Aluminium Zinc Indium Anodes for Marine & Offshore Cathodic Protection
Aluminium Zinc Indium (Al-Zn-In) anodes are high-performance sacrificial anodes designed for cathodic protection of submerged and marine steel structures. Aluminium-based alloy anodes containing zinc and indium are widely selected for suitable seawater applications because of their controlled electrochemical performance and efficient sacrificial protection characteristics.
Aluminium Zinc Indium Anodes
Aluminium Zinc Indium anodes, commonly referred to as Al-Zn-In anodes, are aluminium alloy sacrificial anodes developed for cathodic protection systems operating in suitable marine and seawater environments. The aluminium base provides the principal sacrificial material, while controlled alloying with zinc and indium supports the required electrochemical behaviour of the anode.
These anodes are used to protect steel structures by providing a galvanic current to the structure. During operation, the sacrificial anode is consumed preferentially while reducing corrosion of the connected steel surface.
RELI SLEEVE can manufacture aluminium-based sacrificial anodes in application-specific configurations according to cathodic protection design requirements, approved engineering drawings and applicable customer specifications.
Along with Aluminium Zinc Indium Anodes, our material range includes Aluminium Anodes , Zinc Anodes and Magnesium Anodes .
Types of Sacrificial Anodes
RELI SLEEVE supplies sacrificial anode solutions for different marine, offshore and submerged applications. The required material, shape, dimensions and installation arrangement are selected according to the cathodic protection design.
Aluminium Anodes
Aluminium alloy sacrificial anodes for suitable marine and offshore cathodic protection applications.
View Aluminium Anodes →Zinc Anodes
Zinc sacrificial anodes for suitable seawater and marine corrosion protection systems.
View Zinc Anodes →Magnesium Anodes
Magnesium sacrificial anodes for selected soil, freshwater and other approved cathodic protection applications.
View Magnesium Anodes →Custom Anode Configurations
Project-specific anode shapes, dimensions and mounting arrangements according to approved CP requirements.
Custom Applications →Key Features of Al-Zn-In Anodes
Aluminium Alloy Base
Aluminium provides the primary sacrificial material for suitable marine cathodic protection systems.
Zinc Alloying
Controlled zinc addition forms part of the selected aluminium alloy chemistry used for anode manufacture.
Indium Alloying
Indium is used as an alloying element in selected aluminium sacrificial anode compositions.
Marine Application
Suitable for cathodic protection systems designed for seawater and marine environments.
Application-Specific Design
Anode dimensions and configurations can be developed according to approved engineering requirements.
Flexible Installation
Mounting and electrical continuity arrangements are selected according to the structure and CP design.
Technical Specification
| Product Type | Aluminium Zinc Indium Sacrificial Anode |
|---|---|
| Alloy System | Aluminium – Zinc – Indium |
| Protection Method | Galvanic / Sacrificial Cathodic Protection |
| Primary Application | Marine, Offshore and Submerged Steel Structures |
| Operating Environment | Seawater / Marine Environment, as defined by CP design |
| Anode Material | Aluminium Alloy with Zinc and Indium Alloying Elements |
| Configuration | Application and Project Specific |
| Dimensions | As per Approved Engineering Drawing and CP Design |
| Mounting Arrangement | As per Application and Approved Installation Design |
| Electrical Continuity | As Required by Cathodic Protection Design |
| Design Life | As per Approved Cathodic Protection Design |
| Manufacturing Basis | Applicable Alloy Standard, Customer Specification and Approved Drawing |
Al-Zn-In Anode Grades & Standards
Aluminium Zinc Indium sacrificial anodes can be manufactured according to applicable alloy specifications, project requirements and customer-approved standards. The selected grade depends on the required electrochemical performance and cathodic protection design.
Galvalum III Equivalent
Aluminium alloy composition suitable for specified sacrificial anode applications.
DNV & ISO
Manufacture can be aligned with applicable DNV and ISO requirements.
Alanode
Aluminium alloy anode chemistry can be supplied according to applicable Alanode requirements.
Client Specification
Project-specific alloy chemistry and manufacturing requirements can be followed.
Final alloy grade, chemical composition, dimensions, anode weight and configuration should be confirmed against the approved cathodic protection design and applicable project specification.
Aluminium Zinc Indium Chemical Composition
The following composition ranges represent the aluminium alloy anode chemistry supplied for applicable Galvalum III equivalent, DNV & ISO and Alanode requirements. Actual production chemistry should be confirmed against the applicable purchase specification and approved project documentation.
| Element | Galvalum III (Eqv.) | DNV & ISO | Alanode |
|---|---|---|---|
| Zn | 2.0 – 6.5 | 2.5 – 5.75 | 0.50 – 5.00 |
| In | 0.01 – 0.02 | 0.016 – 0.04 | 0.005 – 0.05 |
| Si | 0.08 – 0.20 | 0.12 Max. | 0.10 Max. |
| Fe | 0.12 Max. | 0.09 Max. | 0.13 Max. |
| Cu | 0.006 Max. | 0.003 Max. | 0.01 Max. |
| Cd | 0.002 Max. | — | — |
| Others (Each) | 0.02 Max. | 0.02 Max. | 0.02 Max. |
| Others (Total) | 0.06 Max. | — | — |
| Al | Remainder | Remainder | Remainder |
Zinc and indium are controlled alloying elements in aluminium sacrificial anodes. Chemical limits may vary according to the selected standard, approved alloy grade and customer specification.
