Dye Penetrant Inspection – FPI

Is used to detect cracks and discontinuities open to the surface which can not be seen by visual inspection. Dye penetrant inspection can be used on most engine parts accessible for this application. The inspection is performed by applying a liquid which penetrates into surface defects. Excessive penetrant liquid is removed and suitable developers applied to draw the penetrant from the surface defects so that visual indications are obtained by color contrast of the penetrant under the influence of a “black light”.