Application
Function and application of Sacrificial Anodes:
Sacrificial anodes protect environmentally friendly against the formation of limescale, rust (corrosion) and pitting in water-bearing systems. The sacrificial anode is based on the electrochemical reaction of different metals (housing made out of steel, sacrificial anode made out of magnesium). The sacrificial anode reacts in water (water is the electrolyte) and reacts with the higher-quality alloy in the piping system. It is also used in enamelled hot water tank, to protect the faults on the enamel coating. Until today it is not possible to produce enamelled drinking water storage tanks without any faults on the enamel coating. Due to the installation of the sacrificial anode you can not only protect those faults in the drinking water storage tanks, but also as a side effect those faults will be coated with a protective layer. This protective layer is created due to the formation of hydroxide ions in the area of cathodes it could lead to precipitation of calcium carbonate. Because of the calcium carbonate the faults in the enamel coating can be covered. But the calcium carbonate can only develop, if there is enough calcium hydrogen carbonate in the electrolyte (drinking water).An inspection of the anodes according to DIN 4753-6 has to be performed after an operating time of two years.
Distinction of Hot Water Storage Tanks
Basically you can divide hot water storage tanks into five types classes. Thereto the assembly of the anodes in the different types of hot water storage tanks is presented:
Typ 1 - Small tank (Electric wall storage heater 30 to 150 litres)
- The anode can be unscrewed through the flange opening- A new anode (often with a M8 bolt) is fitted by means of hole mounting.
Typ 2 - Standard tank enamelled up to 1000 litres
- Part of the anode can be unscrewed through the flange opening- The heat register is mounted firmly
- The anode is mounted in the upper third of the tank (e.g. connection G 5/4“ with signal anode)
- At double walled tanks for heated water flow the anode will be mounted in the lid of the hand opening
Typ 3 - Medium tank enamelled (standing or lying), 1000 to 2500 litres
- The heat register is mounted firmly in the factory (do not remove during maintenance)- The anodes are mounted in the accumulator head through weld joints or push-in sockets
- Larger cleaning opening (flange)
Typ 4 - Large tank made out of steel (standing or lying), above 2500 litres
- The anodes are being welded in- The heat register can be extended during maintenance
Typ 5 - Large tank made out of steel (lying), above 2500 litres
- The anodes is being welded in- The weld joints are located in the tank front wall
- The anodes are installed horizontally
The heat register will be removed during maintenance
