| 62 / | HD | REFRIGERATION |
| 600 | DF | CRYOGENIC TREATMENT OF GAS OR GAS MIXTURE {4} |
| 617 | DF | .~ Separation of gas mixture {3} |
| 640 | DF | .~.~ Air {3} |
| 643 | DF | .~.~.~ Distillation {4} |
| 648 | DF | .~.~.~.~ Downstream operation {2} |
| 653 | DF | .~.~.~.~.~ Flowline pump {1} |
| 654 | ![]() | .~.~.~.~.~.~ Liquid oxygen |