Conversion from Division to Zone electrical classification-why and how the worlds largest oil company made the change

The introduction in the late 1990s of the Zone electrical area classification concept into North American standards provided the catalyst for a major international oil company based in Saudi Arabia to convert from the "Division" to the "Zone" method of area classification. The company initially relied on North American standards to purchase materials but, over the years, sourcing of materials, and design and construction services gradually shifted away from North America. This required the company to restructure their standards and accept materials and installation practices from all over the world. Today, the company standards accept materials and installation techniques from a variety of international sources. The Zone classification system was considered to provide the maximum flexibility and safety in hazardous locations. Therefore, it was considered preferable over the Division system from a cost, safety, maintenance and reliability viewpoint. In late 1999, the company decided to convert from a Division to Zone Classification system. This paper discusses details of why and how the company made the change and the impact of the migration on electrical and instrumentation installations within the company.