Transits and sealing systems for pipes and cables through bund walls around (storage) tanks can be exposed to serious disasters. For example, combustible substances can accumulate inside the walls as a result of a tank leak. Furthermore, in case of fire the bund wall serves as a barrier preventing the fire-fighting water from spilling over into the surroundings. In the event of such disasters, the hydrostatic pressure exerted on the transit and the sealing system increases considerably. To assure customers that the sealing system stays intact in such disaster scenarios, Beele Engineering commissioned an examination of the NOFIRNO sealing system, with positive results. The system proves to be well-suited for use as a sealing technology for transits through bund walls.
Storage of Hazardous Substances
The aboveground storage of combustible substances in vertical cylindrical tanks has its safety risks. This is why the Advisory Council on Hazardous Substances (AGS) has developed safety directives in the form of the Publication Series Hazardous Substances 29 (PGS 29). These directives also specify requirements to be met by transits through the bund wall around a tank pit. This bund wall traps the product(s) from the storage tank(s) or potential fire-extinguishing water. As such, the transit must be liquid-proof and able to withstand the maximum expected hydrostatic pressure, as well as the stored substances. The transits must furthermore be strong and flexible enough to be able to absorb the unexpected settlement of pipes and dikes.
This is why Kiwa developed risk scenarios and functional requirements for transits on the basis of the PGS 29. Worst case scenarios are always used for this purpose. The scenarios are related to liquid-tightness, fire resistance and unexpected settlements.
Beele Engineering’s system has proven itself able to withstand an extremely high water level on the outside of the bund wall and for a 72-hour period is able to withstand fluid leaks at a hydrostatic pressure exerted by a liquid column of several metres. Furthermore, the sealing system stays intact for a period of 2 hours during a pool fire. In addition, the sealing system stays liquid-tight in the event of the longitudinal and lateral movement of the transit. As such the system meets the specifications of the PGS 29 Directive.