Offline Protection with Film Forming Substances

January 19, 2026

Instructor: Dale Stuart, Product Strategy Consultant, Boilers, Chemtreat

Base-loaded units operating within EPRI FAC specifications typically maintain low iron levels (<2 ppb in feedwater, <5 ppb in the drum), reflecting a stable magnetite passive layer. However, during outages, this protective layer can degrade, leading to elevated iron residuals: often up to 1 ppm for a month after restart. These spikes increase the risk of clogged drum level sensors, valve wear and steam carryover.

This session examines how applying film-forming substances (FFS) before an outage can help preserve the passive layer and significantly reduce post-outage iron levels. Attendee takeaways include application strategies, correct dosing and verification of residual levels to ensure effective offline protection and faster return to stable chemistry conditions.