Cap it, Bury it, Forget it.
- Zinc Caps confer excellent cathodic protection to iron mechanical joint fitting and gland ring assemblies.
- Increasing the number of Zinc Caps marginally increases the degree of protection.
- Increasing the number of Zinc Caps greatly increases the length of protection.
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Control Tee after immersion for 1004.5 hours & removal from bath. Close up of ductile iron bolt showing corrosion.
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Elbow protected with 2 zinc caps after immersion in salt solution for about 1100 hours. Solution drained. Close-up of ductile iron bolt with zinc cap after rinsing off silt & flange, but not from zinc cap. Note complete protection of ductile iron nut, bolt, & flange.
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Soil Resistivity
Ohm-Cm |
2 Caps |
6 Caps |
12 Caps |
| 1000 |
5 years |
20 years |
35 years |
| 2000 |
7 years |
30 years |
50 years |
| 3000 |
10 years |
40 years |
65 years |
| 4000 |
12 years |
55 years |
90 years |
| 5000 |
16 years |
70 years |
110 years |
| 6000 |
20 years |
85 years |
140 years |
| 7000 |
25 years |
95 years |
165 years |
The life expectancy of 90 P 190 "Protecto-Caps" installed on a buried
Ductile Iron 90 degree 150 mm bend, with average coating.
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