What is the primary function of a tube expander?

A tube expander is a specialized tool used primarily in the maintenance and assembly of heat exchangers and boilers. Its main function is to mechanically expand the ends of tubes so that they can create a tight fit against the tube sheets or headers. This ensures that there is an effective seal, preventing leaks and maintaining efficiency in heat transfer processes.

When the correct choice states that the primary function of a tube expander is to expand and flare the tube, it captures the essence of its purpose. By expanding the tube, it enhances the contact area between the tube and the receiving part, which is crucial for both structural integrity and the performance of the heat exchanger or boiler system. Additionally, flaring the tube can sometimes help in achieving a better connection with other components.

In contrast, options that refer to breaking loose scale, whether inside or outside the tube, imply a maintenance activity rather than a function of expanding. Beading, while related to tube work, specifically involves creating a bead around the tube end to help with sealing or strengthening but does not encompass the broader expanding capability of a tube expander. Therefore, the choice that highlights expansion and flaring accurately describes the primary purpose of the tool in the context of tube maintenance and installation.