Which systems do all steam boilers operate using?

All steam boilers operate using a feedwater system, fuel system, draft system, and steam system, making this the correct choice.

The feedwater system is essential as it supplies the water that will be converted into steam. This water is heated inside the boiler to generate steam for heating or other processes. The fuel system is vital because it provides the energy necessary to heat the water, which can include various types of fuel, such as natural gas, oil, or coal.

The draft system is also crucial as it manages the airflow in the boiler, ensuring there is enough oxygen for combustion and controlling the removal of flue gases after the fuel has burned. Finally, the steam system is responsible for directing the hot steam away from the boiler for its intended use, whether for heating, driving turbines, or other applications.

Understanding these systems is fundamental for maintaining efficient and safe boiler operations. Other options focus on unrelated systems or components that are not foundational to the operation of steam boilers.