Application of induction methods in equipment testing and maintenance

The induction method is one of the most commonly used solutions for checking the condition of equipment, thereby offering appropriate maintenance.

Eddy current testing (ECT) as a technique for testing finds its roots in electromagnetism. Eddy currents were first observed by François Arago in 1824, but French physicist Léon Foucault is credited with discovering them in 1855. ECT began largely as a result of the English scientist Michael Faraday’s discovery of electromagnetic induction in 1831. Faraday discovered that when there is a closed path through which current can circulate and a time-varying magnetic field passes through a conductor (or vice versa), an electric current flows through this conductor.

With the ability to detect defects that exist across pipe length, Enddy Current Testing is now being applied in the inspection of the tubular heat exchanger system. The most typical representative of the field of heat transfer in technological lines is the beam tube heat exchanger system.

With advantages such as large heat transfer area, non-complicated structure, easy to manufacture and easy to clean equipment, the system is being used in many chemical, thermal, petrochemical, etc. However, with the operation in special conditions such as high pressure, vacuum pressure, subject to chemical and chemical corrosion, abrasion, the risk often occurs to the device is the appearance of Defective surface of heat transfer tube.

In the long run, if these defects are not detected, it will lead to pipe damage. Therefore, to ensure the production capacity of the factory as well as the quality of the product, the most important thing is to detect defects in the pipe during equipment repair and maintenance.

Currently the most common method for detecting defects in heat transfer pipes is the eddy current method. The principle of operation is for a coil of wire, with alternating current to a flat metal plate capable of conducting electricity, then there will be eddy currents generated by the phenomenon of electromagnetic induction. The variation of the magnetic field generated by the eddy current is used to detect defects.

In addition, this method also allows the calculation of the depth of defects to predict the safe operating time for equipment and plan maintenance and repair. Defect detection tubes are tested by the team many times to give the most accurate results. Aggregated data after the evaluation process will help businesses make equipment maintenance and maintenance plans, make appropriate repair plans and predict future phenomena.

Source: Eddy Current Testing wiki