Oxygen is the second largest component of the atmosphere, comprising 20.8% by volume. Gaseous oxygen is colorless, odorless, tasteless, and nonflammable. Oxygen is necessary to support life. It is a strong oxidizer that combines readily with many elements to form an oxide and is necessary to support combustion. 氧是空氣的第二大組成成分，體積占20.8%。氣態氧無色，無嗅，無味，不可燃。氧是維持生命的必要元素。氧是一種強氧化劑，很容易同許多元素反應，生成氧化物。氧還是維持燃燒的必需品。 Oxygen will react with nearly all organic materials and metals. Materials that burn easily in air will burn more vigorously in oxygen. Equipment used in oxygen service must meet stringent cleaning requirements; any system must be constructed of materials that have high ignition temperatures and which are nonreactive with oxygen under the service conditions. Vessels should be manufactured to American Society of Mechanical Engineers (ASME) codes and designed to withstand the temperatures and pressures involved. 氧幾乎同所有的有機材料和金屬發生反應。在空氣中容易燃燒的材料在氧氣中會燃燒的更加劇烈。氧氣設施中使用的設備必須滿足嚴格的清潔要求；系統必須采用具有高點火溫度且在使用條件下同氧不反應的材料建造。容器的制造要滿足美國機械工程師協會（ASME）的標準，容器的設計要使之能經受住有關的溫度和壓力。 Manufacture生產 Oxygen is produced by an air separation unit(ASU) through the liquefaction of atmospheric air and separation of the oxygen by continuous cryogenic distillation. The oxygen is then removed and stored as a cryogenic liquid. Oxygen can also be produced noncryogenically using selective adsorption processes to produce gaseous product. 氧的生產使用空氣分離裝置（ASU），通過大氣的液化和連續低溫蒸餾分離出氧。隨后，氧以低溫液體的狀態搬運和儲存。氧的生產還可以不采用低溫的方法，而是采用選擇性吸附過程來生產氣體產物。 The ASU manufacturing process begins with a main air compressor and ends at the output of the product storage tanks. Air is compressed and sent through a clean-up system where moisture, carbon dioxide, and hydrocarbons are removed. The air then passes through heat exchangers where it is cooled to cryogenic temperature. Next, the air enters a high pressure distillation column where it is physically separated into a vaporous form of nitrogen at the top of the column and a liquid form of “crude” oxygen (~90% O2) at the bottom. ASU生產過程從一個主氣流壓縮機開始，產品儲存罐的輸出后結束。空氣通過一個去除了水蒸汽、二氧化碳和碳氫化合物的清潔系統壓縮和輸運。接著空氣通過熱交換器冷卻到低溫。隨后空氣進入高壓分裂蒸餾塔，分離成氮蒸氣和“原始”液氧（含大約90%的氧），氮蒸氣在蒸餾塔頂部，液氧在蒸餾塔底部。