Boilers can be classified into the following configurations:
Pot Boiler: A water container is heated from a fire heat underneath the “kettle”.
Flued Boiler: One or two large flues—an early type or forerunner of fire- tube boiler.
Fire Tube Boiler: A small amount of air is left in the boiler barreling order to accommodate the steam.
Water Tube Boiler: A furnace is filled with tubes of water. These could be used in high pressure applications.
Flasher Boiler: A specific Water Tube Boiler where close tubes of water is pumped through them.
Fire Tube Boiler with Water- tube firebox: The fire box will contain tubes filled with water which then allows the water to pass through a fire tube boiler.
Sectional Boilers: Water is contained inside cast iron sections, which are assembled on site in order to complete the boiler.