The basic approaches to cathodically protect underground piping using impressed current anodes. These are:Deep AnodeShallow Anode or Distributed Anode BedLinear AnodeAll the above

The basic approaches to cathodically protect underground piping using impressed current anodes are:

1. Deep Anode: This method involves placing the anode deep into the ground, usually in a vertical position. The anode is connected to the positive terminal of a DC power source, and the metal to be protected (the cathode) is connected to the negative terminal. The electrical current flows from the anode, through the soil, and to the cathode, preventing the metal from corroding.

2. Shallow Anode or Distributed Anode Bed: This method involves placing multiple anodes in a shallow bed around the structure to be protected. The anodes are connected to the positive terminal of a DC power source, and the metal to be protected is connected to the negative terminal. The electrical current flows from the anodes, through the soil, and to the cathode, preventing the metal from corroding.

3. Linear Anode: This method involves placing a long, continuous anode in parallel to the structure to be protected. The anode is connected to the positive terminal of a DC power source, and the metal to be protected is connected to the negative terminal. The electrical current flows from the anode, through the soil, and to the cathode, preventing the metal from corroding.

All these methods are effective in protecting underground piping from corrosion. The choice of method depends on the specific conditions and requirements of the project.