Page 211 - Pipeline Rules of Thumb Handbook
P. 211
198 Pipeline Rules of Thumb Handbook
Figure 3. Anode bed resistance vs. number of
anodes. 3-in. ¥ 60-in. vertical graphite anodes in
backfill.
Figure 4. Anode bed resistance vs. number of anodes.
2-in. ¥ 60-in. vertical bare anodes.
Refer to Figure 3. The resistance is 0.56ohms. A rectifier ground bed is to be composed of 10 - 2 ¥
Figure 3 is based on a soil resistivity of 1,000ohms-cm. If 60-in. bare “Duriron” silicon anodes spaced 20ft apart. The
the soil resistivity is different, use a ratio of the actual soil soil resistivity is 3,000ohms-cm. What is the ground bed
resistivity divided by 1,000 and multiply this by the reading resistance? Refer to Figure 4. The resistivity from the chart
obtained from Figure 3. is 0.55ohms. Since the chart is based on soil resistivity of
