During long coast periods of zero-gravity, storage vessels for the cryogenic liquids proposed for use in some power transmission systems undergo random distribution of the liquid and vapor phases therein. Thus, when heat flow into the vessel causes the vessel pressure to build-up requiring venting to maintain a safe value, the likelihood of venting the valuable liquid phase, as well as the vapor, results. To preclude this eventuality, various devices for separating the liquid and vapor phases and venting just the vapor have been studied and carried into the experimentation stages.
