GaUSALUM III DCW
The GaUSALUM DCW III aluminum alloy was designed as an effective, offshore alloy, for use in cold, deep water environments. The low Iron (Fe) content of the alloy ensures that it activates in lower temperatures and protects the platform or pipeline it is connected to for the designed life of the cathodic protection system. For tropical waters, we recommend the GaUSALUM III alloy..
Chemical Composition (% by weight)
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| Iron (Fe) |
0.06 max |
| Silicon (Si) |
0.10 max |
| Copper (Cu) |
0.003 max |
| Zinc (Zn) |
4.75 - 5.25 |
| Indium (In) |
0.016 - 0.025 |
| Cadmium (Cd) |
0.002 max |
| Others (each) |
0.02 max |
| Aluminum (Al) |
remainder |
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Electrochemical
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| Open Circuit Potential |
(-) 1.15 V vs Cu/CuS04 sw. |
| Closed Circuit Potential (1) |
(-) 1.05 V vs Ag/AgCl sw, |
| Seawater Capacity @25C |
1150 A-Hr/lb. (2530 A-Hr/Kg.) |
| Seawater Capacity @5C |
1150 A-Hr/lb (2530 A-hr/Kg.) |
| Seabed Mud Capacity (3) |
950 A-Hr/lb. (2090 A-hr/Kg.) |
| Seabed Mud Capacity @ 5C |
950 A-Hr/lb. (2090 A-hr/Kg.) |
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Physical
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| Alloy Density |
0.098 lb/in3 (2.71 gm/cm3) |
| Cost Ratio |
Low Iron (Fe) Aluminum (Ai) Ingot <0.05 |
| Raw Material & Convesion |
1.10 |
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Recommended Applications
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| Offshore Structures (Platforms, Pipelines, FPS, FPSO, MODU, SPAR, Subsea Structure, Risers, Wind Turbine, etc) |
Any Ocean. Any Depth. Any Temperature. |
| Inshore Structures (Ports, Harbors, Jetties, Wind farms, Locks, Dams, Bridges, Piers, etc.) |
Any Body of Water, Any Depth, Any Temperature with Chloride Ion Concentration > 12 ppt. Resistivity < 200 ohm-cm. |
| Produced Water Vessels & Tanks |
Any produced brine < 140 F(60 C)(4). No improvement over GAUSALUM III DCW alloy. |
| Seawater Ballast Tanks |
Suitable for most seawater applications (5). No improvement over GaUSALUM III DCW. |
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Notes
| 1 - Recommended number to use when designing CP systems. |
| 2 - Activation can be a problem with chemistries at extremes of specification in cold water. |
| 3 - Recommended number to use when designing CP systems for offshore pipelines using bracelet or sub bottom anode systems. |
| 4 - Consult a CP Specialist for guidance at elevated temperatures as performance de-rating will be needed. |
| 5 - Exercise care with variable ballast tanks as dangerous volumes of hydrogen can be generated under certain conditions. |
| For additional guidance in application of these alloys, contact GaUS. |
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