Dye Penetrant Testing


Dye Penetrant Inspection (DPI) – Liquid Penetrant Inspection (LPI) – Liquid Penetrant Testing (PT)

ECE Global Inspection Services offers a complete line of surface examination techniques including Liquid Penetrant and Magnetic Particle NDT applications and techniques. The application of these testing methods by experienced technicians has been proven to give reliable information as to the shape and length of different defects that are open to surface.

This can be very important when indications are noted and additional resources and techniques are needed to assess the overall condition of your component (e.g. Phased Array Ultrasonic Testing).

Many of the technicians employed by ECE Global are multi-disciplined and able to apply the other NDT disciplines that may be necessary to fully determine the suitability of the component for service.


Dye Penetrant Inspection (DPI), also called Liquid Penetrant Inspection (LPI) or Liquid Penetrant Testing (PT), is a widely applied and low-cost inspection method used to locate surface-breaking defects in all non-porous materials (metals, plastics, or ceramics). For applications where a greater sensitivity to smaller defects is required, the fluorescent penetrant method is preferred.

The Penetrant may be applied to all non-ferrous materials and ferrous materials, but for inspection of ferrous components magnetic-particle inspection may be preferred for its subsurface detection capability.

Commonly, DPI is used to detect cracks, surface porosity, lack of penetration in welds and defects resulting from in-service conditions (e.g. fatigue cracks of components or welds) in castings, forgings, and welding surface defects.