Hygienic sealing: Supporting cleaner, compliant pharmaceutical processing

For pharmaceutical companies, where even minimal contamination can ruin a batch, business success depends on managing challenging fluids to maintain product integrity.  

Sealing challenges in hygienic pharmaceutical processes 

This means using technology to create and maintain contamination-averse environments. The sealing systems used on pumps, mixers, vessels and agitators must maintain cleanability and sterility by design throughout production. 

Hygienic designs must reduce or ideally exclude contamination risk altogether by eliminating niches, improving cleanability and ensuring compliance with Food and Drug Administration (FDA) and Good Manufacturing Practice(s) (GMP) and regulatory expectations. In this blog, we look at these requirements individually and how designers meet them at the research and development stage.  

Hygienic design principles in sealing systems 

Cleanability requirements 
Mechanical seals and support systems must withstand Clean-in-Place (CIP) and Sterilise-in-Place (SIP) processes without degrading or releasing particles. It is the responsibility of the solution engineers to design technologies with smooth surfaces and accessible geometries that prevent residue buildup. 

Materials and regulatory expectations 
At a minimum, the materials used in creating sealing systems must comply with U.S. (FDA) and U.K. (GMP) standards. To conform, these solutions must demonstrate resistance – both to the processed chemicals themselves, and the intense steam and sterilisation generated by cleaning cycles. 

Avoiding product traps and dead zones 
The best-designed sealing system, in terms of hygiene, reduce crevices where microbes or residues can accumulate. Design simplicity is key to avoiding contamination and supporting repeatable cleaning. 

CIP/SIP thermal stresses 
Temperature cycling can distort components or increase leakage risk. For example, a full CIP acid wash can reach 122°C (158°F). Therefore, mechanical seals in hygienic processes must withstand repeated sterilisation without wear or loss of performance. 

Handling viscous, biologic or complex media 
Consistent sealing performance is required to prevent contamination or exposure, and high viscosity products and concentrated biologics can stress seals if designs are not optimised for repeated hygienic duty.  

Ensuring batch-to-batch integrity 
Modern pharmaceutical operations depend on predictable sealing conditions across multiple production cycles. Seal failure can lead to deviations, shutdowns, quality investigations or other unexpected departures from approved manufacturing processes and standard operating procedures (SOPs). 

Hygienic sealing technologies used in pharmaceutical equipment 
With 100 years of sealing experience, much of it gained in challenging environments and with difficult materials, John Crane is well-placed to help pharmaceutical operators support successful processes with hygienic sealing systems. Our solutions support cleanability validation and batch-to-batch consistency. 

In the next part of our blog, we look at supporting technologies, such as vessel seals, and the role of support systems and maintenance contracts in maintaining uptime for the owners of pharmaceutical processes.  

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