Definition - What does Galvanic Cell mean?
A galvanic cell can be defined as a cell containing two different metals in contact with each other and having a common electrolyte. It could also refer to two similar metals in contact with each other having dissimilar electrolytes.
A galvanic cell environment can also be created in water and sewer pipelines where two different metals are joined together. This can lead to corrosion and eventually failure of the pipeline.
However; trenchless inspection methods such as push rod cameras and closed circuit television (CCTV) cameras can help detect problem areas, and trenchless rehabilitation methods such as mechanical spot repair using robotic pipe repair and sliplining can be used to rectify the problems.
Trenchlesspedia explains Galvanic Cell
A galvanic cell works on the principle of spontaneous chemical reactions in the cell resulting in an electron transfer in redox reactions. This results in the generation of an electric current that is routed through an outside circuit to supply energy to perform work. However, when this environment is created in sewer and water pipelines, it can spell disaster for the pipe.
When an electrically conductive connection is established between metals of different corrosion potentials, a galvanic cell is formed. This results in the reduction of oxygen on the surfaces of both metals. The oxidation reaction takes place on the metal with higher negative potential, causing faster metal dissolution.
Galvanic cell formation leading to corrosion can be avoided by - creating a galvanic separation by installing a dielectric coupling using a rubber gasket or insulating flanges that prevent the flow of electricity between the metals, using grounding rods, and by wrapping water lines with rubber tubing.