Cast iron boilers are made up of several what?

• A. Tubes
• B. Sections
• C. Units
• D. Pans

Answer: (B)

Cast iron boilers are built from individual pieces called sections that are cast separately and then bolted together to form the full boiler shell. Each section provides part of the water jacket and the path for combustion gases, and when the sections are stacked and sealed, they create the complete heat exchanger inside the boiler. This modular construction lets installers size the boiler by adding or removing sections and makes maintenance easier, because a damaged section can be replaced without rebuilding the entire unit. Tubes describe a different boiler design where heat is transferred through tubes, and pans or other terms aren’t the standard way to describe the main construction of a cast iron boiler, so the concept here is specifically about the sectional, modular nature of these boilers.