TY - JOUR A1 - Schlick-Hasper, Eva A1 - Bethke, John A1 - Jahnke, Wolfgang A1 - Drousch, Björn A1 - Goedecke, Thomas A1 - Kraume, M. T1 - Maximum gauge pressure in dangerous goods packagings under normal conditions of carriage - comparison of direct measurement and calculation JF - Packaging technology & science N2 - The objective of this work was to determine the maximum gauge pressure in the vapour phase above the liquid in different design types of dangerous goods packagings under normal conditions of carriage. The design types investigated were steel and plastic packagings with a volume of approximately 6 l. Two different methods were applied. In method 1, the pressure inside the packaging filled with a certain filling substance (dichloromethane) was directly measured under simulated conditions of carriage (degree of filling: 90%; filling temperature: 15°C; temperature during storage: 31°C). The maximum measured gauge pressures were between 89 mbar for a light plastic jerrican and 336 mbar for a steel drum. In method 2, the gauge pressure was calculated. The consideration of a rigid packaging combined with the assumption of a vapour pressure of zero during filling and sealing can serve as a worst case scenario. The calculated gauge pressure is approximately 1061 mbar. This procedure leads to the highest safety factor and does not require any experimental investigations. For a more realistic approximation of the gauge pressure of a non-rigid packaging, a packaging-specific function of relative expansion can be used, which is determined by a hydraulic pressure test. The calculated values ranged from 105 to 347 mbar. Method 2 provides conservative results. No hazardous filling substance is needed, and it allows a prediction of gauge pressure for other temperatures, substances and filling degrees. Therefore, this method could serve as alternative to UN Model Regulations 6.1.5.5.4 (a). KW - Dangerous goods packagings KW - Gauge pressure KW - Overpressure KW - Relative expansion KW - Data loggers KW - Normal conditions of carriage KW - Gefahrgutverpackungen KW - Überdruck KW - Relative Ausdehnung KW - Datenlogger KW - Normale Beförderungsbedingungen PY - 2015 DO - https://doi.org/10.1002/pts.2111 SN - 0894-3214 VL - 28 IS - 5 SP - 437 EP - 460 PB - Wiley & Sons, Ltd. CY - Chichester, UK AN - OPUS4-33108 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schlick-Hasper, Eva A1 - Seidler, Oliver A1 - Goedecke, Thomas A1 - Kraume, M. T1 - Measurement of helium leakage rates through closures of dangerous goods packagings for the assessment of potentially explosive mixtures in freight containers JF - Packaging technology & science N2 - The objective was to find out whether an explosive atmosphere can be created in a freight container by gaseous leakage flow of vapour-air-mixture through leaks in the closures of dangerous goods packagings filled with hazardous liquids. Because of high temperatures during intercontinental carriage, there is a gauge pressure in the free vapour phase inside the packagings which can cause a gaseous leakage flow. Two different methods were applied: Helium limit leakage rates for 23 quantitatively important hazardous liquids concerning their lower explosion limit (LEL) were calculated for a worst case transport scenario (Method 1). Helium leakage rates of five closure types of dangerous goods packagings with volumes of approximately 6 l were measured using the pressure technique by accumulation (Method 2). All types of closures of steel packagings were uncritical. The maximum measured leakage was 33% of the limit leakage rate. The leakage rates of screw closures of plastic jerricans can exceed the LEL if there are production-related patterns such as non-concentricity of the closures and flashes on the neck. Especially for plastic packagings it is important to minimize gaseous leakage flow, because an explosive atmosphere can also be reached by permeation of the individual filling substance or by a combination of both effects. For the assessment of potentially explosive mixtures in freight containers, both mass transfer mechanisms have to be taken into account. KW - Gefahrgutverpackungen KW - Dichtheit KW - Leckagerate KW - Überdruck KW - Frachtcontainer KW - Untere Explosionsgrenze KW - Dangerous goods packagings KW - Leakproofness KW - Leakage rate KW - Gauge pressure KW - Leak testing KW - Lower explosion limit PY - 2015 DO - https://doi.org/10.1002/pts.2151 SN - 0894-3214 VL - 28 IS - 11 SP - 959 EP - 985 PB - Wiley & Sons, Ltd. CY - Chichester, UK AN - OPUS4-34967 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -