Abstract: A method of vending a containerized product using multiple fillings of the same container. The method includes the steps of placing machine-readable indicia on the container indicative of the price charged for both the container and the product contained therein, and at the time of placement of said indicia, or subsequently to such placement, including at a location adjacent said indicia, a stimulus-responsive machine-readable indicator capable of responding to a stimulus to undergo a change of state which is readable, conjunctively with said indicia, by a machine, to indicate a price to be charged solely for the product in the refilled container.

Abstract: An apparatus for exchanging pressure energy between a fluid having a high energy content as a result of pressurization, and a fluid having a relatively lower pressure. The apparatus includes a rotor which has a plurality of spaced tubes extended in substantially parallel array over a major portion of the rotor length, and each having a separatory member movably mounted therein for reciprocatory displacement in the respective tube. Each of the fluid conveying tubes has its opposite ends movably but sealingly received in recesses in; floating rotor seal plates. Each seal plate further includes an arcuate port which completes the opening formed by both the recess and port through the seal plate. The opposite side of each seal plate from that which contains the recesses into which the respective tubes extend bears sealingly against a fixed stator block.