|
| |
| Use this table to determine the remaining floorplate thickness
required today for the floor to have an acceptable remaining thickness
for the next 10 or 20 years. For Example: If you are going to inspect a 20 year old
tank with no Cathodic Protection and no floor coating, with an original
thickness of 0.250", all areas on the floor 0.175" and thinner should be
repaired for a floor life of 10 years and 0.200" and thinner for a life of 20
years.
|
| |
MFL Threshold Table for Bottom Plates
Outside the Critical Zone
calculated from API-653 3rd Edition Section 4.4.7.1 |
| |
No CP1 & No Coating |
No CP & Thin Coating or
CP & No Coating |
No CP & Thick Coating |
|
Service Life (Or) |
10 |
20 |
10 |
20 |
10 |
20 |
| Original Thickness |
0.250 |
0.312 |
0.250 |
0.312 |
0.250 |
0.312 |
0.250 |
0.312 |
0.250 |
0.312 |
0.250 |
0.312 |
|
Age (Years) |
|
| 5 |
0.220 |
0.270 |
0.235 |
0.290 |
0.200 |
0.245 |
0.220 |
0.270 |
0.185 |
0.225 |
0.210 |
0.260 |
|
10 |
0.200 |
0.245 |
0.220 |
0.270 |
0.175 |
0.210 |
0.200 |
0.245 |
0.150 |
0.185 |
0.185 |
0.225 |
|
20 |
0.175 |
0.210 |
0.200 |
0.245 |
0.150 |
0.175 |
0.175 |
0.210 |
0.120 |
0.140 |
0.150 |
0.185 |
|
30 |
0.160 |
0.185 |
0.190 |
0.225 |
0.140 |
0.155 |
0.160 |
0.185 |
0.100 |
0.120 |
0.130 |
0.155 |
|
40 |
0.150 |
0.175 |
0.175 |
0.210 |
0.130 |
0.145 |
0.150 |
0.175 |
0.090 |
0.105 |
0.120 |
0.140 |
|
50 |
0.150 |
0.165 |
0.170 |
0.195 |
0.125 |
0.140 |
0.145 |
0.165 |
0.085 |
0.095 |
0.110 |
0.125 |
1CP - Cathodic Protection
|
