DIFF Subgroup
F16J 15/121 Full Title
Sealings > between relatively-stationary surfaces (F16J15/46, F16J15/48 take precedence) > with solid packing compressed between sealing surfaces > with non-metallic packing > with metal reinforcement or covering
Of 4 combined children, 0 exist in both systems.
4 codes are CPC-only extensions.