Sea water line flange corrosion ?

hello,

We are getting crevice corrosion in the Carbon steel cement lined pipe flange gasket seating area.Other end of the flange is connected to DSS (Duplex stainess less) strainer without internal coating. CNAF (1.5 mm thick)gasket is used for CS Pipe flange and DSS strainer flange connection. When we opened the pipe,flange gasket was found cut at one end and sticking to the CS flange. Underground line is having impressed CP system and no insulating joint provided between the underground and above ground portion. The above problem is encountered within 3 months of operation at wherever the CS Pipe and DSS strainer is not connected(Valve pit location) .


Please help.
Thanks!

I didn't find the right solution from the Internet.

References:
hghouston.com/resources/discussion-forum...did/4191/scope/posts


Animated Product Ads