3.2.2.7
Anode and Cable Installation
If the method of installation utilizes backfill
support for anodes and
cable, slack in the cable near each anode shall
be provided and the cable
insulation shall be increased in thickness from
2.8 to 4.0 mm 7/64 to 5/32
inch utilizing an approved composite of plastic
and elastomeric materials.
3.2.2.8
Backfill
The well shall be backfilled with calcined petroleum coke breeze or
metallurgical coke breeze surrounding the anodes by a method that does not
from the bottom upward. The well shall be over-filled with coke breeze
allowing for settlement so that the settled level after a number of days is
as high as the level shown. The number of days allowed for settling of the
coke breeze will be determined by the Contracting Officer. If the top
level of coke breeze is below the level shown after settlement, additional
coke breeze shall be put in the well. The backfill used shall not require
tamping. The top portion of the well shall be sealed for 8 m 25 feet to
prevent surface water run-off. All vents shall be vented above the high
water mark and at a safe height.
3.2.2.9
Cable Marker Tape
Traceable marker tape shall be located in the same trench above cathodic
protection cables including structure leads, anode leads, anode header
cables, test station leads, bonding cables, and rectifier electrical power
cables.
3.2.2.10
Pavement Inserts
Pavement inserts shall be installed at a minimum of 30 m 100 foot intervals
for pipelines. The pavement inserts shall be installed directly over the
structure being protected and tested.
3.3
MAGNESIUM ANODE INSTALLATION
Installation shall not proceed without the presence of the Contracting
Officer, unless otherwise authorized. Anode locations may be changed to
clear obstructions when approved. Anodes shall be installed in sufficient
number and of the required type, size, and spacing to obtain a uniform
current distribution surface on the structure. Prepackaged anodes shall be
installed as shown on the drawings.
3.3.1
Installation of Packaged Anodes
Packaged anodes shall be installed completely dry, and shall be lowered
into holes by rope sling or by grasping the cloth gather. The anode lead
wire shall not be used in lowering the anodes. The hole shall be
backfilled with fine soil in 150 mm 6 inch layers and each layer shall be
hand-tamped around the anode. The tamper shall not strike the anode or
lead wire. If immediate testing is to be performed, water shall be added
only after backfilling and tamping has been completed to a point 150 mm 6
inches above the anode. Approximately 8 L 2 gallons of water shall be
poured into the hole; after the water is absorbed by the soil, backfilling
and tamping shall be completed to the top of the hole. Anodes shall be
installed as shown. When rock is found prior to achieving specified depth,
anode may be installed horizontally to a depth at least as deep as the
SECTION 13112A
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