DIFF Subgroup
B01D 39/2003 Full Title
Filtering material for liquid or gaseous fluids > Other self-supporting filtering material > of inorganic material, e.g. asbestos paper, metallic filtering material of non-woven wires (porous ceramic material ; sintering metals C22C1/04; )
Of 2 combined children, 0 exist in both systems.
2 codes are CPC-only extensions.