Hazardous Area Classification (HAC) study is the required analysis for minimizing the likelihood of ignition of flammable material while considering gas/vapour/combustible dust sources and ignition design controls. Oil and Gas Facilities, refinery, chemical, and related industries depend on accurate Hazardous Area Classification documentation and drawings to determine the proper type of electrical equipment permitted in their facilities.

Area classification can be carried out by direct analogy with typical installations described in established codes, or by more quantitative methods that require a more detailed knowledge of the plant. The starting point is to identify sources of release of flammable gas or vapour. These may arise from constant activities; from time to time in normal operation; or as the result of some unplanned event. In addition, inside process equipment may be a hazardous area, if both gas/vapour and air are present, though there is no actual release.

Hazardous areas are classified into zones based on an assessment of the frequency of the occurrence and duration of an explosive gas atmosphere, as follows:

• Zone 0: An area in which an explosive gas atmosphere is present continuously or for long periods;
• Zone 1: An area in which an explosive gas atmosphere is likely to occur in normal operation;
• Zone 2: An area in which an explosive gas atmosphere is not likely to occur in normal operation and, if it occurs, will only exist for a short time.

Relevant standards and codes for Hazardous Area Classification

• IEC 60079 series
• CENELEC 60 079 series
• ANSI/API RP 505 (zone system)
• Gost R 51330-X-99 series
• Model CODE of safe practice Part IP 15 (UK)
• “Non binding guide of good practice for implementing Directive n” 1999/92/EC”
• API RP 505 Classification of locations for at Petroleum facilities

At Capeserve Energy, we provide Hazardous Area Classification studies for Petrochemical, Power, Pharmaceutical, Chemical Processing, and other industries where gas and dust atmosphere present. Our experts are IECEx CoPC certified professionals having more than 25 years of experience in area classification works. The Hazardous Area Classification methodologies addressed by NFPA, API, CSA, EI 15 and the IEC standards produce Hazardous Area Classification schedule and Hazardous Area Classification layouts. Our unique approach to Hazardous Area Classification goes beyond the industry standard for unit boundary limit area classifications to address essential details in boundary extents and ignition source gaps.