What type of steam is characterized by being at 250 psia and 400 degrees Fahrenheit?

The correct answer is superheated steam. Superheated steam is steam that has been heated beyond its saturation point at a given pressure. In this context, at 250 psia, the saturation temperature is lower than 400 degrees Fahrenheit. Thus, steam at this pressure that is also at 400 degrees Fahrenheit cannot be saturated or wet steam; instead, it exceeds the saturation temperature, indicating that it is superheated.

Saturated steam occurs at the boiling point of water for a given pressure, which means any steam at a temperature above that point is classified as superheated. Wet steam contains both liquid and vapor phases, which does not apply here since the heat of 400 degrees Fahrenheit makes the steam fully vaporized and not mixed with water. This clear distinction regarding temperature relative to the saturation point is crucial in identifying the properties of steam in various industrial applications.