Fire-tube boiler (smoke tube boiler
Principle: Flue gas flows inside the pipe, while water flows outside.
Features: Simple structure, low cost, and low water quality requirements; However, it has low pressure, low efficiency and small capacity.
Applicable: Small enterprises, hotels, and heating in residential areas.

Water-tube boiler
Principle: Water flows inside the pipe, while flue gas is heated outside the pipe.
Features: Strong pressure-bearing capacity, high thermal efficiency, and large evaporation capacity; The structure is complex and the water quality requirements are high.
Applicable to scenarios such as power stations and large factories that require high-pressure and large-capacity steam.