Pressure drop through disposable connectors

When it comes to disposable connectors that are used on bag and tubing sets, you have a lot of choice. This is an area where all the major vendors have fairly distinct products, some better than others.

My personal list of preferences include considerations for:

• Cost
• Ergonomics (Weight, is it translucent, can it be easily assembled by a gowned operator?)
• Materials of construction
• Sealing and aseptic reliability

Other lesser issues are hold up volume within the connector itself and drainability - can I get everything out! Everything else being equal, I also prefer a translucent unit over an opaque connector - being able to see what is happening within the connection is helpful.

The above are all pretty straightforward. However, one element that is often important is the actual backpressure at process flowrate through the connector. (That is, the Kv of the valve). Millipore’s Lynx products and Colder’s Steam-Thru II both have significant backpressure for equivalent flowrates compared to Pall’s Kleenpak and Bioquate’s DAC. The reason is quite simple since both Colder and Millipore force the process fluid through a fairly tortuous path around a movable plunger element. Both Pall’s Kleenpak and Bioquate’s DAC use a method of actuation that involves the removing of a film that leaves the full internal bore of the connector available for flow and therefore result in lower backpressure and associated shear.

In March 2007, Pall challenged Bioquate for potentially infringing Kleenpak’s design. At the time of writing, this dispute is unresolved.

25 July 2007 | Uncategorized | Comments