Which component of a top supported boiler is hung from the structural framework?

The steam drum is a crucial component of a top-supported boiler and is typically suspended from the structural framework. Its primary function is to separate steam from the water in the boiler, allowing for efficient steam generation while maintaining optimal water levels. By being hung from the framework, it can effectively handle thermal expansion and offer a stable structure in relation to fluctuations in pressure and temperature that occur during boiler operation.

Supporting the steam drum above the boiler aids in maintaining proper alignment and allows for the necessary piping connections for steam and water to be made easily. This setup is essential for ensuring that the steam drum can effectively carry out its duties without compromising the structural integrity of the boiler itself.

The other components listed do not typically have the same structural design where they rely on being suspended. For example, water tanks are usually mounted on solid bases, heating elements are embedded within the boiler structure, and fuel supply lines run alongside or beneath the boiler, rather than being suspended as is the case with the steam drum.