ExECA flameproof enclosure is a tested explosion-protection construction for equipment that may contain ignition-capable components. It is not intended to stop flammable gas from ever entering, and it is not simply a thick metal box. Its job is to withstand a specified internal explosion and prevent that event from transmitting through the enclosure joints in a way that ignites the surrounding atmosphere.
This article focuses on the physical enclosure: body, cover, flamepaths, fasteners, entries and inspection. For the broader selection sequence, read Flameproof Fundamentals. For Ex d, db and EPL marking, read What is Ex d protection?.
The containment principle
Switches, contactors, relays and other electrical components may create arcs, sparks or hot surfaces. If an ignitable gas mixture is present inside an enclosure and ignition occurs, pressure rises rapidly.
A compliant flameproof enclosure is designed and tested so that:
