Corrosion generally involves carbon dioxide (CO2), sweet corrosion, or hydrogen sulphide (H2S), sour corrosion. In both cases, water must be present for corrosion to occur.
The problems can be minimised through the circulation of corrosion inhibiting chemicals or the selection of corrosion resistant alloys. The primary factors that affect the severity of corrosion are the gas partial pressure, temperature, pH, chloride concentration and flow velocity.
Sweet corrosion is caused by CO2 which dissolves in the water phase to produce carbonic acid. This lowers the pH, resulting in a highly corrosive environment.