Liquid Penetrant Examination is a non-destructive testing method used to detect surface defects in all metallic or non-metallic materials.
Liquid Penetrant Examination is used to find irregularities on relatively smooth, non-porous surfaces.
There are two main types of penetrants, Fluorescent and Visible. For each method there are different methods such as water washable, postemulsifiable-lipophilic, solvent cleaning and postemulsifiable hyperdrophilic. The choice of penetrant method depends on the level of sensitivity, site conditions and other variables.