UFC 3-570-06
JANUARY 31 2003
Figure 2-20. Galvanic Anode Installation
Test Lead
Metallic connection
Anode
Special Backfill
Pipeline
Below Bottom of Pipeline
(Cathode)
Galvanic anodes used in immersion service are usually either directly
attached to the surface being protected, or are suspended adjacent to it. When
replacement of such anodes is necessary, they should be replaced using the same
anodes as were originally used. All mounting hardware should be carefully inspected
and repaired or replaced as necessary to insure that the anodes remain in place and
that electrical contact is maintained.
2-6.4
Galvanic Anode Connection to Structure. Electrical contact between the
galvanic anodes and the structure being protected is vital to the protection of the
structure. In directly attached systems, this contact is achieved through the mounting
system. The anodes are either directly welded or bolted to the structure. For anodes
suspended in water, contact with the structure is achieved either through the mounting
system or through insulated copper jumper wires that are welded to both the anode core
and to the structure being protected. In systems where the anodes are not directly
mounted on the structure being protected, connection is normally achieved using an
insulated copper wire. The wire is either cast into the anode during manufacture or
welded to the anode core. Connection to the structure usually is achieved by welding
the wire to the structure. When additional wire is required for the connection, wire of the
proper size using type TW insulation is usually used.
Thermite welding is widely used in installation, maintenance, and repair of
cathodic protection systems. The process can be used to connect wires to the structure
or anode cores or to connect two or more wires together. All connections and splices
should be insulated when exposed to soil or water to prevent loss of good electrical
contact.
2-38
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