In connection with the introduction of the Atex directive, Non-electrical mechanical equipment became part of the directive. As a result of this CEN has introduced a set of harmonised standards. The harmonised standards are EN 13463 series.
The implementation of these standards has been a slow process for the industry for several reasons. One of the reasons for the slow implementation is that these standards represent a new unknown element and that the mechanical industry is not normally used to dealing with these types of questions. The ignition assessment, self-declaration, and certification process also presents a challenge. For this reason we have found that an increasing number of our clients are involving us in this process.
This standard is the basic method and requirements and contains the common factors that must be considered.
It gives the reference standards, equipment categories, ignition assessment methods and documentation and test requirements.
In many cases, unlike that of electrical equipment, no further protection method may be required.
This standard gives the requirements for protection method (fr) protection by flow restricting enclosures. These enclosures are basically simple enclosures with a high IP rating that will prevent the formation of explosive atmosphere inside the enclosure in other words keep it below the lower explosion limit.
This method may be used as category 3 equipment. Test methods, verification requirements, limitations of use, marking requirements etc is described in the standard.
This standard gives the requirements for protection method (d) protection flameproof enclosures. These enclosures are robust in construction and will prevent an internal explosion from migrating to the outside of the enclosure and ignite a potential explosive atmosphere on the outside.
Test methods, verification requirements, limitations of use, is given in the electrical standard IEC 60079-1. This method may be used on category 2 equipment or if combined with another protection method in category 1.
This standard gives the requirements for protection by constructional safety method (c). This standard is the most commonly used standard as a lot of mechanical equipment that is well constructed does not require any additional protection method.
Basically this is equipment that does not contain any ignition source in normal operation, and that preventive measures or good design brings the risk of mechanical failures (that can cause incendive temperature or sparks) down to a very low level.
This method may be used on category 2 equipment or if combined with another protection method in category 1.
This standard gives the requirements for protection by ignition source (b). The standard is for devices (sensors and control system) that detect impending operations likely to cause an ignition, and manually or automatically prevent a potential ignition source becoming effective.
The ignition prevention level (IPL) level of the system depends on outcome of the hazardous assessment done on the system and the required category level.
The IPL level requirements based on category is given in the standard.
This method may be used on category 1,2 or 3.
This standard is for protection by pressurized enclosures (p) and has been replaced by IEC/EN 60079-2 as used for electrical equipment.
This standard gives the requirements for protection by liquid immersion (k). The standard is for an ignition source that is submerged in a non-flammable liquid.
This will prevent the explosive atmosphere of getting in contact with the ignition source. Typical application would be a gear box. This method may be used on category 1,2 or 3.