Which method of penetrating inspection requires flushing with water?

The water-washable penetrant method is designed specifically to be rinsed off with water. In this technique, the penetrant has a formulation that allows it to be removed easily using water after it has been applied and allowed to develop. This step is crucial since the removal of excess penetrant is essential for proper inspection and for revealing any defects that may be present in the material.

This method contrasts with other penetrant testing methods, such as the solvent-removable penetrant method, which utilizes a solvent for removal instead of water. Similarly, the non-aqueous penetrant method does not involve water at all in its removal process. Therefore, the water-washable method is unique in that it specifically requires water for flushing to ensure that the surface is prepared for inspection and any defects can be accurately detected.

This requirement for water is not universal across all penetrant testing methods, as some methods are designed to work with solvents, thus limiting their application depending on the specific testing conditions and material types.