INTRODUCTION TO EX EQUIPMENT REPAIRS
AEMT INTRODUCTION TO EX EQUIPMENT REPAIRS A guide for users of Ex equipment Wherever there are gas or dust atmospheres, there is the potential for explosions with disastrous results. One of the most serious examples of this in recent years was the Deepwater Horizon incident in 2018. The financial cost to BP of this avoidable catastrophe was some £65 billion. But more importantly, 11 lives were sadly lost, and the explosion started a chain of events which led to the largest marine oil spill in history. Thirty years before Deepwater Horizon, 167 lives were lost when the Piper Alpha oil platform suffered a catastrophic explosion. It is easy to see, therefore, why legislation and schemes relating to hazardous areas and ensuring they are followed is essential. In the EU (and a few non-EU jurisdictions), this critical area falls under the ATEX (ATmosphères EXplosibles) Directive and elsewhere, the IECEx voluntary scheme.
EX-RATED EQUIPMENT
Six zones, three for gas and three for dust, are two standards – IEC 6007910-1 for gasses and IEC 60079-10-2 for combustible dusts – based on the type of atmosphere and the quantity likely to be present. These, in turn, are reflected in the types of explosion protection (Ex protection) techniques or concepts required in products for use in the various zones. For electric rotating machines, for example, these include ‘Ex d’ for flameproof protection, ‘Ex t’ which covers dust, ‘Ex e’ which is increased safety protection, and Ex p for pressurised enclosures. These techniques affect the design of Ex-rated electrical equipment compared to non-Ex-rated alternatives. As a result, electrical products, such as motors, designed for use in Ex zones differ
significantly from those intended for safe or non-hazardous areas. For example, some Ex-certified motors have enclosures that can withstand an internal explosion without rupturing. This
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