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LONGMONT personnel have been involved in a variety of Cathodic engineering projects ranging from Deep-well ground bed installation through pipeline and wharf installation, testing and commissioning.
In conjunction with our clients and associated design house we design, install, test, and commission a variety of Cathodic Protection systems. Integration of systems with Lightning Protection, Electrical Design and Telecommunications system, and statutory earthing in hazardous areas is speciality service we offer.
With experience in Electrical Supply Authority inspections, Electrical Safety is our primary concern and business focus. Through this, we ensure integrated compatibility of systems.
A Brief Outline of Corrosion
Discussion Paper by Terry Mulligan MIEEE MACA 2002
The following discussion is in general terms only. The complexity of the association of elements related to corrosion makes evaluation of any give problem a complex matter and at times an apparently inexact science. This discussion identifies only some of the salient points associated with evaluation and prevention of "Corrosion".
Metals such as Aluminium and Steel are manufactured through a refining process that imparts a tremendous amount of energy to the metals to remove the impurities. [So high are the levels of energy are required for the smelting of Aluminium that it is often referred to as a [‘congealed electricity'.] Once the impurities are removed, other components are added to give the final product the characteristics necessary for a specific application. It is largely this energy, imparted during manufacture, which lends the metal its propensity to corrode or return to the natural state or lower energy level. This levelling is referred to as entropic equalisation.
There are a number of mechanisms that allow the metals to corrode, including corrosive elements such as salts in water, varying concentrations of oxygen in water, temperature variations, the presence of acids and sulphates or even the presence of acid producing bacteria. Regardless of the assisting mechanism, corrosion is electrochemical in nature, involving anodic and cathodic regions on a metal surface. The region is formed by connecting dissimilar metals and in the presence of an electrolyte [water with dissolved salts] also connecting the two metals; a corrosion cell comes into being.
All corrosion cells consist of four distinct components;
The anodic region of the metal erodes [corrodes / rusts]. See Sketch 1.
Electric current generated by the corrosion cell is discharged from the exposed metal surface at the anodic region, [where the surface corrosion occurs] and flows through the electrically conductive electrolyte to where it is received by the exposed metal surface in the cathodic region. The electrically conductive metal between the 'Anode' and the 'Cathode' completes the circuit, with hydrogen gas vented to atmosphere, chlorides being deposited out in the oxidate residue. [Read More]