Electrochemical Performance
Aluminium Zinc Indium anodes are selected for applications where the cathodic protection system requires suitable galvanic activity in the operating electrolyte. Their performance is evaluated as part of the complete cathodic protection design.
| Reference Environment | Seawater at 23°C |
|---|---|
| Open Circuit Potential | More negative than -1.1 V w.r.t. Ag/AgCl |
| Closed Circuit Potential | More negative than -1.05 V w.r.t. Ag/AgCl Reference Electrode |
| Anode Capacity | 2550 – 2750 A.hr/Kg |
The above electrochemical characteristics are specifically associated with aluminium anodes operating in seawater at 23°C. Actual cathodic protection performance depends on alloy composition, electrolyte conditions, temperature, current demand, anode geometry and the approved CP design.
Applications of Aluminium Zinc Indium Anodes
Al-Zn-In sacrificial anodes can be incorporated into cathodic protection systems for a range of submerged steel structures where aluminium alloy anodes are appropriate for the operating conditions.
Offshore Platforms
Protection of submerged steel components of offshore platforms and jacket structures.
Jacket Anodes →Subsea Pipelines
Sacrificial cathodic protection systems for suitable submerged pipeline applications.
Pipeline Bracelet Anodes →Ship Hulls
Marine hull protection using welded or bolted anode configurations as required.
Hull Anodes →Offshore Wind Foundations
Cathodic protection of suitable offshore wind farm foundation structures and substations.
Wind Farm Anodes →Marine Steel Structures
Protection of suitable submerged steel structures in marine environments.
Miscellaneous Anodes →Special Applications
Bespoke anode configurations for application-specific cathodic protection requirements.
Custom Anodes →Aluminium Zinc Indium Anode Configurations
The physical configuration of a sacrificial anode is selected according to the protected structure, available installation space, required current output and cathodic protection design.
Bracelet Configuration
Suitable for selected pipeline cathodic protection arrangements.
Hull Configuration
Designed for installation on ship hulls and marine vessels.
Jacket Configuration
Used for suitable offshore jacket and platform structures.
Custom Configuration
Shape, dimensions and mounting can be developed according to approved project requirements.
Advantages of Al-Zn-In Sacrificial Anodes
- Aluminium alloy based sacrificial protection system.
- Suitable for selected seawater and marine cathodic protection applications.
- Controlled zinc and indium alloying.
- Application-specific anode geometry.
- Suitable for offshore and submerged steel structures.
- Can be manufactured according to approved engineering drawings.
- Can be integrated into project-specific cathodic protection systems.
- Available according to applicable alloy standards and customer specifications.
Aluminium Zinc Indium vs Other Sacrificial Anodes
| Anode Material | Typical Application Environment | Main Selection Consideration |
|---|---|---|
| Aluminium Zinc Indium | Suitable Seawater / Marine Applications | High-performance aluminium alloy sacrificial protection |
| Zinc | Suitable Marine / Seawater Applications | Established marine sacrificial anode applications |
| Magnesium | Selected Soil / Freshwater / Approved Applications | Higher driving voltage for appropriate CP systems |
The correct sacrificial anode material should always be selected based on electrolyte conditions, protected structure, current demand, coating condition, design life and the approved cathodic protection design.
About RELI SLEEVE
RELI SLEEVE is a specialized division of the Reliable Group focused on corrosion protection and engineered solutions for industrial and pipeline applications. The Reliable Group was founded in 1975 and has developed extensive experience serving Oil & Gas, Petrochemical, Power, Water, Infrastructure and Process Industries.
RELI SLEEVE has manufacturing and technical capabilities for application-specific corrosion protection products and engineered anode solutions. Sacrificial anodes can be developed according to approved cathodic protection requirements, customer drawings and applicable material specifications.
The company serves industrial and engineering requirements across international markets, supporting customers with manufacturing, engineering coordination and project-specific supply.
Frequently Asked Questions
What are Aluminium Zinc Indium Anodes?
Aluminium Zinc Indium anodes are aluminium-based sacrificial anodes containing controlled zinc and indium alloying elements. They are used in suitable cathodic protection systems, particularly for marine and seawater applications.
Where are Al-Zn-In anodes used?
They can be used for suitable offshore platforms, subsea pipelines, ship hulls, offshore wind foundations and other submerged steel structures.
What is the role of zinc and indium?
Zinc and indium are controlled alloying elements in selected aluminium sacrificial anode compositions. The alloy chemistry is selected according to the applicable standard and required electrochemical characteristics.
Can RELI SLEEVE manufacture custom Al-Zn-In anodes?
Yes. Anode dimensions, configuration, mounting arrangement and other manufacturing requirements can be developed according to approved engineering drawings and project specifications.
What standards can be followed?
Aluminium alloy sacrificial anodes can be manufactured according to applicable Galvalum III equivalent, DNV & ISO, Alanode or customer-specific requirements.
How is the anode size selected?
Anode size and quantity are determined through the cathodic protection design, considering structure surface area, current demand, coating condition, environmental conditions and required design life.
What other anode materials are available?
RELI SLEEVE's material range includes Aluminium Anodes , Zinc Anodes and Magnesium Anodes , subject to application and cathodic protection requirements.
Need Aluminium Zinc Indium Anodes for Your Project?
Share your anode dimensions, protected structure, operating environment, quantity and project specification with RELI SLEEVE for an application-specific sacrificial anode solution.