Maximum explosion pressure in flameproof enclosures: The effects of the vessel and the ambient temperature

Abstract

Explosion pressures measured in the Westerberg apparatus for determining the design requirements of flameproof enclosures in various flammable atmospheres (as generally used in the U.S.A.) are not the same as pressures measured in a 4-1, spherical explosion vessel generally used in the U.K. Probable causes of the differences are examined. Explosion pressures can be reduced by heat losses to the outer enclosure, and enhanced by local volumes in which spontaneous ignition may occur, transition to turbulent burning, pressure piling, and transition to detonation, all of which are suspected of influencing the results. As a result of detailed examination of the differences, the application of test procedures for flameproof enclosures can be considered.