ATEX

The very idea of ​​an explosion makes us shudder. The force and extent of the destruction of a chemical chain reaction in industrial plants could be immense. Especially in chemical plants or petrol stations, where fuels are produced and bottled, or in the production of sugar and flour, gas or dust explosions of gigantic proportions are (theoretically) conceivable.

As the installer and operator of systems in potentially explosive areas, you therefore need certified products whose properties correspond to the standards that have been established for accident prevention. In the following, you will find out what the ATEX directive means, what potentially explosive gas and dust atmospheres are, what the explosion protection of devices can look like and how ATEX certification is granted.

The short form ATEX stands for the French long form " AT mosphères EX plosibles", consequently explosive atmospheres. ATEX is the simplified name for the product directive 2014/34 / EU of the European Parliament and of the Council on the placing on the market of all devices and protective systems in potentially explosive areas . It addresses manufacturers, importers and users of such equipment. The currently valid guideline was passed on February 26, 2014, applies to the entire European Economic Area and has been implemented in national law across the EU.

Note: The older, but still valid operating directive 1999/92 / EC on worker safety in potentially explosive atmospheres is also called the ATEX directive, but is only of secondary importance for LAPP as a product manufacturer.

Hazardous areas or Ex areas are, according to the directive, "Areas in which the atmosphere can become explosive due to the local and operational conditions".

As a manufacturer of cables, lines, cable glands, connectors and other system components for electrical devices, machines and systems, LAPP must ensure at all times that the products placed on the market comply with the regulations applicable to the area of ​​application.

We state: The ATEX directive defines how EQUIPMENT AND PROTECTIVE SYSTEMS for potentially explosive areas are to be placed on the market. It also provides: "Devices and protective systems must be equipped with suitable entries (cable glands, editor's note) for cables and lines". Cable glands are therefore considered components and must not represent a source of ignition for possible explosions or contribute to an ignition source in potentially explosive areas.

Basically: As soon as devices are used in Ex areas, ATEX certification is required.

By the way: cables and lines do NOT fall within the scope of the ATEX directive. There is therefore no certification. The planning, selection and use of cables in potentially explosive areas is the responsibility of the installers of the system. 

Before we explain to you which ATEX certificates there are in general and for our cable gland area and what they say, back to the starting point :

Put simply, explosion protection (Ex protection) includes all measures that reduce the risk of the formation and ignition of an explosive atmosphere to a minimum or absolutely prevent it. According to the directive, the potentially explosive atmosphere is "a mixture of air and flammable gases, vapors, mists or dusts under atmospheric conditions in which the combustion process is transferred to the entire unburned mixture after ignition".

Gases (including vapors and mists) and dust are substances that can ignite quickly in combination with oxygen and an ignition source, provided that all components occur simultaneously in sufficient quantities and over a certain period of time. The sources of ignition are generally heat, an open fire, but also sparks. At almost 21%, oxygen is also found in sufficient concentration in the air that we breathe.

If the required ignition energy and ignition temperature are reached, an explosion occurs.

If gases ignite, it is a gas explosion; if dust ignites, a dust explosion takes place.

The ATEX directive basically divides the Ex area into two large Ex zones:

• GAS zones (combustible material: gas)
• DUST zones (combustible material: dust)

Both gas and dust zones are subdivided into further sub-zones, depending on how often and for how long explosive gas or dust atmospheres can occur there.

Devices whose placing on the market is to be regulated by the ATEX directive are in turn grouped into two device groups:

• Equipment group I: Equipment for use in mining / surface / underground operations
• Equipment group II: Equipment for use in potentially explosive dust and gas atmospheres

Within the device groups, there are various device categories into which the manufacturer's devices are to be classified. The frequency and duration of explosive gas or dust atmospheres also play a decisive role in the device category. The necessary safety requirements for the devices are determined based on the danger level.

Comparison:

A device from device group II, device category 1 must guarantee a very high level of safety and is intended for areas "in which an explosive atmosphere (...) is present continuously, for a long time or frequently". Even in the event of device malfunctions or error states that rarely occur, the required level of safety must be guaranteed by the device.

A device from device group II, device category 2 must guarantee a high level of safety and is intended for areas "in which an explosive atmosphere (...) occasionally occurs". In the event of device malfunctions or error states that occur frequently, the required level of safety must be guaranteed by the device.

In the event of device malfunctions or error states that occur frequently, the required level of safety must be guaranteed by the device.

Occurrence of gas zones

Gas zones can be found wherever z. B. hydrogen, methane, butane, propane, ethylene promoted or (further) processed. Also wherever outgassing substances such as gasoline are used.

→ Pharmaceutical industry, petrochemicals, underground, offshore, etc.

Occurrence of dust zones

There are dust zones wherever z. B. flour, grain, fluorine, aluminum and dust in general occur.

→ Mills, grinders, industrial dryers, mixing plants, transport pipelines for e.g. grain, silos in which fermentation occurs due to dust and gases, etc.

While safety requirements for devices and protective systems are covered by the ATEX directive, the design requirements for devices and protective systems are determined by the so-called types of protection.

Depending on the protection principle ...

1. ensure that an ignition source cannot occur,
2. prevent an ignition source from becoming effective,
3. prevent the explosive atmosphere from reaching the ignition source,
4. a housing ensures that the explosion does not spread.

A distinction is made between types of protection for gas and dust atmospheres as well as for electrical and non-electrical equipment. The types of protection are described in the multi-part EN IEC 60079. At LAPP, you will find products with types of protection "e" for increased safety.

LAPP can support you with these ATEX products