FFU Overhead corrosion

[lovescroll]

Hello, now we found the overhead corrosion at aromatic plant that lead to the failure of cooling exchanger within 6 months (failure characteristic seems to be occurred at the outside to inside corrosion, Hydrocarbon flow at tube outside cooling water flow at tube inside) , at that position we also inject water wash, neutralizer and filmer also, then pH still in a good condition ( swing between neutral to little basic and acid ). but we found a lot of deposit that's indicated by XRF and we think it is some kind of iron oxide for most and little sulfur compound (70% / 30%) and because of some restriction in lab testing. we can't prove another way with this for now.

i doubt that just under deposit can't be corroded like this, but we can't prove organic acid by the way.
Do you guys face this problem, how do you get rid of it?? 2205SS can be a candidated one ???

Remark: Temperature (lower than 100*C)

 

[georgeverghese]

Not much detail here
a) Which column in the feed fractionation unit ?
b) Is cooling water pressure higher than process side pressure here at this HX?
c) Have you checked chlorides level in the reformate feed - could this be chloride induced pitting corrosion ?