API RP 581 - 3rd Ed.2016 - Add.2-2020 - Risk-Based Inspection Methodology

RISK-BASED INSPECTION METHODOLOGY, PART 2, ANNEX 2.B—DETERMINATION OF CORROSION RATES 2.B-51
Table2.B.5.4M—H 2 SO 4 Corrosion—Estimated Corrosion Rates for Type 316 SS (mm/y)
Acid
Concentration
(wt%)
0.61
m/s
Temperature
30 °C 40 °C 60 °C
1.83 2.13 0.61 1.83 2.13 0.61 1.83
m/s m/s m/s m/s m/s m/s m/s
2.13
m/s
98 0.13 0.25 0.38 0.38 0.76 1.14 2.54 5.08 7.62
92.5 0.25 0.51 0.76 0.76 1.52 2.29 10.16 20.32 25.37
87 0.51 1.02 1.52 1.27 2.54 3.81 20.32 25.37 25.37
82 1.27 2.54 3.81 10.16 20.32 25.37 25.37 25.37 25.37
75 7.62 15.24 22.86 25.37 25.37 25.37 25.37 25.37 25.37
65 15.24 25.37 25.37 25.37 25.37 25.37 25.37 25.37 25.37
50 22.86 25.37 25.37 25.37 25.37 25.37 25.37 25.37 25.37
30 5.08 10.16 15.24 25.37 25.37 25.37 25.37 25.37 25.37
15 0.76 1.52 2.29 1.52 3.05 4.57 5.08 10.16 15.24
8 0.25 0.51 0.76 0.76 1.52 2.29 2.03 4.06 6.1
3.5 0.13 0.25 0.38 0.51 1.02 1.52 1.02 2.03 3.05
2 0.13 0.25 0.38 0.13 0.25 0.38 0.25 0.51 0.76
Table 2.B.5.5—H 2 SO 4 Corrosion—Estimated Corrosion Rates for Alloy 20 (mpy)
Acid
Concentration
(wt%)
3
ft/s
Temperature
100 °F 125 °F 163.5 °F 195.5 °F
8.5
ft/s
10
ft/s
3
ft/s
8.5
ft/s
10
ft/s
3
ft/s
8.5
ft/s
10
ft/s
3
ft/s
8.5
ft/s
10
ft/s
98 2 4 6 5 10 15 15 30 45 40 80 120
92.5 3 6 9 10 20 30 25 50 75 50 100 150
85 3 6 9 10 20 30 30 60 90 60 120 180
70 3 6 9 15 30 45 50 100 150 100 200 300
55 3 6 9 10 20 30 30 60 90 60 120 180
45 3 6 9 10 20 30 30 60 90 50 100 150
35 3 6 9 10 20 30 25 50 75 40 80 120
25 2 4 6 5 10 15 20 40 60 40 80 120
15 2 4 6 5 10 15 20 40 60 35 70 105
8 2 4 6 3 6 9 5 10 15 25 50 75
5 2 4 6 3 6 9 3 6 9 20 40 60