In a fire tube boiler, where is the water located?

In a fire tube boiler, the correct placement of water is inside the shell or outer casing of the boiler while the flue gases pass through the tubes. This design allows the hot flue gases generated by the combustion process to flow through the tubes, transferring heat to the water surrounding the tubes and thus creating steam or hot water for heating purposes.

The water being outside the tubes, as indicated in the correct answer, allows for efficient heat transfer. The heat from the flue gases is exchanged to the water, producing steam which can then be utilized for various applications, such as heating systems or power generation.

Understanding the configuration of a fire tube boiler is crucial for recognizing how effective heat exchange is achieved, and for grasping the principles of safety and operational efficiency in boiler systems.