| Mixed-metal-oxide-coated titanium | Buried pipelines, tank bottoms, reinforced concrete, and seawater systems, subject to anode design and electrolyte conditions. | Available as wire, ribbon, tubular, or mesh forms. Provide a suitable coke-breeze backfill for many groundbed installations; follow the coating supplier’s limits for current density and operating environment. | Check rectifier output, circuit continuity, groundbed resistance, and structure-to-electrolyte potentials. Investigate changes in output or potential rather than relying on rectifier readings alone. | Often designed for approximately 20–50 years, but actual life depends on coating type, current density, electrolyte, and operating conditions. |
| High-silicon cast iron | Deep or shallow groundbeds for pipelines, storage tanks, and other buried steel structures. | Install with the specified conductive backfill and maintain electrical isolation from unintended metallic paths. Deep groundbeds require appropriate casing, venting, and installation records. | Trend individual anode-string current where test facilities allow. Check rectifier performance, groundbed resistance, cable connections, and protection potentials during surveys. | Commonly planned for roughly 15–30 years; consumption and life vary with current output, soil conditions, and anode dimensions. |
| Graphite | Groundbeds for buried structures, particularly where the site conditions and system design are compatible with the material. | Handle carefully because the material is brittle. Use the specified backfill and installation procedure, and protect connecting cables and joints from moisture and mechanical damage. | Monitor current output, circuit resistance, and structure potentials. A gradual rise in resistance or declining output can indicate deterioration or connection problems. | Often planned for approximately 5–15 years, with substantial variation according to current density, moisture, backfill, and installation quality. |
| Platinized titanium or niobium | Specialized applications including seawater and other conductive electrolytes, when the selected substrate and coating are suitable for the service. | Confirm electrolyte chemistry, temperature, current density, and polarity limits before selection. Use compatible cable connections and avoid damage to the active coating during handling. | Measure anode output and structure potentials; inspect accessible connections and compare readings with commissioning baselines. Follow the design’s coating-specific operating limits. | Service life is coating- and application-dependent; design values commonly span about 10–25 years and must be confirmed for the intended operating conditions. |