How liquid penetrant testing works
A low-viscosity penetrant is applied to a clean, dry surface and allowed time to enter discontinuities that are open to the surface. Excess penetrant is removed, developer is applied, and retained penetrant forms visible indications.
Typical PT applications
PT supports examination of stainless-steel and aluminum welds, ferrous and non-ferrous castings, machined surfaces, repaired areas and other suitable non-porous components.
Visible and fluorescent techniques
Visible penetrant is evaluated under suitable white light. Fluorescent penetrant is evaluated under controlled ultraviolet-A conditions and can provide high sensitivity. Technique selection depends on the procedure and inspection requirements.
Where PT does not apply
PT cannot find discontinuities that do not break the surface. Porous or very rough surfaces may also make interpretation unreliable. Ultrasonic testing may be considered when the concern is internal.
Qualified inspection support
VeriTech provides Level II / Level III capability for PT, with controlled processing and clear reporting for Ontario industrial and fabrication projects.
Compare all VeriTech NDE methods or read our method-selection guide.