zinc anode

Category: sacrificial anode

zinc anode

Zinc anodes are used to protect structures submerged in fresh or salt water.

sacrificial anode

zinc anode

Zinc anodes are used to protect structures submerged in fresh or salt water

Zinc anode:

Zinc anodes are used to protect structures submerged in fresh or salt water. Of course, these anodes are also used to protect structures buried in the soil. Common zinc anode standards include ASTM-B 418, BS 7361, DNV-RP-B401, IPS-M-TP-750, NORSOK M-503, and MIL-A-18001K.

Zinc anodes are divided into the following two categories in terms of chemical composition and type of application:

1) Marine zinc alloy (Type I) designed for use in seawater.

2) Standard zinc alloy (Type II) formulated for use in fresh water and soil.

Element	Alloy Type I	Alloy Type II
Aluminum (%)	0.1 – 0.5	0.005 max
Cadmium (%)	0.025 – 0.07	0.003 max
Iron (%)	0.005 max	0.0014 max
Lead (%)	0.006 max	0.003 max
Copper (%)	0.005 max	0.002 max
All others (%)	0.1 max	—
Zinc (%)	Remainder	Remainder

According to the NACE-RP0387 standard, the insert used in zinc anodes must be made of galvanized steel.

According to the BS 7361 standard, the open circuit potential of the zinc anode is about -1.05 V compared to the silver/silver chloride reference electrode, its electrochemical capacity is at least 780 A.h/kg and its consumption rate is at most 11.25 kg/A.year. The efficiency of zinc anodes is also about 90% (the recipe for zinc anode electrochemical test and related calculations is mentioned in the DNV-RP-B401 standard.)

Electrochemical Properties	Sea Water Environment
Electrochemical Capacity .A.h/kg	780
Open Circuit Potential .V	1.05-
(Respect to Ag/AgCl Reference Electrode)	1.05-
Efficiency (%)	90