Massachusetts 2nd Class Fireman's Practice Exam

Steam at 100 PSI and 400 degrees Fahrenheit is classified as what type?

1. Saturated.

2. Wet.

3. Superheated.

4. None of the above.

The correct answer is: Superheated.

Steam at 100 PSI and 400 degrees Fahrenheit is classified as superheated steam because its temperature exceeds the saturation temperature corresponding to that pressure. At 100 PSI, the saturation temperature is approximately 328 degrees Fahrenheit. Since the given steam is at 400 degrees Fahrenheit, it is in a state where it is heated beyond its saturation point, meaning it is not in equilibrium with water. This superheated steam can expand and do work without condensing, making it useful in applications such as power generation and steam turbines. This classification is important in understanding the behavior of steam in various applications, as superheated steam has different properties than saturated or wet steam, particularly in terms of energy content and efficiency in mechanical work.