CATHODIC PROTECTION DIVISION
ONSHORE
• Underground Pipelines
• Tank Bottom Internal
• Tank Bottom External
• Vessel Externa
OFFSHORE
• Offshore Platforms
• Submarine Pipelines
• Jetties and Wharfs
• Offshore Rig
• Seawater Intaking System
FLOATING STRUCTURES
• Ship Hull
• Ballast Tank
• Barge
• Small Craft Boat
• Pontoons
• Offshore sea-going vessels
PROCESS EQUIPMENT
• Heat Exchanger
• Condenser
• Boiler
SACRIFICIAL ANODES
ALUMINIUM ANODES
Aluminum anodes can be used for the protection of storage tanks and are installed on ship hulls and jetties. They also have a specific use for protecting sub-sea pipelines, oil rigs, and semi-submersibles.
CHARACTERISTICS & COMPOSITION
| Iron | 0.13% max |
| Silicon | 0.08 – 0.2% |
| Copper | 0.006% max |
| Zinc | 2 – 6% |
| Indium | 0.01 – 0.02% |
| Others | 0.02% max |
| Aluminum | Remainder |
| Potential Ag/AgCl | -1.05V (min) |
| Anode Capacity Ah/Kg | 2550 (min) |
In addition to the standard compositions mentioned, Vaishnavi Metals also manufactures other compositions to suit the specific requirements of other sites and structures.
ZINC ANODES
Zinc anodes used for cathodic protection are cast from the highest purity zinc (99.995%) alloyed with aluminum and silicon to minimize impurities and cadmium to give uniform dissolution with loose dispersible corrosion products. The most widely used specification for zinc anodes is US Mil Spec 18001J for cathodic protection.
COMPOSITION
| ELEMENTS | STANDARD (Wt.%) | HIGH POTENTIAL (Wt. %) |
| Copper | 0.005% max | 0.005% max |
| Aluminum | 0.10 – 0.50 % | 0.005% max |
| Iron | 0.005 % max | 0.0014% max |
| Cadmium | 0.025 – 0.07% | 0.003% max |
| Lead | 0.006 % max | 0.006% max |
| Others | 0.10% max | ——– |
| Zinc | Remaining | Remaining |
CHARACTERISTICS
Open circuit potential Vs Ag/AgCI — 1.05 V
Capacity – 780 AH/kg
Zinc Anodes perform reliably in water and with resistivities up to 1000 Ohm cm and have a driving potential of 250 mV against protected steel at normal ambient seawater temperatures. This driving potential reduces the temperature rises as zinc should not be used where temperatures above +50 Deg C are likely to occur
Vaishnavi Metals: Anodes Division is currently in the process of expansion to include the manufacture of other sacrificial anodes such as magnesium anodes, anodes for buried structures, mixed metal oxide coated titanium anodes, water heater anodes as well as tank anodes in order to serve all client requirements.