Thank you both for this insightful information and recommendations. Yes this is a hot wall design location in a FCCU regen. cat line. The cold wall design and superalloy approach will both be looked at closely. I appreciate your responses.
I have a large diameter SS304H flange that has several cracks in the process exposed face. Flange has been in 1300F service for 17 years. Cracking seems to have developed after shutdown and exposure to atmosphere. Suspect polythionic acid attack. Has anyone developed a recommended cleaning...
