A flameproof enclosure’s effectiveness stems from its ability to contain flames within, selv når der opstår en eksplosion inde i det elektriske udstyrs kabinet. Denne indeslutning sikres ved at forhindre flammerne i at slippe ud gennem forskellige fugeflader.
Overholdelse af specifikke standarder vedrørende kløften, længde, and surface roughness of these joints is crucial. These gaps not only extinguish the flames but also cool them effectively. They reduce the temperature of the flames passing through to a level insufficient for igniting any eksplosiv mixtures that may be present outside the enclosure.