PARTS WASHING: In selecting an industrial parts washing system it is important to consider the size, shape, and configuration of the parts themselves. Massive weights, large surface areas, acute angles, occluded sections, and blind holes pose special problems, independent of the contaminant(s) to be removed or the chemical cleaner to be used. Proper cleaning of all parts can only result when consideration has been given to these physical variables.
PASSIVATION: Passivation, according the ASTM A380, is "the removal of exogenous iron or iron compounds from the surface of stainless steel by means of a chemical dissolution, most typically by a treatment with an acid solution that will remove the surface contamination, but will not significantly affect the stainless steel itself."
SURFACE TREATMENT: Alodine, also referred to as iridite, is a chromate conversion coating that is applied only to the surface of aluminum. It gives good corrosion protection as well as providing an excellent base for painting. The process, developed for a major commercial aircraft overhaul facility, involves a cold alodine application followed by a cold water rinse and final hot water rinse.
PENETRANT INSPECTION: Fluorescent Penetrant inspection is a widely applied method used to locate surface-breaking defects in all non-porous materials (metals, plastics, or ceramics). FPI is used to detect casting and forging defects, cracks, and leaks in new products, and fatigue cracks on in-service components.
DEGREASING: Basic aqueous degreasing is a washing process. Environmentally safe detergents are used in place of toxic solvents. Using milder chemicals requires greater effectiveness from the cleaning equipment. Specifically, to achieve a desired level of cleanliness a sufficient level of mechanical agitation must be provided. Furthermore, a properly designed aqueous degreasing system will produce results equal to or better than solvent degreasing system and with the benefit of a safe working environment.