Penetrant Testing

The Liquid Penetrant Method is used to detect discontinuities which are open to the surface of the material being examined. This method may be used on both ferrous and nonferrous materials. Liquid Penetrant examination may be used for the detection of surface discontinuities such as cracks, seams, laps, cold shuts, laminations and porosity. We can provide both visible and fluorescent Liquid Penetrant Examination Services.

Scientific Principles

Penetrant solution is applied to the surface of a clean component. The liquid is pulled into surface-breaking defects by capillary action. Excess penetrant material is carefully cleaned from the surface. A developer is applied to pull the trapped penetrant back to the surface where it is spread out and forms an indication. The indication is much easier to see than the actual defect.

Main Uses

Used to locate cracks, porosity, and other defects that break the surface of a material and have enough volume to trap and hold the penetrant material. Liquid penetrant testing is used to inspect large areas very efficiently and will work on most non-porous materials.

Main advantages

• large surface areas or large volumes of parts/materials can be inspected rapidly and at low cost;
• parts with complex geometry are routinely inspected;
• indications are produced directly on surface of the part providing a visual image of the discontinuity;
• equipment investment is minimal.