Arkansas Boiler Operator Practice Exam

Which kind of boiler is comprised of water tubes?

1. Fire tube boiler

2. Water tube boiler

3. Electric boiler

4. Steam boiler

The correct answer is: Water tube boiler

A water tube boiler is designed with its heating elements in the form of tubes filled with water. In this configuration, water is contained inside the tubes, and as heat is applied externally (typically via combustion gases), the water inside the tubes is converted into steam. This design allows for higher pressure and temperature capabilities compared to fire tube boilers, where the flue gases pass through the tubes surrounded by water. Water tube boilers are often favored in industrial applications due to their efficiency, rapid steam generation, and ability to handle fluctuations in steam demand. This makes them suitable for larger-scale operations where higher steam volumes are required. The other types of boilers mentioned have different configurations and principles of operation. For instance, fire tube boilers have the combustion gases passing through tubes surrounded by water, which is the opposite of a water tube design. Electric boilers utilize electric elements to heat water directly without combustion, and steam boilers refer to a broader category that may include both water tube and fire tube designs but does not specifically denote that the boiler is built with water tubes.