Liquid Penetrant Testing (PT)
Description
This testing method involves coating the test object with a solution that contains either a visible or fluorescent dye. Excess solution is removed from the object's surface but remains in surface-breaking defects. A developer is then applied to extract the penetrant from these defects. With fluorescent dyes, ultraviolet light makes the bleed-out fluoresce brightly, allowing imperfections to be easily observed. For visible dyes, a vivid contrast
Application
Liquid Penetrant Testing (PT) is a non-destructive material testing method that uses capillary forces to find surface cracks or pores and make them visible. It can detect surface-breaking flaws such as cracks, laps and porosity. It is commonly used for welds, castings, and machined parts.
step by step Process
- Cleaning: Remove surface contaminants to ensure dye penetration.
- Application: Apply a liquid penetrant (fluorescent or visible dye) and allow it to seep into defects.
- Excess Removal: Clean the surface to remove excess penetrant.
- Developer Application: Apply a developer to draw out penetrant from defects, making them visible.
- Inspection: Inspect under white light or UV light for indications of defects. All interpretations and discontinuities found are evaluated, sized, and compared to the applicable code, standard or customer specifications to determine if they meet the requirements to be deemed acceptable or rejectable.
- Post-Cleaning: Clean the part.