Mechanical ATEX Equipment

Mechanical (non-electrical) equipment, such as pumps, fans, mixers, screw conveyors, bucket elevators and conveyor belts, may contain ignition sources capable of igniting an explosive atmosphere.

When such equipment is intended for use in potentially explosive atmospheres, it must comply with the requirements of the ATEX Directive 2014/34/EU.

However, not all mechanical equipment automatically falls within the scope of ATEX. The determining factor is whether the equipment has its own potential ignition source. Even when ATEX Directive 2014/34/EU does not apply, the suitability of the equipment for use in potentially explosive atmospheres must still be assessed.

Ignition Hazard Assessment according to EN ISO 80079-36

For mechanical ATEX equipment, the Ignition Hazard Assessment (IHA) according to EN ISO 80079-36 forms the basis for explosion-safe design.

This assessment identifies and evaluates potential ignition sources, such as hot surfaces, mechanically generated sparks, friction, electrostatic discharges and overheating of bearings or seals.

The assessment generally involves the following steps:

1. Establishing the intended application, the required ATEX equipment category and Equipment Protection Level (EPL).
2. Identifying potential ignition sources and the conditions under which they may occur.
3. Evaluating ignition hazards during normal operation and, depending on the required equipment category, during expected and rare malfunctions.
4. Determining the necessary protective measures and evaluating any remaining ignition hazards.

Both internal and external potentially explosive atmospheres must be considered, where applicable.

Types of Protection according to EN ISO 80079-37

Where potential ignition sources are present, protective measures may be necessary to prevent them from becoming effective.

EN ISO 80079-37 specifies three types of protection:

• Constructional safety 'c': preventing effective ignition sources through suitable mechanical design and construction.
• Control of ignition source 'b': monitoring critical parameters and taking appropriate action before an ignition source becomes effective.
• Liquid immersion 'k': preventing ignition by keeping potential ignition sources immersed in a protective liquid.

These types of protection may be applied individually or in combination. Mechanical equipment complying with these standards is marked Ex h.

Read more about the transition from EN 13463 to EN ISO 80079-36 and -37.

ATEX Certification of Mechanical Equipment

The applicable conformity assessment procedure depends on the ATEX equipment category. For non-electrical equipment of Group II, the following generally applies:

• Category 3G/3D: the manufacturer may perform the conformity assessment and declare conformity without the involvement of a Notified Body.
• Category 2G/2D: the manufacturer may also perform the conformity assessment, but must lodge the technical documentation with a Notified Body.
• Category 1G/1D: conformity assessment involving a Notified Body is mandatory.

An EU-type examination is therefore not always required. However, the manufacturer must demonstrate compliance with the applicable Essential Health and Safety Requirements (EHSRs).

This must be supported by technical documentation, including the Ignition Hazard Assessment, design drawings, technical justifications, instructions, ATEX marking and EU Declaration of Conformity.

Mechanical Equipment and IECEx

Mechanical equipment can also be certified under the IECEx 02 Certification Scheme, based on ISO 80079-36 and ISO 80079-37.

Unlike ATEX, IECEx does not permit self-declaration of conformity. Assessment and certification must be performed by a recognised IECEx Certification Body (ExCB).

Existing Mechanical Equipment

Mechanical equipment placed on the EU market and put into service before 1 July 2003 does not have to comply retrospectively with ATEX Directive 2014/34/EU.

However, the employer must ensure that the equipment is suitable for safe use in the intended potentially explosive atmosphere. Substantial modifications may require a new conformity assessment.

How Can MIBEX Assist You?

MIBEX supports manufacturers and machine builders with the ATEX assessment of mechanical equipment. Our services range from Ignition Hazard Assessments and advice on suitable types of protection to preparing technical documentation, equipment markings, instructions and EU Declarations of Conformity.

We provide practical, technically sound solutions and, where required, assistance with ATEX and IECEx certification.

Do you have questions about the ATEX assessment of your mechanical equipment? Please feel free to contact us.