Purging, Type X : In the United States and Canada, a method of reducing the classification within an enclosure from Division 1 to Nonhazardous (unclassified)
EESiFlo North America, Terminology and Glossary: Explosion Proof & Hazardous Areas, Pennsylvania, USA 2002, flowmeterdirectory.com/flowmeter_terminology, (Mrtm/ Explo Proof and Haz Areas - Amer) {561}