collected for evaluation of anions by ion chromatography in the laboratory observation on the outer surface of tube revealed the corrosion attack in many locations. St of black insulator was also observed on the outer surface. Then, two samples of stainless steel tubes containing the corrosion pits cut and r for examination in with were oratory. They can be divided into two groups as follows: (1)tube sample with corrosion in the base(as labeled SC-1) as illustrated in a and(2) tube sample with corrosion in the weld(as labeled with WD-1) as shown 3b in Fra 3-2. Chemical analyses Bulk composition of the failed tube sample using spark emission spectrometer is presented in Table 1.The results were compared with the specification of ASTM A270 TP316L according to ASTM standard practice for Seamless and Welded