Does anyone have any experience with a rapid fouling mechanism in a newly retubed waste heat steam generator? We retubed the hot pass of our SRU reaction furnace waste heat boiler due to excessive corrosion on the tube side. We did not do any internal cleaning of the boiler, shell side, prior to restarting the unit. We have since lost about 10% duty on the boiler, and it appears to be shell side fouling. Has anyone else run into this or failed a WHSG because of similar circumstances? Do you have a recommended cleaning/startup procedure for your steam generators after retubes or repair?