PT Free Quiz

 

 

Applications of liquid Penetrant Testing (PT)

PT works by capillary action and is a widely applied and low-cost inspection method used to check surface-breaking defects in all non-porous materials (metals, plastics, or ceramics).

 

ADVANTAGES OF PT

• The method has high sensitivity to small surface discontinuities.
• The method has few material limitations, i.e. metallic and non-metallic, magnetic and nonmagnetic, and conductive and nonconductive materials may be inspected.
• Large areas and large volumes of parts/materials can be inspected rapidly and at low cost.
• Parts with complex geometric shapes are routinely inspected.
• Indications are produced directly on the surface of the part and constitute a visual representation of the
• Aerosol spray cans make penetrant materials very portable.
• Penetrant materials and associated equipment are relatively inexpensive.

 

 

LIMITATIONS OF PT

• Only surface breaking defects can be detected.
• Only materials with a relatively nonporous surface can be inspected.
• Pre-cleaning is critical since contaminants can mask defects.
• Metal smearing from machining, grinding, and grit or vapor blasting must be removed prior to LPI.
• The inspector must have direct access to the surface being inspected.
• Surface finish and roughness can affect inspection sensitivity
• Multiple process operations must be performed and controlled.
• Post cleaning of acceptable parts or materials is required.
• Chemical handling and proper disposal is required.