Open Access

The objective of this research was to determine the resistance of frequently used sealing materials such as FKM, FVMQ, VMQ, EPDM, CR, CSM, IIR, PA, NBR and PUR in fuels and heating oil with and without admixtures of biogenic sources such as E10, diesel fuel with 5 % biodiesel, non-aged and 2 year aged B10 (heating oil with 10 % biodiesel), pure diesel, standard heating oil and premium grade fuel Super plus at 20 °C, 40 °C and 70 °C. Mass, tensile strength and breaking elongation of the test specimens were determined before and after the exposure for 84 days in the fuels. The visual examination of some elastomer test specimens clearly showed the great volume increase until break or partial dissolution. Shore hardness A and D (for PA) were determined before and after exposure of the test specimens in the biofuels for 42 days. There is not determined a threshold for the reduction in tensile properties and Shore hardness in the international standards. Therefore a threshold of 15 % was determined for the evaluation of the compatibility. In summary, it can be therefore stated that the chemical resistance of the fluoropolymers FKM and FVMQ in fuels and biofuels is the best one.

Materials compatibility is a major concern whenever the fuel composition is changed in a fuel system. Therefore frequently used sealing materials such as FKM (fluorocarbon rubber), FVMQ (methyl-fluoro-silicone rubber), VMQ (methyl-vinyl-silicone rubber), EPDM (ethylene-propylene-diene rubber), CR (chloroprene rubber), CSM (chlorosulfonated polyethylene), IIR (butyl rubber), PA (polyamides), N8R (acrylonitrile-butadiene rubber) and PUR (polyester urethane rubber) were exposed to E1 0, diese I fuel with 5% biodiesel, non-aged and 2 year aged 810 (heating oil with 10% biodiesel), and for comparison to pure diese! fuel, standard heating oil and Super plus without bioethanol at 20 °C, 40 oc and 70 oc for 84 days. Mass, tensile strength and breaking elongation of the test specimens were determined before and after the exposure. The visual examination of some elastomer test specimens clearly showed the great volume increase until break or partial dissolution. Shore hardness A and D (for PA) were determined before and after exposure of the test specimens to the biofuels for 42 days. There is not determined a threshold for the reduction in tensile properties and Shore hardness in the international standards. Therefore a threshold of 15% was determined for the evaluation of the compatibility. The sealing materials FKM, EPDM, N8R, FMVQ, CSM and PA were evaluated on the basis of this threshold as resistant in E1 0 at 20 oc and 40 °C. FKM, FVMQ and PA were resistant at 40 oc , and none of the materials were resistant at 70 °C. FKM and FVMQ absorbed much less 810 and swelled less. CR, CSM, EPDM, IIR, N8R and VMQ were not resistant to 810 at all at 20 oc, 40 oc and 70 oc as the decrease in the tensile properties was significantly over 50%. FVMQ and PA could be evaluated as resistant in non-aged and two year aged 810 at 20 oc and 40 oc, whereas FKM was resistant up to 70 °C. FKM, PA and PUR were evaluated as resistant in standard heating oil and pure diese! fuel at temperatures up to 40°C, only FKM was resistant up to 70°C. FVMQ, FKM, N8R, VMQ, CR and IIR can be evaluated as resistant in premium grade fuel Super plus without ethanol at 20 oc. FKM, FVMQ, VMQ and IIR were still resistant at 40 °C. FKM and FVMQ were evaluated as resistant with restrictions at 70 °C. ln summary, it can be therefore stated that the chemical resistance of the fluoropolymers FKM and FVMQ in fuels and biofuels is the best one.

Die derzeitigen Explosivstoffschutz-Anforderungen des Regelwerks ADR basieren auf einem überholten Stand der Technik. Die Unklarheiten führen bei den Ausrüstern und Betreibern der Gefahrgutfahrzeuge zu Unsicherheiten mit existenziellen Risiken und Kosten. Um eine Überarbeitung der ergänzenden Vorschriften für EX/III-Fahrzeuge zur Beförderung von explosiven Stoffen und Gegenständen der Klasse 1 in Versandstücken voranzutreiben, ist deshalb eine Untersuchung der Gefahren erforderlich, denen explosive Stoffe und Gegenstände während der Beförderung ausgesetzt sind. Hierzu werden auf Grundlage der heutigen Vorschriften bestehende konstruktive Lösungen untersucht und deren Wirksamkeit gegenüber einer typischen Wärmebelastung von außen festgestellt. Erforderlich dafür ist zunächst die Charakterisierung der Wärmeeinträge durch Kalorimeterversuche mit typischen Unfallbelastungen. Daraus abzuleiten sind dann idealisierte Belastungsszenarien, welche als Voraussetzung für eine Normungsarbeit angesehen werden sollen. Im letzten Schritt soll ein Textentwurf für die Erneuerung der bestehenden Vorschriften des ADR verfasst und im Anschluss international abgestimmt werden.

Packages for the transport of spent nuclear fuel are designed to endure severe accidents. To obtain approval, these transport packages must adhere to the specification-based criteria of the international transport regulations SSR-6 of the International Atomic Energy Agency (IAEA). To ensure compliance with these requirements, specific mechanical and thermal tests need to be addressed with respect to the package type. Typically, SSR-6 prescribes a mechanical test followed by a thermal fire test as part of different testing scenarios. To approve the latter test of the sequence, BAM performs calorimeter tests in advance with so-called fire reference packages for characterizing the actual fire and its impact on the package to be tested. Packages are designed with different geometry sizes depending on their purpose. For previous tests, the implemented test setups in the fire test stand were sufficiently dimensioned and could cover all requirements in this respect. However, to cover additional testing needs in the future, BAM is expanding the test setup for the purpose of testing significantly larger packages. In previous test setups one ring burner for propane surrounding the test specimen was sufficient. The limiting size in this configuration was the design height of the transport package to be tested. According to the thermal test of the IAEA-Regulations [1], a 30-minute fully engulfing 800°C pool fire or an equally severe fire, e.g., propane gas fire, must be applied to the transport package. Possible adjustments such as nozzle cross-section and propane mass flow can be adjusted to a certain extent. Further modifications, to cover significantly higher and larger packages all-around with a fully engulfing fire, must be accomplished with an additional, second burner ring. Both burner rings had the same dimensions and were mounted on top of each other at different heights to create a significantly larger volume of fire that completely engulfs the package including its impact limiter. To meet the IAEA regulatory boundary conditions, the enhanced fire test stand with the second burner ring is tested with a large fire reference package and will then be used for real-size transport packages after all parameters are successfully met. This fire reference package represents the external geometry of a generic transport cask for radioactive material and is equipped with numerous temperature sensors to record temperature curves at the interior wall surfaces.

Übersicht zu Baumusterzulassungsverfahren von Gefahrguttanks und deren aktuelle Problemfelder, Hinweise zur Optimierung des Verfahrens, Überblick über neue BK3-Container im Europäischen Binnenverkehr, Prüfung und Zulassung, Entwicklung eines standardisieren Prüfverfahrens