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Alloys for the Manufacture of Pharmaceutical Equipment and Processing Systems

Adam Fabriwerk
May 27, 2021
alloys composition

Pharmaceutical and Bio-pharmaceutical Processing is subject to very high standards of hygiene and sanitation, so choosing the right materials for the fabrication of processing equipment is of vital importance. The industry is heavily regulated and manufacturing materials must pass rigorous standards so as not to alter or compromise the purity of the products being manufactured.

Stainless Steel

Stainless Steel has long been the preferred material for pharmaceutical applications because of its corrosion resistance and excellent durability. Stainless steel is called “stain-less”, because of its ability to resist corrosion or "stains". It contains chromium which reacts with oxygen on the surface to create a thin protective barrier. This corrosion resistant property makes stainless steel the preferred substrate for good manufacturing practice (GMP) applications, especially for surfaces with product contact.

There are over 200 different types of stainless steel with different properties that suit various customer requirements. Certain grades of stainless steel are inert to most acidic and alkaline liquids which helps to avoid the risk of contamination. Stainless steel can withstand the aggressive cleaning routines required by the pharmaceutical and bio-pharmaceutical industries, including high pressure washes, or chemical washes.

Benefits of Stainless Steel for Pharmaceutical Manufacturing

Corrosion Resistance

In the strict manufacturing environment standards of aseptic manufacturing, the integrity and sterile nature of the system must be preserved. If corrosion leads to contamination entire batches of product will need to be discarded and the equipment will be out of commission. Stainless steel provides good resistance to harsh chemical compounds, rigorous cleaning processes whether Clean-in-Place, or cleaning after batch operation.

Heat Resistance

Stainless steel is highly stable under different environmental conditions. It has a high temperature tolerance which makes it ideal to withstand heat-based sanitation.

Durability and Ease of Use

Stainless steel is a highly durable material with good formability and can be used to manufacture mixing vessels, pumps, piping, storage tanks, valves and other parts easily.

Aesthetic Appearance

Stainless steel’s property of corrosion resistance makes it easy to clean and maintain, so it continues to look new. Equipment is electropolished to enhance the cleanability, passivity, and appearance of the equipment.

Adam Fabriwerk has decades of experience manufacturing equipment for the pharmaceutical and bio-pharmaceutical industries, and our high quality equipment and vessels are manufactured with the grade of stainless steel that is most suited to the final application.

Austenitic stainless-steel series (e.g., 304, 304 L, 316 and 316L) is widely used pharmaceutical applications because of excellent corrosion resistance, ease of fabrication and affordability. L stands for a low content of carbon (304L and 316L has a 0.03% carbon maximum as compared to 0.08% in 304 and 316 grade).

Grade 316, 316L has better chemical resistance than Grade 304, 304L and is mainly used in applications that have contact with chemical product. 316 contains 2% molybdenum whereas 304 contains no trace of molybdenum . The molybdenum added to grade 316 increases corrosion resistance, makes the grade stronger and more durable, and increases its ability to resist acids and chlorides.

Less often used, Alloy 904L, is also a low carbon austenitic stainless steel that is designed for moderate to high corrosion resistance in a wide range of process environments. It has a high chromium and nickel content, as well as molybdenum and copper which gives it excellent corrosion resistance. The copper improves its resistance to strong reducing acids, and the increased content of nickel and molybdenum makes it resistant to stress corrosion cracking. 904L is also highly scratch resistant because it has a much higher Rockwell hardness.

Super Alloys

Superalloys are complex, high-performance alloys, with a high tolerance of oxidising environments and high temperatures. They maintain their strength and corrosion resistance in the harshest of conditions and severely corrosive environments. Use of super alloys are prevalent in the aerospace, health, energy, oil & gas, chemical processing and pharmaceutical industries.

Hastelloy C-22 alloy is one of the most versatile nickel-chromium-molybdenum-tungsten alloys. This alloy has improved resistance to corrosion vs stainless steel due to its higher percentage of nickel. C-22 demonstrates improved corrosion resistance to both uniform and localized corrosion. C-22 is used in severely corrosive media with high chloride and temperature applications such as buffer solutions, active pharmaceutical ingredients (API), fabric softeners, cleaning supplies etc. C-22 alloy is recognized by the ASME BPE standard, and by the U. S. FDA

Within the strict regulatory norms of the pharmaceutical industry, Adam Fabriwerk is well versed in using stainless steel and other high performance alloys across the different process equipment and fabrication vessels, to offer the best corrosion resistance, aesthetics and longevity of the equipment.

Sources

Free, Michael L. “Why doesn’t Stainless Steel Rust” Scientific American, 12 March 2001, https://www.scientificamerican.com/article/

Pharma Pathway “Pharmaceutical Stainless Steel – Types, Composition & Difference”, 30 March 2020, https://pharmapathway.com/pharmaceutical-stainless-steel-types-composition-difference-2/

Brothers, Eric. “Superalloys use growing rapidly - Frost & Sullivan”, 23 April 2020, https://www.aerospacemanufacturinganddesign.com/article/superalloys-use-growing-rapidly-frost-sullivan/

Pharmaceutical Online, “Hastelloy C-22”, https://www.pharmaceuticalonline.com/doc/hastelloy-c-22-0002

AZoM, “Stainless Steel - Grade 904L” 7, Nov 2001, https://www.azom.com/article.aspx?ArticleID=1022