GRAPHITE
IRON ANODE
GENERAL
Graphite anodes are considered
a reliable impressed current anode and are used extensively throughout the
industry. Low in cost, graphite anodes, used in conjunction with coke breeze
backfill, provide long-term performance characteristics for many cathodic
protection applications.
The graphite anodes are
composed of high quality petroleum coke which is mixed with coal tar binders
and extruded into various diameter rods and heated repeatedly at temperature in
excess of 2600˚C and then cooled. The high percentage of carbon which can
deliver effective protection at a relatively low consumption rate.
While graphite anodes will
operate in aqueous environments, they perform best under dry soil conditions.
Use of a backfill effectively increases the graphite anodes discharge surface
area and lowers anode to earth resistance. The anodes have been successfully
used in both conventional and deep groundbed applications and demonstrate
exceptional protection in a high chloride environment.
CHARACTERISTICS
|
Properties |
Plain
Graphite |
Impregnated
Graphite |
Unit
|
|
Bulk Density |
1.55 |
1.65 |
g/cm3
|
|
Porosity |
30 |
19 |
H2O% |
|
Flexural Strength |
15 |
20 |
N/mm2
|
|
Compressive Strength |
19 |
44 |
N/mm2
|
|
Electrical |
7.5 |
14 |
II Ωμm
|
|
Resistivity |
12 |
20 |
┴
Ωμm |
|
Thermal Conductivity |
198 |
38 |
II W/mK
|
|
Mean Linear Thermal Coefficient of Expansion |
0.9 |
1.9 |
II I/K |
|
Ash |
<0.5 |
<0.5 |
% |
CONSUMPTION RATES
|
Environment |
Current
Density (Amp/m2) |
Consumption
Rate (Kg/Amp.yr) |
|
Carbonaceous Backfill |
10 |
0.1 - 0.3 |
|
Fresh Water |
2.5 - 3 |
0.1 - 0.3 |
|
Sea Water |
10 |
0.3 - 0.5 |
ORDERING INFORMATION
Graphite Iron Anodes are
available in Rod shapes.
Custom sizes of anodes can be
specified upon order to meet customer's requirement.
Specify the following details
upon ordering:
1.
Anode Dimension
2.
Anode Quantity (Individual
Anodes; String Anodes per Set)
3.
Cable Tail Size, Length, Insulation Type