Flame proof Vs Explosion Proof

[onthemove]

In Flameprrof(Ex-d) explosion is allowed inside, but the flame is not allowed to travel outside the enclosure. In Explosion prrof (Ex-e) no spark or explosion is allowed inside.
Other explosion proof variants like Ex-n, Ex-p, Ex-q etc.

[ummux]

Quote "In Explosion proof (Ex-e) no spark or explosion is allowed inside. Other explosion proof variants like Ex-n, Ex-p, Ex-q etc."

Above message about Explosion Proof is not correct. Ex e is "increased safety", Ex n is non incendive (or non sparking), Ex p and Ex q are also other types of protection methods. They are not revelant to explosionproof.

Explosion proof is normally used in North America (and some South America countries) whereas Flameproof is termed elsewhere. Flameproof uses the marking Ex d, explosionproof do not use term Ex d. They are under the same protection principle (which ignition is acceptable to occur inside the enclosure but will not propagate to outside through the gap. ) However the testing method (how many times for sample tests), the safety factor (1.5 for Ex d, 4 for explosionproof), and retrofit (field drill acceptable for Ex d, not allowable for explosion proof) requirements are different.