Cascade Filling System

A cascade filling system is a high-pressure gas cylinder storage system used to refill smaller compressed gas cylinders. It works by connecting the cylinder being filled to a bank of storage cylinders in sequence, starting with the one at the lowest usable pressure and moving to higher-pressure cylinders to finish the fill, so pressure equalizes between the storage cylinder and the receiving cylinder at each step rather than requiring a compressor to run continuously. The storage bank also acts as a reservoir, letting a lower-capacity compressor keep up with demand by recharging the cylinders between fills. Cascade filling systems are used to fill diving cylinders and blend gas mixtures such as nitrox and trimix, to fuel compressed natural gas vehicles at CNG stations, and to store hydrogen at hydrogen refueling stations. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/