Eddy current testing is a non-destructive testing method that is widely used to inspect tubes in heat exchangers, steam generators, condensers, air coolers and feed water heaters.
This method is the most common technique used to inspect non-ferrous pipes. Eddy current technology is very reliable and can detect pipe conditions related to overall wall thickness reduction and the presence of local defects such as dents and cracks, especially when appropriate probes are used and the probability of detecting defects is high. The standard inspection technique for smooth pipes uses two separate channels to receive data: the “absolute” channel (reduction in wall thickness) and the “differential” channel (local defects). When inspecting finned tubes (chillers) the A / C probe is used to reduce the noise associated with the fins.Detailed analysis can be performed using software tools that determine the location of defects relative to the ID / OD of the pipe wall through phase analysis of the depth curves generated from the calibration standard. Software tools also make it possible to combine baffle signatures and assess hidden defects behind baffle supports.
Eddy current testing of pipes is an effective method to evaluate the condition and useful life of pipes, especially in the power generation, petrochemical, chemical, fertilizer and air conditioning industries. This technique is applied to identify corrosion, dents, cracks, erosion and other changes in the internal and external surfaces of pipes.
It is a high speed inspection method and one of its main advantages is that it can be done through paint and coatings.This technique is only suitable for non-ferrous materials such as stainless steel, copper and titanium. We also inspect far-field eddy currents and magnetic eddy currents on carbon tubes.
Advantages of pipe inspection using the ECT method
• High inspection rate, so that 80-100 pipes or more can be inspected per hour
• Inspection of ferrous and non-ferrous materials
• Comparison of reproducibility of results between historical test results and subsequent tests to determine corrosion rate and remaining life
• Detection of the difference between the direction of ID and OD defects by ECT
• ECT’s sensitivity to gradual loss of wall thickness, cracks, small dents, etc
