ATEX

The mere idea of an explosion makes us shudder. The impact and extent of destruction of a chemical chain reaction in an industrial facility could be enormous. Gas or dust explosions of gigantic proportions are (theoretically) conceivable, especially in chemical factories or service stations, where fuels are produced and filled, or also in the production of sugar and flour.

As the installer and operator of systems in potentially explosive areas, you therefore need certified products whose properties comply with the standards that have been established for accident prevention. Find out below what the ATEX Directive states, what explosive gas and dust atmospheres are, what the explosion protection of devices can look like and how ATEX certification is issued.

The abbreviation ATEX stands for the French long form "ATatmosphères EXplosibles”, i.e. explosive atmospheres. ATEX is the simplified designation for the Product Directive2014/34/EU of the European Parliament and Council on the marketing of all devices and protective systems in potentially explosive atmospheres. It addresses manufacturers, importers and users of such equipment. The currently valid directive was passed on 26February 2014, applies to the entire European Economic Area and has been implemented into national law throughout the EU.

Note: The older but still valid Directive 1999/92/EC on occupational safety in explosive atmospheres is titled as ATEX Directive, but is only viewed as secondary by LAPP as a product manufacturer.

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

As a manufacturer of cables, wires, conduit glands, plug connections 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 adhere to the following: The ATEX directive defines how the marketing of DEVICES AND PROTECTIVE SYSTEMS for potentially explosive areas should look. It also states that "devices and protective systems must be equipped with suitable entries (conduit glands, editorial note) for cables and wires". Conduit glands are therefore considered components and must not be an ignition source for potential explosions or contribute to an ignition source in potentially explosive areas.

In principle, an ATEX certification is required whenever devices are used in an Ex area.

Incidentally, cables and wires do NOT fall within the scope of application of the ATEX Directive. As a result, they have no certification. The planning, selection and use of cables in potentially explosive areas is the responsibility of the plant installers.

Before we explain which ATEX certifications are available generally and for our conduit gland range, and what they declare, let's head back to the starting point:

In simple terms, explosion protection (ex-protection) includes all measures that minimise or fully prevent the risk of the generation and ignition of an explosive atmosphere. According to the directive, the explosive atmosphere is "a mixture of air and combustible gases, vapours, mists or dusts under atmospheric conditions in which the combustion process spreads to the entire unburned mixture after ignition has taken place".

Gases (also vapours and mist) and dust are materials that can ignite quickly when combined with oxygen and an ignition source, provided that all components are in sufficient quantities and occur simultaneously over a specific period of time. Heat, an open fire and sparks are generally considered to be ignition sources. At almost 21%, there is a sufficient concentration of oxygen just in the air that we breathe.

If the required Ignition energy and Ignition temperature are achieved, an explosion occurs.

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

The ATEX Directive essentially divides the Ex area into two large Ex zones:

·        GAS zones (flammable material: gas)

·        DUST zones (flammable material: dust)

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

Devices whose marketing must be regulated by the ATEX Directive are divided into two device groups:

·        Device group I: Devices for use in mining/overground/underground operations

·        Device group II: Devices for use in dust and gas atmospheres at risk of explosion

There are various device categories within the device groups in which the manufacturer's devices must be grouped. The frequency and duration of explosive gas or dust atmospheres also play a crucial role in the device category. The necessary safety requirements for the equipment are determined based on the hazard level.

Comparison:

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

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

Occurrence of gas zones

Gas zones are found wherever hydrogen, methane, butane, propane and ethylene are extracted or (further) processed, for example. Another such place is where outgassing substances such as petrol are used.

→ The pharmaceutical industry, petrochemicals, underwater, offshore, etc.

Occurrence of dust zones

Dust zones are present where flour, grains, fluorine, aluminium and dust are generally present.

→ Mills, grinding plants, industrial dryers, mixers, transport pipelines for e.g. grains, silos in which fermentation is produced by 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 what are known as ignition protection classes. Depending on the protection principle, it

1. must be ensured that an ignition source cannot occur,
2. must be prevented that an ignition source becomes effective,
3. must be prevented that the potentially explosive atmosphere reaches the ignition source,
4. must be ensured via a housing that the explosion does not spread.

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

An ATEX certification can be issued by an approved testing agency that verifies the explosion protection of an electrical or non-electrical device for a device category. After the conformity assessment procedure has been completed, an ATEX certification is issued, which allows the product to be used in a very specific potentially explosive environment.

Process:

• The manufacturer determines the ignition protection class and thus the design requirements for its product.
• A testing body checks whether the product meets the safety requirements of the ATEX Directive.
• The manufacturer receives an ATEX certificate and can introduce its product to the market.

How to find ATEX products at LAPP

Within the conduit gland range, you can find ATEX-certified products using our smart Conduit gland finder. Our conduit glands can be assigned to device group II and can be used in all Ex areas with the exception of zone 0. Select the properties "for Ex zone gas" or "for Ex zone dust" as search criteria and browse through our product range.

Have you thought about the corresponding accessories such as blanking plugs and enlargers?

Incidentally, our conduit glands are not just compliant with the ATEX Directive, they are also IECEx-certified according to IEC 60079 and can therefore be used internationally.

How do you interpret the certifications of our products?

In the download area of the respective product, you will find the EU type examination certificate and the IECEx certificate for the product and can find the certified ATEX product labelling within these documents.

Explanation using the example of the SKINTOP® MS-M ATEX:

This is why LAPP is an excellent choice for Ex products

• LAPP production site constructed according to DIN ISO 9001/9002
• LAPP production process compliant with the ATEX Directive
• EC type examination certificate (design and construction of the product according to ATEX Directive)
• Product certification IECEx according to EN IEC 60079
• Multi-language operating instructions