How are top supported boilers primarily distinguished in their structure?

Top supported boilers are characterized by their unique structural support mechanism, which involves hangers connected to structural steel. This design allows the boiler to be suspended from above rather than resting on a solid foundation or concrete supports. The use of hangers provides flexibility, allowing for movement and expansion due to thermal changes during operation, which is critical in preventing damage and ensuring the longevity of the boiler.

This method of support enables the boiler to be installed in various environments, often where space is limited or where a foundation might not be feasible. The suspension system not only serves a functional purpose in terms of weight distribution and movement accommodation, but it also contributes to easier maintenance and access to the boiler components.

In contrasting designs, other support methods either do not allow for the same level of flexibility or prevent the boiler from moving with the changes in temperature and pressure. For instance, foundations or concrete supports limit movement and adaptation to thermal expansion, while a fixed base design implies no movement whatsoever, which could lead to potential structural issues under operational conditions.