Dye penetrant inspection (DPI), also called liquid penetrant inspection (LPI) or penetrant testing (PT),
is a widely applied and low-cost inspection method used to locate surface-breaking defects in all non-porous
materials (metals, plastics, or ceramics). The penetrant may be applied to all non-ferrous materials and
ferrous materials, although for ferrous components magnetic-particle inspection is often used instead for
its subsurface detection capability. LPI is used to detect casting, forging and welding surface
defects such as hairline cracks, surface porosity, leaks in new products, and fatigue cracks
on in-service components.
The above photo show our flanges are under liquid penetrant inspection (LPI)~
Good quality comes from strict inspection~
