fire tube; furnace flue; smoke tube
Technical term for a tube through which hot gases pass in a boiler or furnace. Compare 煙管 (えんかん) sense 2, which is a synonym.
See also: 煙管 (えんかん)
A crack was found in the boiler's fire tube.
The furnace flue of this furnace is made of heat-resistant steel.
signal flare; fusee
Compound of 炎 (flame) and 管 (tube, pipe). A technical term likely coined in the context of boiler engineering.