Inspecting plate heat exchangers using dye penetrant testing

After cleaning, the plates are thoroughly inspected for corrosion, holes or cracks by dye penetrant testing. Using this method, which originated in the aviation industry, even the finest hairline cracks in the plate can be made visible.

After cleaning, the entire surface of each single plate is sprayed with a fluorescent paint. After the appropriate exposure time, the plate is rotated and thoroughly inspected under UV light in the darkened test room. Damaged plates are marked accordingly and sorted out. Flawless plates are now cleaned again by means of high pressure. In addition, the plates are checked for deformation and the gasket grooves are checked. If necessary, the gasket grooves are reworked.