Penetrant Inspection is a non-destructive method of testing whereby a penetrant is applied to the surface of a part by means of spraying, brushing or submerging. The penetrant is left for a period known as ‘dwell time’. Once the required dwell time has passed, the excess penetrant is removed to leave a clean surface. Penetrant enters any surface breaking down defects by capillary attraction. When the developer is applied, the penetrant is drawn out of the surface-breaking defects by reverse capillary attraction. The red penetrant is then visible against the white developer giving a good contrast.

Penetrant inspection can be used in several sensitivity levels, visible or fluorescent, solvent removable or water washable and post-emulsification.

Parts that can be inspected are:

• Butt and Fillet welds all materials

• Storage tanks and pipework

• Machined metallic parts such as Aluminium, Austenitic stainless steel, copper, bronze, brass

• Plastics

• Glass

• Vitrified ceramics