The treatment against flow induced localized corrosion phenomena (FILC) is generally performed by choosing materials of improved protective performances. The alternative solution, which consists in acting directly on the flow has only been considered in the recent years. The analysis presented here describes chemical actuators-polymer solutions and surfactant solutions-which are used to reduce the turbulent drag. Microscopic origin of the phenomenon is emphasized with resulting effect on large turbulent structures, which are thought to be responsible of FILC. From the knowledge of the main flow characteristics in drag-reducing conditions, a criterion for the onset of FILC has been expressed which shows a huge increase of the time required to see the appearance of the damage. The use of surfactant Solutions instead of polymer solutions for practical applications is strongly suggested in view of the reversible degradation that undergo the thread-like micelles involved in the mechanism, whereas polymer coils are irreversibly degraded with a resulting loss of the Drag-Reduction effect. (C) 2003 Elsevier Science Ltd. All rights reserved.