Nace CP 1, Course Manual

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Installing C.P. Components 8:15
CP 1 – Cathodic Protection Tester Course Manual
©
NACE International, 2000
07/01/04
Prepackaged Anodes
Prepackaged anodes should be inspected to ensure that backfill material
surrounds the anode. The white, powdery backfill within the package serves
two purposes. It absorbs water, thus helping to keep the anode wet,
permitting it to function properly. The backfill also absorbs corrosion
products from the anode; this prevents the products from sticking to the
anode and increasing its resistance to ground. Consequently, if the anode is
not surrounded by the backfill, the anode may not function properly.
The cloth or cardboard package containing the anode backfill material
should be intact. If the packaging container is torn or broken, the anode
should not be used. Prepackaged anodes are supplied in waterproof
containers; the container must be removed before installation. Prepackaged
anodes should be kept dry during storage; also, they should not be pre-
wetted or soaked prior to installation.
The lead wire must be securely connected to the anode and should be
inspected to ensure that it is not damaged.
Galvanic anodes should be backfilled with compacted native soil, not sand,
pea gravel, or other high resistance material. Anodes should be wet down
after backfilling or left to absorb natural soil moisture. Care should be
exercised so that lead wires and connections are not damaged during
backfill operations. Lead wires should have sufficient slack in them to
avoid strain.
Typical prepackaged anode installations are shown in Figures 8.13 and
8.14.