Steam or pressure specifications can be expressed in which of the following units?

The correct answer is PSI (pounds per square inch) because it is a common unit of pressure used in many technical contexts, including steam and pressure specifications. PSI is particularly relevant in industrial and engineering applications, where steam pressure must be precisely regulated for safety and operational efficiency. When discussing steam or pressure, it is essential to communicate the pressure level clearly, and PSI provides a standard way that is widely understood in various fields, such as culinary steam cooking and industrial processes.

Other options represent alternative units of pressure. Inches of mercury, for example, is often used in specific scientific contexts, such as barometry, but it is less common in practical applications related to steam specifications. Atmospheres are a unit of pressure equally useful in some scientific settings, but they are less frequently used in practical environments where PSI is more prevalent. Millibars are primarily used in meteorology to measure atmospheric pressure, making them less applicable to steam pressure specifications. In industrial and culinary spaces, PSI remains the most relevant and commonly used unit of measure for steam and pressure.