MCC-NH Gas Fitters Practice Exam

What can cast iron be used for in gas fitting?

1. High-pressure gas lines

2. Piping underground

3. Nothing

4. Low-temperature applications

The correct answer is: Nothing

In gas fitting, cast iron is not typically used for any applications due to its brittleness and susceptibility to cracking under stress or pressure, especially when exposed to temperature fluctuations or environmental conditions. Cast iron does not possess the flexibility or durability required for handling gas safely, particularly in instances where movement or temperature variations may occur. High-pressure gas lines require materials that can withstand significant stress and strain, whereas cast iron is not designed for such applications. Piping underground must also be resistant to corrosion and able to accommodate environmental changes, which cast iron fails to do effectively. In low-temperature applications, materials that can respond flexibly and maintain integrity under thermal expansion and contraction are preferred over cast iron. Thus, the characterization of cast iron as unsuitable for use in gas fitting underscores the importance of choosing appropriate materials that ensure safety and reliability in gas systems.