An oil sequestering, air-drying cartridge device comprises a pair of tandem fluid diodes for respectively preventing backflow of moist air into an oil coalescing filter and preventing backflow of dry air into a desiccant material. The device comprises an outer cartridge skin and a middle shell concentrically nested between the cartridge skin and an inner shell. The middle shell houses channel walls having offset wave-like contours that prevent backflow of moist air into the oil filter, and the inner shell comprises similar channel walls that prevent backflow of dry air into the desiccant, which is positioned between the inner and middle shells.