Boilers are essential in many factories and power plants.
They create steam by heating water—and that steam is used for power, heat, or chemical processes.
But how do boilers work inside? What parts do they have?
This article will explain the basic structure of a boiler in simple words—especially the roles of fire tubes and water tubes.
What Is a Boiler?
A boiler is a machine that heats water to make steam.
This steam is used to power machines, heat buildings, or help in chemical reactions.
Two Main Types of Boilers
There are two basic types of boilers, based on how they handle fire and water:
1. Fire Tube Boiler
- Hot gas from a burner flows through metal tubes.
- Water surrounds these tubes.
- The hot gas heats the tubes, and the tubes heat the water.
- Simple and easy to use, but not for very high pressure.
2. Water Tube Boiler
- Water flows inside the tubes.
- Hot gas surrounds the outside of the tubes.
- The water in the tubes gets hot and becomes steam.
- Used for high-pressure steam and large-scale factories.
Key Boiler Parts
- Furnace (or Firebox): Where the fuel burns.
- Drum or Shell: Holds water or steam.
- Tubes: Either carry hot gas or water.
- Burner: Adds fuel and starts combustion.
- Chimney/Stack: Releases exhaust gas.
Where Are Boilers Used?
- Power plants (to spin turbines)
- Chemical factories (to supply heat or drive reactions)
- Food processing (for cooking, sterilizing)
- Buildings (for heating)
Conclusion
Boilers are key machines in many industries.
By understanding their basic structure—fire tubes, water tubes, and the furnace—you can better manage, maintain, or even design them.
If you’re starting as an engineer or technician, this knowledge is a great first step.