Omaha 3rd Grade NAPE Stationary Engineers Practice Test

The purpose of a deaerator in a steam system is to remove dissolved gases from boiler feedwater. These dissolved gases, particularly oxygen and carbon dioxide, can cause significant corrosion in the boiler and steam systems. By using a deaerator, the feedwater is treated to eliminate these gases, thereby improving the longevity and efficiency of the system. By effectively removing these harmful gases, the deaerator helps ensure that the boiler operates safely and efficiently, preventing issues such as scale buildup and pitting which can lead to costly repairs and downtime.

In contrast, increasing steam pressure, adding chemicals for water treatment, or cooling steam before condensation are not functions of a deaerator. The primary role is specifically focused on preparing the feedwater for the boiler by ensuring it is free of harmful gases.