Passivation Process Benches/Tank Systems

Passivation Process Benches/Tank Systems

Passivation process tank systems that are provided by HPI Processes, Inc. are manufactured by using the newest innovative technology. Passivation is defined as a non-electrolytic process that typically uses nitric acid to remove free iron from the surface which will form an inert, protective oxide layer that will strengthen the metal against rust and oxidation. This process makes it the preferred method of corrosion control for many industries. Ideal for medical device and aerospace industries, our processes and equipment are manufactured to the highest industry standards. Any business that requires contaminate-free, corrosion-resistant parts and components can reap the benefits of having a high quality Passivation Process Line.
Complete process benches or manual/automated process tank systems available for your passivation applications.

What is Passivation Process and Why is it Necessary?

The passivation process forms a protective film over stainless steel. Stainless steel passivation encompasses the reformation of chromium oxide layer which is damaged due to abrasive materials and chemicals. This layer protects stainless steel from corrosion and rusting. This is also useful for titanium parts and components. According to ASTM A380 standard, passivation is a chemical treatment that removes exogenous iron compounds from a stainless steel surface. This is a mild oxidant-based treatment using nitric acid solution that removes any sort of surface contamination and yet does not change any properties of stainless steel.

Passivation and re-passivation are necessary as stainless steel parts in many applications have prolonged exposure to abrasive chemicals which removes the oxides from the chromium oxide film on the surface. This exposes the iron content in steel which may lead to oxidation and rusting. This process is widely used in tanks with chemicals, acids, contaminated water, and so on. This is because only regular cleaning of these tanks does not help.

What is the Right Time for Passivation?


While this depends on the application requirement, here are some factors that may help decide the right time for passivation.

  • You may want to consider passivation of the entire tank, or certain areas which experience welding, abrasion, buffing inside the tanks, or only on certain affected areas.
  • An important factor is the possible depletion of the chromium oxide layer immediately during the next load after passivation. This largely depends on the types of chemicals it is exposed to.
  • Consider if the tank would further deteriorate due to abrasion and corrosion, if not passivated. If the answer is yes, opt for passivation.
  • Passivation slows pitting significantly, and if the tank is less exposed to abrasive and corrosive materials and the chromium oxide film is retained, this would certainly offer a better output. This could be the result of just one passivation cycle per year, depending on the tank’s capacity, corrosion, and other related factors.

Types of Passivation Equipment We Offer

All our passivation equipment feature 316 stainless steel construction. We offer forced air-drying feature in our benches. They come with the conductivity activated rinse feature, wherein the water once dirty flows through the cascading rinse tanks automatically. This reduces water consumption. All our rinse and cleaning tanks use ultrasonic technology. We provide the following types of passivation equipment.

  • Bench-top Ultrasonic: We offer these ultrasonic passivation systems with tanks in various sizes. It comprises a parts washer or cleaner, passivation tank with filtration and circulation, parts dryer, and overflow rinse tank. With this, you can passivate a variety of acidic and harsh fluids.
  • Wet Bench: We offer wet benches passivation systems which are reasonably big units or even like cabinets. They are multipurpose benches, wherein multiple functions can be performed, such as passivation, washing, drying, rinsing, and so on.
  • Ultrasonic Automated: We offer automated ultrasonic passivation systems to industries which require high precision and have zero tolerance for contamination such as medical devices. This can passivate a variety of metals, stainless steel variants, and so on.
  • Agitated Immersion Multi-Tank: This type uses citric acid solutions and detergents for cleaning. They offer a multilevel passivation system which facilitates parts washing, filtration, oil removal, and so on. Once the oil is thoroughly removed from joints, cavities, hidden areas, and so on, the parts are immersed in a detergent solution or citric acid and free iron is removed from the surface.

Applications of Passivation Equipment

Here are some application areas of our passivation equipment.

  • Cleaning, rinsing, and passivation are the basic steps in this process. All these three steps can be combined using the right passivation line and the automatic ultrasonic passivation systems.
  • These machines on their own or when equipped with other systems such as pump filter systems, heaters, and so on offer additional features such as a hot cleaning solution, hot air drying, water-based rinsing of stainless steel equipment surfaces, and more.
  • While passivation is different from electropolishing, we do offer equipment for the latter. Stainless steel passivation through electropolishing further protects the steel surface from rusting and corrosion. This is more beneficial than using nitric acid solution, and helps increase the chromium oxide layer. Also, this process is suited for almost all types of stainless steel.

Benefits of Partnering with Us

Our experience and expertise in custom tanks and metal finishing systems allow us to offer you the best suitable customized passivation equipment. Aside from this, there are many benefits of partnering with us. Here are some of them.

  • When we customize, we consider your application requirements at length, and also your budget.
  • Most of our passivation machines can accommodate tanks of any size, while the standard is around two to three gallons.
  • We deliver application specific passivation equipment such as for aerospace, manufacturing units, medical, and so on.
  • We offer quick turnaround times without compromising on quality.
  • Our well-equipped facility allows us to make advanced passivation systems with multiple features and functionalities.
  • We are focused on quality and have tough testing and quality control measures in place. Each equipment is tested in terms of structure, safety, design, and functionality before it is shipped out.

HPI Processes, Inc. provides industrial passivation machines and equipment to give your machined parts a good surface finish and an additional layer of protection from corrosive and reactive elements. Our team of experts can offer you all the required technical assistance regarding the selection of these passivation tanks. In case of any enquiries or requirement sharing, you can contact us via phone or email.

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