Zinc Sacrificial Anode for Cathodic Protection

Specifications

Chemical Composition

Al 0.1–0.5%; Cd 0.025–0.07% ; Fe max 0.005%; Cu max 0.005%; Pb max 0.006%; Zn remainder

Electrochemical Capacity

Soil 780, seawater 780, marine sediments 700 Ah/kg

Closed-Circuit Potential

Soil −1.05 V (Cu/CuSO₄); seawater −1.00 V and sediments −0.95 V (Ag/AgCl)

Consumption Rate

About 11.2 kg/A·yr (soil and seawater)

Anode Shapes

Trapezoidal, cylindrical, bracelet, tapered and bowling ball

Insert Type

Steel; stand-off (45° or 90°) or other

Insert Shape

Normal plate, tubular or none

Connection Type

Weld on, bolt on, cable suspension, blind flange, redhead mount, bluehead mount, eye bolt or without wire

Backfill (soil anodes)

Mixture of gypsum, bentonite and sodium sulfate

Application Limits

Soil use with backfill; soil resistivity max 50 Ω·m; operating temperature max 50 °C

Tests

Chemical analysis; electrochemical test; mechanical strength; maximum core-to-cable electrical resistance of 0.01 ohm.

Tolerances

Length and width ±3%; straightness max 2% of length; weight ±5%