The containment method involves containing an explosion within the enclosure of the equipment.
By doing so, it prevents any sparks or flames from escaping into a hazardous environment and causing further fires or explosions.
This method is commonly used with components that generate sparks, such as switchgear, control panels, or transformers.
An explosion-proof enclosure is marked with the symbol (Ex d).
Explosion-Proof Enclosures (Ex d)
![ex proof symbol](https://www.forbesmarshall.com/wp-content/uploads/2024/11/exproof-logo.webp)
Symbol for ATEX certified electrical equipment for explosive atmospheres.
These enclosures, also known as flameproof enclosures, are designed to encase components that could ignite an explosive atmosphere, such as through sparking.
To qualify as explosion-proof, these enclosures must adhere to the following criteria:
- All joints leading to the external environment must be flameproof.
- The enclosure must be robust enough to endure an internal explosion without any rupture or permanent deformation.
- The surface temperature of the enclosure must always remain below the ignition temperature of the surrounding gas-air mixture.