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(COVID-19) In support of manufacturing supply chains and healthcare sectors, all Astro Pak facilities are open and providing continuous service to our customers.

Passivation

Astro Pak has over 60 years of experience perfecting our passivation chemistries and processes.  We bring that expertise, along with our state-of-the-art equipment and highly trained personnel, on-site to your facility to perform preoperational or maintenance cleaning and passivation on your systems and equipment.

For components, parts, and sub-systems that can be serviced out-of-place, Astro Pak’s nationwide shop facilities are well suited to affordably meet your cleaning requirements.  We have state-of-the-art facilities that can accommodate parts of all sizes and volumes, including dip tanks up to 40ft and overhead bridge cranes with 7.5-ton lifting capacity for oversized parts. Additionally, we offer pick-up and delivery services as well as cGMP compliant documentation packages at the end of each job.  Our highly skilled technicians and controlled environments ensure consistent quality and compliance to industry and customer-specific standards.

During an audit tour from a regulatory agency, the lead Astro Pak technician had answers for things that I did not even know that I had to worry about.

-Senior Utilities Engineer, Boehringer-Ingelheim

Our Passivation Standards

Astro Pak prides itself on a long legacy of meeting and exceeding the standards set forth by a variety of organizations in numerous industries, including ASTM, ASME, SAE, SEMI and FDA, to name a few.

Trust the Experts in Passivation

Astro Pak has been perfecting its passivation chemistries and processes for over 60 years. Our proprietary Ultra Pass® passivation process is renowned for its environmentally friendly blend of high-purity ingredients, including chelants that bind with metal ions rendering them incapable of redepositing on surfaces.  As a result, the material handling requirements and other impacts on-site are greatly reduced.

Beyond that, the Ultra Pass® passivation process provides superior results, capable of producing an optimized passive layer on the surface of stainless steels, yielding unmatched corrosion resistance. Our studies have shown that the chrome to iron ratios achieved by Ultra Pass® passivation far exceeds ASME BPE recommended minimums and meets or exceeds the requirements of many industries including semiconductor, aerospace, pharmaceutical, and biotechnology.

Frequently Asked Questions

What materials can be passivated?

Most stainless steels (especially austenitic types) can be passivated, but levels of improvement vary between alloy type and quality of surface chemistry present.

Does passivation remove rust?

Passivation removes iron and small amounts of very light rouge from the surface thus enhancing corrosion resistance. Heavier amounts of rouge must be derouged to prepare for the passivation treatment.

How much rouge is Ok upon visual inspection?

That depends upon the quality level desired and the sensitivity of the product process to low levels of iron or iron oxides. It also depends upon the methods used to refine the final product, including filtration, evaporation/drying, or iron’s effect on the biotech process. Generally, lightly discolored wipes or faintly visible rouge is acceptable, distinctly colored wipes or significant surface discoloration is unacceptable. Use of filtration testing to measure the amount and size of particles in the process fluids can be used as a guide to evaluate the effect of rouge coming off the surface.

How do you test passivation?

By taking samples before and after the passivation treatment and testing them for chromium to iron ratio, one can quantify the quality of the passive film. The semi-conductor and pharmaceutical industry have set stringent measurable standards for systems or levels of purity.

Does passivation affect surface finish?

No, only on a molecular level. Passivation enhances the chemistry of the passive layer by increasing the ratio of very stable chromium atoms to the more reactive iron atoms in the upper three to five atomic layers of the metal’s surface.

Does passivation remove material?

Passivation does not remove material. Passivation enhances the ability of the treated surfaces to resist corrosion.

Why is pitting corrosion dangerous?

As the pit develops, it starts out shallow and deepens but the debris inside the pit cannot be removed. The pitting process will continue until it creates a hole in the pipe or surface.

Can passivation be removed?

Generally speaking – No. However, one can consider that corrosion undoes passivation by attacking the passive film. Reducing environments will undo passivation and render the surface active or corroded. The passive layer is very thin (2 to 5 molecular layers) and can be eliminated by welding or polishing, by reducing environments and corrosion.

What is the difference between passivation and derouging?

Derouging is the removal of visible iron oxides and other metal oxides from the surface. Passivation is the removal of iron or iron oxide from the surface in the passive film or top 3 to 4 molecular layer. Derouging uses stronger acids to remove large visible accumulations of iron oxides to a visually clean condition. Passivation is designed to remove the small amount of free iron from the visually clean surface.

Can the passive layer be removed?

The passive layer is very thin (2 to 5 molecular layers) and can be removed by welding, polishing, by reducing environments and corrosion.

How long does it take to passivate stainless steel?

Typical passivation process takes 8 to 10 hours in small systems and generally 12 hours for larger systems. Derouging alone can take 4 to 24 hours depending upon the condition of the surface.

Why is passivation needed?

Passivation enhances the chemistry of the passive layer by increasing the ratio of very stable chromium atoms to the more reactive iron atoms in the upper three to five atomic layers of the metal’s surface.

Can stainless steel become pitted?

Yes. Visually the surface looks like it has spots (white, black or brown) hazing or roughness. The pits need to be sanded/polished out and electropolished. If the pits are very deep, then the surface will need to be ground, welded and then polished and electropolished.

How can pitting corrosion be prevented?

Regular scheduled preventive maintenance and reduction of corrosive conditions – i.e reduce the use and concentration of chloride containing solutions or choose more resistant alloys where chlorides and heat are present.

Systems & Equipment Experience

  • Process and Storage Vessels and Tanks
  • Product and Distribution Piping
  • Water for Injection (WFI) Tanks and Stills
  • Bioreactors, Fermenters, Lyophilizes
  • Clean Steam Generators and Clean Steam Systems
  • Sterilizers and Autoclaves
  • Reverse Osmosis, DI, Pure Water
  • Clean in Place (CIP)
  • Boilers
  • Heat Exchangers
  • Tubing and Hoses
  • Spools, Flanges, Gaskets
  • Valves (Relief, Ball, Butterfly, Needle, Gate)
  • Gauges (Pressure, Flow meter, Hydraulic, Cryogenic)
  • Fittings, Fasteners
  • Components and Hardware
  • Transducers and Sensors
  • Any stainless steel parts, equipment or systems

Compliance

  • ASTM A380
  • ASTM A967
  • ASTM F86
  • SEMATECH
  • AMS 2700
  • ASME BPE

Markets Served

  • Aerospace, Military & Defense
  • BioPharmaceutical
  • Semiconductor
  • Laser
  • Household & Personal Care
  • Medical Device
  • HeathCare
  • Water & Wastewater
  • Chemical Manufacturing & Distribution
  • Power Generation
  • Food & Beverage
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