Aluminum sacrificial anode and design requirements


Aluminum sacrificial anode and its applications:

Aluminum anodes are routinely used in seawater and soil with low resistivity. In order to prevent the formation of the Al2O3 oxide layer, passivation and increase the efficiency of the anode, metals such as mercury, zinc, indium and silicon are used to alloy and make the oxidized layer porous. The capacity of aluminum anode alloys is approximately 3 times that of zinc anodes and is made according to NACE RP0387, IPS-M-750/6, DNV RPB401 standards. Considering that the aluminum anode contains mercury compounds and mercury is a toxic substance, during the lifetime of this anode, due to the decrease in the amount of aluminum in it, the percentage of mercury will increase, so proper safety measures should be taken during replacement. should be adopted and the methods that produce a lot of heat should not be used to separate the aluminum anode (such as stoning, etc.). Today, the use of mercury in aluminum anodes is almost obsolete due to environmental problems, and indium is used as an activator. According to the conditions of the place of use and the customer’s request, aluminum anodes have different shapes, dimensions and weights.

The three main applications of aluminum anodes are: protection of submarine pipes (with Breslet geometry), ship hulls and marine facility structures, the characteristics of these anodes are given later. Also, these andes with jacket geometry are used in the protection of offshore platforms and sea docks.

Aluminum sacrificial anode and design requirements

 Chemical analysis of indium aluminum anode based on standards(NACE RP0387, IPS-M-750/6, DNV RP B401)

                    element    Type 1Type 2Type 3
                    Iron0.13 % Max0.13 % Max0.13 % Max
                 silicon0.11 – 0.210.11 – 0.210.11 – 0.21
                    copper0.006 Max0.006 Max0.006 Max
                   Roy0.3 – 0.053.0 – 6.02.0 – 4.0
                   mercury0.3 – 0.50.35 – 0.5——
                  Indium—–——0.01 – 0.02

               Other Element


0.02 Max


0.02 Max


0.02 Max


        Potential (Ag/AgCl)-1.05 V-1.05 V-1.05 V
 Electrochemical capacity (A.Hr/Kg)287527502700

Technical specifications and requirements for the design of aluminum sacrificial anodes:

As mentioned, the three main applications of aluminum anodes are: protection of submarine pipelines (with Breslet geometry), ship hulls and marine facility structures (jacket anodes). In this section, the various geometries of this anode are summarized depending on the type of use.

             Sleeved anodes for submarine pipelines(Braclet)                                                               Anode of ship hulls and floats (Ship Hulls) 

Bracelet              Hull

Anode for the protection of marine structures                                                    Anode jacket for the protection of sea docks and marine offshore platformsmarinejacket

Installation and design technical considerations :

    • Aluminum anodes have different methods for installation, such as: direct welding to the structure under protection, connection by bolts and nuts, hand binding, etc., and the installation of said anodes must be done according to the relevant executive instructions.
    • Aluminum anodes should not be covered with paint in any way.
    • Aluminum anodes are also made in different shapes and sizes based on the customer’s design and request.
    • According to the NACE-RP0387 standard, the insert used in aluminum anodes must be made of ordinary steel.

 Al Overal                                                                                     

An example of installing an aluminum jacket anode to a structure using the welding method made by BornaGodaz Company

Bernagdas aluminum anode technical catalog

BornaGodaz Aluminum Anode Catalogue

Aluminum casting production line

Aluminum casting furnace

KEPCO project aluminum anode

Amir Kabir platform project aluminum anode

Anode aluminum jacket Sadra project (1)

Anode aluminum jacket Sadra project (2)PotentialAnode of ship hulls and floatsSleeved anodes for submarine pipelines