Research Report on the Determination of Potentially Explosive Areas in Storage Tanks Published

This report evaluates a project in which a floating roof tank for petrol was monitored with regard to its emission behaviour in a long-term measurement. The floating roof tank has a capacity of 12 000 m3 and is used for the storage of Super E5 petrol. Since the floating roof tank is not a closed system, emissions of volatile organic fuel components cannot be excluded. Consequently, the possibility of the formation of a hazardous explosive area must also be considered. The floating roof tank and the adjacent areas are hazardous areas, to which zones of different probability of occurrence of a hazardous explosive atmosphere are assigned. These assignments in accordance with TRGS 509 are based on the state of the art of science and technology.

In the project, the emission behaviour is to be theoretically estimated using API 2517/2519 and VDI 3479. Long-term measurements are carried out with a detector network of IR transmission detectors. The aim of the project was the metrological assessment of whether the actual emission behaviour corresponds to the zone allocation or deviates from it. The measurement results show that current zone allocation by the TRGS 509, especially for the areas in the collection room, at the discharge surfaces and at the tank wall (zone 1), appears to be overly conservative.