Having issues with corrosion inside your autoclave? Consolidated Sterilizer Systems is the only manufacturer that offers nickel clad chambers.

Written By: Kevin Theis

Autoclave Chamber Material: Stainless Steel vs Nickel-Clad

Current, state-of-the-art laboratory autoclave chambers are manufactured using stainless steel. In the past, autoclave manufacturers constructed sterilizers using nickel-clad, a highly corrosion-resistant material. The industry has shifted due to the rising cost of “cladding” over the last 10-15 years, heading in the direction of primarily 316L stainless steel.

Why should you care?

Because while stainless steel has many excellent properties, some common misconceptions about its versatility can lead to premature corrosion of this material. In short, there is a time and place where nickel-clad chambers are worth the investment.

Stainless Steel Autoclave Chambers

Stainless steel is a versatile material that is used in many industries from food preparation and medical devices to manufacturing equipment and semiconductors. Within the medical and laboratory equipment fields, the most popular metal of choice is “type 316L” stainless steel. This material has gained so much popularity because of its strength, stability, and ease of cleaning.

But although stainless steel is the preferred method of construction, there are many instances where nickel-clad should be considered. As its name implies, stainless steel is “less” prone to staining (and corrosion) than regular steel but unfortunately, it is not stain “proof”. Let’s explore this topic further.

Causes of Corrosion

Corrosion of stainless steel autoclave chambers can occur from a number of different sources ranging from poor water or steam quality to chemical contamination. Here are some common culprits:

  • Chlorides, sulfates, chlorine, hypochlorites, bleach, and acids aggressively attack stainless steel and can cause significant damage to the autoclave chamber and plumbing.
  • Hypochlorites, acids and bleaches are so caustic that they should never be sterilized or used to clean an autoclave. Keep in mind that autoclaves require a combination of heat and moisture to perform proper sterilization. So when high-temperature steam is combined with certain chemicals, the corrosion within the autoclave is accelerated.
  • High-concentration salt solutions such as seawater have a large amount of chlorides and should not be sterilized in stainless steel autoclaves.
  • Tap water with high amounts of chlorine or chlorides should not be used to generate steam for a stainless steel autoclave.

Nickel-Clad Autoclave Chambers

If high-concentration salt solutions (see above) will be sterilized in the autoclave or if the feed-water or tap-water for steam generation has high chloride content, then purchasing a sterilizer with a nickel-clad chamber (versus stainless steel) is recommended. Even though stainless steel has many benefits, nickel-clad is superior to stainless steel in conditions with high chloride concentrations.

The term “nickel-clad” stems from a process called Cladding. In the case of an autoclave chamber, the cladding process involves nickel being bonded to carbon steel to improve its durability and strength. Cladded steel plate is often used in corrosive environments where other materials or coating methods are not suitable.

Best Practices for All Autoclave Chambers

Cleaning

The life of the autoclave will be extended and damage will be greatly minimized if the chamber is cleaned immediately after each use. Look for an autoclave chamber cleaning solution that is specially formulated to remove contaminants on a stainless steel surface – the last thing you want to do is use a cleaning agent that corrodes the autoclave chamber.

Passivation

If solutions with mild chloride content will be sterilized, then “passivation” of the autoclave chamber is recommended. Passivating a stainless steel chamber occurs at the factory and is a process that makes the surface more corrosion resistant by restoring its protective oxide layer. The combination of passivation coupled with diligent cleaning of the chamber will greatly extend the chamber life.

It should be noted that typical LB, agar, and tryptic-soy solutions have a much lower chloride content than high-salt solutions and in turn are safer for stainless steel autoclaves.

 

Here are a couple of pictures from Indiana University and a recent install of nickel clad units and a picture of the old stainless steel unit.

Previous Stainless Steel Unit

New Nickel Clad Unit

President, DAI Scientific

Kevin is the owner, president and a sales rep for DAI Scientific. He brings over 25 years of experience working with customers in academic, clinical, industrial and bio/pharma laboratories. Kevin plays an important role in DAI’s direction and strategy, and he regularly works with architects, engineers and lab planners to ensure that products work with their designs and fit their intended application. He also prides himself on being up to date with industry developments and advancements; he frequently attends seminars to educate himself to better serve his clients.

Kevin enjoys his secondary role as a sales rep for DAI because it keeps him in touch with customer needs and helps inform future requirements of the industry. Under Kevin’s direction, DAI achieved the 16 Million Dollar Club award in 2019 and received Lancer’s “Outstanding Sales Performance” award in 2017, 2015 and 2012.

Kevin’s background includes a bachelor’s degree in communications from the University of Wisconsin-Stevens Point.

Awards received:
2012, 2015, 2017 from Lancer for “Outstanding Sales Performance”
2025 Elitech for “#1 in Instrument Sales”
PHC (Formally Panasonic and Sanyo) Has given us several awards as we passed certain milestones.
16 Million Dollar Club 2019
11 million Dollar Club 2018
10 million dollar club 2015
5 million dollar club 2011