DIFF Subgroup
F22D 1/46 Exhaust-steam preheaters
Introduced: September 1968
Full Title
Full titles differ between systems:
IPC:
Feed-water heaters, e.g. preheaters > specially adapted for locomotives > Exhaust-steam preheaters
CPC:
Feed-water heaters, i.e. economisers or like preheaters > specially adapted for locomotives > Exhaust-steam preheaters
No child classifications to compare. This is a leaf node in both IPC and CPC.