Pipeline Corrosion Control

Lida MMO Wire Anodes by De Nora Tech

Created by: Pipeline Corrosion Control

Last updated 11/2025

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Description

LIDA wire anodes, by De Nora, are made of copper cored, titanium wire with a mixed metal oxide (MMO) coating. The mixed metal oxide is a crystalline, electrically conductive coating that activates the titanium and enables it to function as an anode. The anodes are manufactured in two standard diameters: 1.5 mm (0.06") and 3.0 mm (0.12"). When applied on titanium, the coating has an extremely low consumption rate measured in terms of milligrams per year. As a result of this low consumption rate, the wire diameter remains nearly constant during the life of the anode. The low consumption rate of the mixed metal oxide coating, at the recommended operating current densities, results in projected anode lifetimes from 15 to 20 years. Longer or shorter lifetimes may be obtained by varying the current output per foot of wire. This information in demonstrated in the accompanying graphs, which relate amperes per lineal foot to lifetime in years. While the LIDA anode wire is available in 1,000 foot reels from the factory, Farwest can customize the anode wire for easy field installation. This includes fabrication for canister applications, "piggy-back" systems for undertank or linear anode projects and more. Contact a Farwest Corrosion representative for help in your design needs. Anode Coating The MMO coating used on the andoe wire is suitable for most cathodic protection applications, but output varies with application. De Nora's MMO coating demonstrates a very high chemical stability, even in environments with low pH values. Unlike other impressed current anodes, the De Nora coating is not affected by the generation of chlorine. Applications Canistered Anodes Horizontal or Vertical Groundbeds Water Storage Tanks Above Ground Storage Tanks Underground Storage Tanks Water Treatment Equipment Features & Benefits High Current Output Low Coating Wear Rate Highly Conductive Copper Core ANSI/AWWA Standard D 104-91 Lower Cost Per Ampere Year Constant Electrical Resistance Minimizes Voltage Drop Typical Lead Wire Connection Detail A typical connection between the LIDA wire anode and a anode header cable is shown below. Connections such as this have been used successfully in canistered anodes and other anode solutions since 1987. Resistivity vs. Anode Length Proper current distribution is an important factor in the design and proper use of an anode wire for each application. The graphs of Electrolyte Resistivity versus Maximum Wire Length are shown for selected voltage drops down the line. The voltage drop values represent the percentage decrease in actual driving voltage for the beginning to the end of a particular anode system. For example, if a wire voltage drop of 10% or less is desired for proper current distribution in 1000 ohm-cm water, anode segments 45 feet should not be exceeded between electrical connections to a header cable with the 1.5 mm diameter wire. By comparison, use of the 3.0 mm diameter wire will permit the use of 110 foot segments, while still allowing the desired 10% voltage drop. As with all electronic conductors, the operating temperature of the wire affects the resistance. The table shows this effect by assuming the wire will operate at the temperature of the surrounding electrolyte. The change in resistivity also changes the maximum current handling capacity of the wire. Wire Size (mm) 1.5 mm dia. 3.0 mm dia. Resistance, ohms/meter @ 25oC 0.0188 0.0034 Resistance, ohms/meter @ 70oC 0.0221 0.0040 Max Wire Amperage @ 25oC 21 36 Max Wire Amperage @ 70oC 7 7 Regardless of the type of impressed current anode used, proper anode bed design is paramount to optimum, low resistance performance. For soil applications, De Nora Corporation recommends the use of quality, conductive, carbonaceous backfill, a vent pipe, anode centralizers, suitable cable, and good design practices and understanding.