ensure that an external atmosphere cannot re-enter the enclosure.
EN 13463-8:2003 Non electrical equipment for use in potentially explosive atmospheres – Protection by liquid immersion (symbol: k) - The enclosure has a suitable liquid to prevent the explosive atmosphere reaching the ignition source or to cool a hot surface