An acronym for Adjustable Pressure Phase Separator. The APPS is a system that takes cryogenic liquid from a higher pressure source (120 psig for example), and reconditions it to a lower pressure (50 psig for example). An APPS unit makes it possible to utilize one bulk storage tank for two applications, one being a higher pressure than the other. This unique system often eliminates the need for two bulk storage tanks to serve the two different applications.