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.
|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.