ALUMINIUM
ANODE
GENERAL
Aluminium alloyed with traces
of Mercury, Zinc and Silicon produces and anode with a capacity over three
times that of zinc and a driving potential of 250mV against the protected
structure. Therefore Aluminium anodes are commonly used in saltwater or offshore
environment due to their relatively low consumption rate of approximately 7 lbs
per amp-year.
TYPICAL APPLICATIONS
In saltwater environments
where electrical resistivities are usually quite low, Aluminium anodes are the
most economical choice for corrosion protection. These anodes offer higher
current efficiency and lower anode consumption than both magnesium and zinc in
aqueous saline areas.
Galvalum I has an open circuit
potential of 1.05 V (vs Ag/AgCl reference cell), contain a nominal amount of
mercury
and is recommended for use only in free flowing saltwater environment.
Galvalum III has an open
circuit potential of 1.10 V (vs Ag/AgCl reference cell), produces a higher
ampacity and better performance in higher temperature environment, lower
chloride
water and saline mud electrolytes.
CHEMICAL COMPOSITION
|
Element |
Normal
(%) |
|
Zinc |
2.5 - 7.5 |
|
Indium |
0.015 - 0.040 |
|
Cadmium |
≤0.002 |
|
Silicon |
≤0.12 |
|
Iron |
≤0.09 |
|
Copper |
≤0.003 |
|
Aluminium |
Remainder |
Chemical composition based on
DNV Standard. Other compositions are also available upon request.
Electrochemical Capacity :
2540 to 2730 Amp.hr/Kg (ambient temperature)
Closed Circuit Potential :
-1.05V (seawater) w.r.t Ag/AgCl Reference Electrode
AVAILABLE TYPES OF ALUMINIUM ANODES
Aluminium anodes can be casted
into various shapes such as:
1.
Stand-off Flat Bar Core
2.
Stand-off Cylindrical Core
3.
Cylindrical Bracelet Anode
4.
Tapered Bracelet Anode
5.
Weld-on Type / Bolt-on Type Hull Anode
Stand-Off Flat Bar Core Anode
Bracelet Anode
Order Information
Shapes and sizes of anodes can
be specified upon order to meet customer's requirement.
Specify the following details
upon ordering:
1.
Anode Quantity
2.
Anode Shape/ Type
3.
Anode Weight
4.
Anode Dimension
5.
Chemical Composition (If required)