Describe sacrificial anodic protection with neat diagram.

Describe sacrificial anodic protection with neat diagram.
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Method: The metallic structure to be protected from corrosion is connected to anodic metal (upper placed in galvanic series) by an insulated wire. Thus externally added metal like Zn, Al, Mg, etc will be more active, acts as anode and gets corroded. And the main metal is protected; hence it is called as sacrificial anode. For better electrical contact, the active metal is placed in back fill (coal and NaCl). After consumption of active metal completely, it is replaced by fresh piece. Magnesium or zinc rods are bolted along the sides of ship. Zinc rods are inserted into boiler or hot water tanks to prevent corrosion. The protection of underground pipelines is shown in Fig.

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