Class 5 Boiler Practice Exam 2025 - Free Boiler Certification Practice Questions and Study Guide

Saturated steam is defined as steam that is in equilibrium with water at a specific temperature and pressure. It exists at the boiling point of water, meaning that any additional heat added to the saturated steam will not increase its temperature but will convert some of the liquid water into steam, maintaining the balance between liquid and vapor phases. This equilibrium is key in applications where the properties of steam must be precisely managed, such as heating systems or steam turbines.

In contrast, superheated steam is steam that has been heated beyond its boiling point without any increase in pressure. This means it does not contain any liquid water; hence it is drier and has a higher thermal energy content than saturated steam at the same pressure. As a result, superheated steam can achieve greater efficiency in energy transfer processes because it can be used to do work without the phase change that occurs in saturated steam, where some energy goes into converting water to steam. Therefore, the statement about saturated steam being at boiling point with water in equilibrium accurately distinguishes its unique characteristics from those of superheated steam.