The Nitric Acid Process

A NITRIC ACID PASSIVATION SYSTEM CASE HISTORY

nitric acid passivation system history

Nitric Acid Passivation Systems for precision aerospace components consist of five stages in MK Immersion Washers. The line runs from right to left. Ventilation ductwork is provided for all wet stages. Roller conveyor sections are on each platform and between stages as required to provide smooth lateral transfer of baskets from stage to stage.

Construction materials include 304 stainless steel, 316L stainless steel alloy 20Cb-3 heating elements and Nema 4 X control panels.

This is the nitric acid process:

  • Wash: The parts are batch-loaded into 18″L x 18″W x 6″H stainless steel baskets and placed on the first transport elevator in Stage One. Using a high-alkaline detergent at 170 degrees F, the parts are washed using vertical agitation.
  • Rinse: The basket is laterally transferred over special platform roller conveyor sections to Stage Two. Using hot water at 150 degrees F, the parts are rinsed using vertical agitation.
  • Passivation Using Nitric Acid: The basket is laterally transferred over special platform roller conveyor sections to Stage Three. Using a 25% solution of nitric acid at 135 degrees F, the parts are passivated using vertical agitation.
  • Rinse: The basket of parts is then laterally transferred over platform roller conveyors to Stage Four. Using DI water at 150 degrees F, the parts are rinsed using vertical agitation.
  • Hot Air Blowoff Drying: The basket of parts is then laterally transferred over platform roller conveyors to Stage Five. Using hot air at 150 degrees F, the parts are dried. Ramco Hot Air Knife Blow-Off Dryers get maximum evaporation and provide rapid drying without excessive heat. This concludes the nitric acid process.

nitric acid passivation

nitric acid passivation history