Dye Penetrant Test (DPT) is also known as Liquid Penetrant Inspection (LPI) or Penetrant Test (PT) It is one of the most widely used Non Destructive Test (NDT) methods. It can be used to inspect almost all non-porous materials such as metals, plastics, ceramics etc. We can detect any SURFACE discontinuity (or flaw) by this method such as surface cracks, porosity, pinholes etc.
PT is based upon a natural phenomenon called CAPILLARY ACTION. By the virtue of capillary action, a liquid tends to flow or seep into narrow spaces
(or openings) even against the external forces like gravity. This phenomenon occurs due to the molecular attraction.
