It is a non-destructive technique of a superficial nature, that is, it can be used to find open defects on the inspection surface. The liquid penetrant technique is based on the principle of capillarity which allows, by means of an ink with the appropriate physical characteristics, to completely wet the part and penetrate the discontinuities and then be shown to the eyes of the inspector with the help of a developing agent.
The liquid penetrant technique is widely accepted because it is easy to interpret once the technique has been properly applied, since a discontinuity, even a thin and closed one, can generate indications larger than the real surface dimension. The double effect of the developer allows dilution and drainage of the penetrant in the discontinuity generating a colorful indication (red, purple or blue) against a white background that contrasts with the indication generating a positive effect in the eyes of the examiner.
At ISS, SRL we have experienced inspectors with a vast knowledge of ASTM standards and building codes such as ASME, AWS and API codes and certified as level II inspectors in the technique of Penetrating Liquids (PT) under the scheme of the American Society of Non Destructive Testing (ASNT).
We also have portable equipment, Magnaflux liquid penetrant kits, visible and fluorescent, black light lamps, gauge kits calibrated by metrology laboratories, inspection procedures under the ASNT scheme, artificial lighting systems, white light meters and minor equipment necessary to comply with the different international inspection standards.