Used (2) x 140 TPD cryogenic oxygen plants. These plants produce oxygen in gas and liquid (5 TPD LOX) forms. Turndown ratio 70%. The plant has a major upgrade in 1994. Air undergoes filtration and compression using 3-stage centrifugal compressors (100% or 70%). Compressed air is then cooled in a water-cooled aftercooler and further cooled in reversing heat exchangers. In the distillation columns, the cold air is separated into oxygen product and waste nitrogen. An intermediate air stream is diverted to the expansion turbine for refrigeration. Liquid oxygen is extracted from the low-pressure column and stored, while gas oxygen is warmed against incoming air and released at 16 Psia. Waste nitrogen cleans the reversing exchanger passages, is warmed against incoming air, and released. Silica gel traps remove entrained hydrocarbons from the main condenser.