As nouns the difference between downcomer and downcomes
is that downcomer is a large external pipe in a water-tube boiler, carrying unheated water from the steam drum down to the water drum as part of the circulation path while downcomes is .
downcomer
English
Noun
(
en noun)
A large external pipe in a water-tube boiler, carrying unheated water from the steam drum down to the water drum as part of the circulation path.