Source:http://linkedlifedata.com/resource/umls/id/C0182122
UMD: Small containers (i.e., canisters) designed for temporary storage of oxygen before delivery to a single patient. These containers may store oxygen gas or liquid oxygen (LOX). Oxygen gas canisters may store the equivalent (at standard pressure) of two to three liters of oxygen at relatively high pressures or the equivalent of 20 to 25 liters at higher pressures. LOX canisters usually consist of a small-capacity (e.g., one liter) double-vessel tank; an insulated inner vessel contains the liquid oxygen at a temperature of -183°C (-297°F) and an outer vessel for protection; one liter of liquid oxygen provides 860 liters of gas. Vacuum in the space between both vessels insulates the liquid oxygen from the environment in a way similar to a thermos bottle; the canister may include a vent line for slow release of the gas from the boiling liquid. Oxygen canisters are intended mainly for use with individual ambulatory oxygen delivery units; they are typically refilled from larger containers located at users'