3rd Class Power Engineering (3B1) Practice Exam

The purpose of steam drum U bolts in a boiler system is primarily to allow linear movement with temperature variations. In a boiler, the steam drum experiences significant changes in temperature as it heats up and cools down during operation. These temperature fluctuations can lead to thermal expansion and contraction of the drum and associated piping. U bolts are designed to accommodate this movement, allowing for expansion without creating excessive stress or strain on the connections and structural components. This flexibility is essential to maintaining the integrity of the boiler system and preventing damage, such as cracking or failure, associated with rigid attachments that cannot adapt to thermal changes.

While some may think that stability or support for heavy equipment are key functions, the primary role of U bolts in this context specifically relates to managing thermal expansion and maintaining system flexibility. Additionally, preventing corrosion is crucial for boiler longevity but is not directly linked to the mechanical role of U bolts in accommodating movement; that function typically involves materials and coatings that protect against corrosive environments rather than structural supports like U bolts.