International aspects of electrical trace heating in potentially explosive atmospheres

Since the introduction of electrical trace heating systems in industry, approximately half a century ago, there has been a potential conflict of interest between trace heating equipment and the requirements of potentially explosive atmospheres. This conflict is a direct result of applications within oil, gas and petrochemical industries that require trace heating systems for operation-and the generation of electrical heat energy by electric surface heating systems. The problem was, and still remains, that the trace heating system is required to develop as much heat energy as possible (with as few materials as possible) whilst the task of the declared hazardous area within a plant is to avoid as much heat as possible. Here, the author examines the international standards aspects of electrical trace heating in hazardous areas.