Liquid Penetrant Testing (LPT)

Penetrant testing is used to reveal emerging surface defects such as cracks on the surface of all non-porous materials. Penetrant testing detects cracks, chips, porosity, pitting, etc. on parts at different stages of manufacturing, during preparation for welding and during welding. Penetrant testing detects metal fatigue (fatigue cracks, etc.), pitting, etc. on installations in service.

Our Strengths


  • ASNT/CSWIP/PCN/ISO9712 qualified personnel
  • Continuous in-house training & competency monitoring
  • Vast experience in various industry


  • Sherwin Chemicals

Advantages of PT

Limitations of PT

  • High sensitivity to small surface discontinuities
  • Suitable for large range of materials: metallic and non-metallic, magnetic and non-magnetic, and conductive and non-conductive
  • Large surface areas and large volumes parts can be inspected rapidly and at low cost
  • Parts with complex geometry can be tested without changing the inspection procedure
  • Indications are produced directly on the surface of the part
  • Aerosol spray cans make penetrant materials very portable
  • Required materials and equipment are relatively inexpensive
  • Only surface breaking defects can be detected
  • Only materials with relatively nonporous surface can be inspected
  • Precleaning is critical
  • Metal smearing from machining, grinding, and grit or vapor blasting must be removed prior to inspection.
  • Surface finish and roughness can affect inspection sensitivity
  • Multiple process operations must be performed with waiting intervals
  • Post cleaning of acceptable parts or materials is required
  • Handling and proper disposal of chemicals is required