ISA RP12.4

Abstract

This recommended practice applies to equipment made suitable for use in hazardous (classified) locations by the use of a pressurizing system. <br>This recommended practice applies both to equipment with and without an internal release of a flammable gas or vapor. <br>This recommended practice does not apply to occupied portions of buildings such as ventilated or pressurized control rooms. <br><strong>Purpose</strong> <br>This recommended practice provides guidance to those who design and install pressurized systems for hazardous (classified) locations, and should be used in conjunction with ANSI/NFPA 496, Purged and Pressurized Enclosures for Electrical Equipment. <br>This recommended practice provides performance and test recommendations so that the enclosure and components mounted internally or protruding through the enclosure are unlikely to cause ignition of a surrounding flammable atmosphere. <br>This recommended practice provides performance and test recommendations so that users are unlikely to be injured by rupture of the enclosure due to failure of the pressure-regulating devices in the PROTECTIVE GAS SUPPLY.