Erosion/corrosion of tube ends parts is the most widespread reason for damages in heat exchange machines, including such problems as erosion of inlet openings, corrosive cracking, crevice corrosion and damages in outer tube diameters.
CTI shields, with a length of 100 to 4000 mm, are used for preventive protection and repair of tube end parts. CTI shields are installed in tube end parts with the use of mechanical and hydraulic expansion, fully covering the most damageable parts of heat exchange tubes. Not only do the shields protect properly functioning tubes from possible damage, but also restore a significant part of previously blanked-off tubes, bringing them back to active operation.
Correct material selection for shields is crucially important. Usually, it is based on the compatibility degree between the alloy and tube’s source material. It increases the resistance to erosion/corrosion as well as takes into consideration their galvanic compatibility.
Materials suitable for shield manufacturing:
The restoration technology of tube ends parts with the aid of shields is not “temporary repair”, for it ensures practically full restoration of operability of heat exchange machines. In some cases it enables to prolong its service life for over twenty years.
Services of shield installation in new heat exchange machines gain more and more popularity in the world. It enables to significantly increase the service life of heat exchangers with the relatively low cost of such service.