ATEX approval for starting systems

ATEX (“Atmospheres Explosibles”) is a safety standard defined by the European Union in 1994. It defines a set of regulations governing equipment and protective systems intended for use in potentially explosive atmospheres. Although it originated in Europe, ATEX approval is used worldwide as a ready-made safety standard.

IPU design and manufacture starting systems with ATEX approval for two markets:

1. 1. 1. Underground mining
         • IPU starting systems are used on FSVs (free-steer vehicles), underground rail systems, winches, wire lines, compressors and fire systems.
      2. Oil and gas platforms and drilling rigs
         • IPU starting systems are used on emergency fire pumps, offshore power packs, winches, wire lines and compressors.

The regulations the define ATEX approval are contained in three documents. You can download them from the bottom of this page:

1. 1. 1. The ATEX Directive (EU 94/9/EC)
      2. The Consolidated Text of the ATEX Directive
      3. The Application Guidance for the ATEX Directive which was last updated in December 2013

ATEX approval for starting systems

No safety directive can refer specifically to all the equipment that might be affected by it. It comes as no surprise that starting systems are not listed by name.

It does, however, cover all forms of equipment which are capable of creating an explosion through their own source of ignition (excluding cookers, heaters, etc. which are meant to provide ignition). Starting systems clearly fall into this category because they could cause sparks when the rapidly spinning pinion touches an engine’s ring-gear.

One of the critical design elements that helps IPU’s starting systems conform to ATEX is the use of a pre-engaged starting process. “Pre-engaged” means that the starter’s pinion teeth are fully meshed with the engine’s ring gear before the high-speed cranking sequence begins. This eliminates the risk of sparks associated with inertia starters.

ATEX approval for starter casings

The latest ATEX guidelines strongly discourage the use of aluminium:

Friction impacts … involving … light metals (e.g. aluminium and magnesium) … may initiate an aluminothermic (thermite) reaction which can give rise to particularly incendive sparking.

While it is theoretically possible for a starter with an aluminium case to gain ATEX approval, any operator that suffers an accident that was exacerbated by the ferocity of a thermite reaction will have to explain their decision.

Thermite reactions cause brief periods of intense heat. They require a fuel such as aluminium and an oxidiser such as iron(III) oxide (known to you and me as “rust”). They were responsible for 11 mine explosions in the US in the 1950s. It is inviting another disaster to put these two materials close together in a mine, on an oil platform or in any other potentially explosive atmosphere.

ATEX and British Standards

ATEX encompaases two British Standard that affect the offshore and mining industries:

BS EN 1834-1:2000 and BS EN 1834-2:2000 cover reciprocating internal combustion engines and require that mechanical starters shall be of the pre-engaged type.

• • • EN1834-1:2000 is the standard applied to diesel engines operating in a gas explosive or potentially explosive atmosphere (i.e. offshore platforms and drilling rigs).
    • EN1834-2:2000 is the standard applied for diesel engines in a potentially explosive atmosphere in mining applications.

BS EN 13463-1:2009 specifies the basic methods and requirements for the design, construction, testing and marking of non-electrical equipment in explosive or flammable atmospheres.