Penetrant or liquid penetrant testing (PT) refers to a surface type non-destructive testing method that allows a liquid (containing dye to increase visibility) to fill an empty void, which is open to the surface, due to the capillary action of the liquid. Once the excess penetrant is removed from the surface a developer is applied to the surface which allows the penetrant to be absorbed into a contrasting medium (normally white powder) revealing the presence of a discontinuity. Penetrant testing can effectively be applied to any type of material, as long as the discontinuity sought, is
open to the surface.
If you enjoyed chemistry at school and your interest in liquids exceeds that of swimming and the occasional beer, then we invite you to start your career in one of the most basic yet useful NDT methods around.
Inspection techniques depend on whether the dye used is under normal light or backlight conditions (or both), the type of penetrant, excess penetrant removal process as well as developer used during testing.
Furthermore, since temperature has an effect on the liquid properties such as viscosity and evaporation special techniques are applicable at excessively high and low Temperatures.
The training course is based on general theory as well as sector specific applications relating, but not limited to, the following standards and specifications:
- ASME Boiler & Pressure Vessel Code – Section V – Subsection A – Article 1 & 6
- ASME Boiler & Pressure Vessel Code – Section V – Subsection B – Article 24
- ISO 3452 Parts 1 PT – General Principals
- ISO 3452 Parts 2 PT – Testing of penetrant materials
- ISO 3452 Parts 3 PT – Reference test blocks
- ISO 3452 Parts 4 PT – Equipment
- ISO 3452 Parts 5 PT – Testing at temperatures > 50 °C
- ISO 3452 Parts 6 PT – Testing at temperatures < 10 °C
- ISO 12706 PT – Vocabulary
- ISO 23277 PT – Acceptance Levels