The international identifier for explosion-proof equipment is represented by Ex. It is derived from the word “Explosive”, and the explosion-proof capability of the equipment is clearly indicated by this mark.
The dust explosion-proof method known as “protection by enclosure” is denoted by tD.
The core design principle is established as follows: the ingress of external combustible dust is effectively blocked by a high-strength enclosure, and any internal dust explosion pressure is safely withstood. Consequently, the leakage of flames and high-temperature gases is prevented by the enclosure so that the external environment is not ignited.
