By Leon VanWormer, MBA, Sartorius Stedim Biotech
Although traditional stainless steel equipment has lost a great deal of market penetration to single-use alternatives over the past decade, there still is a need for quality filter cartridge systems for sterilizing and polishing filtration processes. The most common current applications would be sterilizing grade storage tank venting and | or process air filtration. This makes sense because disposable capsule filters cannot handle the temperatures and pressures of SIP | CIP which is required for maintaining sterility of these tanks.
Additionally, there are size limitations of current bag technologies whereas stainless steel offers a competitive advantage due to almost no volume design restrictions. With respect to process air filtration, skidded systems and distribution loops of clean utilities (namely, WFI and clean steam), are typically based on conventional stainless steel designs for fluid integrity and construction material handling reasons. Stainless steel filter cartridge housings would also be considered for large batch liquid filtration requiring multiple filters (multi-round) or where extractable & leachables may be a concern.