Carryover is any contaminant that leaves the boiler with steam. It can be in a solid, liquid, or vapor form. The most common form of carryover is boiler water droplets that contain dissolved and suspended solids.
Boiler water carryover can cause deposits to form in valves, heat exchangers, turbines, and superheaters. If deposits are significant, heat transfer and/or turbine efficiency may be reduced. Additionally, carryover can strip away the protective magnetic layer on steam lines, remove the film formed by filming amine programs, cause erosion-induced corrosion, and result in product quality problems in processes using live steam.