One of Dacon's specialties is inspection of heat exchanger tubes. Dacon offers a complete package of tube inspection techniques. Dacon has the right solution for almost every possible tube that can be found in boilers, condensers, air fin coolers or other heat exchangers. For every specific tube and situation the suitable technique or combination of techniques can be chosen...

General information on Tube Inspection Techniques

Eddy Current (EC)
EC offers inspection in non–carbon content (non-ferrous) tubes, including non-ferrous finned tubes. Local defects as well as overall wall-loss can be detected and quantified. EC can detect both internal and external defects and can distinguish between them. Cracks can be detected depending on their size and orientation. Normally only a basic cleaning of the tubes is sufficient. EC is notably the fastest of the available tools. Approximately 450 tubes, with a standard 6 meter length, can be done on a first inspection day. Speed can go up to as many as 700 tubes per day on additional days of inspection.

Remote Field Technique (RFT)
As EC cannot be used in ferrous tubes, another technique should be applied. One of the commonly used techniques is the Remote Field Technique. This technique is very suitable for detection and quantification of overall wall-loss. Local defects can be detected and quantified provided that they have some volume (diameter pit >5 mm). RFT can detect both in- and external defects but it is not possible to distinguish between them. Defects under or close to the tube sheet are hard or not possible to detect. Only a basic cleaning of the tubes will be sufficient. RFT is slightly slower than EC. Approximately 300 tubes, with a standard 6 meter length, can be done on a first inspection day. Speed can go up to as many as 450 tubes on additional inspection days.