This document applies to the classification of locations for both temporarily and permanently installed electrical equipment, The suitability of locations for the placement of non-electrical equipment is not within the scope of this document. Piping systems used for odorized natural gas used as fuel for cooking, heating, air conditioning, laundry and similar appliances are also beyond the scope of this document. A possible catastrophe such as a well blowout or a process vessel rupture is not covered; such an extreme condition requires emergency measures at the time of occurrence. Recommendations for determining the degree and extent of classified locations for specific examples of situations commonly encountered in petroleum facilities are given in Sections A, B, and C. While it is important for area classifications at refineries, production and drilling facilities, and pipeline facilities to agree to some extent, there are differences in production, drilling, transportation and refining facilities - accounting for, at least in part, that three different documents were prepared originally. Some differences include the types and quantities of products handled, the physical size of typical facilities, and varying housing/shelter practices. Section A is applicable to Iocations in which flammable petroleum gases and volatile flammable liquids are processed, stored, loaded, unloaded, or otherwise handled in petroleum refineries. Section B is applicable to locations surrounding oil and gas drilling and workover rigs and facilities on land and on marine fixed and mobile platforms where flammable petroleum gas and volatile liquids are produced, processed (for example, compressed), stored, transferred (for example, pumped), or otherwise handled prior to entering the transportation facilities. Section C is applicable to onshore and offshore facilities handling the delivery of flammable or combustible petroleum liquids or flammable gases. Pipeline facilities may include pump and compressor stations, storage facilities, manifold areas, valve sites and pipeline rightof- way areas.