Study on sealing characteristics of elastomer O-rings under low temperature

This study considers four kinds of elastomers often employed in the containment system of a cask. Under various low temperature conditions the relation between load and displacement characteristics (spring constant) and that between load and sealing performance are shown as data related with the above points, using temperature as a parameter, to clarify the sealing performance and simultaneously propose points to consider as for low temperature characteristics in designing containment system. The following conclusions were obtained from the investigation presented here: (1) If an elastomer does not retain elasticity body under the temperatures of -40degC but can maintain the resistance force between the O-ring and the flange, it can be considered they are capable of retaining seal. (2) When selecting sealing materials, they should not only be evaluated with respect to material properties, but should also be tested as described in this report and assessed for deterioration. (3) The most important point is that the containment system is designed taking into account of the sealing characteristics of selected elastomer sufficient based on the imposed load. (J.P.N.)