Understanding the Different Names and Terminology for Steam

Utility steam is sometimes called “live steam” or “plant steam.” It is steam produced from the boiler operation using softened water, reverse osmosis, or water otherwise treated for the boiler. Utility steam makes up the majority of the steam consumed by industrial process applications. Utility steam is a dry and invisible fluid that contains both sensible and latent energy, which can be provided to the process as saturated or superheated steam. 

Saturated steam is a state that steam can achieve with certain heating parameters. Saturated steam results from water being heated to a boiling point. More heat is then added until the steam vaporizes (latent heat of vaporization). Saturated steam occurs when both the liquid and the gas phases are present at a given temperature and pressure. Saturated heat has properties that give saturated steam many advantages over superheated steam, including: rapid, even heating throughout the heat transfer, the ability to control temperature through pressure, and a high heat transfer coefficient. In particular, this high coefficient is why heat exchangers primarily use saturated steam instead of superheated steam.

Superheated steam is created by the process of continually heating saturated steam until it is heated beyond the saturated steam point, thus increasing the steam temperature without increasing the pressure. The properties of superheated steam include having a higher temperature and lower density than saturated steam at the same pressure. Superheated steam is used in a variety of ways due to its ability to cool and still retain the same state and not produce condensate. These properties make superheated steam crucial in its ability to power devices such as turbines.