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fire-tube boiler

American  
[fahyuhr-toob, -tyoob] / ˈfaɪərˌtub, -ˌtyub /

noun

  1. any boiler for generating steam by passing hot gases and other combustible products through tubes fire tubes immersed in water to a chimney or uptake.

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.