ATEX Certification

Some guidelines to the ATEX Directive as it applies to pneumatic and other products supplied by H. Kuhnke Ltd.

ATEX Product Marking

Typical equipment marking comprises groups of information which may be shown as one string, or on different lines

CE Mark & number of notified body responsible
Series or model number
EX + xx (Equipment Group, which is either I, mining, or IIA, or IIB or IIC defining particular gases, or II with no suffix defining all gases.) + N (Equipment Category which is 1, 2 or 3) + G, D or GD (indicating G = gases, vapours and mists and/or D = dust) + yy (Protection Concept, one or two lower case letters) + IIA or IIB or IIC or II (defining the gas group) + Tx (eg T4 defining the max surface temperature which will be generated, sometimes just the code, sometimes with a value eg T4 135°C) + Ta (the ambient temperature, often indicated as x°C ≤Ta≤y°C) (if no Ta is shown then ambient is -20°C - +40°C).
Other information may be suffixes, eg IP rating or operating pressure.

We recommend the illustration shown on this reputable link http://www.siracertification.com

Certificates

Pneumatic equipment (valves, cylinders and logic equipment such as timers and counters) is non-electrical. ATEX certification was designed with electrical equipment in mind, and in general applies to electrical and electronic products where ignition of combustible gases and dusts might occur. It is a European Directive, but which will be used in the US with I-Safe rating.

ATEX regulations are extended to mechanical equipment where heat is generated, or a source of ignition is possible, but the rules for certification & use are different. This applies to pneumatic devices particularly where heat is generated, as with cylinders, or where static charges may occur.

Manufacturers of non-electrical equipment intended for use in Zones 1/21 and 2/22 (category 2 and 3 equipment) do not need to undertake the EC type examination certificate route that is required for electrical equipment under ATEX (and category 1 mechanical equipment). Instead compliance is achieved by "self certifying" the equipment by complying to "Internal Control of Production" (Annex VIII of the ATEX Directive). This in turn requires compilation and submission of a technical file in a sealed package to a Notified Body for storage of the file (for category 2 non-electrical equipment). Certificates shown on this page relate to this procedure for the Kuhnke brand pneumatic valves and cylinders which carry the ATEX approval. Similarly a Declaration of Conformity is included, and is available here.

Copy of receipt for storage by Notified Body of ATEX technical file for Kuhnke pneumatic valves and Kuhnke pneumatic cylinders. [Non-electrical products procedure under ATEX directive for category 2 equipment]	(92Kb)
Copy Declaration of Conformity (Dichiarazione Di Conformità) for Kuhnke ATEX certified pneumatic cylinders and valves listed in these web pages. Please note these documents are in Italian, Kuhnke ATEX certified products are manufactured in Italy.	(52Kb)
Copy of appropriate operating instructions and intended use statement for Kuhnke ATEX certified cylinders and valves listed on these pages.	(288Kb)

Kuhnke brand pneumatic valves & cylinders have not been approved for Zone 0, Category 1.

Kuhnke brand pneumatic valves & cylinders for use in a Zone 2 environment (category 3 equipment) can be declared compliant

The certification and standards referred to for Kuhnke pneumatic valves and cylinders in this section of our website define the products as category 2 for use in Zone 1 or 21 (and 2 or 22) and are marked:
CE 0496 EX II,2 GD c T4 135°C -10≤Ta+50°C IP6x max 8Bar 1Hz.

this defines the products suitable for use in Zone 1 or 21 (gas and dust) with a maximum surface temperature of 135°C in ambient temperatures -10 to +50°C. Maximum operating pressure is 8 bar, and maximum cycle time is 1Hz. The IP6x indicates a variable IP rating against ingress of water depending on connections and fitting.

Hazardous Zones, Equipment Categories & Protection Concepts

A) Hazardous Zones - Gases, Vapours & Mists

Zone 0 "Worst Scenario"	A place in which an explosive atmosphere consisting of a mixture with air of dangerous substance in the form of gas, vapour or mist is present continuously or for long periods or frequency, over 1000 hours / year or >10% of the time.
Zone 1	A place in which an explosive atmosphere consisting of a mixture with air of dangerous substance in the form of gas, vapour or mist is present during normal operation occasionally, over 100 hours / year or >1% of the time.
Zone 2	A place in which an explosive atmosphere consisting of a mixture with air of dangerous substance in the form of gas, vapour or mist is not likely to occur in normal operation but if it does occur will persist for a short period only, typically under 10 hours/year or 0-0.01% of the time

B) Hazardous Zones - Dusts

Zone 20	A place in which an explosive atmosphere in the form of cloud of combustible dust in air is present continuously or for long periods or frequently, over 1000 hours / year or >10% of the time.
Zone 21	A place in which an explosive atmosphere in the form of cloud of combustible dust in air is present under normal operation occasionally, over 100 hours / year or >1% of the time.
Zone 22	A place in which an explosive atmosphere in the form of cloud of combustible dust in air is present in normal operation but if it does occur will persist for a short period only, typically under 10 hours/year or 0-0.01% of the time

Note: Layers, deposits and heaps of combustible dust must be considered as another source which can form an explosive atmosphere.

C) Equipment Categories

The hazardous area zone classification and corresponding equipment categories are:

Zone 0 or Zone 20 = Category 1 Equipment
Zone 1 or Zone 21 = Category 2 Equipment
Zone 2 or Zone 22 = Category 3 Equipment

Note: Category 1 equipment can also be used in zones 1 & 21, and category 1 & 2 equipment can be used in zone 2 & 22.

D) Protection Concepts

There are many code letters used to define protection concepts, typically one or two lower case letters. Different codes are used for electrical, non-electrical and dust protection. Each indicates typical zones in which the product may be used & EN standards that apply. The "c" that appears in the Kuhnke valve and cylinder certification indicates "ignition hazards eliminated by good engineering methods"