Corrosion detection and monitoring

After reliable corrosion testing, one chooses the appropriate or acceptable material or inhibitor for use in the industrial process of interest. The next step involves inspection at 

Inspection is usually done by nondestructive techniques. This is usually known as nondestructive examination (NDE). The general term nondestructive evaluation describes the various terms used such as nondestructive inspection (NDI), nondestructive testing (NDT) and nondestructive examination (NDEx). Some of the aspects or purpose of these techniques involve detection and evaluation of flaws, leaks, dimensions, location (position), microstructures, mechanical properties and stress. 

Some of the factors involved in choosing a particular nondestructive evaluation technique are the primary reason or objective, the type of flaw to be detected, the size and orientation of the flaw, the location of the flaw in the sample, the size and shape of the sample and the nature of the sample. It is also necessary to know the type of flaws that are acceptable or unacceptable in the sense that flaws may be deleterious or nondeleter-ious. The size, type, orientation and location of the flaws determine whether they are acceptable or unacceptable as per the code, or standard given by American Society of Mechanical Engineers Pressure Vessel Code, American Welding Society Structural Welding Code or any other applicable code or standard. 

The technique used in the characterization of the flaws in the sample depends upon whether the flaw is on the surface or in the interior of the sample. Some of the common methods used in the nondestructive evaluation of the flaws are noted below  

Visual Independent of Magnetic field Sample thickness 

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Periodic inspection of equipment or plant for detection and monitoring corrosion should be followed by a written report, detailing all the observations and the necessary actions to be taken in future maintenance so that unexpected premature failures can be avoided. It is also necessary that all personnel involved are aware of the observations in the periodic inspection report on corrosion detection and monitoring in order to avoid future premature failures. 

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