specification that indicates an enclosure is capable of withstanding and confining internal explosions
AN ENCLOSURE CAPABLE OF WITHSTANDING AN EXPLOSION OF A SPECIFIED GAS OR VAPOR WHICH MAY OCCUR WITHIN IT AND OF PREVENTING THE IGNITION OF A SPECIFIED GAS OR VAPOR SURROUNDING THE ENCLOSURE BY SPARKS,FLASHES OR EXPLOSION OF THE GAS OR VAPOR WITHIN IT MUST ALSO OPERATE AT SUCH AN EXTERNAL TEMPERATURE THAT A SURROUNDING FLAMMABLE ATMOSPHERE WILL NOT BE IGNITED
Apparatus enclosed in a case that is capable of withstanding an explosion of a specified gas or vapor that may occur within it and of preventing the ignition of a specified gas or vapor surrounding the enclosure by sparks, flashes, or explosion of the gas or vapor within and that operates at such an external temperature that a surrounding flammable atmosphere will not be ignited