What device is used to collect steam or water from several sources in a boiler system?

The device used to collect steam or water from several sources in a boiler system is a header. A header serves as a central collection point for steam or water that is generated or collected from various locations within the system. In a typical boiler setup, multiple feed lines or risers may deliver steam or water to the header, which then distributes it appropriately to different components of the system, such as steam distribution lines or other equipment.

Headers are crucial for ensuring even distribution and efficient flow of steam and water throughout the boiler system. They help maintain pressure consistency and can also aid in managing the thermal dynamics of the system. This centralization is vital for effective operation, allowing for control and monitoring of the flow and temperature of the steam or water being transferred.

While the other choices have their functions in a boiler system, they do not serve the same purpose as a header. A manifold distributes fluid but typically lacks the centralized collection aspect. A furnace is the area where fuel is burned to create heat, and a waterleg refers to part of the boiler that carries water but is not used to collect from multiple sources. Thus, the header is the right answer for the function specified in the question.