DIFF Subgroup
C01B 21/0405 Full Title
Nitrogen; Compounds thereof > Purification or separation of nitrogen (by liquefying F25J)
Of 3 combined children, 0 exist in both systems.
3 codes are CPC-only extensions.
C01B 21/0405 Nitrogen; Compounds thereof > Purification or separation of nitrogen (by liquefying F25J)
Of 3 combined children, 0 exist in both systems.
3 codes are CPC-only extensions.