We have faced deep pitting corrosion of caustic line opearting at ambient (40 c) condition. caustic concentration is about 50%. under what condition such type of pitting will occur. is it possible for casutic to get deposited on the wall surface under ambient condition.

Hi , My Name is selvan I would like to knowis it possible to use SS 316 L materials for the caustic injection skid Thanking you in advance

[updated:LAST EDITED ON Feb-27-09 AT 08:45 AM (CDT)]My company recieved some 3 & 400nb sch120 A106 pipe a few months ago with an inteded use on a gas compressor station. The pipe was fabricated & PWHT'd. After PWHT with the laquer removed the internal & external surfaces look "pitted" or dimpled. From what I have read pitting is generally associated with alloys or stainless/nickel etc & not with carbon which generally corodes evenly. My theory about the appearance of the surface of the materials is that the surface coating (laquer) was poorly applied & general corrosion has occured between the coating & the material surface. I would appreciate any comments or information in regards to pitting in carbon materials etc I would also appreciate any suggestions on how to deal with the problem ie is there anything else I can do other than UT the materials in order to proove the integrity of the materials.