PENETRANT INSPECTION (PT) SERVICE

Liquid penetrant testing (PT) checks material defects exposed to the surface by flowing special penetration liquids into the defect and drawing the liquid with the developer. There are two types of penetrants; fluorescent or color contrast (dye) penetrant. These can be used with any of three intermediate cleaning methods – washed with water, post-emulsified and removed with solvent. The dye penetrant method (color contrast) requires sufficient visible light to provide appropriate examination conditions, while the fluorescent penetrant method must be used with ultraviolet or “black light” in dark conditions.

This method is used to inspect various product forms including castings, forgings and welding. Structural steel, automotive, petrochemical, power generation and aerospace industries are a few examples that use penetrant inspection.