Massachusetts 2nd Class Fireman's Practice Exam

What type of material is typically used for boiler tubes?

1. Aluminum

2. Brass

3. Steel

4. Copper

The correct answer is: Steel

Boiler tubes are primarily made of steel due to its high strength, durability, and ability to withstand high temperatures and pressures, which are common conditions in boiler operations. Steel has excellent thermal conductivity and can handle the thermal expansion and contraction that occurs as boilers heat up and cool down. It also has good resistance to corrosion, especially when treated or alloyed, which is crucial in environments involving steam and water. While other materials like copper and brass are used in specific applications, they do not possess the same overall durability and strength required for high-pressure boiler environments. Aluminum, while lightweight and resistant to corrosion, is not suitable for high-temperature applications due to its relatively low melting point and poor strength at elevated temperatures. Therefore, steel is the optimal and standard choice for constructing boiler tubes.