[ Pharmaceuticals ]
[ Pharmaceuticals ]
of various textures and adherences. While often cosmetic, rouge can indicate changes in surface chemistry requiring assessment, cleaning, or repassivation. Because pharmaceutical processes routinely demand strict hygiene standards, the selection, fabrication, surface finish, and maintenance of stainless steel equipment are critical. Regulatory expectations( e. g., GMP) generally require the use of corrosionresistant materials throughout the production train— from raw material preparation through formulation, sterilisation, filling, and packaging. Key equipment categories using stainless steels include:
• Raw-material handling and granulation systems for powders and intermediates
• Thermal control equipment such as heat exchangers, cooling towers, and specialty dryers
• Sterilisation systems( e. g., autoclaves, SIP) to ensure aseptic conditions
• Quality-control instrumentation housed in stainless enclosures for durability and cleanability
• Tablet and capsule manufacturing equipment for pressing, encapsulation, and coating
• Cleaning and packaging equipment, including CIP / SIP systems, fillers, sealers, and labeling machines
• Specialised processing systems such as lyophilisers, homogenisers, mixers, and blenders
• Filling and finishing systems for vials, syringes, cartridges, and assembled combination products requiring high precision and strict contamination control
Given the scale and diversity of stainless-steel use in pharmaceutical manufacturing, appropriate material selection, proper fabrication, inspection, and regular surface maintenance are essential to ensure product purity, regulatory compliance, and long-term equipment integrity. Like most process industries, a small number of stainless-steel grades dominate pharmaceutical equipment due to their availability, costeffectiveness, corrosion resistance, and fabrication versatility.
Common grades in pharmaceutical applications Like most process industries,
The pharma industry employs a broad range of stainless-steel equipment across its processing chain, such as this centrifuge. Photo: Dreamstime.
pharmaceutical manufacturing relies on a limited number of stainless-steel grades because of their availability, cost, and fabrication versatility. 304 / 304L- These are the most widely used stainless steels globally. In pharmaceutical plants, they are applied in general-purpose equipment, storage vessels, and non-critical piping. The low-carbon 304L variant minimises sensitisation during welding. However, these grades have lower pitting and crevice corrosion resistance than molybdenum-containing steels. 316 / 316L- The standard materials for pharmaceutical process systems. Molybdenum addition improves resistance to pitting and crevice corrosion in chloride-bearing solutions. Grade 316L, with its low carbon content, reduces sensitisation risk during welding and is compatible with CIP / SIP cycles and clean-in-place systems. These alloys combine corrosion resistance, hygienic surface finish, and good availability.
316Ti- A titanium-stabilised modification of 316 stainless steel. Titanium binds carbon and nitrogen, improving resistance to intergranular corrosion and sensitisation during hightemperature exposure such as welding. Typical composition: 16 – 18 % Cr, 10 – 14 % Ni, 2 – 3 % Mo, and Ti ≥5 ×( C + N). Used for reactors, heat-exposed vessels, and process lines where highertemperature stability is required.
904L- A super-austenitic stainless steel containing approximately 19-23 % Cr, 23-28 % Ni, 4-5 % Mo, and 1-2 % Cu.
This alloy offers outstanding resistance to reducing and acidic environments, such as sulfuric or phosphoric acids. In pharmaceuticals, it is used selectively in systems where 316L performance is inadequate, such as aggressive cleaning or speciality chemical processes. 2205 Duplex- A duplex alloy containing about 22 % Cr, 5 % Ni, 3 % Mo, and nitrogen, producing a balanced ferritic – austenitic microstructure. It delivers higher strength and superior resistance to pitting, crevice corrosion, and stresscorrosion cracking compared with 316L. Used in reactors, pressure vessels, and heat exchangers where both strength and corrosion resistance are critical. Equipment in the pharma industry is manufactured cost-effectively by balancing the costs of raw materials, processing, and quality against equipment design.
Comparative corrosion behaviour Across common pharmaceutical alloys, 316 / 316L and 2205 generally provide better corrosion resistance than 304 / 304L, with 904L offering the highest resistance among the grades listed. Duplex 2205 typically outperforms 316L in pitting and crevice corrosion, while 304L has the lowest resistance in chloride-containing environments.
• 304 / 304L- Most economical options; acceptable for less aggressive environments but lowest pitting and crevice corrosion resistance among the grades discussed.
• 316 / 316L- Molybdenum addition
52 Stainless Steel World April 2026 www. stainless-steel-world. net