A gland-steam condenser condenses the steam and air mixture discharged from the turbine shaft seals. In a typical shell-and-tube design, the gland-steam mixture enters the shell side while cooling water flows through the tubes. Heat passes through the tube walls, causing the steam to condense into water.

The condensate collects at the bottom of the condenser and is returned to the condensate or feedwater system. An exhaust fan, steam ejector, or vacuum system removes air and other non-condensable gases from the shell side. This maintains the required gland-exhaust vacuum, limits steam leakage around the turbine shaft, and prevents air from entering the turbine and reducing condenser vacuum.