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.
Control Tee after immersion for 1004.5 hours & removal from bath. Close up of ductile iron bolt showing corrosion.
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.
| 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.
Before:
After:
