How hygienic sealing supports pharmaceutical processing (Part 2)

For pharmaceutical operators, maintaining product integrity often depends on maintaining a hygienic seal. A successful seal design for this industry means overcoming the multiple challenges that prevent operators from achieving maximum operational uptime.   

In this blog, we look at the role of mechanical seals, supporting systems and maintenance programmes in maintaining efficient and compliant pharmaceutical processing.  

Vessel and agitator seals 

These mechanical seals are crucial in pharmaceutical processing for maintaining process integrity. They create a reliable barrier between the internal environment and the external factors that can affect product purity.  

Popular in ultra-clean pharmaceutical and biotechnology applications, the Type 5280 is a hygienic agitator seal for steel vessels. It applies Qualified Hygienic Design (QHD) guidelines and GMP standards to enable cleaning and sterilisation of the wetted parts of the product with the seal in place (CIP, SIP). The seal family includes the Type 5281 for glass-lined and the Type 5282 for special alloy vessels. 

Similarly, the self-lubricating Type 32 dry-running seal operates with an optional debris well and without external fluid support, reducing contamination risks and meeting pharmaceutical and chemical processing standards.  

Swapping out the seal faces on the CK-725W vessel and mixer seal will convert it to a contacting dry-running seal (Type CK 725D).  

The Type CK-726 is designed for steel-made agitated chemical reaction vessels to DIN 28136, can switch between wet and dry operation, and offers debris well and cooling flange options. Meanwhile, the Type CK 728 is available in liquid-lubricated (W), gas-lubricated (G), dry-running (D) or a unique gas/dry face combination (GD) format. 

Formed metal bellows  

Suitable for general pharmaceutical sealing duties, the Type GL1B is made from Inconel 625, a high-performance nickel-chromium-molybdenum alloy, to create a double-ply, axial-flexible formed metal bellows seal that meets the dimensional requirements of DIN 24960 L 1K.  

Easy to clean and sterilise in place, the smooth profile of the Type 515E and Type 515H formed metal bellows resists clogging and is ideally suited to fibrous liquids in biotechnology and pharmaceutical applications. The Type 515C and Type 515W cartridge seals are designed for easy installation and maintenance and fit most popular DIN and ANSI pump sizes without modification. 

Edge-welded metal bellows  

Available in dual and single-cartridge arrangements, the Type 604 (stationary) and Type 609 (rotating) are available in either AM350 or Alloy 718 metallurgies with a double-ply metal bellows option for higher-pressure applications, and both suit pharmaceutical applications up to 425°C (800°F). 

The rotating Alloy-20 bellows of the Type 680 provide corrosion resistance and is suitable for a wide range of pharmaceutical services. The Type 680 is also available with a wide range of elastomer materials.  

The Type 670 is an Alloy C-276 metal bellows seal suitable for aggressive chemical applications, while the Type 676, with a rotating AM350 stainless steel bellows, is well-suited for mild corrosive and abrasive pharmaceutical applications. 

Seal support systems 

Support systems for the pharmaceutical industry must maintain cleanliness and prevent containment loss. John Crane barrier fluid reservoirs, heat exchangers, gas supply panels and flush systems underpin reliable mechanical seal operation. 

Extra help: Reliability support and remote monitoring  

Any sealing solution is just part of the wider picture for those running pharmaceutical processes. Structured support that maintains sealing system hygiene and performance is essential to ensure that individual seals continue to perform at the levels intended is key for technology running CIP and SIP. The John Crane Performance Plus™ modular service framework can optimise equipment performance. 

The Reliability Support Programme (RSP), a subset of the wider Managed Reliability Programme, is a dedicated service contract that can extend the life of mechanical seals and rotating equipment, address recurring failures and provide targeted support for wet seals without a full-time on-site engineer.