The pressure of the spray is optimized to meet the cleaning requirements. There can be many rinse tank arrangements for an aqueous cleaning system, but designs that incorporate cascading rinse tanks will reduce water usage. For example, if a cleaning system is using three rinse tanks, overflow from the final rinse tank is fed into the intermediate rinse tank, while overflow from the inter-mediate tank is fed into the primary rinse tank. System makeup water is supplied to the final rinse tank and overflow from the primary rinse tank is disposed of in an environmentally sound manner. Research is being conducted on methods to further reduce water usage by closing the water cycle, thus making it a continuous process requiring little or no make-up water.
Impurities remain on the parts if spots appear afterward.
Spots can be the result of inefficient rinsing cycles or contaminated rinse water. Reorganization of the rinse process or water treatment can solve this problem. Newark AFB uses an aqueous process for the precision cleaning of components of inertial guidance and navigation systems. The sophisticated parts that form the nucleus of these systems are extremely susceptible to microscopic contamination. To meet the demand of cleanliness, the aqueous system incorporates the use of ultrasonics and highly-deionized water during the wash and rinse cycles.