The mechanical deaeration process is one of the most economical methods for removing corrosive gases such as dissolved oxygen from boiler feed water. Dissolved oxygen in feed water is the major cause of boiler corrosion. A standard .03 design removes dissolved oxygen to a maximum level of .03 cubic centimeters per liter of feed water; rating can also be expressed as 44 parts per billion of oxygen in the feed water by weight. A standard .005 design removes dissolved oxygen to a maximum level of .005 cubic centimeters per liter of feed water; rating can be expressed as 7 parts per billion of oxygen per liter of feed water.

The atmospheric design provides unrestricted venting of the non-condensing gases. Both atmospheric deaerators and pressurized deaerators are available with either spray style or tray style designs. Unit may be two-tank design with surge tank or two-compartment tank. Tank construction conforms to section VIII of the ASME code and can be ASME code stamped. Tank material may be black steel or stainless steel; tank can be lined with plasite. A typical package includes the deaerator tank mounted on a stand of appropriate height along with all operating controls, feed pumps assembled and piped.